| Message ID | 20191004135519.191657-1-nuno.sa@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,1/2] iio: temperature: Add support for LTC2983 | expand |
On Fri, 4 Oct 2019 15:55:18 +0200 Nuno Sá <nuno.sa@analog.com> wrote: > The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature > Measurement System. It measures a wide variety of temperature sensors and > digitally outputs the result, in °C or °F, with 0.1°C accuracy and > 0.001°C resolution. It can measure the temperature of all standard > thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire RTDs, > thermistors and diodes. > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> Two things inline that I'd missed before. Otherwise looks good. Thanks, Jonathan > --- > Changes in v2: > * Added some needed blank lines (for readability); > * Allocate iio_chan in the setup() function; > * Rename reset to sleep; > * Remove unneeded dev_dbg calls; > * Remove unneeded line wrapping; > * Remove unneeded comments; > * Remove extend_names. Use the standard ABI; > * Adapt the scales to report in millivolt and milli degrees; > * Adapt the of_property readings to the renaming of the properties; > * For custom thermistors, excitation-current cannot be set to Auto range. > > Changes in v3: > * Use normal `devm_request_irq`; > * Handle and decode the new devicetree properties for sensor configuration. > > MAINTAINERS | 7 + > drivers/iio/temperature/Kconfig | 10 + > drivers/iio/temperature/Makefile | 1 + > drivers/iio/temperature/ltc2983.c | 1554 +++++++++++++++++++++++++++++ > 4 files changed, 1572 insertions(+) > create mode 100644 drivers/iio/temperature/ltc2983.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index f0c03740b9fb..14a256e785ca 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -9491,6 +9491,13 @@ S: Maintained > F: Documentation/devicetree/bindings/iio/dac/ltc1660.txt > F: drivers/iio/dac/ltc1660.c > > +LTC2983 IIO TEMPERATURE DRIVER > +M: Nuno Sá <nuno.sa@analog.com> > +W: http://ez.analog.com/community/linux-device-drivers > +L: linux-iio@vger.kernel.org > +S: Supported > +F: drivers/iio/temperature/ltc2983.c > + > LTC4261 HARDWARE MONITOR DRIVER > M: Guenter Roeck <linux@roeck-us.net> > L: linux-hwmon@vger.kernel.org > diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig > index 737faa0901fe..04b5a67b593c 100644 > --- a/drivers/iio/temperature/Kconfig > +++ b/drivers/iio/temperature/Kconfig > @@ -4,6 +4,16 @@ > # > menu "Temperature sensors" > > +config LTC2983 > + tristate "Analog Devices Multi-Sensor Digital Temperature Measurement System" > + depends on SPI Select REGMAP_SPI needed I think. > + help > + Say yes here to build support for the LTC2983 Multi-Sensor > + high accuracy digital temperature measurement system. > + > + To compile this driver as a module, choose M here: the module > + will be called ltc2983. > + > config MAXIM_THERMOCOUPLE > tristate "Maxim thermocouple sensors" > depends on SPI > diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile > index baca4776ca0d..d6b850b0cf63 100644 > --- a/drivers/iio/temperature/Makefile > +++ b/drivers/iio/temperature/Makefile > @@ -3,6 +3,7 @@ > # Makefile for industrial I/O temperature drivers > # > > +obj-$(CONFIG_LTC2983) += ltc2983.o > obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o > obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o > obj-$(CONFIG_MAX31856) += max31856.o > diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c > new file mode 100644 > index 000000000000..f899c1d75f8a > --- /dev/null > +++ b/drivers/iio/temperature/ltc2983.c > @@ -0,0 +1,1554 @@ ... > +static int ltc2983_chan_read(struct ltc2983_data *st, > + const struct ltc2983_sensor *sensor, int *val) > +{ > + u32 start_conversion = 0; > + int ret; > + unsigned long time; > + __be32 temp; > + > + /* > + * Do not allow channel readings if device is in sleep state. > + * A read/write on the spi bus would bring the device prematurely > + * out of sleep. > + */ > + if (st->sleep) > + return -EPERM; > + > + start_conversion = LTC2983_STATUS_START(true); > + start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan); > + dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n", > + sensor->chan, start_conversion); > + /* start conversion */ > + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion); > + if (ret) > + return ret; > + > + reinit_completion(&st->completion); > + /* > + * wait for conversion to complete. > + * 300 ms should be more than enough to complete the conversion. > + * Depending on the sensor configuration, there are 2/3 conversions > + * cycles of 82ms. > + */ > + time = wait_for_completion_timeout(&st->completion, > + msecs_to_jiffies(300)); > + if (!time) { > + dev_warn(&st->spi->dev, "Conversion timed out\n"); > + return -ETIMEDOUT; > + } > + > + /* read the converted data */ > + ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan), > + &temp, sizeof(temp)); I'd missed this before. regmap_bulk_read can directly use the supplied buffer for dma. Hence it needs to be dma safe. That means you have to have it in it's own cacheline. There is no way of enforcing that on the stack so either allocate it locally from the heap, or put it at the end of the data structure and mark it __cacheline_aligned (we make sure those structures are also cacheline aligned and on the heap specifically to allow us to do that trick). > + if (ret) > + return ret; > + > + *val = __be32_to_cpu(temp); > + > + if (!(LTC2983_RES_VALID_MASK & *val)) { > + dev_err(&st->spi->dev, "Invalid conversion detected\n"); > + return -EIO; > + } > + > + ret = sensor->fault_handler(st, *val); > + if (ret) > + return ret; > + > + *val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT); > + return 0; > +} > + ...
On Sun, 2019-10-06 at 11:37 +0100, Jonathan Cameron wrote: > [External] > > On Fri, 4 Oct 2019 15:55:18 +0200 > Nuno Sá <nuno.sa@analog.com> wrote: > > > The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature > > Measurement System. It measures a wide variety of temperature > > sensors and > > digitally outputs the result, in °C or °F, with 0.1°C accuracy and > > 0.001°C resolution. It can measure the temperature of all standard > > thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire RTDs, > > thermistors and diodes. > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > > Two things inline that I'd missed before. Otherwise looks good. > > Thanks, > > Jonathan > > > --- > > Changes in v2: > > * Added some needed blank lines (for readability); > > * Allocate iio_chan in the setup() function; > > * Rename reset to sleep; > > * Remove unneeded dev_dbg calls; > > * Remove unneeded line wrapping; > > * Remove unneeded comments; > > * Remove extend_names. Use the standard ABI; > > * Adapt the scales to report in millivolt and milli degrees; > > * Adapt the of_property readings to the renaming of the > > properties; > > * For custom thermistors, excitation-current cannot be set to Auto > > range. > > > > Changes in v3: > > * Use normal `devm_request_irq`; > > * Handle and decode the new devicetree properties for sensor > > configuration. > > > > MAINTAINERS | 7 + > > drivers/iio/temperature/Kconfig | 10 + > > drivers/iio/temperature/Makefile | 1 + > > drivers/iio/temperature/ltc2983.c | 1554 > > +++++++++++++++++++++++++++++ > > 4 files changed, 1572 insertions(+) > > create mode 100644 drivers/iio/temperature/ltc2983.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index f0c03740b9fb..14a256e785ca 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -9491,6 +9491,13 @@ S: Maintained > > F: Documentation/devicetree/bindings/iio/dac/ltc1660.txt > > F: drivers/iio/dac/ltc1660.c > > > > +LTC2983 IIO TEMPERATURE DRIVER > > +M: Nuno Sá <nuno.sa@analog.com> > > +W: http://ez.analog.com/community/linux-device-drivers > > +L: linux-iio@vger.kernel.org > > +S: Supported > > +F: drivers/iio/temperature/ltc2983.c > > + > > LTC4261 HARDWARE MONITOR DRIVER > > M: Guenter Roeck <linux@roeck-us.net> > > L: linux-hwmon@vger.kernel.org > > diff --git a/drivers/iio/temperature/Kconfig > > b/drivers/iio/temperature/Kconfig > > index 737faa0901fe..04b5a67b593c 100644 > > --- a/drivers/iio/temperature/Kconfig > > +++ b/drivers/iio/temperature/Kconfig > > @@ -4,6 +4,16 @@ > > # > > menu "Temperature sensors" > > > > +config LTC2983 > > + tristate "Analog Devices Multi-Sensor Digital Temperature > > Measurement System" > > + depends on SPI > > Select REGMAP_SPI needed I think. ack. > > + help > > + Say yes here to build support for the LTC2983 Multi-Sensor > > + high accuracy digital temperature measurement system. > > + > > + To compile this driver as a module, choose M here: the module > > + will be called ltc2983. > > + > > config MAXIM_THERMOCOUPLE > > tristate "Maxim thermocouple sensors" > > depends on SPI > > diff --git a/drivers/iio/temperature/Makefile > > b/drivers/iio/temperature/Makefile > > index baca4776ca0d..d6b850b0cf63 100644 > > --- a/drivers/iio/temperature/Makefile > > +++ b/drivers/iio/temperature/Makefile > > @@ -3,6 +3,7 @@ > > # Makefile for industrial I/O temperature drivers > > # > > > > +obj-$(CONFIG_LTC2983) += ltc2983.o > > obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o > > obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o > > obj-$(CONFIG_MAX31856) += max31856.o > > diff --git a/drivers/iio/temperature/ltc2983.c > > b/drivers/iio/temperature/ltc2983.c > > new file mode 100644 > > index 000000000000..f899c1d75f8a > > --- /dev/null > > +++ b/drivers/iio/temperature/ltc2983.c > > @@ -0,0 +1,1554 @@ > ... > > > +static int ltc2983_chan_read(struct ltc2983_data *st, > > + const struct ltc2983_sensor *sensor, int *val) > > +{ > > + u32 start_conversion = 0; > > + int ret; > > + unsigned long time; > > + __be32 temp; > > + > > + /* > > + * Do not allow channel readings if device is in sleep state. > > + * A read/write on the spi bus would bring the device > > prematurely > > + * out of sleep. > > + */ > > + if (st->sleep) > > + return -EPERM; > > + > > + start_conversion = LTC2983_STATUS_START(true); > > + start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan); > > + dev_dbg(&st->spi->dev, "Start conversion on chan:%d, > > status:%02X\n", > > + sensor->chan, start_conversion); > > + /* start conversion */ > > + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, > > start_conversion); > > + if (ret) > > + return ret; > > + > > + reinit_completion(&st->completion); > > + /* > > + * wait for conversion to complete. > > + * 300 ms should be more than enough to complete the > > conversion. > > + * Depending on the sensor configuration, there are 2/3 > > conversions > > + * cycles of 82ms. > > + */ > > + time = wait_for_completion_timeout(&st->completion, > > + msecs_to_jiffies(300)); > > + if (!time) { > > + dev_warn(&st->spi->dev, "Conversion timed out\n"); > > + return -ETIMEDOUT; > > + } > > + > > + /* read the converted data */ > > + ret = regmap_bulk_read(st->regmap, > > LTC2983_CHAN_RES_ADDR(sensor->chan), > > + &temp, sizeof(temp)); > > I'd missed this before. regmap_bulk_read can directly use the > supplied buffer > for dma. Hence it needs to be dma safe. That means you have to have > it > in it's own cacheline. There is no way of enforcing that on the > stack so > either allocate it locally from the heap, or put it at the end of the > data structure and mark it __cacheline_aligned (we make sure those > structures > are also cacheline aligned and on the heap specifically to allow us > to do that > trick). Just for my understanding. I do see the the need of using __cacheline_aligned on the struct parameter we want to align. I was now trying to understand your comment on parenthesis. Why do we need that trick? Wouldn't be sufficient to have the struct element marked with __cacheline_aligned? > > > + if (ret) > > + return ret; > > + > > + *val = __be32_to_cpu(temp); > > + > > + if (!(LTC2983_RES_VALID_MASK & *val)) { > > + dev_err(&st->spi->dev, "Invalid conversion > > detected\n"); > > + return -EIO; > > + } > > + > > + ret = sensor->fault_handler(st, *val); > > + if (ret) > > + return ret; > > + > > + *val = sign_extend32((*val) & LTC2983_DATA_MASK, > > LTC2983_DATA_SIGN_BIT); > > + return 0; > > +} > > + > ... Thanks! Nuno Sá
On Mon, 7 Oct 2019 09:10:06 +0000 "Sa, Nuno" <Nuno.Sa@analog.com> wrote: > On Sun, 2019-10-06 at 11:37 +0100, Jonathan Cameron wrote: > > [External] > > > > On Fri, 4 Oct 2019 15:55:18 +0200 > > Nuno Sá <nuno.sa@analog.com> wrote: > > > > > The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature > > > Measurement System. It measures a wide variety of temperature > > > sensors and > > > digitally outputs the result, in °C or °F, with 0.1°C accuracy and > > > 0.001°C resolution. It can measure the temperature of all standard > > > thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire RTDs, > > > thermistors and diodes. > > > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > > > > Two things inline that I'd missed before. Otherwise looks good. > > > > Thanks, > > > > Jonathan > > > > > --- > > > Changes in v2: > > > * Added some needed blank lines (for readability); > > > * Allocate iio_chan in the setup() function; > > > * Rename reset to sleep; > > > * Remove unneeded dev_dbg calls; > > > * Remove unneeded line wrapping; > > > * Remove unneeded comments; > > > * Remove extend_names. Use the standard ABI; > > > * Adapt the scales to report in millivolt and milli degrees; > > > * Adapt the of_property readings to the renaming of the > > > properties; > > > * For custom thermistors, excitation-current cannot be set to Auto > > > range. > > > > > > Changes in v3: > > > * Use normal `devm_request_irq`; > > > * Handle and decode the new devicetree properties for sensor > > > configuration. > > > > > > MAINTAINERS | 7 + > > > drivers/iio/temperature/Kconfig | 10 + > > > drivers/iio/temperature/Makefile | 1 + > > > drivers/iio/temperature/ltc2983.c | 1554 > > > +++++++++++++++++++++++++++++ > > > 4 files changed, 1572 insertions(+) > > > create mode 100644 drivers/iio/temperature/ltc2983.c > > > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > > index f0c03740b9fb..14a256e785ca 100644 > > > --- a/MAINTAINERS > > > +++ b/MAINTAINERS > > > @@ -9491,6 +9491,13 @@ S: Maintained > > > F: Documentation/devicetree/bindings/iio/dac/ltc1660.txt > > > F: drivers/iio/dac/ltc1660.c > > > > > > +LTC2983 IIO TEMPERATURE DRIVER > > > +M: Nuno Sá <nuno.sa@analog.com> > > > +W: http://ez.analog.com/community/linux-device-drivers > > > +L: linux-iio@vger.kernel.org > > > +S: Supported > > > +F: drivers/iio/temperature/ltc2983.c > > > + > > > LTC4261 HARDWARE MONITOR DRIVER > > > M: Guenter Roeck <linux@roeck-us.net> > > > L: linux-hwmon@vger.kernel.org > > > diff --git a/drivers/iio/temperature/Kconfig > > > b/drivers/iio/temperature/Kconfig > > > index 737faa0901fe..04b5a67b593c 100644 > > > --- a/drivers/iio/temperature/Kconfig > > > +++ b/drivers/iio/temperature/Kconfig > > > @@ -4,6 +4,16 @@ > > > # > > > menu "Temperature sensors" > > > > > > +config LTC2983 > > > + tristate "Analog Devices Multi-Sensor Digital Temperature > > > Measurement System" > > > + depends on SPI > > > > Select REGMAP_SPI needed I think. > > ack. > > > > + help > > > + Say yes here to build support for the LTC2983 Multi-Sensor > > > + high accuracy digital temperature measurement system. > > > + > > > + To compile this driver as a module, choose M here: the module > > > + will be called ltc2983. > > > + > > > config MAXIM_THERMOCOUPLE > > > tristate "Maxim thermocouple sensors" > > > depends on SPI > > > diff --git a/drivers/iio/temperature/Makefile > > > b/drivers/iio/temperature/Makefile > > > index baca4776ca0d..d6b850b0cf63 100644 > > > --- a/drivers/iio/temperature/Makefile > > > +++ b/drivers/iio/temperature/Makefile > > > @@ -3,6 +3,7 @@ > > > # Makefile for industrial I/O temperature drivers > > > # > > > > > > +obj-$(CONFIG_LTC2983) += ltc2983.o > > > obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o > > > obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o > > > obj-$(CONFIG_MAX31856) += max31856.o > > > diff --git a/drivers/iio/temperature/ltc2983.c > > > b/drivers/iio/temperature/ltc2983.c > > > new file mode 100644 > > > index 000000000000..f899c1d75f8a > > > --- /dev/null > > > +++ b/drivers/iio/temperature/ltc2983.c > > > @@ -0,0 +1,1554 @@ > > ... > > > > > +static int ltc2983_chan_read(struct ltc2983_data *st, > > > + const struct ltc2983_sensor *sensor, int *val) > > > +{ > > > + u32 start_conversion = 0; > > > + int ret; > > > + unsigned long time; > > > + __be32 temp; > > > + > > > + /* > > > + * Do not allow channel readings if device is in sleep state. > > > + * A read/write on the spi bus would bring the device > > > prematurely > > > + * out of sleep. > > > + */ > > > + if (st->sleep) > > > + return -EPERM; > > > + > > > + start_conversion = LTC2983_STATUS_START(true); > > > + start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan); > > > + dev_dbg(&st->spi->dev, "Start conversion on chan:%d, > > > status:%02X\n", > > > + sensor->chan, start_conversion); > > > + /* start conversion */ > > > + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, > > > start_conversion); > > > + if (ret) > > > + return ret; > > > + > > > + reinit_completion(&st->completion); > > > + /* > > > + * wait for conversion to complete. > > > + * 300 ms should be more than enough to complete the > > > conversion. > > > + * Depending on the sensor configuration, there are 2/3 > > > conversions > > > + * cycles of 82ms. > > > + */ > > > + time = wait_for_completion_timeout(&st->completion, > > > + msecs_to_jiffies(300)); > > > + if (!time) { > > > + dev_warn(&st->spi->dev, "Conversion timed out\n"); > > > + return -ETIMEDOUT; > > > + } > > > + > > > + /* read the converted data */ > > > + ret = regmap_bulk_read(st->regmap, > > > LTC2983_CHAN_RES_ADDR(sensor->chan), > > > + &temp, sizeof(temp)); > > > > I'd missed this before. regmap_bulk_read can directly use the > > supplied buffer > > for dma. Hence it needs to be dma safe. That means you have to have > > it > > in it's own cacheline. There is no way of enforcing that on the > > stack so > > either allocate it locally from the heap, or put it at the end of the > > data structure and mark it __cacheline_aligned (we make sure those > > structures > > are also cacheline aligned and on the heap specifically to allow us > > to do that > > trick). > > Just for my understanding. I do see the the need of using > __cacheline_aligned on the struct parameter we want to align. I was now > trying to understand your comment on parenthesis. Why do we need that > trick? Wouldn't be sufficient to have the struct element marked with > __cacheline_aligned? > Ah. That is down to what __cacheline_aligned actually does and how we create the region accessed by iio_priv() If we have a stand alone structure allocated with kmalloc with an element marked __cacheline_aligned it will indeed have the correct alignment. iio_priv is done by increasing the size of the memory allocation done in iio_device_alloc, the iio_priv() pointer then gives us the address of a region beyond the end of the iio_dev structure. That region has to also be cacheline aligned so that when we find the location of the __cacheline_aligned element of the structure we are putting there (basically an offset from iio_priv) it will also have the right alignment. The compiler has no way of knowing we are doing this stuff so it just adds padding to the private structure on the assumption the structure itself is aligned. Jonathan > > > > > + if (ret) > > > + return ret; > > > + > > > + *val = __be32_to_cpu(temp); > > > + > > > + if (!(LTC2983_RES_VALID_MASK & *val)) { > > > + dev_err(&st->spi->dev, "Invalid conversion > > > detected\n"); > > > + return -EIO; > > > + } > > > + > > > + ret = sensor->fault_handler(st, *val); > > > + if (ret) > > > + return ret; > > > + > > > + *val = sign_extend32((*val) & LTC2983_DATA_MASK, > > > LTC2983_DATA_SIGN_BIT); > > > + return 0; > > > +} > > > + > > ... > > Thanks! > Nuno Sá
On Mon, 2019-10-07 at 12:52 +0100, Jonathan Cameron wrote: > > On Mon, 7 Oct 2019 09:10:06 +0000 > "Sa, Nuno" <Nuno.Sa@analog.com> wrote: > > > On Sun, 2019-10-06 at 11:37 +0100, Jonathan Cameron wrote: > > > [External] > > > > > > On Fri, 4 Oct 2019 15:55:18 +0200 > > > Nuno Sá <nuno.sa@analog.com> wrote: > > > > > > > The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature > > > > Measurement System. It measures a wide variety of temperature > > > > sensors and > > > > digitally outputs the result, in °C or °F, with 0.1°C accuracy > > > > and > > > > 0.001°C resolution. It can measure the temperature of all > > > > standard > > > > thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire > > > > RTDs, > > > > thermistors and diodes. > > > > > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > > > > > > Two things inline that I'd missed before. Otherwise looks good. > > > > > > Thanks, > > > > > > Jonathan > > > > > > > --- > > > > Changes in v2: > > > > * Added some needed blank lines (for readability); > > > > * Allocate iio_chan in the setup() function; > > > > * Rename reset to sleep; > > > > * Remove unneeded dev_dbg calls; > > > > * Remove unneeded line wrapping; > > > > * Remove unneeded comments; > > > > * Remove extend_names. Use the standard ABI; > > > > * Adapt the scales to report in millivolt and milli degrees; > > > > * Adapt the of_property readings to the renaming of the > > > > properties; > > > > * For custom thermistors, excitation-current cannot be set to > > > > Auto > > > > range. > > > > > > > > Changes in v3: > > > > * Use normal `devm_request_irq`; > > > > * Handle and decode the new devicetree properties for sensor > > > > configuration. > > > > > > > > MAINTAINERS | 7 + > > > > drivers/iio/temperature/Kconfig | 10 + > > > > drivers/iio/temperature/Makefile | 1 + > > > > drivers/iio/temperature/ltc2983.c | 1554 > > > > +++++++++++++++++++++++++++++ > > > > 4 files changed, 1572 insertions(+) > > > > create mode 100644 drivers/iio/temperature/ltc2983.c > > > > > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > > > index f0c03740b9fb..14a256e785ca 100644 > > > > --- a/MAINTAINERS > > > > +++ b/MAINTAINERS > > > > @@ -9491,6 +9491,13 @@ S: Maintained > > > > F: Documentation/devicetree/bindings/iio/dac/ltc1660.txt > > > > F: drivers/iio/dac/ltc1660.c > > > > > > > > +LTC2983 IIO TEMPERATURE DRIVER > > > > +M: Nuno Sá <nuno.sa@analog.com> > > > > +W: http://ez.analog.com/community/linux-device-drivers > > > > +L: linux-iio@vger.kernel.org > > > > +S: Supported > > > > +F: drivers/iio/temperature/ltc2983.c > > > > + > > > > LTC4261 HARDWARE MONITOR DRIVER > > > > M: Guenter Roeck <linux@roeck-us.net> > > > > L: linux-hwmon@vger.kernel.org > > > > diff --git a/drivers/iio/temperature/Kconfig > > > > b/drivers/iio/temperature/Kconfig > > > > index 737faa0901fe..04b5a67b593c 100644 > > > > --- a/drivers/iio/temperature/Kconfig > > > > +++ b/drivers/iio/temperature/Kconfig > > > > @@ -4,6 +4,16 @@ > > > > # > > > > menu "Temperature sensors" > > > > > > > > +config LTC2983 > > > > + tristate "Analog Devices Multi-Sensor Digital > > > > Temperature > > > > Measurement System" > > > > + depends on SPI > > > > > > Select REGMAP_SPI needed I think. > > > > ack. > > > > > > + help > > > > + Say yes here to build support for the LTC2983 Multi- > > > > Sensor > > > > + high accuracy digital temperature measurement system. > > > > + > > > > + To compile this driver as a module, choose M here: > > > > the module > > > > + will be called ltc2983. > > > > + > > > > config MAXIM_THERMOCOUPLE > > > > tristate "Maxim thermocouple sensors" > > > > depends on SPI > > > > diff --git a/drivers/iio/temperature/Makefile > > > > b/drivers/iio/temperature/Makefile > > > > index baca4776ca0d..d6b850b0cf63 100644 > > > > --- a/drivers/iio/temperature/Makefile > > > > +++ b/drivers/iio/temperature/Makefile > > > > @@ -3,6 +3,7 @@ > > > > # Makefile for industrial I/O temperature drivers > > > > # > > > > > > > > +obj-$(CONFIG_LTC2983) += ltc2983.o > > > > obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o > > > > obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o > > > > obj-$(CONFIG_MAX31856) += max31856.o > > > > diff --git a/drivers/iio/temperature/ltc2983.c > > > > b/drivers/iio/temperature/ltc2983.c > > > > new file mode 100644 > > > > index 000000000000..f899c1d75f8a > > > > --- /dev/null > > > > +++ b/drivers/iio/temperature/ltc2983.c > > > > @@ -0,0 +1,1554 @@ > > > ... > > > > > > > +static int ltc2983_chan_read(struct ltc2983_data *st, > > > > + const struct ltc2983_sensor *sensor, > > > > int *val) > > > > +{ > > > > + u32 start_conversion = 0; > > > > + int ret; > > > > + unsigned long time; > > > > + __be32 temp; > > > > + > > > > + /* > > > > + * Do not allow channel readings if device is in sleep > > > > state. > > > > + * A read/write on the spi bus would bring the device > > > > prematurely > > > > + * out of sleep. > > > > + */ > > > > + if (st->sleep) > > > > + return -EPERM; > > > > + > > > > + start_conversion = LTC2983_STATUS_START(true); > > > > + start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor- > > > > >chan); > > > > + dev_dbg(&st->spi->dev, "Start conversion on chan:%d, > > > > status:%02X\n", > > > > + sensor->chan, start_conversion); > > > > + /* start conversion */ > > > > + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, > > > > start_conversion); > > > > + if (ret) > > > > + return ret; > > > > + > > > > + reinit_completion(&st->completion); > > > > + /* > > > > + * wait for conversion to complete. > > > > + * 300 ms should be more than enough to complete the > > > > conversion. > > > > + * Depending on the sensor configuration, there are 2/3 > > > > conversions > > > > + * cycles of 82ms. > > > > + */ > > > > + time = wait_for_completion_timeout(&st->completion, > > > > + msecs_to_jiffies(300 > > > > )); > > > > + if (!time) { > > > > + dev_warn(&st->spi->dev, "Conversion timed > > > > out\n"); > > > > + return -ETIMEDOUT; > > > > + } > > > > + > > > > + /* read the converted data */ > > > > + ret = regmap_bulk_read(st->regmap, > > > > LTC2983_CHAN_RES_ADDR(sensor->chan), > > > > + &temp, sizeof(temp)); > > > > > > I'd missed this before. regmap_bulk_read can directly use the > > > supplied buffer > > > for dma. Hence it needs to be dma safe. That means you have to > > > have > > > it > > > in it's own cacheline. There is no way of enforcing that on the > > > stack so > > > either allocate it locally from the heap, or put it at the end of > > > the > > > data structure and mark it __cacheline_aligned (we make sure > > > those > > > structures > > > are also cacheline aligned and on the heap specifically to allow > > > us > > > to do that > > > trick). > > > > Just for my understanding. I do see the the need of using > > __cacheline_aligned on the struct parameter we want to align. I was > > now > > trying to understand your comment on parenthesis. Why do we need > > that > > trick? Wouldn't be sufficient to have the struct element marked > > with > > __cacheline_aligned? > > > > Ah. That is down to what __cacheline_aligned actually does and > how we create the region accessed by iio_priv() > > If we have a stand alone structure allocated with kmalloc with an > element marked __cacheline_aligned it will indeed have the correct > alignment. > > iio_priv is done by increasing the size of the memory allocation > done in iio_device_alloc, the iio_priv() pointer then gives us > the address of a region beyond the end of the iio_dev structure. Got it. > That region has to also be cacheline aligned so that when we find > the location of the __cacheline_aligned element of the structure > we are putting there (basically an offset from iio_priv) it will > also have the right alignment. Understood. Then, the only thing I'm still wondering is that we need to have the guarantee that kmalloc also returns a pointer which is at least __cacheline_aligned for our iio_dev struct so that, our private struct has the correct alignment (and thus the element). Is this correct? > The compiler has no way of knowing we are doing this stuff so it > just adds padding to the private structure on the assumption > the structure itself is aligned. > > Jonathan > > Thanks for your help and explanation! Nuno Sá
Ho Jonathan, Something that came up in another device review and I'm doing the same mistake here. On Fri, 2019-10-04 at 15:55 +0200, Nuno Sá wrote: > > The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature > Measurement System. It measures a wide variety of temperature sensors > and > digitally outputs the result, in °C or °F, with 0.1°C accuracy and > 0.001°C resolution. It can measure the temperature of all standard > thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire RTDs, > thermistors and diodes. > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > --- > Changes in v2: > * Added some needed blank lines (for readability); > * Allocate iio_chan in the setup() function; > * Rename reset to sleep; > * Remove unneeded dev_dbg calls; > * Remove unneeded line wrapping; > * Remove unneeded comments; > * Remove extend_names. Use the standard ABI; > * Adapt the scales to report in millivolt and milli degrees; > * Adapt the of_property readings to the renaming of the properties; > * For custom thermistors, excitation-current cannot be set to Auto > range. > > Changes in v3: > * Use normal `devm_request_irq`; > * Handle and decode the new devicetree properties for sensor > configuration. > > MAINTAINERS | 7 + > drivers/iio/temperature/Kconfig | 10 + > drivers/iio/temperature/Makefile | 1 + > drivers/iio/temperature/ltc2983.c | 1554 > +++++++++++++++++++++++++++++ > 4 files changed, 1572 insertions(+) > create mode 100644 drivers/iio/temperature/ltc2983.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index f0c03740b9fb..14a256e785ca 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -9491,6 +9491,13 @@ S: Maintained > F: Documentation/devicetree/bindings/iio/dac/ltc1660.txt > F: drivers/iio/dac/ltc1660.c > > +LTC2983 IIO TEMPERATURE DRIVER > +M: Nuno Sá <nuno.sa@analog.com> > +W: http://ez.analog.com/community/linux-device-drivers > +L: linux-iio@vger.kernel.org > +S: Supported > +F: drivers/iio/temperature/ltc2983.c > + > LTC4261 HARDWARE MONITOR DRIVER > M: Guenter Roeck <linux@roeck-us.net> > L: linux-hwmon@vger.kernel.org > diff --git a/drivers/iio/temperature/Kconfig > b/drivers/iio/temperature/Kconfig > index 737faa0901fe..04b5a67b593c 100644 > --- a/drivers/iio/temperature/Kconfig > +++ b/drivers/iio/temperature/Kconfig > @@ -4,6 +4,16 @@ > # > menu "Temperature sensors" > > +config LTC2983 > + tristate "Analog Devices Multi-Sensor Digital Temperature > Measurement System" > + depends on SPI > + help > + Say yes here to build support for the LTC2983 Multi-Sensor > + high accuracy digital temperature measurement system. > + > + To compile this driver as a module, choose M here: the module > + will be called ltc2983. > + > config MAXIM_THERMOCOUPLE > tristate "Maxim thermocouple sensors" > depends on SPI > diff --git a/drivers/iio/temperature/Makefile > b/drivers/iio/temperature/Makefile > index baca4776ca0d..d6b850b0cf63 100644 > --- a/drivers/iio/temperature/Makefile > +++ b/drivers/iio/temperature/Makefile > @@ -3,6 +3,7 @@ > # Makefile for industrial I/O temperature drivers > # > > +obj-$(CONFIG_LTC2983) += ltc2983.o > obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o > obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o > obj-$(CONFIG_MAX31856) += max31856.o > diff --git a/drivers/iio/temperature/ltc2983.c > b/drivers/iio/temperature/ltc2983.c > new file mode 100644 > index 000000000000..f899c1d75f8a > --- /dev/null > +++ b/drivers/iio/temperature/ltc2983.c > @@ -0,0 +1,1554 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Analog Devices LTC2983 Multi-Sensor Digital Temperature > Measurement System > + * driver > + * > + * Copyright 2019 Analog Devices Inc. > + */ > +#include <linux/bitfield.h> > +#include <linux/completion.h> > +#include <linux/device.h> > +#include <linux/kernel.h> > +#include <linux/iio/iio.h> > +#include <linux/interrupt.h> > +#include <linux/list.h> > +#include <linux/module.h> > +#include <linux/of_gpio.h> > +#include <linux/regmap.h> > +#include <linux/spi/spi.h> > + > +/* register map */ > +#define LTC2983_STATUS_REG 0x0000 > +#define LTC2983_TEMP_RES_START_REG 0x0010 > +#define LTC2983_TEMP_RES_END_REG 0x005F > +#define LTC2983_GLOBAL_CONFIG_REG 0x00F0 > +#define LTC2983_MULT_CHANNEL_START_REG 0x00F4 > +#define LTC2983_MULT_CHANNEL_END_REG 0x00F7 > +#define LTC2983_MUX_CONFIG_REG 0x00FF > +#define LTC2983_CHAN_ASSIGN_START_REG 0x0200 > +#define LTC2983_CHAN_ASSIGN_END_REG 0x024F > +#define LTC2983_CUST_SENS_TBL_START_REG 0x0250 > +#define LTC2983_CUST_SENS_TBL_END_REG 0x03CF > + > +#define LTC2983_DIFFERENTIAL_CHAN_MIN 2 > +#define LTC2983_MAX_CHANNELS_NR 20 > +#define LTC2983_MIN_CHANNELS_NR 1 > +#define LTC2983_SLEEP 0x97 > +#define LTC2983_CUSTOM_STEINHART_SIZE 24 > +#define LTC2983_CUSTOM_SENSOR_ENTRY_SZ 6 > +#define LTC2983_CUSTOM_STEINHART_ENTRY_SZ 4 > + > +#define LTC2983_CHAN_START_ADDR(chan) \ > + (((chan - 1) * 4) + > LTC2983_CHAN_ASSIGN_START_REG) > +#define LTC2983_CHAN_RES_ADDR(chan) \ > + (((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG) > +#define LTC2983_THERMOCOUPLE_DIFF_MASK BIT(3) > +#define LTC2983_THERMOCOUPLE_SGL(x) \ > + FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MA > SK, x) > +#define LTC2983_THERMOCOUPLE_OC_CURR_MASK GENMASK(1, 0) > +#define LTC2983_THERMOCOUPLE_OC_CURR(x) \ > + FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR > _MASK, x) > +#define LTC2983_THERMOCOUPLE_OC_CHECK_MASK BIT(2) > +#define LTC2983_THERMOCOUPLE_OC_CHECK(x) \ > + FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, > x) > + > +#define LTC2983_THERMISTOR_DIFF_MASK BIT(2) > +#define LTC2983_THERMISTOR_SGL(x) \ > + FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK > , x) > +#define LTC2983_THERMISTOR_R_SHARE_MASK BIT(1) > +#define LTC2983_THERMISTOR_R_SHARE(x) \ > + FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_M > ASK, x) > +#define LTC2983_THERMISTOR_C_ROTATE_MASK BIT(0) > +#define LTC2983_THERMISTOR_C_ROTATE(x) \ > + FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_ > MASK, x) > + > +#define LTC2983_DIODE_DIFF_MASK BIT(2) > +#define LTC2983_DIODE_SGL(x) \ > + FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x) > +#define LTC2983_DIODE_3_CONV_CYCLE_MASK BIT(1) > +#define LTC2983_DIODE_3_CONV_CYCLE(x) \ > + FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_M > ASK, x) > +#define LTC2983_DIODE_AVERAGE_ON_MASK BIT(0) > +#define LTC2983_DIODE_AVERAGE_ON(x) \ > + FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MAS > K, x) > + > +#define LTC2983_RTD_4_WIRE_MASK BIT(3) > +#define LTC2983_RTD_ROTATION_MASK BIT(1) > +#define LTC2983_RTD_C_ROTATE(x) \ > + FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x) > +#define LTC2983_RTD_KELVIN_R_SENSE_MASK GENMASK(3, 2) > +#define LTC2983_RTD_N_WIRES_MASK GENMASK(3, 2) > +#define LTC2983_RTD_N_WIRES(x) \ > + FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x) > +#define LTC2983_RTD_R_SHARE_MASK BIT(0) > +#define LTC2983_RTD_R_SHARE(x) \ > + FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1) > + > +#define LTC2983_COMMON_HARD_FAULT_MASK GENMASK(31, 30) > +#define LTC2983_COMMON_SOFT_FAULT_MASK GENMASK(27, 25) > + > +#define LTC2983_STATUS_START_MASK BIT(7) > +#define LTC2983_STATUS_START(x) FIELD_PREP(LTC2983_ST > ATUS_START_MASK, x) > + > +#define LTC2983_STATUS_CHAN_SEL_MASK GENMASK(4, 0) > +#define LTC2983_STATUS_CHAN_SEL(x) \ > + FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK > , x) > + > +#define LTC2983_TEMP_UNITS_MASK BIT(2) > +#define LTC2983_TEMP_UNITS(x) FIELD_PREP(LTC2983_TEMP > _UNITS_MASK, x) > + > +#define LTC2983_NOTCH_FREQ_MASK GENMASK(1, 0) > +#define LTC2983_NOTCH_FREQ(x) FIELD_PREP(LTC2983_NOTC > H_FREQ_MASK, x) > + > +#define LTC2983_RES_VALID_MASK BIT(24) > +#define LTC2983_DATA_MASK GENMASK(23, 0) > +#define LTC2983_DATA_SIGN_BIT 23 > + > +#define LTC2983_CHAN_TYPE_MASK GENMASK(31, 27) > +#define LTC2983_CHAN_TYPE(x) FIELD_PREP(LTC2983_CHAN_TYPE_MA > SK, x) > + > +/* cold junction for thermocouples and rsense for rtd's and > thermistor's */ > +#define LTC2983_CHAN_ASSIGN_MASK GENMASK(26, 22) > +#define LTC2983_CHAN_ASSIGN(x) FIELD_PREP(LTC2983_CHAN > _ASSIGN_MASK, x) > + > +#define LTC2983_CUSTOM_LEN_MASK GENMASK(5, 0) > +#define LTC2983_CUSTOM_LEN(x) FIELD_PREP(LTC2983_CUST > OM_LEN_MASK, x) > + > +#define LTC2983_CUSTOM_ADDR_MASK GENMASK(11, 6) > +#define LTC2983_CUSTOM_ADDR(x) FIELD_PREP(LTC2983_CUST > OM_ADDR_MASK, x) > + > +#define LTC2983_THERMOCOUPLE_CFG_MASK GENMASK(21, 18) > +#define LTC2983_THERMOCOUPLE_CFG(x) \ > + FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MAS > K, x) > +#define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK GENMASK(31, 29) > +#define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK GENMASK(28, 25) > + > +#define LTC2983_RTD_CFG_MASK GENMASK(21, 18) > +#define LTC2983_RTD_CFG(x) FIELD_PREP(LTC2983_RTD_CFG_MASK > , x) > +#define LTC2983_RTD_EXC_CURRENT_MASK GENMASK(17, 14) > +#define LTC2983_RTD_EXC_CURRENT(x) \ > + FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK > , x) > +#define LTC2983_RTD_CURVE_MASK GENMASK(13, 12) > +#define LTC2983_RTD_CURVE(x) FIELD_PREP(LTC2983_RTD_CURVE_MA > SK, x) > + > +#define LTC2983_THERMISTOR_CFG_MASK GENMASK(21, 19) > +#define LTC2983_THERMISTOR_CFG(x) \ > + FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, > x) > +#define LTC2983_THERMISTOR_EXC_CURRENT_MASK GENMASK(18, 15) > +#define LTC2983_THERMISTOR_EXC_CURRENT(x) \ > + FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, > x) > + > +#define LTC2983_DIODE_CFG_MASK GENMASK(26, 24) > +#define LTC2983_DIODE_CFG(x) FIELD_PREP(LTC2983_DIODE_CFG_MA > SK, x) > +#define LTC2983_DIODE_EXC_CURRENT_MASK GENMASK(23, 22) > +#define LTC2983_DIODE_EXC_CURRENT(x) \ > + FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MA > SK, x) > +#define LTC2983_DIODE_IDEAL_FACTOR_MASK GENMASK(21, 0) > +#define LTC2983_DIODE_IDEAL_FACTOR(x) \ > + FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_M > ASK, x) > + > +#define LTC2983_R_SENSE_VAL_MASK GENMASK(26, 0) > +#define LTC2983_R_SENSE_VAL(x) FIELD_PREP(LTC2983_R_SE > NSE_VAL_MASK, x) > + > +#define LTC2983_ADC_SINGLE_ENDED_MASK BIT(26) > +#define LTC2983_ADC_SINGLE_ENDED(x) \ > + FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MAS > K, x) > + > +enum { > + LTC2983_SENSOR_THERMOCOUPLE = 1, > + LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9, > + LTC2983_SENSOR_RTD = 10, > + LTC2983_SENSOR_RTD_CUSTOM = 18, > + LTC2983_SENSOR_THERMISTOR = 19, > + LTC2983_SENSOR_THERMISTOR_STEINHART = 26, > + LTC2983_SENSOR_THERMISTOR_CUSTOM = 27, > + LTC2983_SENSOR_DIODE = 28, > + LTC2983_SENSOR_SENSE_RESISTOR = 29, > + LTC2983_SENSOR_DIRECT_ADC = 30, > +}; > + > +#define to_thermocouple(_sensor) \ > + container_of(_sensor, struct ltc2983_thermocouple, > sensor) > + > +#define to_rtd(_sensor) \ > + container_of(_sensor, struct ltc2983_rtd, sensor) > + > +#define to_thermistor(_sensor) \ > + container_of(_sensor, struct ltc2983_thermistor, > sensor) > + > +#define to_diode(_sensor) \ > + container_of(_sensor, struct ltc2983_diode, sensor) > + > +#define to_rsense(_sensor) \ > + container_of(_sensor, struct ltc2983_rsense, sensor) > + > +#define to_adc(_sensor) \ > + container_of(_sensor, struct ltc2983_adc, sensor) > + > +struct ltc2983_data { > + struct regmap *regmap; > + struct spi_device *spi; > + struct mutex lock; > + struct completion completion; > + struct iio_chan_spec *iio_chan; > + struct ltc2983_sensor **sensors; > + u32 mux_delay_config; > + u32 filter_notch_freq; > + u16 custom_table_size; > + u8 num_channels; > + u8 iio_channels; > + bool temp_farenheit; > + bool sleep; > +}; > + > +struct ltc2983_sensor { > + int (*fault_handler)(const struct ltc2983_data *st, const u32 > result); > + int (*assign_chan)(struct ltc2983_data *st, > + const struct ltc2983_sensor *sensor); > + /* specifies the sensor channel */ > + u32 chan; > + /* sensor type */ > + u32 type; > +}; > + > +struct ltc2983_custom_sensor { > + /* raw table sensor data */ > + u8 *table; > + size_t size; > + /* address offset */ > + s8 offset; > + bool is_steinhart; > +}; > + > +struct ltc2983_thermocouple { > + struct ltc2983_sensor sensor; > + struct ltc2983_custom_sensor *custom; > + u32 sensor_config; > + u32 cold_junction_chan; > +}; > + > +struct ltc2983_rtd { > + struct ltc2983_sensor sensor; > + struct ltc2983_custom_sensor *custom; > + u32 sensor_config; > + u32 r_sense_chan; > + u32 excitation_current; > + u32 rtd_curve; > +}; > + > +struct ltc2983_thermistor { > + struct ltc2983_sensor sensor; > + struct ltc2983_custom_sensor *custom; > + u32 sensor_config; > + u32 r_sense_chan; > + u32 excitation_current; > +}; > + > +struct ltc2983_diode { > + struct ltc2983_sensor sensor; > + u32 sensor_config; > + u32 excitation_current; > + u32 ideal_factor_value; > +}; > + > +struct ltc2983_rsense { > + struct ltc2983_sensor sensor; > + u32 r_sense_val; > +}; > + > +struct ltc2983_adc { > + struct ltc2983_sensor sensor; > + bool single_ended; > +}; > + > +/* > + * Convert to Q format numbers. These number's are integers where > + * the number of integer and fractional bits are specified. The > resolution > + * is given by 1/@resolution and tell us the number of fractional > bits. For > + * instance a resolution of 2^-10 means we have 10 fractional bits. > + */ > +static u32 __convert_to_raw(const u64 val, const u32 resolution) > +{ > + u64 __res = val * resolution; > + > + /* all values are multiplied by 1000000 to remove the fraction > */ > + do_div(__res, 1000000); > + > + return __res; > +} > + > +static u32 __convert_to_raw_sign(const u64 val, const u32 > resolution) > +{ > + s64 __res = -(s32)val; > + > + __res = __convert_to_raw(__res, resolution); > + > + return (u32)-__res; > +} > + > +static int __ltc2983_fault_handler(const struct ltc2983_data *st, > + const u32 result, const u32 > hard_mask, > + const u32 soft_mask) > +{ > + const struct device *dev = &st->spi->dev; > + > + if (result & hard_mask) { > + dev_err(dev, "Invalid conversion: Sensor HARD > fault\n"); > + return -EIO; > + } else if (result & soft_mask) { > + /* just print a warning */ > + dev_warn(dev, "Suspicious conversion: Sensor SOFT > fault\n"); > + } > + > + return 0; > +} > + > +static int __ltc2983_chan_assign_common(const struct ltc2983_data > *st, > + const struct ltc2983_sensor > *sensor, > + u32 chan_val) > +{ > + u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan); > + __be32 __chan_val; > + > + chan_val |= LTC2983_CHAN_TYPE(sensor->type); > + dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg, > + chan_va > l); > + __chan_val = cpu_to_be32(chan_val); > + return regmap_bulk_write(st->regmap, reg, &__chan_val, > + sizeof(__chan_val)); > +} > + > +static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data > *st, > + struct ltc2983_custom_sensor > *custom, > + u32 *chan_val) > +{ > + u32 reg; > + u8 mult = custom->is_steinhart ? > LTC2983_CUSTOM_STEINHART_ENTRY_SZ : > + LTC2983_CUSTOM_SENSOR_ENTRY_SZ; > + const struct device *dev = &st->spi->dev; > + /* > + * custom->size holds the raw size of the table. However, when > + * configuring the sensor channel, we must write the number of > + * entries of the table minus 1. For steinhart sensors 0 is > written > + * since the size is constant! > + */ > + const u8 len = custom->is_steinhart ? 0 : > + (custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1; > + /* > + * Check if the offset was assigned already. It should be for > steinhart > + * sensors. When coming from sleep, it should be assigned for > all. > + */ > + if (custom->offset < 0) { > + /* > + * This needs to be done again here because, from the > moment > + * when this test was done (successfully) for this > custom > + * sensor, a steinhart sensor might have been added > changing > + * custom_table_size... > + */ > + if (st->custom_table_size + custom->size > > + (LTC2983_CUST_SENS_TBL_END_REG - > + LTC2983_CUST_SENS_TBL_START_REG) + 1) { > + dev_err(dev, > + "Not space left(%d) for new custom > sensor(%zu)", > + st- > >custom_table_size, > + custom->size); > + return -EINVAL; > + } > + > + custom->offset = st->custom_table_size / > + LTC2983_CUSTOM_SENSOR_ENTRY_SZ; > + st->custom_table_size += custom->size; > + } > + > + reg = (custom->offset * mult) + > LTC2983_CUST_SENS_TBL_START_REG; > + > + *chan_val |= LTC2983_CUSTOM_LEN(len); > + *chan_val |= LTC2983_CUSTOM_ADDR(custom->offset); > + dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, > sz:%zu", > + reg, custom- > >offset, > + custom->size); > + /* write custom sensor table */ > + return regmap_bulk_write(st->regmap, reg, custom->table, > custom->size); > +} > + > +static struct ltc2983_custom_sensor *__ltc2983_custom_sensor_new( > + struct ltc2983_data > *st, > + const struct > device_node *np, > + const bool > is_steinhart, > + const u32 resolution, > + const bool has_signed) > +{ > + struct ltc2983_custom_sensor *new_custom; > + u8 index, n_entries, tbl = 0; > + struct device *dev = &st->spi->dev; > + /* > + * For custom steinhart, the full u32 is taken. For all the > others > + * the MSB is discarded. > + */ > + const u8 n_size = (is_steinhart == true) ? 4 : 3; > + > + n_entries = of_property_count_elems_of_size(np, "adi,custom- > sensor", > + sizeof(u64)); > + /* n_entries must be an even number */ > + if (!n_entries || (n_entries % 2) != 0) { > + dev_err(dev, "Number of entries either 0 or not > even\n"); > + return ERR_PTR(-EINVAL); > + } > + > + new_custom = devm_kzalloc(dev, sizeof(*new_custom), > GFP_KERNEL); > + if (!new_custom) > + return ERR_PTR(-ENOMEM); > + > + new_custom->size = n_entries * n_size; > + /* check Steinhart size */ > + if (is_steinhart && new_custom->size != > LTC2983_CUSTOM_STEINHART_SIZE) { > + dev_err(dev, "Steinhart sensors size(%zu) must be 24", > + new_custom- > >size); > + return ERR_PTR(-EINVAL); > + } > + /* Check space on the table. */ > + if (st->custom_table_size + new_custom->size > > + (LTC2983_CUST_SENS_TBL_END_REG - > + LTC2983_CUST_SENS_TBL_START_REG) + 1) { > + dev_err(dev, "No space left(%d) for new custom > sensor(%zu)", > + st->custom_table_size, new_custom- > >size); > + return ERR_PTR(-EINVAL); > + } > + > + /* allocate the table */ > + new_custom->table = devm_kzalloc(dev, new_custom->size, > GFP_KERNEL); > + if (!new_custom->table) > + return ERR_PTR(-ENOMEM); > + > + for (index = 0; index < n_entries; index++) { > + u64 temp = 0, j; > + > + of_property_read_u64_index(np, "adi,custom-sensor", > index, > + &temp); > + /* > + * Steinhart sensors are configured with raw values in > the > + * devicetree. For the other sensors we must convert > the > + * value to raw. The odd index's correspond to > temperarures > + * and always have 1/1024 of resolution. Temperatures > also > + * come in kelvin, so signed values is not possible > + */ > + if (!is_steinhart) { > + if ((index % 2) != 0) > + temp = __convert_to_raw(temp, 1024); > + else if (has_signed && (s64)temp < 0) > + temp = __convert_to_raw_sign(temp, > resolution); > + else > + temp = __convert_to_raw(temp, > resolution); > + } > + > + for (j = 0; j < n_size; j++) > + new_custom->table[tbl++] = > + temp >> (8 * (n_size - j - 1)); > + } > + > + new_custom->is_steinhart = is_steinhart; > + /* > + * This is done to first add all the steinhart sensors to the > table, > + * in order to maximize the table usage. If we mix adding > steinhart > + * with the other sensors, we might have to do some roundup to > make > + * sure that sensor_addr - 0x250(start address) is a multiple > of 4 > + * (for steinhart), and a multiple of 6 for all the other > sensors. > + * Since we have const 24 bytes for steinhart sensors and 24 is > + * also a multiple of 6, we guarantee that the first non- > steinhart > + * sensor will sit in a correct address without the need of > filling > + * addresses. > + */ > + if (is_steinhart) { > + new_custom->offset = st->custom_table_size / > + LTC2983_CUSTOM_STEINHART_ENTRY_ > SZ; > + st->custom_table_size += new_custom->size; > + } else { > + /* mark as unset. This is checked later on the assign > phase */ > + new_custom->offset = -1; > + } > + > + return new_custom; > +} > + > +static int ltc2983_thermocouple_fault_handler(const struct > ltc2983_data *st, > + const u32 result) > +{ > + return __ltc2983_fault_handler(st, result, > + LTC2983_THERMOCOUPLE_HARD_FAULT_ > MASK, > + LTC2983_THERMOCOUPLE_SOFT_FAULT_ > MASK); > +} > + > +static int ltc2983_common_fault_handler(const struct ltc2983_data > *st, > + const u32 result) > +{ > + return __ltc2983_fault_handler(st, result, > + LTC2983_COMMON_HARD_FAULT_MASK, > + LTC2983_COMMON_SOFT_FAULT_MASK); > +} > + > +static int ltc2983_thermocouple_assign_chan(struct ltc2983_data *st, > + const struct ltc2983_sensor *sensor) > +{ > + struct ltc2983_thermocouple *thermo = to_thermocouple(sensor); > + u32 chan_val; > + > + chan_val = LTC2983_CHAN_ASSIGN(thermo->cold_junction_chan); > + chan_val |= LTC2983_THERMOCOUPLE_CFG(thermo->sensor_config); > + > + if (thermo->custom) { > + int ret; > + > + ret = __ltc2983_chan_custom_sensor_assign(st, thermo- > >custom, > + &chan_val); > + if (ret) > + return ret; > + } > + return __ltc2983_chan_assign_common(st, sensor, chan_val); > +} > + > +static int ltc2983_rtd_assign_chan(struct ltc2983_data *st, > + const struct ltc2983_sensor *sensor) > +{ > + struct ltc2983_rtd *rtd = to_rtd(sensor); > + u32 chan_val; > + > + chan_val = LTC2983_CHAN_ASSIGN(rtd->r_sense_chan); > + chan_val |= LTC2983_RTD_CFG(rtd->sensor_config); > + chan_val |= LTC2983_RTD_EXC_CURRENT(rtd->excitation_current); > + chan_val |= LTC2983_RTD_CURVE(rtd->rtd_curve); > + > + if (rtd->custom) { > + int ret; > + > + ret = __ltc2983_chan_custom_sensor_assign(st, rtd- > >custom, > + &chan_val); > + if (ret) > + return ret; > + } > + return __ltc2983_chan_assign_common(st, sensor, chan_val); > +} > + > +static int ltc2983_thermistor_assign_chan(struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_thermistor *thermistor = to_thermistor(sensor); > + u32 chan_val; > + > + chan_val = LTC2983_CHAN_ASSIGN(thermistor->r_sense_chan); > + chan_val |= LTC2983_THERMISTOR_CFG(thermistor->sensor_config); > + chan_val |= > + LTC2983_THERMISTOR_EXC_CURRENT(thermistor- > >excitation_current); > + > + if (thermistor->custom) { > + int ret; > + > + ret = __ltc2983_chan_custom_sensor_assign(st, > + thermistor- > >custom, > + &chan_val); > + if (ret) > + return ret; > + } > + return __ltc2983_chan_assign_common(st, sensor, chan_val); > +} > + > +static int ltc2983_diode_assign_chan(struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_diode *diode = to_diode(sensor); > + u32 chan_val; > + > + chan_val = LTC2983_DIODE_CFG(diode->sensor_config); > + chan_val |= LTC2983_DIODE_EXC_CURRENT(diode- > >excitation_current); > + chan_val |= LTC2983_DIODE_IDEAL_FACTOR(diode- > >ideal_factor_value); > + > + return __ltc2983_chan_assign_common(st, sensor, chan_val); > +} > + > +static int ltc2983_r_sense_assign_chan(struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_rsense *rsense = to_rsense(sensor); > + u32 chan_val; > + > + chan_val = LTC2983_R_SENSE_VAL(rsense->r_sense_val); > + > + return __ltc2983_chan_assign_common(st, sensor, chan_val); > +} > + > +static int ltc2983_adc_assign_chan(struct ltc2983_data *st, > + const struct ltc2983_sensor *sensor) > +{ > + struct ltc2983_adc *adc = to_adc(sensor); > + u32 chan_val; > + > + chan_val = LTC2983_ADC_SINGLE_ENDED(adc->single_ended); > + > + return __ltc2983_chan_assign_common(st, sensor, chan_val); > +} > + > +static struct ltc2983_sensor *ltc2983_thermocouple_new( > + const struct device_node > *child, > + struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_thermocouple *thermo; > + struct device_node *phandle; > + u32 oc_current; > + int ret; > + > + thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), > GFP_KERNEL); > + if (!thermo) > + return ERR_PTR(-ENOMEM); > + > + if (of_property_read_bool(child, "adi,single-ended")) > + thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1); > + > + ret = of_property_read_u32(child, "adi,sensor-oc-current- > microamp", > + &oc_current); > + if (!ret) { > + switch (oc_current) { > + case 10: > + thermo->sensor_config |= > + LTC2983_THERMOCOUPLE_OC_CURR(0) > ; > + break; > + case 100: > + thermo->sensor_config |= > + LTC2983_THERMOCOUPLE_OC_CURR(1) > ; > + break; > + case 500: > + thermo->sensor_config |= > + LTC2983_THERMOCOUPLE_OC_CURR(2) > ; > + break; > + case 1000: > + thermo->sensor_config |= > + LTC2983_THERMOCOUPLE_OC_CURR(3) > ; > + break; > + default: > + dev_err(&st->spi->dev, > + "Invalid open circuit current:%u", > oc_current); > + return ERR_PTR(-EINVAL); > + } > + > + thermo->sensor_config |= > LTC2983_THERMOCOUPLE_OC_CHECK(1); > + } > + /* validate channel index */ > + if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) > && > + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { > + dev_err(&st->spi->dev, > + "Invalid chann:%d for differential > thermocouple", > + sensor- > >chan); > + return ERR_PTR(-EINVAL); > + } > + > + phandle = of_parse_phandle(child, "adi,cold-junction-handle", > 0); > + if (phandle) { > + int ret; > + > + ret = of_property_read_u32(phandle, "reg", > + &thermo- > >cold_junction_chan); > + if (ret) { > + /* > + * This would be catched later but we can just > return > + * the error right away. > + */ > + dev_err(&st->spi->dev, "Property reg must be > given\n"); > + of_node_put(phandle); > + return ERR_PTR(-EINVAL); > + } > + } > + > + /* check custom sensor */ > + if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) { > + thermo->custom = __ltc2983_custom_sensor_new(st, child, > false, > + 16384, > true); > + if (IS_ERR(thermo->custom)) { > + of_node_put(phandle); > + return ERR_CAST(thermo->custom); > + } > + } > + > + /* set common parameters */ > + thermo->sensor.fault_handler = > ltc2983_thermocouple_fault_handler; > + thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan; > + > + of_node_put(phandle); > + return &thermo->sensor; > +} > + > +static struct ltc2983_sensor *ltc2983_rtd_new(const struct > device_node *child, > + struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_rtd *rtd; > + int ret = 0; > + struct device *dev = &st->spi->dev; > + struct device_node *phandle; > + u32 excitation_current = 0, n_wires = 0; > + > + rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL); > + if (!rtd) > + return ERR_PTR(-ENOMEM); > + > + phandle = of_parse_phandle(child, "adi,rsense-handle", 0); > + if (!phandle) { > + dev_err(dev, "Property adi,rsense-handle missing or > invalid"); > + return ERR_PTR(-EINVAL); > + } > + > + ret = of_property_read_u32(phandle, "reg", &rtd->r_sense_chan); > + if (ret) { > + dev_err(dev, "Property reg must be given\n"); > + goto fail; > + } > + > + ret = of_property_read_u32(child, "adi,number-of-wires", > &n_wires); > + if (!ret) { > + switch (n_wires) { > + case 2: > + rtd->sensor_config = LTC2983_RTD_N_WIRES(0); > + break; > + case 3: > + rtd->sensor_config = LTC2983_RTD_N_WIRES(1); > + break; > + case 4: > + rtd->sensor_config = LTC2983_RTD_N_WIRES(2); > + break; > + case 5: > + /* 4 wires, Kelvin Rsense */ > + rtd->sensor_config = LTC2983_RTD_N_WIRES(3); > + break; > + default: > + dev_err(dev, "Invalid number of wires:%u\n", > n_wires); > + ret = -EINVAL; > + goto fail; > + } > + } > + > + if (of_property_read_bool(child, "adi,rsense-share")) { > + /* Current rotation is only available with rsense > sharing */ > + if (of_property_read_bool(child, "adi,current-rotate")) > { > + if (n_wires == 2 || n_wires == 3) { > + dev_err(dev, > + "Rotation not allowed for 2/3 > Wire RTDs"); > + ret = -EINVAL; > + goto fail; > + } > + rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1); > + } else { > + rtd->sensor_config |= LTC2983_RTD_R_SHARE(1); > + } > + } > + /* > + * rtd channel indexes are a bit more complicated to validate. > + * For 4wire RTD with rotation, the channel selection cannot be > + * >=19 since the chann + 1 is used in this configuration. > + * For 4wire RTDs with kelvin rsense, the rsense channel cannot > be > + * <=1 since chanel - 1 and channel - 2 are used. > + */ > + if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) { > + /* 4-wire */ > + u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN, > + max = LTC2983_MAX_CHANNELS_NR; > + > + if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK) > + max = LTC2983_MAX_CHANNELS_NR - 1; > + > + if (((rtd->sensor_config & > LTC2983_RTD_KELVIN_R_SENSE_MASK) > + == LTC2983_RTD_KELVIN_R_SENSE_MASK) && > + (rtd->r_sense_chan <= min)) { > + /* kelvin rsense*/ > + dev_err(dev, > + "Invalid rsense chann:%d to use in > kelvin rsense", > + rtd- > >r_sense_chan); > + > + ret = -EINVAL; > + goto fail; > + } > + > + if (sensor->chan < min || sensor->chan > max) { > + dev_err(dev, "Invalid chann:%d for the rtd > config", > + sensor- > >chan); > + > + ret = -EINVAL; > + goto fail; > + } > + } else { > + /* same as differential case */ > + if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { > + dev_err(&st->spi->dev, > + "Invalid chann:%d for RTD", sensor- > >chan); > + > + ret = -EINVAL; > + goto fail; > + } > + } > + > + /* check custom sensor */ > + if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) { > + rtd->custom = __ltc2983_custom_sensor_new(st, child, > false, > + 2048, false); > + if (IS_ERR(rtd->custom)) { > + of_node_put(phandle); > + return ERR_CAST(rtd->custom); > + } > + } > + > + /* set common parameters */ > + rtd->sensor.fault_handler = ltc2983_common_fault_handler; > + rtd->sensor.assign_chan = ltc2983_rtd_assign_chan; > + > + ret = of_property_read_u32(child, "adi,excitation-current- > microamp", > + &excitation_current); > + if (ret) { > + /* default to 5uA */ > + rtd->excitation_current = 1; > + } else { > + switch (excitation_current) { > + case 5: > + rtd->excitation_current = 0x01; > + break; > + case 10: > + rtd->excitation_current = 0x02; > + break; > + case 25: > + rtd->excitation_current = 0x03; > + break; > + case 50: > + rtd->excitation_current = 0x04; > + break; > + case 100: > + rtd->excitation_current = 0x05; > + break; > + case 250: > + rtd->excitation_current = 0x06; > + break; > + case 500: > + rtd->excitation_current = 0x07; > + break; > + case 1000: > + rtd->excitation_current = 0x08; > + break; > + default: > + dev_err(&st->spi->dev, > + "Invalid value for excitation > current(%u)", > + excitation_curr > ent); > + ret = -EINVAL; > + goto fail; > + } > + } > + > + of_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve); > + > + of_node_put(phandle); > + return &rtd->sensor; > +fail: > + of_node_put(phandle); > + return ERR_PTR(ret); > +} > + > +static struct ltc2983_sensor *ltc2983_thermistor_new( > + const struct device_node > *child, > + struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_thermistor *thermistor; > + struct device *dev = &st->spi->dev; > + struct device_node *phandle; > + u32 excitation_current = 0; > + int ret = 0; > + > + thermistor = devm_kzalloc(dev, sizeof(*thermistor), > GFP_KERNEL); > + if (!thermistor) > + return ERR_PTR(-ENOMEM); > + > + phandle = of_parse_phandle(child, "adi,rsense-handle", 0); > + if (!phandle) { > + dev_err(dev, "Property adi,rsense-handle missing or > invalid"); > + return ERR_PTR(-EINVAL); > + } > + > + ret = of_property_read_u32(phandle, "reg", &thermistor- > >r_sense_chan); > + if (ret) { > + dev_err(dev, "rsense channel must be configured...\n"); > + goto fail; > + } > + > + if (of_property_read_bool(child, "adi,single-ended")) { > + thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1); > + } else if (of_property_read_bool(child, "adi,rsense-share")) { > + /* rotation is only possible if sharing rsense */ > + if (of_property_read_bool(child, "adi,current-rotate")) > + thermistor->sensor_config = > + LTC2983_THERMISTOR_C_RO > TATE(1); > + else > + thermistor->sensor_config = > + LTC2983_THERMISTOR_R_SH > ARE(1); > + } > + /* validate channel index */ > + if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) > && > + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { > + dev_err(&st->spi->dev, > + "Invalid chann:%d for differential thermistor", > + sensor- > >chan); > + ret = -EINVAL; > + goto fail; > + } > + > + /* check custom sensor */ > + if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) { > + thermistor->custom = __ltc2983_custom_sensor_new(st, > child, > + sensor->type == > LTC2983_SENSOR_THERMISTOR_STEINHART ? > + true : false, > 64, > + false); > + if (IS_ERR(thermistor->custom)) { > + of_node_put(phandle); > + return ERR_CAST(thermistor->custom); > + } > + } > + /* set common parameters */ > + thermistor->sensor.fault_handler = > ltc2983_common_fault_handler; > + thermistor->sensor.assign_chan = > ltc2983_thermistor_assign_chan; > + > + ret = of_property_read_u32(child, "adi,excitation-current- > nanoamp", > + &excitation_current); > + if (ret) { > + /* Auto range is not allowed for custom sensors */ > + if (sensor->type >= > LTC2983_SENSOR_THERMISTOR_STEINHART) > + /* default to 1uA */ > + thermistor->excitation_current = 0x03; > + else > + /* default to auto-range */ > + thermistor->excitation_current = 0x0c; > + } else { > + switch (excitation_current) { > + case 0: > + /* auto range */ > + if (sensor->type >= > + LTC2983_SENSOR_THERMISTOR_STEINHART) { > + dev_err(&st->spi->dev, > + "Auto Range not allowed for > custom sensors\n"); > + ret = -EINVAL; > + goto fail; > + } > + thermistor->excitation_current = 0x0c; > + break; > + case 250: > + thermistor->excitation_current = 0x01; > + break; > + case 500: > + thermistor->excitation_current = 0x02; > + break; > + case 1000: > + thermistor->excitation_current = 0x03; > + break; > + case 5000: > + thermistor->excitation_current = 0x04; > + break; > + case 10000: > + thermistor->excitation_current = 0x05; > + break; > + case 25000: > + thermistor->excitation_current = 0x06; > + break; > + case 50000: > + thermistor->excitation_current = 0x07; > + break; > + case 100000: > + thermistor->excitation_current = 0x08; > + break; > + case 250000: > + thermistor->excitation_current = 0x09; > + break; > + case 500000: > + thermistor->excitation_current = 0x0a; > + break; > + case 1000000: > + thermistor->excitation_current = 0x0b; > + break; > + default: > + dev_err(&st->spi->dev, > + "Invalid value for excitation > current(%u)", > + excitation_curr > ent); > + ret = -EINVAL; > + goto fail; > + } > + } > + > + of_node_put(phandle); > + return &thermistor->sensor; > +fail: > + of_node_put(phandle); > + return ERR_PTR(ret); > +} > + > +static struct ltc2983_sensor *ltc2983_diode_new( > + const struct device_node > *child, > + const struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_diode *diode; > + u32 temp = 0, excitation_current = 0; > + int ret; > + > + diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), > GFP_KERNEL); > + if (!diode) > + return ERR_PTR(-ENOMEM); > + > + if (of_property_read_bool(child, "adi,single-ended")) > + diode->sensor_config = LTC2983_DIODE_SGL(1); > + > + if (of_property_read_bool(child, "adi,three-conversion- > cycles")) > + diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1); > + > + if (of_property_read_bool(child, "adi,average-on")) > + diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1); > + > + /* validate channel index */ > + if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) && > + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { > + dev_err(&st->spi->dev, > + "Invalid chann:%d for differential thermistor", > + sensor- > >chan); > + return ERR_PTR(-EINVAL); > + } > + /* set common parameters */ > + diode->sensor.fault_handler = ltc2983_common_fault_handler; > + diode->sensor.assign_chan = ltc2983_diode_assign_chan; > + > + ret = of_property_read_u32(child, "adi,excitation-current- > microamp", > + &excitation_current); > + if (!ret) { > + switch (excitation_current) { > + case 10: > + diode->excitation_current = 0x00; > + break; > + case 20: > + diode->excitation_current = 0x01; > + break; > + case 40: > + diode->excitation_current = 0x02; > + break; > + case 80: > + diode->excitation_current = 0x03; > + break; > + default: > + dev_err(&st->spi->dev, > + "Invalid value for excitation > current(%u)", > + excitation_curr > ent); > + return ERR_PTR(-EINVAL); > + } > + } > + > + of_property_read_u32(child, "adi,ideal-factor-value", &temp); > + > + /* 2^20 resolution */ > + diode->ideal_factor_value = __convert_to_raw(temp, 1048576); > + > + return &diode->sensor; > +} > + > +static struct ltc2983_sensor *ltc2983_r_sense_new(struct device_node > *child, > + struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_rsense *rsense; > + int ret; > + u64 temp; > + > + rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), > GFP_KERNEL); > + if (!rsense) > + return ERR_PTR(-ENOMEM); > + > + /* validate channel index */ > + if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { > + dev_err(&st->spi->dev, "Invalid chann:%d for r_sense", > + sensor->chan); > + return ERR_PTR(-EINVAL); > + } > + /* get raw value */ > + ret = of_property_read_u64(child, "adi,rsense-val-micro-ohms", > &temp); > + if (ret) { > + dev_err(&st->spi->dev, "Property adi,rsense-val-micro- > ohms missing\n"); > + return ERR_PTR(-EINVAL); > + } > + > + /* 2^10 resolution */ > + rsense->r_sense_val = __convert_to_raw(temp, 1024); > + > + /* set common parameters */ > + rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan; > + > + return &rsense->sensor; > +} > + > +static struct ltc2983_sensor *ltc2983_adc_new(struct device_node > *child, > + struct ltc2983_data *st, > + const struct ltc2983_sensor > *sensor) > +{ > + struct ltc2983_adc *adc; > + > + adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL); > + if (!adc) > + return ERR_PTR(-ENOMEM); > + > + if (of_property_read_bool(child, "adi,single-ended")) > + adc->single_ended = true; > + > + if (!adc->single_ended && > + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { > + dev_err(&st->spi->dev, "Invalid chan:%d for > differential adc\n", > + sensor- > >chan); > + return ERR_PTR(-EINVAL); > + } > + /* set common parameters */ > + adc->sensor.assign_chan = ltc2983_adc_assign_chan; > + adc->sensor.fault_handler = ltc2983_common_fault_handler; > + > + return &adc->sensor; > +} > + > +static int ltc2983_chan_read(struct ltc2983_data *st, > + const struct ltc2983_sensor *sensor, int *val) > +{ > + u32 start_conversion = 0; > + int ret; > + unsigned long time; > + __be32 temp; > + > + /* > + * Do not allow channel readings if device is in sleep state. > + * A read/write on the spi bus would bring the device > prematurely > + * out of sleep. > + */ > + if (st->sleep) > + return -EPERM; > + > + start_conversion = LTC2983_STATUS_START(true); > + start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan); > + dev_dbg(&st->spi->dev, "Start conversion on chan:%d, > status:%02X\n", > + sensor->chan, start_conversion); > + /* start conversion */ > + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, > start_conversion); > + if (ret) > + return ret; > + > + reinit_completion(&st->completion); > + /* > + * wait for conversion to complete. > + * 300 ms should be more than enough to complete the > conversion. > + * Depending on the sensor configuration, there are 2/3 > conversions > + * cycles of 82ms. > + */ > + time = wait_for_completion_timeout(&st->completion, > + msecs_to_jiffies(300)); > + if (!time) { > + dev_warn(&st->spi->dev, "Conversion timed out\n"); > + return -ETIMEDOUT; > + } > + > + /* read the converted data */ > + ret = regmap_bulk_read(st->regmap, > LTC2983_CHAN_RES_ADDR(sensor->chan), > + &temp, sizeof(temp)); > + if (ret) > + return ret; > + > + *val = __be32_to_cpu(temp); > + > + if (!(LTC2983_RES_VALID_MASK & *val)) { > + dev_err(&st->spi->dev, "Invalid conversion > detected\n"); > + return -EIO; > + } > + > + ret = sensor->fault_handler(st, *val); > + if (ret) > + return ret; > + > + *val = sign_extend32((*val) & LTC2983_DATA_MASK, > LTC2983_DATA_SIGN_BIT); > + return 0; > +} > + > +static int ltc2983_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct ltc2983_data *st = iio_priv(indio_dev); > + int ret; > + > + /* sanity check */ > + if (chan->address >= st->num_channels) { > + dev_err(&st->spi->dev, "Invalid chan address:%ld", > + chan->address); > + return -EINVAL; > + } > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&st->lock); > + ret = ltc2983_chan_read(st, st->sensors[chan->address], > val); > + mutex_unlock(&st->lock); > + return ret ?: IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + switch (chan->type) { > + case IIO_TEMP: > + /* value in milli degrees */ > + *val = 1000; > + /* 2^10 */ > + *val2 = 1024; > + return IIO_VAL_FRACTIONAL; > + case IIO_VOLTAGE: > + /* value in millivolt */ > + *val = 1000; > + /* 2^21 */ > + *val2 = 2097152; > + return IIO_VAL_FRACTIONAL; > + default: > + return -EINVAL; > + } > + } > + > + return -EINVAL; > +} > + > +static int ltc2983_reg_access(struct iio_dev *indio_dev, > + unsigned int reg, > + unsigned int writeval, > + unsigned int *readval) > +{ > + struct ltc2983_data *st = iio_priv(indio_dev); > + > + /* check comment in ltc2983_chan_read() */ > + if (st->sleep) > + return -EPERM; > + > + if (readval) > + return regmap_read(st->regmap, reg, readval); > + else > + return regmap_write(st->regmap, reg, writeval); > +} > + > +static irqreturn_t ltc2983_irq_handler(int irq, void *data) > +{ > + struct ltc2983_data *st = data; > + > + complete(&st->completion); > + return IRQ_HANDLED; > +} > + > +#define LTC2983_CHAN(__type, index, __address) ({ \ > + struct iio_chan_spec __chan = { \ > + .type = __type, \ > + .indexed = 1, \ > + .channel = index, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > + .address = __address, \ > + }; \ > + __chan; \ > +}) > + > +static int ltc2983_parse_dt(struct ltc2983_data *st) > +{ > + struct device_node *child; > + struct device *dev = &st->spi->dev; > + int ret = 0, chan = 0, channel_avail_mask = 0; > + > + if (!of_property_read_bool(dev->of_node, "adi,temperature- > celcius")) > + st->temp_farenheit = true; > + > + of_property_read_u32(dev->of_node, "adi,mux-delay-config-us", > + &st->mux_delay_config); > + > + of_property_read_u32(dev->of_node, "adi,filter-notch-freq", > + &st->filter_notch_freq); > + > + st->num_channels = of_get_available_child_count(dev->of_node); > + st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st- > >sensors), > + GFP_KERNEL); > + if (!st->sensors) > + return -ENOMEM; > + > + st->iio_channels = st->num_channels; > + for_each_available_child_of_node(dev->of_node, child) { > + struct ltc2983_sensor sensor; > + > + ret = of_property_read_u32(child, "reg", &sensor.chan); > + if (ret) { > + dev_err(dev, "reg property must given for child > nodes\n"); > + return ret; > + } > + > + /* check if we have a valid channel */ > + if (sensor.chan < LTC2983_MIN_CHANNELS_NR || > + sensor.chan > LTC2983_MAX_CHANNELS_NR) { > + dev_err(dev, > + "chan:%d must be from 1 to 20\n", > sensor.chan); > + return -EINVAL; > + } else if (channel_avail_mask & BIT(sensor.chan)) { > + dev_err(dev, "chan:%d already in use\n", > sensor.chan); > + return -EINVAL; > + } > + > + ret = of_property_read_u32(child, "adi,sensor-type", > + &sensor.type); > + if (ret) { > + dev_err(dev, > + "adi,sensor-type property must given > for child nodes\n"); > + return ret; > + } > + > + dev_dbg(dev, "Create new sensor, type %u, chann %u", > + sensor. > type, > + sensor. > chan); > + > + if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE && > + sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) > { > + st->sensors[chan] = > ltc2983_thermocouple_new(child, st, > + &s > ensor); > + } else if (sensor.type >= LTC2983_SENSOR_RTD && > + sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) { > + st->sensors[chan] = ltc2983_rtd_new(child, st, > &sensor); > + } else if (sensor.type >= LTC2983_SENSOR_THERMISTOR && > + sensor.type <= > LTC2983_SENSOR_THERMISTOR_CUSTOM) { > + st->sensors[chan] = > ltc2983_thermistor_new(child, st, > + &sen > sor); > + } else if (sensor.type == LTC2983_SENSOR_DIODE) { > + st->sensors[chan] = ltc2983_diode_new(child, > st, > + &sensor); > + } else if (sensor.type == > LTC2983_SENSOR_SENSE_RESISTOR) { > + st->sensors[chan] = ltc2983_r_sense_new(child, > st, > + &sensor > ); > + /* don't add rsense to iio */ > + st->iio_channels--; > + } else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) { > + st->sensors[chan] = ltc2983_adc_new(child, st, > &sensor); > + } else { > + dev_err(dev, "Unknown sensor type %d\n", > sensor.type); > + return -EINVAL; > + } > + > + if (IS_ERR(st->sensors[chan])) { > + dev_err(dev, "Failed to create sensor %ld", > + PTR_ERR(st- > >sensors[chan])); > + return PTR_ERR(st->sensors[chan]); > + } > + /* set generic sensor parameters */ > + st->sensors[chan]->chan = sensor.chan; > + st->sensors[chan]->type = sensor.type; > + > + channel_avail_mask |= BIT(sensor.chan); > + chan++; > + } > + > + return 0; > +} > + > +static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio) > +{ > + u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0; > + u32 global_cfg = 0; > + int ret; > + unsigned long time; > + > + /* make sure the device is up */ > + time = wait_for_completion_timeout(&st->completion, > + msecs_to_jiffies(250)); > + > + if (!time) { > + dev_err(&st->spi->dev, "Device startup timed out\n"); > + return -ETIMEDOUT; > + } > + > + st->iio_chan = devm_kzalloc(&st->spi->dev, > + st->iio_channels * sizeof(*st- > >iio_chan), > + GFP_KERNEL); > + > + if (!st->iio_chan) > + return -ENOMEM; > + > + global_cfg = LTC2983_NOTCH_FREQ(st->filter_notch_freq); > + global_cfg |= LTC2983_TEMP_UNITS(st->temp_farenheit); > + regmap_write(st->regmap, LTC2983_GLOBAL_CONFIG_REG, > global_cfg); > + regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG, st- > >mux_delay_config); > + > + for (chan = 0; chan < st->num_channels; chan++) { > + u32 chan_type = 0, *iio_chan; > + > + ret = st->sensors[chan]->assign_chan(st, st- > >sensors[chan]); > + if (ret) > + return ret; > + /* > + * The assign_iio flag is necessary for when the device > is > + * coming out of sleep. In that case, we just need to > + * re-configure the device channels. > + * We also don't assign iio channels for rsense. > + */ > + if (st->sensors[chan]->type == > LTC2983_SENSOR_SENSE_RESISTOR || > + !assign_iio) > + continue; > + > + /* assign iio channel */ > + if (st->sensors[chan]->type != > LTC2983_SENSOR_DIRECT_ADC) { > + chan_type = IIO_TEMP; > + iio_chan = &iio_chan_t; > + } else { > + chan_type = IIO_VOLTAGE; > + iio_chan = &iio_chan_v; > + } > + > + /* > + * add chan as the iio .address so that, we can > directly > + * reference the sensor given the iio_chan_spec > + */ > + st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, > (*iio_chan)++, > + chan); > + } > + > + return 0; > +} > + > +static const struct regmap_range ltc2983_reg_ranges[] = { > + regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG), > + regmap_reg_range(LTC2983_TEMP_RES_START_REG, > LTC2983_TEMP_RES_END_REG), > + regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, > LTC2983_GLOBAL_CONFIG_REG), > + regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG, > + LTC2983_MULT_CHANNEL_END_REG), > + regmap_reg_range(LTC2983_MUX_CONFIG_REG, > LTC2983_MUX_CONFIG_REG), > + regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG, > + LTC2983_CHAN_ASSIGN_END_REG), > + regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG, > + LTC2983_CUST_SENS_TBL_END_REG), > +}; > + > +static const struct regmap_access_table ltc2983_reg_table = { > + .yes_ranges = ltc2983_reg_ranges, > + .n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges), > +}; > + > +/* > + * The reg_bits are actually 12 but the device needs the first > *complete* > + * byte for the command (R/W). > + */ > +static const struct regmap_config ltc2983_regmap_config = { > + .reg_bits = 24, > + .val_bits = 8, > + .wr_table = <c2983_reg_table, > + .rd_table = <c2983_reg_table, > + .read_flag_mask = GENMASK(1, 0), > + .write_flag_mask = BIT(1), > +}; > + > +static const struct iio_info ltc2983_iio_info = { > + .read_raw = ltc2983_read_raw, > + .debugfs_reg_access = ltc2983_reg_access, > +}; > + > +static int ltc2983_probe(struct spi_device *spi) > +{ > + struct ltc2983_data *st; > + struct iio_dev *indio_dev; > + const char *name = spi_get_device_id(spi)->name; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + > + st->regmap = devm_regmap_init_spi(spi, <c2983_regmap_config); > + if (IS_ERR(st->regmap)) { > + dev_err(&spi->dev, "Failed to initialize regmap\n"); > + return PTR_ERR(st->regmap); > + } > + > + mutex_init(&st->lock); > + init_completion(&st->completion); > + st->spi = spi; > + spi_set_drvdata(spi, st); > + > + ret = ltc2983_parse_dt(st); > + if (ret) > + return ret; > + /* > + * let's request the irq now so it is used to sync the device > + * startup in ltc2983_setup() > + */ > + ret = devm_request_irq(&spi->dev, spi->irq, > ltc2983_irq_handler, > + IRQF_TRIGGER_RISING, name, st); > + if (ret) { > + dev_err(&spi->dev, "failed to request an irq, %d", > ret); > + return ret; > + } > + > + ret = ltc2983_setup(st, true); > + if (ret) > + return ret; > + > + indio_dev->dev.parent = &spi->dev; > + indio_dev->name = name; > + indio_dev->num_channels = st->iio_channels; > + indio_dev->channels = st->iio_chan; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = <c2983_iio_info; > + > + return devm_iio_device_register(&spi->dev, indio_dev); > +} > + > +static int __maybe_unused ltc2983_resume(struct device *dev) > +{ > + struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev)); > + int ret; > + > + mutex_lock(&st->lock); > + /* dummy read to bring the device out of sleep */ > + regmap_read(st->regmap, LTC2983_STATUS_REG, &ret); > + /* we need to re-assign the channels */ > + ret = ltc2983_setup(st, false); > + st->sleep = false; > + mutex_unlock(&st->lock); > + > + return ret; > +} > + > +static int __maybe_unused ltc2983_suspend(struct device *dev) > +{ > + struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev)); > + int ret; > + > + mutex_lock(&st->lock); > + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, > LTC2983_SLEEP); > + st->sleep = true; This flag is unneeded since all userland tasks are frozen before the hw suspend()/resume() callbacks are called. When coming out of sleep, things go in the reverse order so I do not have to care about code trying to read the attributes. Furthermore, doing `mutex_lock()` here is dangerous since some frozen task can held it... At very least I think it should be trylock. But I don't really think the mutex_* calls are needed here so I'm thinking in dropping this and the sleep flag in v4. > + mutex_unlock(&st->lock); > + > + return ret; > +} > + > +static SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend, > ltc2983_resume); > + > +static const struct spi_device_id ltc2983_id_table[] = { > + { "ltc2983" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(spi, ltc2983_id_table); > + > +static const struct of_device_id ltc2983_of_match[] = { > + { .compatible = "adi,ltc2983" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, ltc2983_id_table); > + > +static struct spi_driver ltc2983_driver = { > + .driver = { > + .name = "ltc2983", > + .of_match_table = ltc2983_of_match, > + .pm = <c2983_pm_ops, > + }, > + .probe = ltc2983_probe, > + .id_table = ltc2983_id_table, > +}; > + > +module_spi_driver(ltc2983_driver); > + > +MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>"); > +MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature > sensors"); > +MODULE_LICENSE("GPL");
diff --git a/MAINTAINERS b/MAINTAINERS index f0c03740b9fb..14a256e785ca 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9491,6 +9491,13 @@ S: Maintained F: Documentation/devicetree/bindings/iio/dac/ltc1660.txt F: drivers/iio/dac/ltc1660.c +LTC2983 IIO TEMPERATURE DRIVER +M: Nuno Sá <nuno.sa@analog.com> +W: http://ez.analog.com/community/linux-device-drivers +L: linux-iio@vger.kernel.org +S: Supported +F: drivers/iio/temperature/ltc2983.c + LTC4261 HARDWARE MONITOR DRIVER M: Guenter Roeck <linux@roeck-us.net> L: linux-hwmon@vger.kernel.org diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig index 737faa0901fe..04b5a67b593c 100644 --- a/drivers/iio/temperature/Kconfig +++ b/drivers/iio/temperature/Kconfig @@ -4,6 +4,16 @@ # menu "Temperature sensors" +config LTC2983 + tristate "Analog Devices Multi-Sensor Digital Temperature Measurement System" + depends on SPI + help + Say yes here to build support for the LTC2983 Multi-Sensor + high accuracy digital temperature measurement system. + + To compile this driver as a module, choose M here: the module + will be called ltc2983. + config MAXIM_THERMOCOUPLE tristate "Maxim thermocouple sensors" depends on SPI diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile index baca4776ca0d..d6b850b0cf63 100644 --- a/drivers/iio/temperature/Makefile +++ b/drivers/iio/temperature/Makefile @@ -3,6 +3,7 @@ # Makefile for industrial I/O temperature drivers # +obj-$(CONFIG_LTC2983) += ltc2983.o obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o obj-$(CONFIG_MAX31856) += max31856.o diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c new file mode 100644 index 000000000000..f899c1d75f8a --- /dev/null +++ b/drivers/iio/temperature/ltc2983.c @@ -0,0 +1,1554 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System + * driver + * + * Copyright 2019 Analog Devices Inc. + */ +#include <linux/bitfield.h> +#include <linux/completion.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/iio/iio.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of_gpio.h> +#include <linux/regmap.h> +#include <linux/spi/spi.h> + +/* register map */ +#define LTC2983_STATUS_REG 0x0000 +#define LTC2983_TEMP_RES_START_REG 0x0010 +#define LTC2983_TEMP_RES_END_REG 0x005F +#define LTC2983_GLOBAL_CONFIG_REG 0x00F0 +#define LTC2983_MULT_CHANNEL_START_REG 0x00F4 +#define LTC2983_MULT_CHANNEL_END_REG 0x00F7 +#define LTC2983_MUX_CONFIG_REG 0x00FF +#define LTC2983_CHAN_ASSIGN_START_REG 0x0200 +#define LTC2983_CHAN_ASSIGN_END_REG 0x024F +#define LTC2983_CUST_SENS_TBL_START_REG 0x0250 +#define LTC2983_CUST_SENS_TBL_END_REG 0x03CF + +#define LTC2983_DIFFERENTIAL_CHAN_MIN 2 +#define LTC2983_MAX_CHANNELS_NR 20 +#define LTC2983_MIN_CHANNELS_NR 1 +#define LTC2983_SLEEP 0x97 +#define LTC2983_CUSTOM_STEINHART_SIZE 24 +#define LTC2983_CUSTOM_SENSOR_ENTRY_SZ 6 +#define LTC2983_CUSTOM_STEINHART_ENTRY_SZ 4 + +#define LTC2983_CHAN_START_ADDR(chan) \ + (((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG) +#define LTC2983_CHAN_RES_ADDR(chan) \ + (((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG) +#define LTC2983_THERMOCOUPLE_DIFF_MASK BIT(3) +#define LTC2983_THERMOCOUPLE_SGL(x) \ + FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MASK, x) +#define LTC2983_THERMOCOUPLE_OC_CURR_MASK GENMASK(1, 0) +#define LTC2983_THERMOCOUPLE_OC_CURR(x) \ + FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR_MASK, x) +#define LTC2983_THERMOCOUPLE_OC_CHECK_MASK BIT(2) +#define LTC2983_THERMOCOUPLE_OC_CHECK(x) \ + FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, x) + +#define LTC2983_THERMISTOR_DIFF_MASK BIT(2) +#define LTC2983_THERMISTOR_SGL(x) \ + FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK, x) +#define LTC2983_THERMISTOR_R_SHARE_MASK BIT(1) +#define LTC2983_THERMISTOR_R_SHARE(x) \ + FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_MASK, x) +#define LTC2983_THERMISTOR_C_ROTATE_MASK BIT(0) +#define LTC2983_THERMISTOR_C_ROTATE(x) \ + FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_MASK, x) + +#define LTC2983_DIODE_DIFF_MASK BIT(2) +#define LTC2983_DIODE_SGL(x) \ + FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x) +#define LTC2983_DIODE_3_CONV_CYCLE_MASK BIT(1) +#define LTC2983_DIODE_3_CONV_CYCLE(x) \ + FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_MASK, x) +#define LTC2983_DIODE_AVERAGE_ON_MASK BIT(0) +#define LTC2983_DIODE_AVERAGE_ON(x) \ + FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MASK, x) + +#define LTC2983_RTD_4_WIRE_MASK BIT(3) +#define LTC2983_RTD_ROTATION_MASK BIT(1) +#define LTC2983_RTD_C_ROTATE(x) \ + FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x) +#define LTC2983_RTD_KELVIN_R_SENSE_MASK GENMASK(3, 2) +#define LTC2983_RTD_N_WIRES_MASK GENMASK(3, 2) +#define LTC2983_RTD_N_WIRES(x) \ + FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x) +#define LTC2983_RTD_R_SHARE_MASK BIT(0) +#define LTC2983_RTD_R_SHARE(x) \ + FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1) + +#define LTC2983_COMMON_HARD_FAULT_MASK GENMASK(31, 30) +#define LTC2983_COMMON_SOFT_FAULT_MASK GENMASK(27, 25) + +#define LTC2983_STATUS_START_MASK BIT(7) +#define LTC2983_STATUS_START(x) FIELD_PREP(LTC2983_STATUS_START_MASK, x) + +#define LTC2983_STATUS_CHAN_SEL_MASK GENMASK(4, 0) +#define LTC2983_STATUS_CHAN_SEL(x) \ + FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK, x) + +#define LTC2983_TEMP_UNITS_MASK BIT(2) +#define LTC2983_TEMP_UNITS(x) FIELD_PREP(LTC2983_TEMP_UNITS_MASK, x) + +#define LTC2983_NOTCH_FREQ_MASK GENMASK(1, 0) +#define LTC2983_NOTCH_FREQ(x) FIELD_PREP(LTC2983_NOTCH_FREQ_MASK, x) + +#define LTC2983_RES_VALID_MASK BIT(24) +#define LTC2983_DATA_MASK GENMASK(23, 0) +#define LTC2983_DATA_SIGN_BIT 23 + +#define LTC2983_CHAN_TYPE_MASK GENMASK(31, 27) +#define LTC2983_CHAN_TYPE(x) FIELD_PREP(LTC2983_CHAN_TYPE_MASK, x) + +/* cold junction for thermocouples and rsense for rtd's and thermistor's */ +#define LTC2983_CHAN_ASSIGN_MASK GENMASK(26, 22) +#define LTC2983_CHAN_ASSIGN(x) FIELD_PREP(LTC2983_CHAN_ASSIGN_MASK, x) + +#define LTC2983_CUSTOM_LEN_MASK GENMASK(5, 0) +#define LTC2983_CUSTOM_LEN(x) FIELD_PREP(LTC2983_CUSTOM_LEN_MASK, x) + +#define LTC2983_CUSTOM_ADDR_MASK GENMASK(11, 6) +#define LTC2983_CUSTOM_ADDR(x) FIELD_PREP(LTC2983_CUSTOM_ADDR_MASK, x) + +#define LTC2983_THERMOCOUPLE_CFG_MASK GENMASK(21, 18) +#define LTC2983_THERMOCOUPLE_CFG(x) \ + FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MASK, x) +#define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK GENMASK(31, 29) +#define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK GENMASK(28, 25) + +#define LTC2983_RTD_CFG_MASK GENMASK(21, 18) +#define LTC2983_RTD_CFG(x) FIELD_PREP(LTC2983_RTD_CFG_MASK, x) +#define LTC2983_RTD_EXC_CURRENT_MASK GENMASK(17, 14) +#define LTC2983_RTD_EXC_CURRENT(x) \ + FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK, x) +#define LTC2983_RTD_CURVE_MASK GENMASK(13, 12) +#define LTC2983_RTD_CURVE(x) FIELD_PREP(LTC2983_RTD_CURVE_MASK, x) + +#define LTC2983_THERMISTOR_CFG_MASK GENMASK(21, 19) +#define LTC2983_THERMISTOR_CFG(x) \ + FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, x) +#define LTC2983_THERMISTOR_EXC_CURRENT_MASK GENMASK(18, 15) +#define LTC2983_THERMISTOR_EXC_CURRENT(x) \ + FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, x) + +#define LTC2983_DIODE_CFG_MASK GENMASK(26, 24) +#define LTC2983_DIODE_CFG(x) FIELD_PREP(LTC2983_DIODE_CFG_MASK, x) +#define LTC2983_DIODE_EXC_CURRENT_MASK GENMASK(23, 22) +#define LTC2983_DIODE_EXC_CURRENT(x) \ + FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MASK, x) +#define LTC2983_DIODE_IDEAL_FACTOR_MASK GENMASK(21, 0) +#define LTC2983_DIODE_IDEAL_FACTOR(x) \ + FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_MASK, x) + +#define LTC2983_R_SENSE_VAL_MASK GENMASK(26, 0) +#define LTC2983_R_SENSE_VAL(x) FIELD_PREP(LTC2983_R_SENSE_VAL_MASK, x) + +#define LTC2983_ADC_SINGLE_ENDED_MASK BIT(26) +#define LTC2983_ADC_SINGLE_ENDED(x) \ + FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MASK, x) + +enum { + LTC2983_SENSOR_THERMOCOUPLE = 1, + LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9, + LTC2983_SENSOR_RTD = 10, + LTC2983_SENSOR_RTD_CUSTOM = 18, + LTC2983_SENSOR_THERMISTOR = 19, + LTC2983_SENSOR_THERMISTOR_STEINHART = 26, + LTC2983_SENSOR_THERMISTOR_CUSTOM = 27, + LTC2983_SENSOR_DIODE = 28, + LTC2983_SENSOR_SENSE_RESISTOR = 29, + LTC2983_SENSOR_DIRECT_ADC = 30, +}; + +#define to_thermocouple(_sensor) \ + container_of(_sensor, struct ltc2983_thermocouple, sensor) + +#define to_rtd(_sensor) \ + container_of(_sensor, struct ltc2983_rtd, sensor) + +#define to_thermistor(_sensor) \ + container_of(_sensor, struct ltc2983_thermistor, sensor) + +#define to_diode(_sensor) \ + container_of(_sensor, struct ltc2983_diode, sensor) + +#define to_rsense(_sensor) \ + container_of(_sensor, struct ltc2983_rsense, sensor) + +#define to_adc(_sensor) \ + container_of(_sensor, struct ltc2983_adc, sensor) + +struct ltc2983_data { + struct regmap *regmap; + struct spi_device *spi; + struct mutex lock; + struct completion completion; + struct iio_chan_spec *iio_chan; + struct ltc2983_sensor **sensors; + u32 mux_delay_config; + u32 filter_notch_freq; + u16 custom_table_size; + u8 num_channels; + u8 iio_channels; + bool temp_farenheit; + bool sleep; +}; + +struct ltc2983_sensor { + int (*fault_handler)(const struct ltc2983_data *st, const u32 result); + int (*assign_chan)(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor); + /* specifies the sensor channel */ + u32 chan; + /* sensor type */ + u32 type; +}; + +struct ltc2983_custom_sensor { + /* raw table sensor data */ + u8 *table; + size_t size; + /* address offset */ + s8 offset; + bool is_steinhart; +}; + +struct ltc2983_thermocouple { + struct ltc2983_sensor sensor; + struct ltc2983_custom_sensor *custom; + u32 sensor_config; + u32 cold_junction_chan; +}; + +struct ltc2983_rtd { + struct ltc2983_sensor sensor; + struct ltc2983_custom_sensor *custom; + u32 sensor_config; + u32 r_sense_chan; + u32 excitation_current; + u32 rtd_curve; +}; + +struct ltc2983_thermistor { + struct ltc2983_sensor sensor; + struct ltc2983_custom_sensor *custom; + u32 sensor_config; + u32 r_sense_chan; + u32 excitation_current; +}; + +struct ltc2983_diode { + struct ltc2983_sensor sensor; + u32 sensor_config; + u32 excitation_current; + u32 ideal_factor_value; +}; + +struct ltc2983_rsense { + struct ltc2983_sensor sensor; + u32 r_sense_val; +}; + +struct ltc2983_adc { + struct ltc2983_sensor sensor; + bool single_ended; +}; + +/* + * Convert to Q format numbers. These number's are integers where + * the number of integer and fractional bits are specified. The resolution + * is given by 1/@resolution and tell us the number of fractional bits. For + * instance a resolution of 2^-10 means we have 10 fractional bits. + */ +static u32 __convert_to_raw(const u64 val, const u32 resolution) +{ + u64 __res = val * resolution; + + /* all values are multiplied by 1000000 to remove the fraction */ + do_div(__res, 1000000); + + return __res; +} + +static u32 __convert_to_raw_sign(const u64 val, const u32 resolution) +{ + s64 __res = -(s32)val; + + __res = __convert_to_raw(__res, resolution); + + return (u32)-__res; +} + +static int __ltc2983_fault_handler(const struct ltc2983_data *st, + const u32 result, const u32 hard_mask, + const u32 soft_mask) +{ + const struct device *dev = &st->spi->dev; + + if (result & hard_mask) { + dev_err(dev, "Invalid conversion: Sensor HARD fault\n"); + return -EIO; + } else if (result & soft_mask) { + /* just print a warning */ + dev_warn(dev, "Suspicious conversion: Sensor SOFT fault\n"); + } + + return 0; +} + +static int __ltc2983_chan_assign_common(const struct ltc2983_data *st, + const struct ltc2983_sensor *sensor, + u32 chan_val) +{ + u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan); + __be32 __chan_val; + + chan_val |= LTC2983_CHAN_TYPE(sensor->type); + dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg, + chan_val); + __chan_val = cpu_to_be32(chan_val); + return regmap_bulk_write(st->regmap, reg, &__chan_val, + sizeof(__chan_val)); +} + +static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st, + struct ltc2983_custom_sensor *custom, + u32 *chan_val) +{ + u32 reg; + u8 mult = custom->is_steinhart ? LTC2983_CUSTOM_STEINHART_ENTRY_SZ : + LTC2983_CUSTOM_SENSOR_ENTRY_SZ; + const struct device *dev = &st->spi->dev; + /* + * custom->size holds the raw size of the table. However, when + * configuring the sensor channel, we must write the number of + * entries of the table minus 1. For steinhart sensors 0 is written + * since the size is constant! + */ + const u8 len = custom->is_steinhart ? 0 : + (custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1; + /* + * Check if the offset was assigned already. It should be for steinhart + * sensors. When coming from sleep, it should be assigned for all. + */ + if (custom->offset < 0) { + /* + * This needs to be done again here because, from the moment + * when this test was done (successfully) for this custom + * sensor, a steinhart sensor might have been added changing + * custom_table_size... + */ + if (st->custom_table_size + custom->size > + (LTC2983_CUST_SENS_TBL_END_REG - + LTC2983_CUST_SENS_TBL_START_REG) + 1) { + dev_err(dev, + "Not space left(%d) for new custom sensor(%zu)", + st->custom_table_size, + custom->size); + return -EINVAL; + } + + custom->offset = st->custom_table_size / + LTC2983_CUSTOM_SENSOR_ENTRY_SZ; + st->custom_table_size += custom->size; + } + + reg = (custom->offset * mult) + LTC2983_CUST_SENS_TBL_START_REG; + + *chan_val |= LTC2983_CUSTOM_LEN(len); + *chan_val |= LTC2983_CUSTOM_ADDR(custom->offset); + dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, sz:%zu", + reg, custom->offset, + custom->size); + /* write custom sensor table */ + return regmap_bulk_write(st->regmap, reg, custom->table, custom->size); +} + +static struct ltc2983_custom_sensor *__ltc2983_custom_sensor_new( + struct ltc2983_data *st, + const struct device_node *np, + const bool is_steinhart, + const u32 resolution, + const bool has_signed) +{ + struct ltc2983_custom_sensor *new_custom; + u8 index, n_entries, tbl = 0; + struct device *dev = &st->spi->dev; + /* + * For custom steinhart, the full u32 is taken. For all the others + * the MSB is discarded. + */ + const u8 n_size = (is_steinhart == true) ? 4 : 3; + + n_entries = of_property_count_elems_of_size(np, "adi,custom-sensor", + sizeof(u64)); + /* n_entries must be an even number */ + if (!n_entries || (n_entries % 2) != 0) { + dev_err(dev, "Number of entries either 0 or not even\n"); + return ERR_PTR(-EINVAL); + } + + new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL); + if (!new_custom) + return ERR_PTR(-ENOMEM); + + new_custom->size = n_entries * n_size; + /* check Steinhart size */ + if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) { + dev_err(dev, "Steinhart sensors size(%zu) must be 24", + new_custom->size); + return ERR_PTR(-EINVAL); + } + /* Check space on the table. */ + if (st->custom_table_size + new_custom->size > + (LTC2983_CUST_SENS_TBL_END_REG - + LTC2983_CUST_SENS_TBL_START_REG) + 1) { + dev_err(dev, "No space left(%d) for new custom sensor(%zu)", + st->custom_table_size, new_custom->size); + return ERR_PTR(-EINVAL); + } + + /* allocate the table */ + new_custom->table = devm_kzalloc(dev, new_custom->size, GFP_KERNEL); + if (!new_custom->table) + return ERR_PTR(-ENOMEM); + + for (index = 0; index < n_entries; index++) { + u64 temp = 0, j; + + of_property_read_u64_index(np, "adi,custom-sensor", index, + &temp); + /* + * Steinhart sensors are configured with raw values in the + * devicetree. For the other sensors we must convert the + * value to raw. The odd index's correspond to temperarures + * and always have 1/1024 of resolution. Temperatures also + * come in kelvin, so signed values is not possible + */ + if (!is_steinhart) { + if ((index % 2) != 0) + temp = __convert_to_raw(temp, 1024); + else if (has_signed && (s64)temp < 0) + temp = __convert_to_raw_sign(temp, resolution); + else + temp = __convert_to_raw(temp, resolution); + } + + for (j = 0; j < n_size; j++) + new_custom->table[tbl++] = + temp >> (8 * (n_size - j - 1)); + } + + new_custom->is_steinhart = is_steinhart; + /* + * This is done to first add all the steinhart sensors to the table, + * in order to maximize the table usage. If we mix adding steinhart + * with the other sensors, we might have to do some roundup to make + * sure that sensor_addr - 0x250(start address) is a multiple of 4 + * (for steinhart), and a multiple of 6 for all the other sensors. + * Since we have const 24 bytes for steinhart sensors and 24 is + * also a multiple of 6, we guarantee that the first non-steinhart + * sensor will sit in a correct address without the need of filling + * addresses. + */ + if (is_steinhart) { + new_custom->offset = st->custom_table_size / + LTC2983_CUSTOM_STEINHART_ENTRY_SZ; + st->custom_table_size += new_custom->size; + } else { + /* mark as unset. This is checked later on the assign phase */ + new_custom->offset = -1; + } + + return new_custom; +} + +static int ltc2983_thermocouple_fault_handler(const struct ltc2983_data *st, + const u32 result) +{ + return __ltc2983_fault_handler(st, result, + LTC2983_THERMOCOUPLE_HARD_FAULT_MASK, + LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK); +} + +static int ltc2983_common_fault_handler(const struct ltc2983_data *st, + const u32 result) +{ + return __ltc2983_fault_handler(st, result, + LTC2983_COMMON_HARD_FAULT_MASK, + LTC2983_COMMON_SOFT_FAULT_MASK); +} + +static int ltc2983_thermocouple_assign_chan(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_thermocouple *thermo = to_thermocouple(sensor); + u32 chan_val; + + chan_val = LTC2983_CHAN_ASSIGN(thermo->cold_junction_chan); + chan_val |= LTC2983_THERMOCOUPLE_CFG(thermo->sensor_config); + + if (thermo->custom) { + int ret; + + ret = __ltc2983_chan_custom_sensor_assign(st, thermo->custom, + &chan_val); + if (ret) + return ret; + } + return __ltc2983_chan_assign_common(st, sensor, chan_val); +} + +static int ltc2983_rtd_assign_chan(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_rtd *rtd = to_rtd(sensor); + u32 chan_val; + + chan_val = LTC2983_CHAN_ASSIGN(rtd->r_sense_chan); + chan_val |= LTC2983_RTD_CFG(rtd->sensor_config); + chan_val |= LTC2983_RTD_EXC_CURRENT(rtd->excitation_current); + chan_val |= LTC2983_RTD_CURVE(rtd->rtd_curve); + + if (rtd->custom) { + int ret; + + ret = __ltc2983_chan_custom_sensor_assign(st, rtd->custom, + &chan_val); + if (ret) + return ret; + } + return __ltc2983_chan_assign_common(st, sensor, chan_val); +} + +static int ltc2983_thermistor_assign_chan(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_thermistor *thermistor = to_thermistor(sensor); + u32 chan_val; + + chan_val = LTC2983_CHAN_ASSIGN(thermistor->r_sense_chan); + chan_val |= LTC2983_THERMISTOR_CFG(thermistor->sensor_config); + chan_val |= + LTC2983_THERMISTOR_EXC_CURRENT(thermistor->excitation_current); + + if (thermistor->custom) { + int ret; + + ret = __ltc2983_chan_custom_sensor_assign(st, + thermistor->custom, + &chan_val); + if (ret) + return ret; + } + return __ltc2983_chan_assign_common(st, sensor, chan_val); +} + +static int ltc2983_diode_assign_chan(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_diode *diode = to_diode(sensor); + u32 chan_val; + + chan_val = LTC2983_DIODE_CFG(diode->sensor_config); + chan_val |= LTC2983_DIODE_EXC_CURRENT(diode->excitation_current); + chan_val |= LTC2983_DIODE_IDEAL_FACTOR(diode->ideal_factor_value); + + return __ltc2983_chan_assign_common(st, sensor, chan_val); +} + +static int ltc2983_r_sense_assign_chan(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_rsense *rsense = to_rsense(sensor); + u32 chan_val; + + chan_val = LTC2983_R_SENSE_VAL(rsense->r_sense_val); + + return __ltc2983_chan_assign_common(st, sensor, chan_val); +} + +static int ltc2983_adc_assign_chan(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_adc *adc = to_adc(sensor); + u32 chan_val; + + chan_val = LTC2983_ADC_SINGLE_ENDED(adc->single_ended); + + return __ltc2983_chan_assign_common(st, sensor, chan_val); +} + +static struct ltc2983_sensor *ltc2983_thermocouple_new( + const struct device_node *child, + struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_thermocouple *thermo; + struct device_node *phandle; + u32 oc_current; + int ret; + + thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL); + if (!thermo) + return ERR_PTR(-ENOMEM); + + if (of_property_read_bool(child, "adi,single-ended")) + thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1); + + ret = of_property_read_u32(child, "adi,sensor-oc-current-microamp", + &oc_current); + if (!ret) { + switch (oc_current) { + case 10: + thermo->sensor_config |= + LTC2983_THERMOCOUPLE_OC_CURR(0); + break; + case 100: + thermo->sensor_config |= + LTC2983_THERMOCOUPLE_OC_CURR(1); + break; + case 500: + thermo->sensor_config |= + LTC2983_THERMOCOUPLE_OC_CURR(2); + break; + case 1000: + thermo->sensor_config |= + LTC2983_THERMOCOUPLE_OC_CURR(3); + break; + default: + dev_err(&st->spi->dev, + "Invalid open circuit current:%u", oc_current); + return ERR_PTR(-EINVAL); + } + + thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1); + } + /* validate channel index */ + if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) && + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { + dev_err(&st->spi->dev, + "Invalid chann:%d for differential thermocouple", + sensor->chan); + return ERR_PTR(-EINVAL); + } + + phandle = of_parse_phandle(child, "adi,cold-junction-handle", 0); + if (phandle) { + int ret; + + ret = of_property_read_u32(phandle, "reg", + &thermo->cold_junction_chan); + if (ret) { + /* + * This would be catched later but we can just return + * the error right away. + */ + dev_err(&st->spi->dev, "Property reg must be given\n"); + of_node_put(phandle); + return ERR_PTR(-EINVAL); + } + } + + /* check custom sensor */ + if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) { + thermo->custom = __ltc2983_custom_sensor_new(st, child, false, + 16384, true); + if (IS_ERR(thermo->custom)) { + of_node_put(phandle); + return ERR_CAST(thermo->custom); + } + } + + /* set common parameters */ + thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler; + thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan; + + of_node_put(phandle); + return &thermo->sensor; +} + +static struct ltc2983_sensor *ltc2983_rtd_new(const struct device_node *child, + struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_rtd *rtd; + int ret = 0; + struct device *dev = &st->spi->dev; + struct device_node *phandle; + u32 excitation_current = 0, n_wires = 0; + + rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL); + if (!rtd) + return ERR_PTR(-ENOMEM); + + phandle = of_parse_phandle(child, "adi,rsense-handle", 0); + if (!phandle) { + dev_err(dev, "Property adi,rsense-handle missing or invalid"); + return ERR_PTR(-EINVAL); + } + + ret = of_property_read_u32(phandle, "reg", &rtd->r_sense_chan); + if (ret) { + dev_err(dev, "Property reg must be given\n"); + goto fail; + } + + ret = of_property_read_u32(child, "adi,number-of-wires", &n_wires); + if (!ret) { + switch (n_wires) { + case 2: + rtd->sensor_config = LTC2983_RTD_N_WIRES(0); + break; + case 3: + rtd->sensor_config = LTC2983_RTD_N_WIRES(1); + break; + case 4: + rtd->sensor_config = LTC2983_RTD_N_WIRES(2); + break; + case 5: + /* 4 wires, Kelvin Rsense */ + rtd->sensor_config = LTC2983_RTD_N_WIRES(3); + break; + default: + dev_err(dev, "Invalid number of wires:%u\n", n_wires); + ret = -EINVAL; + goto fail; + } + } + + if (of_property_read_bool(child, "adi,rsense-share")) { + /* Current rotation is only available with rsense sharing */ + if (of_property_read_bool(child, "adi,current-rotate")) { + if (n_wires == 2 || n_wires == 3) { + dev_err(dev, + "Rotation not allowed for 2/3 Wire RTDs"); + ret = -EINVAL; + goto fail; + } + rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1); + } else { + rtd->sensor_config |= LTC2983_RTD_R_SHARE(1); + } + } + /* + * rtd channel indexes are a bit more complicated to validate. + * For 4wire RTD with rotation, the channel selection cannot be + * >=19 since the chann + 1 is used in this configuration. + * For 4wire RTDs with kelvin rsense, the rsense channel cannot be + * <=1 since chanel - 1 and channel - 2 are used. + */ + if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) { + /* 4-wire */ + u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN, + max = LTC2983_MAX_CHANNELS_NR; + + if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK) + max = LTC2983_MAX_CHANNELS_NR - 1; + + if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK) + == LTC2983_RTD_KELVIN_R_SENSE_MASK) && + (rtd->r_sense_chan <= min)) { + /* kelvin rsense*/ + dev_err(dev, + "Invalid rsense chann:%d to use in kelvin rsense", + rtd->r_sense_chan); + + ret = -EINVAL; + goto fail; + } + + if (sensor->chan < min || sensor->chan > max) { + dev_err(dev, "Invalid chann:%d for the rtd config", + sensor->chan); + + ret = -EINVAL; + goto fail; + } + } else { + /* same as differential case */ + if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { + dev_err(&st->spi->dev, + "Invalid chann:%d for RTD", sensor->chan); + + ret = -EINVAL; + goto fail; + } + } + + /* check custom sensor */ + if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) { + rtd->custom = __ltc2983_custom_sensor_new(st, child, false, + 2048, false); + if (IS_ERR(rtd->custom)) { + of_node_put(phandle); + return ERR_CAST(rtd->custom); + } + } + + /* set common parameters */ + rtd->sensor.fault_handler = ltc2983_common_fault_handler; + rtd->sensor.assign_chan = ltc2983_rtd_assign_chan; + + ret = of_property_read_u32(child, "adi,excitation-current-microamp", + &excitation_current); + if (ret) { + /* default to 5uA */ + rtd->excitation_current = 1; + } else { + switch (excitation_current) { + case 5: + rtd->excitation_current = 0x01; + break; + case 10: + rtd->excitation_current = 0x02; + break; + case 25: + rtd->excitation_current = 0x03; + break; + case 50: + rtd->excitation_current = 0x04; + break; + case 100: + rtd->excitation_current = 0x05; + break; + case 250: + rtd->excitation_current = 0x06; + break; + case 500: + rtd->excitation_current = 0x07; + break; + case 1000: + rtd->excitation_current = 0x08; + break; + default: + dev_err(&st->spi->dev, + "Invalid value for excitation current(%u)", + excitation_current); + ret = -EINVAL; + goto fail; + } + } + + of_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve); + + of_node_put(phandle); + return &rtd->sensor; +fail: + of_node_put(phandle); + return ERR_PTR(ret); +} + +static struct ltc2983_sensor *ltc2983_thermistor_new( + const struct device_node *child, + struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_thermistor *thermistor; + struct device *dev = &st->spi->dev; + struct device_node *phandle; + u32 excitation_current = 0; + int ret = 0; + + thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL); + if (!thermistor) + return ERR_PTR(-ENOMEM); + + phandle = of_parse_phandle(child, "adi,rsense-handle", 0); + if (!phandle) { + dev_err(dev, "Property adi,rsense-handle missing or invalid"); + return ERR_PTR(-EINVAL); + } + + ret = of_property_read_u32(phandle, "reg", &thermistor->r_sense_chan); + if (ret) { + dev_err(dev, "rsense channel must be configured...\n"); + goto fail; + } + + if (of_property_read_bool(child, "adi,single-ended")) { + thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1); + } else if (of_property_read_bool(child, "adi,rsense-share")) { + /* rotation is only possible if sharing rsense */ + if (of_property_read_bool(child, "adi,current-rotate")) + thermistor->sensor_config = + LTC2983_THERMISTOR_C_ROTATE(1); + else + thermistor->sensor_config = + LTC2983_THERMISTOR_R_SHARE(1); + } + /* validate channel index */ + if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) && + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { + dev_err(&st->spi->dev, + "Invalid chann:%d for differential thermistor", + sensor->chan); + ret = -EINVAL; + goto fail; + } + + /* check custom sensor */ + if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) { + thermistor->custom = __ltc2983_custom_sensor_new(st, child, + sensor->type == LTC2983_SENSOR_THERMISTOR_STEINHART ? + true : false, 64, + false); + if (IS_ERR(thermistor->custom)) { + of_node_put(phandle); + return ERR_CAST(thermistor->custom); + } + } + /* set common parameters */ + thermistor->sensor.fault_handler = ltc2983_common_fault_handler; + thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan; + + ret = of_property_read_u32(child, "adi,excitation-current-nanoamp", + &excitation_current); + if (ret) { + /* Auto range is not allowed for custom sensors */ + if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) + /* default to 1uA */ + thermistor->excitation_current = 0x03; + else + /* default to auto-range */ + thermistor->excitation_current = 0x0c; + } else { + switch (excitation_current) { + case 0: + /* auto range */ + if (sensor->type >= + LTC2983_SENSOR_THERMISTOR_STEINHART) { + dev_err(&st->spi->dev, + "Auto Range not allowed for custom sensors\n"); + ret = -EINVAL; + goto fail; + } + thermistor->excitation_current = 0x0c; + break; + case 250: + thermistor->excitation_current = 0x01; + break; + case 500: + thermistor->excitation_current = 0x02; + break; + case 1000: + thermistor->excitation_current = 0x03; + break; + case 5000: + thermistor->excitation_current = 0x04; + break; + case 10000: + thermistor->excitation_current = 0x05; + break; + case 25000: + thermistor->excitation_current = 0x06; + break; + case 50000: + thermistor->excitation_current = 0x07; + break; + case 100000: + thermistor->excitation_current = 0x08; + break; + case 250000: + thermistor->excitation_current = 0x09; + break; + case 500000: + thermistor->excitation_current = 0x0a; + break; + case 1000000: + thermistor->excitation_current = 0x0b; + break; + default: + dev_err(&st->spi->dev, + "Invalid value for excitation current(%u)", + excitation_current); + ret = -EINVAL; + goto fail; + } + } + + of_node_put(phandle); + return &thermistor->sensor; +fail: + of_node_put(phandle); + return ERR_PTR(ret); +} + +static struct ltc2983_sensor *ltc2983_diode_new( + const struct device_node *child, + const struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_diode *diode; + u32 temp = 0, excitation_current = 0; + int ret; + + diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL); + if (!diode) + return ERR_PTR(-ENOMEM); + + if (of_property_read_bool(child, "adi,single-ended")) + diode->sensor_config = LTC2983_DIODE_SGL(1); + + if (of_property_read_bool(child, "adi,three-conversion-cycles")) + diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1); + + if (of_property_read_bool(child, "adi,average-on")) + diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1); + + /* validate channel index */ + if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) && + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { + dev_err(&st->spi->dev, + "Invalid chann:%d for differential thermistor", + sensor->chan); + return ERR_PTR(-EINVAL); + } + /* set common parameters */ + diode->sensor.fault_handler = ltc2983_common_fault_handler; + diode->sensor.assign_chan = ltc2983_diode_assign_chan; + + ret = of_property_read_u32(child, "adi,excitation-current-microamp", + &excitation_current); + if (!ret) { + switch (excitation_current) { + case 10: + diode->excitation_current = 0x00; + break; + case 20: + diode->excitation_current = 0x01; + break; + case 40: + diode->excitation_current = 0x02; + break; + case 80: + diode->excitation_current = 0x03; + break; + default: + dev_err(&st->spi->dev, + "Invalid value for excitation current(%u)", + excitation_current); + return ERR_PTR(-EINVAL); + } + } + + of_property_read_u32(child, "adi,ideal-factor-value", &temp); + + /* 2^20 resolution */ + diode->ideal_factor_value = __convert_to_raw(temp, 1048576); + + return &diode->sensor; +} + +static struct ltc2983_sensor *ltc2983_r_sense_new(struct device_node *child, + struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_rsense *rsense; + int ret; + u64 temp; + + rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL); + if (!rsense) + return ERR_PTR(-ENOMEM); + + /* validate channel index */ + if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { + dev_err(&st->spi->dev, "Invalid chann:%d for r_sense", + sensor->chan); + return ERR_PTR(-EINVAL); + } + /* get raw value */ + ret = of_property_read_u64(child, "adi,rsense-val-micro-ohms", &temp); + if (ret) { + dev_err(&st->spi->dev, "Property adi,rsense-val-micro-ohms missing\n"); + return ERR_PTR(-EINVAL); + } + + /* 2^10 resolution */ + rsense->r_sense_val = __convert_to_raw(temp, 1024); + + /* set common parameters */ + rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan; + + return &rsense->sensor; +} + +static struct ltc2983_sensor *ltc2983_adc_new(struct device_node *child, + struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_adc *adc; + + adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL); + if (!adc) + return ERR_PTR(-ENOMEM); + + if (of_property_read_bool(child, "adi,single-ended")) + adc->single_ended = true; + + if (!adc->single_ended && + sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) { + dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n", + sensor->chan); + return ERR_PTR(-EINVAL); + } + /* set common parameters */ + adc->sensor.assign_chan = ltc2983_adc_assign_chan; + adc->sensor.fault_handler = ltc2983_common_fault_handler; + + return &adc->sensor; +} + +static int ltc2983_chan_read(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor, int *val) +{ + u32 start_conversion = 0; + int ret; + unsigned long time; + __be32 temp; + + /* + * Do not allow channel readings if device is in sleep state. + * A read/write on the spi bus would bring the device prematurely + * out of sleep. + */ + if (st->sleep) + return -EPERM; + + start_conversion = LTC2983_STATUS_START(true); + start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan); + dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n", + sensor->chan, start_conversion); + /* start conversion */ + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion); + if (ret) + return ret; + + reinit_completion(&st->completion); + /* + * wait for conversion to complete. + * 300 ms should be more than enough to complete the conversion. + * Depending on the sensor configuration, there are 2/3 conversions + * cycles of 82ms. + */ + time = wait_for_completion_timeout(&st->completion, + msecs_to_jiffies(300)); + if (!time) { + dev_warn(&st->spi->dev, "Conversion timed out\n"); + return -ETIMEDOUT; + } + + /* read the converted data */ + ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan), + &temp, sizeof(temp)); + if (ret) + return ret; + + *val = __be32_to_cpu(temp); + + if (!(LTC2983_RES_VALID_MASK & *val)) { + dev_err(&st->spi->dev, "Invalid conversion detected\n"); + return -EIO; + } + + ret = sensor->fault_handler(st, *val); + if (ret) + return ret; + + *val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT); + return 0; +} + +static int ltc2983_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ltc2983_data *st = iio_priv(indio_dev); + int ret; + + /* sanity check */ + if (chan->address >= st->num_channels) { + dev_err(&st->spi->dev, "Invalid chan address:%ld", + chan->address); + return -EINVAL; + } + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); + ret = ltc2983_chan_read(st, st->sensors[chan->address], val); + mutex_unlock(&st->lock); + return ret ?: IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_TEMP: + /* value in milli degrees */ + *val = 1000; + /* 2^10 */ + *val2 = 1024; + return IIO_VAL_FRACTIONAL; + case IIO_VOLTAGE: + /* value in millivolt */ + *val = 1000; + /* 2^21 */ + *val2 = 2097152; + return IIO_VAL_FRACTIONAL; + default: + return -EINVAL; + } + } + + return -EINVAL; +} + +static int ltc2983_reg_access(struct iio_dev *indio_dev, + unsigned int reg, + unsigned int writeval, + unsigned int *readval) +{ + struct ltc2983_data *st = iio_priv(indio_dev); + + /* check comment in ltc2983_chan_read() */ + if (st->sleep) + return -EPERM; + + if (readval) + return regmap_read(st->regmap, reg, readval); + else + return regmap_write(st->regmap, reg, writeval); +} + +static irqreturn_t ltc2983_irq_handler(int irq, void *data) +{ + struct ltc2983_data *st = data; + + complete(&st->completion); + return IRQ_HANDLED; +} + +#define LTC2983_CHAN(__type, index, __address) ({ \ + struct iio_chan_spec __chan = { \ + .type = __type, \ + .indexed = 1, \ + .channel = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .address = __address, \ + }; \ + __chan; \ +}) + +static int ltc2983_parse_dt(struct ltc2983_data *st) +{ + struct device_node *child; + struct device *dev = &st->spi->dev; + int ret = 0, chan = 0, channel_avail_mask = 0; + + if (!of_property_read_bool(dev->of_node, "adi,temperature-celcius")) + st->temp_farenheit = true; + + of_property_read_u32(dev->of_node, "adi,mux-delay-config-us", + &st->mux_delay_config); + + of_property_read_u32(dev->of_node, "adi,filter-notch-freq", + &st->filter_notch_freq); + + st->num_channels = of_get_available_child_count(dev->of_node); + st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors), + GFP_KERNEL); + if (!st->sensors) + return -ENOMEM; + + st->iio_channels = st->num_channels; + for_each_available_child_of_node(dev->of_node, child) { + struct ltc2983_sensor sensor; + + ret = of_property_read_u32(child, "reg", &sensor.chan); + if (ret) { + dev_err(dev, "reg property must given for child nodes\n"); + return ret; + } + + /* check if we have a valid channel */ + if (sensor.chan < LTC2983_MIN_CHANNELS_NR || + sensor.chan > LTC2983_MAX_CHANNELS_NR) { + dev_err(dev, + "chan:%d must be from 1 to 20\n", sensor.chan); + return -EINVAL; + } else if (channel_avail_mask & BIT(sensor.chan)) { + dev_err(dev, "chan:%d already in use\n", sensor.chan); + return -EINVAL; + } + + ret = of_property_read_u32(child, "adi,sensor-type", + &sensor.type); + if (ret) { + dev_err(dev, + "adi,sensor-type property must given for child nodes\n"); + return ret; + } + + dev_dbg(dev, "Create new sensor, type %u, chann %u", + sensor.type, + sensor.chan); + + if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE && + sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) { + st->sensors[chan] = ltc2983_thermocouple_new(child, st, + &sensor); + } else if (sensor.type >= LTC2983_SENSOR_RTD && + sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) { + st->sensors[chan] = ltc2983_rtd_new(child, st, &sensor); + } else if (sensor.type >= LTC2983_SENSOR_THERMISTOR && + sensor.type <= LTC2983_SENSOR_THERMISTOR_CUSTOM) { + st->sensors[chan] = ltc2983_thermistor_new(child, st, + &sensor); + } else if (sensor.type == LTC2983_SENSOR_DIODE) { + st->sensors[chan] = ltc2983_diode_new(child, st, + &sensor); + } else if (sensor.type == LTC2983_SENSOR_SENSE_RESISTOR) { + st->sensors[chan] = ltc2983_r_sense_new(child, st, + &sensor); + /* don't add rsense to iio */ + st->iio_channels--; + } else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) { + st->sensors[chan] = ltc2983_adc_new(child, st, &sensor); + } else { + dev_err(dev, "Unknown sensor type %d\n", sensor.type); + return -EINVAL; + } + + if (IS_ERR(st->sensors[chan])) { + dev_err(dev, "Failed to create sensor %ld", + PTR_ERR(st->sensors[chan])); + return PTR_ERR(st->sensors[chan]); + } + /* set generic sensor parameters */ + st->sensors[chan]->chan = sensor.chan; + st->sensors[chan]->type = sensor.type; + + channel_avail_mask |= BIT(sensor.chan); + chan++; + } + + return 0; +} + +static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio) +{ + u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0; + u32 global_cfg = 0; + int ret; + unsigned long time; + + /* make sure the device is up */ + time = wait_for_completion_timeout(&st->completion, + msecs_to_jiffies(250)); + + if (!time) { + dev_err(&st->spi->dev, "Device startup timed out\n"); + return -ETIMEDOUT; + } + + st->iio_chan = devm_kzalloc(&st->spi->dev, + st->iio_channels * sizeof(*st->iio_chan), + GFP_KERNEL); + + if (!st->iio_chan) + return -ENOMEM; + + global_cfg = LTC2983_NOTCH_FREQ(st->filter_notch_freq); + global_cfg |= LTC2983_TEMP_UNITS(st->temp_farenheit); + regmap_write(st->regmap, LTC2983_GLOBAL_CONFIG_REG, global_cfg); + regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG, st->mux_delay_config); + + for (chan = 0; chan < st->num_channels; chan++) { + u32 chan_type = 0, *iio_chan; + + ret = st->sensors[chan]->assign_chan(st, st->sensors[chan]); + if (ret) + return ret; + /* + * The assign_iio flag is necessary for when the device is + * coming out of sleep. In that case, we just need to + * re-configure the device channels. + * We also don't assign iio channels for rsense. + */ + if (st->sensors[chan]->type == LTC2983_SENSOR_SENSE_RESISTOR || + !assign_iio) + continue; + + /* assign iio channel */ + if (st->sensors[chan]->type != LTC2983_SENSOR_DIRECT_ADC) { + chan_type = IIO_TEMP; + iio_chan = &iio_chan_t; + } else { + chan_type = IIO_VOLTAGE; + iio_chan = &iio_chan_v; + } + + /* + * add chan as the iio .address so that, we can directly + * reference the sensor given the iio_chan_spec + */ + st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, (*iio_chan)++, + chan); + } + + return 0; +} + +static const struct regmap_range ltc2983_reg_ranges[] = { + regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG), + regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG), + regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG), + regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG, + LTC2983_MULT_CHANNEL_END_REG), + regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG), + regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG, + LTC2983_CHAN_ASSIGN_END_REG), + regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG, + LTC2983_CUST_SENS_TBL_END_REG), +}; + +static const struct regmap_access_table ltc2983_reg_table = { + .yes_ranges = ltc2983_reg_ranges, + .n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges), +}; + +/* + * The reg_bits are actually 12 but the device needs the first *complete* + * byte for the command (R/W). + */ +static const struct regmap_config ltc2983_regmap_config = { + .reg_bits = 24, + .val_bits = 8, + .wr_table = <c2983_reg_table, + .rd_table = <c2983_reg_table, + .read_flag_mask = GENMASK(1, 0), + .write_flag_mask = BIT(1), +}; + +static const struct iio_info ltc2983_iio_info = { + .read_raw = ltc2983_read_raw, + .debugfs_reg_access = ltc2983_reg_access, +}; + +static int ltc2983_probe(struct spi_device *spi) +{ + struct ltc2983_data *st; + struct iio_dev *indio_dev; + const char *name = spi_get_device_id(spi)->name; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + + st->regmap = devm_regmap_init_spi(spi, <c2983_regmap_config); + if (IS_ERR(st->regmap)) { + dev_err(&spi->dev, "Failed to initialize regmap\n"); + return PTR_ERR(st->regmap); + } + + mutex_init(&st->lock); + init_completion(&st->completion); + st->spi = spi; + spi_set_drvdata(spi, st); + + ret = ltc2983_parse_dt(st); + if (ret) + return ret; + /* + * let's request the irq now so it is used to sync the device + * startup in ltc2983_setup() + */ + ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler, + IRQF_TRIGGER_RISING, name, st); + if (ret) { + dev_err(&spi->dev, "failed to request an irq, %d", ret); + return ret; + } + + ret = ltc2983_setup(st, true); + if (ret) + return ret; + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = name; + indio_dev->num_channels = st->iio_channels; + indio_dev->channels = st->iio_chan; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = <c2983_iio_info; + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static int __maybe_unused ltc2983_resume(struct device *dev) +{ + struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev)); + int ret; + + mutex_lock(&st->lock); + /* dummy read to bring the device out of sleep */ + regmap_read(st->regmap, LTC2983_STATUS_REG, &ret); + /* we need to re-assign the channels */ + ret = ltc2983_setup(st, false); + st->sleep = false; + mutex_unlock(&st->lock); + + return ret; +} + +static int __maybe_unused ltc2983_suspend(struct device *dev) +{ + struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev)); + int ret; + + mutex_lock(&st->lock); + ret = regmap_write(st->regmap, LTC2983_STATUS_REG, LTC2983_SLEEP); + st->sleep = true; + mutex_unlock(&st->lock); + + return ret; +} + +static SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend, ltc2983_resume); + +static const struct spi_device_id ltc2983_id_table[] = { + { "ltc2983" }, + {}, +}; +MODULE_DEVICE_TABLE(spi, ltc2983_id_table); + +static const struct of_device_id ltc2983_of_match[] = { + { .compatible = "adi,ltc2983" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ltc2983_id_table); + +static struct spi_driver ltc2983_driver = { + .driver = { + .name = "ltc2983", + .of_match_table = ltc2983_of_match, + .pm = <c2983_pm_ops, + }, + .probe = ltc2983_probe, + .id_table = ltc2983_id_table, +}; + +module_spi_driver(ltc2983_driver); + +MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>"); +MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors"); +MODULE_LICENSE("GPL");
The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature Measurement System. It measures a wide variety of temperature sensors and digitally outputs the result, in °C or °F, with 0.1°C accuracy and 0.001°C resolution. It can measure the temperature of all standard thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire RTDs, thermistors and diodes. Signed-off-by: Nuno Sá <nuno.sa@analog.com> --- Changes in v2: * Added some needed blank lines (for readability); * Allocate iio_chan in the setup() function; * Rename reset to sleep; * Remove unneeded dev_dbg calls; * Remove unneeded line wrapping; * Remove unneeded comments; * Remove extend_names. Use the standard ABI; * Adapt the scales to report in millivolt and milli degrees; * Adapt the of_property readings to the renaming of the properties; * For custom thermistors, excitation-current cannot be set to Auto range. Changes in v3: * Use normal `devm_request_irq`; * Handle and decode the new devicetree properties for sensor configuration. MAINTAINERS | 7 + drivers/iio/temperature/Kconfig | 10 + drivers/iio/temperature/Makefile | 1 + drivers/iio/temperature/ltc2983.c | 1554 +++++++++++++++++++++++++++++ 4 files changed, 1572 insertions(+) create mode 100644 drivers/iio/temperature/ltc2983.c