| Message ID | 20181120141713.9963-3-cmc@babblebit.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for Microchip MCP41xxx/42xxx potentiometers | expand |
On Tue, 20 Nov 2018, Chris Coffey wrote: Hello, some minor comments below, otherwise looks good regards, p. > This patch adds driver support for the Microchip MCP41xxx/42xxx family > of digital potentiometers: > > DEVICE Wipers Positions Resistance (kOhm) > MCP41010 1 256 10 > MCP41050 1 256 50 > MCP41100 1 256 100 > MCP42010 2 256 10 > MCP42050 2 256 50 > MCP42100 2 256 100 > > Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > Signed-off-by: Chris Coffey <cmc@babblebit.net> > --- > drivers/iio/potentiometer/Kconfig | 12 +++ > drivers/iio/potentiometer/Makefile | 1 + > drivers/iio/potentiometer/mcp41010.c | 204 +++++++++++++++++++++++++++++++++++ > 3 files changed, 217 insertions(+) > create mode 100644 drivers/iio/potentiometer/mcp41010.c > > diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig > index 79ec2eba49..6303cbe799 100644 > --- a/drivers/iio/potentiometer/Kconfig > +++ b/drivers/iio/potentiometer/Kconfig > @@ -90,6 +90,18 @@ config MCP4531 > To compile this driver as a module, choose M here: the > module will be called mcp4531. > > +config MCP41010 > + tristate "Microchip MCP41xxx/MCP42xxx Digital Potentiometer driver" > + depends on SPI > + help > + Say yes here to build support for the Microchip > + MCP41010, MCP41050, MCP41100, > + MCP42010, MCP42050, MCP42100 > + digital potentiometer chips. > + > + To compile this driver as a module, choose M here: the > + module will be called mcp41010. > + > config TPL0102 > tristate "Texas Instruments digital potentiometer driver" > depends on I2C > diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile > index 4af657883c..8ff55138cf 100644 > --- a/drivers/iio/potentiometer/Makefile > +++ b/drivers/iio/potentiometer/Makefile > @@ -11,4 +11,5 @@ obj-$(CONFIG_MAX5487) += max5487.o > obj-$(CONFIG_MCP4018) += mcp4018.o > obj-$(CONFIG_MCP4131) += mcp4131.o > obj-$(CONFIG_MCP4531) += mcp4531.o > +obj-$(CONFIG_MCP41010) += mcp41010.o > obj-$(CONFIG_TPL0102) += tpl0102.o > diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c > new file mode 100644 > index 0000000000..4a91066cb1 > --- /dev/null > +++ b/drivers/iio/potentiometer/mcp41010.c > @@ -0,0 +1,204 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Industrial I/O driver for Microchip digital potentiometers > + * > + * Copyright (c) 2018 Chris Coffey <cmc@babblebit.net> > + * Based on: Slawomir Stepien's code from mcp4131.c > + * > + * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > + * > + * DEVID #Wipers #Positions Resistance (kOhm) > + * mcp41010 1 256 10 > + * mcp41050 1 256 50 > + * mcp41100 1 256 100 > + * mcp42010 2 256 10 > + * mcp42050 2 256 50 > + * mcp42100 2 256 100 > + */ > + > +#include <linux/cache.h> > +#include <linux/err.h> > +#include <linux/export.h> wondering if export.h is needed? > +#include <linux/iio/iio.h> > +#include <linux/iio/types.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/spi/spi.h> > + > +#define MCP41010_MAX_WIPERS 2 > +#define MCP41010_WRITE BIT(4) > +#define MCP41010_WIPER_MAX 255 > +#define MCP41010_WIPER_CHANNEL BIT(0) > + > +struct mcp41010_cfg { > + char name[16]; > + int wipers; > + int kohms; > +}; > + > +enum mcp41010_type { > + MCP41010, > + MCP41050, > + MCP41100, > + MCP42010, > + MCP42050, > + MCP42100, > +}; > + > +static const struct mcp41010_cfg mcp41010_cfg[] = { > + [MCP41010] = { .name = "mcp41010", .wipers = 1, .kohms = 10, }, > + [MCP41050] = { .name = "mcp41050", .wipers = 1, .kohms = 50, }, > + [MCP41100] = { .name = "mcp41100", .wipers = 1, .kohms = 100, }, > + [MCP42010] = { .name = "mcp42010", .wipers = 2, .kohms = 10, }, > + [MCP42050] = { .name = "mcp42050", .wipers = 2, .kohms = 50, }, > + [MCP42100] = { .name = "mcp42100", .wipers = 2, .kohms = 100, }, > +}; > + > +struct mcp41010_data { > + struct spi_device *spi; > + const struct mcp41010_cfg *cfg; > + struct mutex lock; /* Protect write sequences */ > + unsigned int value[MCP41010_MAX_WIPERS]; /* Cache wiper values */ > + u8 buf[2] ____cacheline_aligned; > +}; > + > +#define MCP41010_CHANNEL(ch) { \ > + .type = IIO_RESISTANCE, \ > + .indexed = 1, \ > + .output = 1, \ > + .channel = (ch), \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > +} > + > +static const struct iio_chan_spec mcp41010_channels[] = { > + MCP41010_CHANNEL(0), > + MCP41010_CHANNEL(1), > +}; > + > +static int mcp41010_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct mcp41010_data *data = iio_priv(indio_dev); > + int channel = chan->channel; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + *val = data->value[channel]; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + *val = 1000 * data->cfg->kohms; > + *val2 = MCP41010_WIPER_MAX; > + return IIO_VAL_FRACTIONAL; > + } > + > + return -EINVAL; > +} > + > +static int mcp41010_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + int err; > + struct mcp41010_data *data = iio_priv(indio_dev); > + int channel = chan->channel; > + > + if (mask != IIO_CHAN_INFO_RAW) > + return -EINVAL; > + > + if (val > MCP41010_WIPER_MAX || val < 0) > + return -EINVAL; > + > + mutex_lock(&data->lock); > + > + data->buf[0] = MCP41010_WIPER_CHANNEL << channel; > + data->buf[0] |= MCP41010_WRITE; > + data->buf[1] = val & 0xff; > + > + err = spi_write(data->spi, data->buf, 2); 2 is the sizeof(data->buf) > + if (!err) > + data->value[channel] = val; > + > + mutex_unlock(&data->lock); > + > + return err; > +} > + > +static const struct iio_info mcp41010_info = { > + .read_raw = mcp41010_read_raw, > + .write_raw = mcp41010_write_raw, > +}; > + > +static int mcp41010_probe(struct spi_device *spi) > +{ > + int err; > + struct device *dev = &spi->dev; > + struct mcp41010_data *data; > + struct iio_dev *indio_dev; > + > + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + spi_set_drvdata(spi, indio_dev); > + data->spi = spi; > + data->cfg = of_device_get_match_data(&spi->dev); > + if (!data->cfg) > + data->cfg = &mcp41010_cfg[spi_get_device_id(spi)->driver_data]; > + > + mutex_init(&data->lock); > + > + indio_dev->dev.parent = dev; > + indio_dev->info = &mcp41010_info; > + indio_dev->channels = mcp41010_channels; > + indio_dev->num_channels = data->cfg->wipers; > + indio_dev->name = data->cfg->name; > + > + err = devm_iio_device_register(dev, indio_dev); > + if (err) > + dev_info(&spi->dev, "Unable to register %s\n", indio_dev->name); > + > + return err; > +} > + > +static const struct of_device_id mcp41010_match[] = { > + { .compatible = "microchip,mcp41010", .data = &mcp41010_cfg[MCP41010] }, > + { .compatible = "microchip,mcp41050", .data = &mcp41010_cfg[MCP41050] }, > + { .compatible = "microchip,mcp41100", .data = &mcp41010_cfg[MCP41100] }, > + { .compatible = "microchip,mcp42010", .data = &mcp41010_cfg[MCP42010] }, > + { .compatible = "microchip,mcp42050", .data = &mcp41010_cfg[MCP42050] }, > + { .compatible = "microchip,mcp42100", .data = &mcp41010_cfg[MCP42100] }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, mcp41010_match); > + > +static const struct spi_device_id mcp41010_id[] = { > + { "mcp41010", MCP41010 }, > + { "mcp41050", MCP41050 }, > + { "mcp41100", MCP41100 }, > + { "mcp42010", MCP42010 }, > + { "mcp42050", MCP42050 }, > + { "mcp42100", MCP42100 }, > + {} > +}; > +MODULE_DEVICE_TABLE(spi, mcp41010_id); > + > +static struct spi_driver mcp41010_driver = { > + .driver = { > + .name = "mcp41010", > + .of_match_table = mcp41010_match, > + }, > + .probe = mcp41010_probe, > + .id_table = mcp41010_id, > +}; > + > +module_spi_driver(mcp41010_driver); > + > +MODULE_AUTHOR("Chris Coffey <cmc@babblebit.net>"); > +MODULE_DESCRIPTION("MCP41010 digital potentiometer"); > +MODULE_LICENSE("GPL v2"); >
On Tue, Nov 20, 2018 at 03:30:05PM +0100, Peter Meerwald-Stadler wrote: > On Tue, 20 Nov 2018, Chris Coffey wrote: > > Hello, > > some minor comments below, otherwise looks good > > regards, p. > Hi Peter, Thank you for the review. One comment below. > > This patch adds driver support for the Microchip MCP41xxx/42xxx family > > of digital potentiometers: > > > > DEVICE Wipers Positions Resistance (kOhm) > > MCP41010 1 256 10 > > MCP41050 1 256 50 > > MCP41100 1 256 100 > > MCP42010 2 256 10 > > MCP42050 2 256 50 > > MCP42100 2 256 100 > > > > Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > > > Signed-off-by: Chris Coffey <cmc@babblebit.net> > > --- > > drivers/iio/potentiometer/Kconfig | 12 +++ > > drivers/iio/potentiometer/Makefile | 1 + > > drivers/iio/potentiometer/mcp41010.c | 204 +++++++++++++++++++++++++++++++++++ > > 3 files changed, 217 insertions(+) > > create mode 100644 drivers/iio/potentiometer/mcp41010.c > > > > diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig > > index 79ec2eba49..6303cbe799 100644 > > --- a/drivers/iio/potentiometer/Kconfig > > +++ b/drivers/iio/potentiometer/Kconfig > > @@ -90,6 +90,18 @@ config MCP4531 > > To compile this driver as a module, choose M here: the > > module will be called mcp4531. > > > > +config MCP41010 > > + tristate "Microchip MCP41xxx/MCP42xxx Digital Potentiometer driver" > > + depends on SPI > > + help > > + Say yes here to build support for the Microchip > > + MCP41010, MCP41050, MCP41100, > > + MCP42010, MCP42050, MCP42100 > > + digital potentiometer chips. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called mcp41010. > > + > > config TPL0102 > > tristate "Texas Instruments digital potentiometer driver" > > depends on I2C > > diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile > > index 4af657883c..8ff55138cf 100644 > > --- a/drivers/iio/potentiometer/Makefile > > +++ b/drivers/iio/potentiometer/Makefile > > @@ -11,4 +11,5 @@ obj-$(CONFIG_MAX5487) += max5487.o > > obj-$(CONFIG_MCP4018) += mcp4018.o > > obj-$(CONFIG_MCP4131) += mcp4131.o > > obj-$(CONFIG_MCP4531) += mcp4531.o > > +obj-$(CONFIG_MCP41010) += mcp41010.o > > obj-$(CONFIG_TPL0102) += tpl0102.o > > diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c > > new file mode 100644 > > index 0000000000..4a91066cb1 > > --- /dev/null > > +++ b/drivers/iio/potentiometer/mcp41010.c > > @@ -0,0 +1,204 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Industrial I/O driver for Microchip digital potentiometers > > + * > > + * Copyright (c) 2018 Chris Coffey <cmc@babblebit.net> > > + * Based on: Slawomir Stepien's code from mcp4131.c > > + * > > + * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > + * > > + * DEVID #Wipers #Positions Resistance (kOhm) > > + * mcp41010 1 256 10 > > + * mcp41050 1 256 50 > > + * mcp41100 1 256 100 > > + * mcp42010 2 256 10 > > + * mcp42050 2 256 50 > > + * mcp42100 2 256 100 > > + */ > > + > > +#include <linux/cache.h> > > +#include <linux/err.h> > > +#include <linux/export.h> > > wondering if export.h is needed? > You're right; turns out it's not needed. I'll fix this in v4. [snip]
On Tue, 20 Nov 2018 22:20:11 +0000 Chris Coffey <cmc@babblebit.net> wrote: > On Tue, Nov 20, 2018 at 03:30:05PM +0100, Peter Meerwald-Stadler wrote: > > On Tue, 20 Nov 2018, Chris Coffey wrote: > > > > Hello, > > > > some minor comments below, otherwise looks good > > > > regards, p. > > > > Hi Peter, > > Thank you for the review. One comment below. > > > > This patch adds driver support for the Microchip MCP41xxx/42xxx family > > > of digital potentiometers: > > > > > > DEVICE Wipers Positions Resistance (kOhm) > > > MCP41010 1 256 10 > > > MCP41050 1 256 50 > > > MCP41100 1 256 100 > > > MCP42010 2 256 10 > > > MCP42050 2 256 50 > > > MCP42100 2 256 100 > > > > > > Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > > > > > Signed-off-by: Chris Coffey <cmc@babblebit.net> > > > --- > > > drivers/iio/potentiometer/Kconfig | 12 +++ > > > drivers/iio/potentiometer/Makefile | 1 + > > > drivers/iio/potentiometer/mcp41010.c | 204 +++++++++++++++++++++++++++++++++++ > > > 3 files changed, 217 insertions(+) > > > create mode 100644 drivers/iio/potentiometer/mcp41010.c > > > > > > diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig > > > index 79ec2eba49..6303cbe799 100644 > > > --- a/drivers/iio/potentiometer/Kconfig > > > +++ b/drivers/iio/potentiometer/Kconfig > > > @@ -90,6 +90,18 @@ config MCP4531 > > > To compile this driver as a module, choose M here: the > > > module will be called mcp4531. > > > > > > +config MCP41010 > > > + tristate "Microchip MCP41xxx/MCP42xxx Digital Potentiometer driver" > > > + depends on SPI > > > + help > > > + Say yes here to build support for the Microchip > > > + MCP41010, MCP41050, MCP41100, > > > + MCP42010, MCP42050, MCP42100 > > > + digital potentiometer chips. > > > + > > > + To compile this driver as a module, choose M here: the > > > + module will be called mcp41010. > > > + > > > config TPL0102 > > > tristate "Texas Instruments digital potentiometer driver" > > > depends on I2C > > > diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile > > > index 4af657883c..8ff55138cf 100644 > > > --- a/drivers/iio/potentiometer/Makefile > > > +++ b/drivers/iio/potentiometer/Makefile > > > @@ -11,4 +11,5 @@ obj-$(CONFIG_MAX5487) += max5487.o > > > obj-$(CONFIG_MCP4018) += mcp4018.o > > > obj-$(CONFIG_MCP4131) += mcp4131.o > > > obj-$(CONFIG_MCP4531) += mcp4531.o > > > +obj-$(CONFIG_MCP41010) += mcp41010.o > > > obj-$(CONFIG_TPL0102) += tpl0102.o > > > diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c > > > new file mode 100644 > > > index 0000000000..4a91066cb1 > > > --- /dev/null > > > +++ b/drivers/iio/potentiometer/mcp41010.c > > > @@ -0,0 +1,204 @@ > > > +// SPDX-License-Identifier: GPL-2.0 > > > +/* > > > + * Industrial I/O driver for Microchip digital potentiometers > > > + * > > > + * Copyright (c) 2018 Chris Coffey <cmc@babblebit.net> > > > + * Based on: Slawomir Stepien's code from mcp4131.c > > > + * > > > + * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > > + * > > > + * DEVID #Wipers #Positions Resistance (kOhm) > > > + * mcp41010 1 256 10 > > > + * mcp41050 1 256 50 > > > + * mcp41100 1 256 100 > > > + * mcp42010 2 256 10 > > > + * mcp42050 2 256 50 > > > + * mcp42100 2 256 100 > > > + */ > > > + > > > +#include <linux/cache.h> > > > +#include <linux/err.h> > > > +#include <linux/export.h> > > > > wondering if export.h is needed? > > > > You're right; turns out it's not needed. I'll fix this in v4. > > [snip] Given both the issues Peter raised were trivial and I couldn't see any others, I've applied this with the changes Peter suggested. Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan
On Sun, Nov 25, 2018 at 12:30:28PM +0000, Jonathan Cameron wrote: > On Tue, 20 Nov 2018 22:20:11 +0000 > Chris Coffey <cmc@babblebit.net> wrote: > > > On Tue, Nov 20, 2018 at 03:30:05PM +0100, Peter Meerwald-Stadler wrote: > > > On Tue, 20 Nov 2018, Chris Coffey wrote: > > > > > > Hello, > > > > > > some minor comments below, otherwise looks good > > > > > > regards, p. > > > > > > > Hi Peter, > > > > Thank you for the review. One comment below. > > > > > > This patch adds driver support for the Microchip MCP41xxx/42xxx family > > > > of digital potentiometers: > > > > > > > > DEVICE Wipers Positions Resistance (kOhm) > > > > MCP41010 1 256 10 > > > > MCP41050 1 256 50 > > > > MCP41100 1 256 100 > > > > MCP42010 2 256 10 > > > > MCP42050 2 256 50 > > > > MCP42100 2 256 100 > > > > > > > > Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > > > > > > > Signed-off-by: Chris Coffey <cmc@babblebit.net> > > > > --- > > > > drivers/iio/potentiometer/Kconfig | 12 +++ > > > > drivers/iio/potentiometer/Makefile | 1 + > > > > drivers/iio/potentiometer/mcp41010.c | 204 +++++++++++++++++++++++++++++++++++ > > > > 3 files changed, 217 insertions(+) > > > > create mode 100644 drivers/iio/potentiometer/mcp41010.c > > > > > > > > diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig > > > > index 79ec2eba49..6303cbe799 100644 > > > > --- a/drivers/iio/potentiometer/Kconfig > > > > +++ b/drivers/iio/potentiometer/Kconfig > > > > @@ -90,6 +90,18 @@ config MCP4531 > > > > To compile this driver as a module, choose M here: the > > > > module will be called mcp4531. > > > > > > > > +config MCP41010 > > > > + tristate "Microchip MCP41xxx/MCP42xxx Digital Potentiometer driver" > > > > + depends on SPI > > > > + help > > > > + Say yes here to build support for the Microchip > > > > + MCP41010, MCP41050, MCP41100, > > > > + MCP42010, MCP42050, MCP42100 > > > > + digital potentiometer chips. > > > > + > > > > + To compile this driver as a module, choose M here: the > > > > + module will be called mcp41010. > > > > + > > > > config TPL0102 > > > > tristate "Texas Instruments digital potentiometer driver" > > > > depends on I2C > > > > diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile > > > > index 4af657883c..8ff55138cf 100644 > > > > --- a/drivers/iio/potentiometer/Makefile > > > > +++ b/drivers/iio/potentiometer/Makefile > > > > @@ -11,4 +11,5 @@ obj-$(CONFIG_MAX5487) += max5487.o > > > > obj-$(CONFIG_MCP4018) += mcp4018.o > > > > obj-$(CONFIG_MCP4131) += mcp4131.o > > > > obj-$(CONFIG_MCP4531) += mcp4531.o > > > > +obj-$(CONFIG_MCP41010) += mcp41010.o > > > > obj-$(CONFIG_TPL0102) += tpl0102.o > > > > diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c > > > > new file mode 100644 > > > > index 0000000000..4a91066cb1 > > > > --- /dev/null > > > > +++ b/drivers/iio/potentiometer/mcp41010.c > > > > @@ -0,0 +1,204 @@ > > > > +// SPDX-License-Identifier: GPL-2.0 > > > > +/* > > > > + * Industrial I/O driver for Microchip digital potentiometers > > > > + * > > > > + * Copyright (c) 2018 Chris Coffey <cmc@babblebit.net> > > > > + * Based on: Slawomir Stepien's code from mcp4131.c > > > > + * > > > > + * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf > > > > + * > > > > + * DEVID #Wipers #Positions Resistance (kOhm) > > > > + * mcp41010 1 256 10 > > > > + * mcp41050 1 256 50 > > > > + * mcp41100 1 256 100 > > > > + * mcp42010 2 256 10 > > > > + * mcp42050 2 256 50 > > > > + * mcp42100 2 256 100 > > > > + */ > > > > + > > > > +#include <linux/cache.h> > > > > +#include <linux/err.h> > > > > +#include <linux/export.h> > > > > > > wondering if export.h is needed? > > > > > > > You're right; turns out it's not needed. I'll fix this in v4. > > > > [snip] > Given both the issues Peter raised were trivial and I couldn't > see any others, I've applied this with the changes Peter suggested. > > Applied to the togreg branch of iio.git and pushed out as testing > for the autobuilders to play with it. > > Thanks, > > Jonathan > Brilliant. Thanks again to you and everyone else for the reviews and feedback. Chris
diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig index 79ec2eba49..6303cbe799 100644 --- a/drivers/iio/potentiometer/Kconfig +++ b/drivers/iio/potentiometer/Kconfig @@ -90,6 +90,18 @@ config MCP4531 To compile this driver as a module, choose M here: the module will be called mcp4531. +config MCP41010 + tristate "Microchip MCP41xxx/MCP42xxx Digital Potentiometer driver" + depends on SPI + help + Say yes here to build support for the Microchip + MCP41010, MCP41050, MCP41100, + MCP42010, MCP42050, MCP42100 + digital potentiometer chips. + + To compile this driver as a module, choose M here: the + module will be called mcp41010. + config TPL0102 tristate "Texas Instruments digital potentiometer driver" depends on I2C diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile index 4af657883c..8ff55138cf 100644 --- a/drivers/iio/potentiometer/Makefile +++ b/drivers/iio/potentiometer/Makefile @@ -11,4 +11,5 @@ obj-$(CONFIG_MAX5487) += max5487.o obj-$(CONFIG_MCP4018) += mcp4018.o obj-$(CONFIG_MCP4131) += mcp4131.o obj-$(CONFIG_MCP4531) += mcp4531.o +obj-$(CONFIG_MCP41010) += mcp41010.o obj-$(CONFIG_TPL0102) += tpl0102.o diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c new file mode 100644 index 0000000000..4a91066cb1 --- /dev/null +++ b/drivers/iio/potentiometer/mcp41010.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Industrial I/O driver for Microchip digital potentiometers + * + * Copyright (c) 2018 Chris Coffey <cmc@babblebit.net> + * Based on: Slawomir Stepien's code from mcp4131.c + * + * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf + * + * DEVID #Wipers #Positions Resistance (kOhm) + * mcp41010 1 256 10 + * mcp41050 1 256 50 + * mcp41100 1 256 100 + * mcp42010 2 256 10 + * mcp42050 2 256 50 + * mcp42100 2 256 100 + */ + +#include <linux/cache.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/iio/iio.h> +#include <linux/iio/types.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/spi/spi.h> + +#define MCP41010_MAX_WIPERS 2 +#define MCP41010_WRITE BIT(4) +#define MCP41010_WIPER_MAX 255 +#define MCP41010_WIPER_CHANNEL BIT(0) + +struct mcp41010_cfg { + char name[16]; + int wipers; + int kohms; +}; + +enum mcp41010_type { + MCP41010, + MCP41050, + MCP41100, + MCP42010, + MCP42050, + MCP42100, +}; + +static const struct mcp41010_cfg mcp41010_cfg[] = { + [MCP41010] = { .name = "mcp41010", .wipers = 1, .kohms = 10, }, + [MCP41050] = { .name = "mcp41050", .wipers = 1, .kohms = 50, }, + [MCP41100] = { .name = "mcp41100", .wipers = 1, .kohms = 100, }, + [MCP42010] = { .name = "mcp42010", .wipers = 2, .kohms = 10, }, + [MCP42050] = { .name = "mcp42050", .wipers = 2, .kohms = 50, }, + [MCP42100] = { .name = "mcp42100", .wipers = 2, .kohms = 100, }, +}; + +struct mcp41010_data { + struct spi_device *spi; + const struct mcp41010_cfg *cfg; + struct mutex lock; /* Protect write sequences */ + unsigned int value[MCP41010_MAX_WIPERS]; /* Cache wiper values */ + u8 buf[2] ____cacheline_aligned; +}; + +#define MCP41010_CHANNEL(ch) { \ + .type = IIO_RESISTANCE, \ + .indexed = 1, \ + .output = 1, \ + .channel = (ch), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ +} + +static const struct iio_chan_spec mcp41010_channels[] = { + MCP41010_CHANNEL(0), + MCP41010_CHANNEL(1), +}; + +static int mcp41010_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct mcp41010_data *data = iio_priv(indio_dev); + int channel = chan->channel; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + *val = data->value[channel]; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + *val = 1000 * data->cfg->kohms; + *val2 = MCP41010_WIPER_MAX; + return IIO_VAL_FRACTIONAL; + } + + return -EINVAL; +} + +static int mcp41010_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + int err; + struct mcp41010_data *data = iio_priv(indio_dev); + int channel = chan->channel; + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + if (val > MCP41010_WIPER_MAX || val < 0) + return -EINVAL; + + mutex_lock(&data->lock); + + data->buf[0] = MCP41010_WIPER_CHANNEL << channel; + data->buf[0] |= MCP41010_WRITE; + data->buf[1] = val & 0xff; + + err = spi_write(data->spi, data->buf, 2); + if (!err) + data->value[channel] = val; + + mutex_unlock(&data->lock); + + return err; +} + +static const struct iio_info mcp41010_info = { + .read_raw = mcp41010_read_raw, + .write_raw = mcp41010_write_raw, +}; + +static int mcp41010_probe(struct spi_device *spi) +{ + int err; + struct device *dev = &spi->dev; + struct mcp41010_data *data; + struct iio_dev *indio_dev; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + spi_set_drvdata(spi, indio_dev); + data->spi = spi; + data->cfg = of_device_get_match_data(&spi->dev); + if (!data->cfg) + data->cfg = &mcp41010_cfg[spi_get_device_id(spi)->driver_data]; + + mutex_init(&data->lock); + + indio_dev->dev.parent = dev; + indio_dev->info = &mcp41010_info; + indio_dev->channels = mcp41010_channels; + indio_dev->num_channels = data->cfg->wipers; + indio_dev->name = data->cfg->name; + + err = devm_iio_device_register(dev, indio_dev); + if (err) + dev_info(&spi->dev, "Unable to register %s\n", indio_dev->name); + + return err; +} + +static const struct of_device_id mcp41010_match[] = { + { .compatible = "microchip,mcp41010", .data = &mcp41010_cfg[MCP41010] }, + { .compatible = "microchip,mcp41050", .data = &mcp41010_cfg[MCP41050] }, + { .compatible = "microchip,mcp41100", .data = &mcp41010_cfg[MCP41100] }, + { .compatible = "microchip,mcp42010", .data = &mcp41010_cfg[MCP42010] }, + { .compatible = "microchip,mcp42050", .data = &mcp41010_cfg[MCP42050] }, + { .compatible = "microchip,mcp42100", .data = &mcp41010_cfg[MCP42100] }, + {} +}; +MODULE_DEVICE_TABLE(of, mcp41010_match); + +static const struct spi_device_id mcp41010_id[] = { + { "mcp41010", MCP41010 }, + { "mcp41050", MCP41050 }, + { "mcp41100", MCP41100 }, + { "mcp42010", MCP42010 }, + { "mcp42050", MCP42050 }, + { "mcp42100", MCP42100 }, + {} +}; +MODULE_DEVICE_TABLE(spi, mcp41010_id); + +static struct spi_driver mcp41010_driver = { + .driver = { + .name = "mcp41010", + .of_match_table = mcp41010_match, + }, + .probe = mcp41010_probe, + .id_table = mcp41010_id, +}; + +module_spi_driver(mcp41010_driver); + +MODULE_AUTHOR("Chris Coffey <cmc@babblebit.net>"); +MODULE_DESCRIPTION("MCP41010 digital potentiometer"); +MODULE_LICENSE("GPL v2");
This patch adds driver support for the Microchip MCP41xxx/42xxx family of digital potentiometers: DEVICE Wipers Positions Resistance (kOhm) MCP41010 1 256 10 MCP41050 1 256 50 MCP41100 1 256 100 MCP42010 2 256 10 MCP42050 2 256 50 MCP42100 2 256 100 Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf Signed-off-by: Chris Coffey <cmc@babblebit.net> --- drivers/iio/potentiometer/Kconfig | 12 +++ drivers/iio/potentiometer/Makefile | 1 + drivers/iio/potentiometer/mcp41010.c | 204 +++++++++++++++++++++++++++++++++++ 3 files changed, 217 insertions(+) create mode 100644 drivers/iio/potentiometer/mcp41010.c