| Message ID | 1484301038-16386-2-git-send-email-jacopo+renesas@jmondi.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
On 13/01/17 09:50, Jacopo Mondi wrote: > From: Jacopo Mondi <jacopo@jmondi.org> > > Add iio driver for Maxim MAX11100 single-channel ADC. > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > Tested-by: Marek Vasut <marek.vasut@gmail.com> > Small issue with DMA using SPI controllers and the location of buffer in your read. Otherwise looks good to me. Jonathan > --- > drivers/iio/adc/Kconfig | 9 +++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 187 +++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 197 insertions(+) > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 38bc319..c32bc7a 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -307,6 +307,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI_MASTER > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index d36c4be..5684369 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -31,6 +31,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 0000000..78e2a45 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,187 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > +#include <linux/delay.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/regulator/consumer.h> > +#include <linux/spi/spi.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/buffer.h> > +#include <linux/iio/driver.h> > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref_mv / 2 ^ 16) > + * > + * LSB is used to calculate analog voltage value > + * from the number of ADC steps count > + * > + * Ain = (count * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct regulator *vref_reg; > + struct spi_device *spi; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_single(struct iio_dev *indio_dev, int *val) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + uint8_t buffer[3]; > + > + ret = spi_read(state->spi, buffer, sizeof(buffer)); Buffer needs to be __cacheline_aligned to safely use spi_read on spi controllers that use DMA. Two easy ways of doing this, either allocate buffer using kmalloc or take advantage of the fact that spi_priv() is cache line aligned and stick you buffer at the end of your private structure and mark it __cacheline_aligned to ensure it also appropriately aligned in it's own cacheline. > + if (ret) { > + dev_err(&indio_dev->dev, "SPI transfer failed\n"); > + return ret; > + } > + > + /* the first 8 bits sent out from ADC must be 0s */ > + if (buffer[0]) { > + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); > + return -EINVAL; > + } > + > + *val = (buffer[1] << 8) | buffer[2]; > + > + return 0; > +} > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long info) > +{ > + int ret, vref_uv; > + struct max11100_state *state = iio_priv(indio_dev); > + > + switch (info) { > + case IIO_CHAN_INFO_RAW: > + ret = max11100_read_single(indio_dev, val); > + if (ret) > + return ret; > + > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + vref_uv = regulator_get_voltage(state->vref_reg); > + if (vref_uv < 0) > + /* dummy regulator "get_voltage" returns -EINVAL */ > + return -EINVAL; > + > + *val = vref_uv / 1000; > + *val2 = MAX11100_LSB_DIV; > + return IIO_VAL_FRACTIONAL; > + } > + > + return -EINVAL; > +} > + > +static const struct iio_info max11100_info = { > + .driver_module = THIS_MODULE, > + .read_raw = max11100_read_raw, > +}; > + > +static int max11100_probe(struct spi_device *spi) > +{ > + int ret; > + struct iio_dev *indio_dev; > + struct max11100_state *state; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state)); > + if (!indio_dev) > + return -ENOMEM; > + > + spi_set_drvdata(spi, indio_dev); > + > + state = iio_priv(indio_dev); > + state->spi = spi; > + state->desc = &max11100_desc; > + > + indio_dev->dev.parent = &spi->dev; > + indio_dev->dev.of_node = spi->dev.of_node; > + indio_dev->info = &max11100_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = state->desc->channels; > + indio_dev->num_channels = state->desc->num_chan; > + > + state->vref_reg = devm_regulator_get(&spi->dev, "vref"); > + if (IS_ERR(state->vref_reg)) > + return PTR_ERR(state->vref_reg); > + > + ret = regulator_enable(state->vref_reg); > + if (ret) > + return ret; > + > + ret = iio_device_register(indio_dev); > + if (ret) > + goto disable_regulator; > + > + return 0; > + > +disable_regulator: > + regulator_disable(state->vref_reg); > + > + return ret; > +} > + > +static int max11100_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + struct max11100_state *state = iio_priv(indio_dev); > + > + regulator_disable(state->vref_reg); > + > + iio_device_unregister(indio_dev); > + > + return 0; > +} > + > +static const struct of_device_id max11100_ids[] = { > + {.compatible = "maxim,max11100"}, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, max11100_ids); > + > +static struct spi_driver max11100_driver = { > + .driver = { > + .name = "max11100", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(max11100_ids), > + }, > + .probe = max11100_probe, > + .remove = max11100_remove, > +}; > + > +module_spi_driver(max11100_driver); > + > +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); > +MODULE_DESCRIPTION("Maxim max11100 ADC Driver"); > +MODULE_LICENSE("GPL v2"); >
On 01/13/2017 10:50 AM, Jacopo Mondi wrote: > From: Jacopo Mondi <jacopo@jmondi.org> > > Add iio driver for Maxim MAX11100 single-channel ADC. > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > Tested-by: Marek Vasut <marek.vasut@gmail.com> > > --- > drivers/iio/adc/Kconfig | 9 +++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 187 +++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 197 insertions(+) > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 38bc319..c32bc7a 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -307,6 +307,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI_MASTER > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index d36c4be..5684369 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -31,6 +31,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 0000000..78e2a45 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,187 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > +#include <linux/delay.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/regulator/consumer.h> > +#include <linux/spi/spi.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/buffer.h> > +#include <linux/iio/driver.h> > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref_mv / 2 ^ 16) > + * > + * LSB is used to calculate analog voltage value > + * from the number of ADC steps count > + * > + * Ain = (count * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct regulator *vref_reg; > + struct spi_device *spi; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_single(struct iio_dev *indio_dev, int *val) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + uint8_t buffer[3]; > + > + ret = spi_read(state->spi, buffer, sizeof(buffer)); > + if (ret) { > + dev_err(&indio_dev->dev, "SPI transfer failed\n"); > + return ret; > + } > + > + /* the first 8 bits sent out from ADC must be 0s */ > + if (buffer[0]) { > + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); > + return -EINVAL; > + } > + > + *val = (buffer[1] << 8) | buffer[2]; > + > + return 0; > +} > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long info) > +{ > + int ret, vref_uv; > + struct max11100_state *state = iio_priv(indio_dev); > + > + switch (info) { > + case IIO_CHAN_INFO_RAW: > + ret = max11100_read_single(indio_dev, val); > + if (ret) > + return ret; > + > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + vref_uv = regulator_get_voltage(state->vref_reg); > + if (vref_uv < 0) > + /* dummy regulator "get_voltage" returns -EINVAL */ > + return -EINVAL; > + > + *val = vref_uv / 1000; > + *val2 = MAX11100_LSB_DIV; > + return IIO_VAL_FRACTIONAL; > + } > + > + return -EINVAL; > +} > + > +static const struct iio_info max11100_info = { > + .driver_module = THIS_MODULE, > + .read_raw = max11100_read_raw, > +}; > + > +static int max11100_probe(struct spi_device *spi) > +{ > + int ret; > + struct iio_dev *indio_dev; > + struct max11100_state *state; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state)); > + if (!indio_dev) > + return -ENOMEM; > + > + spi_set_drvdata(spi, indio_dev); > + > + state = iio_priv(indio_dev); > + state->spi = spi; > + state->desc = &max11100_desc; > + > + indio_dev->dev.parent = &spi->dev; > + indio_dev->dev.of_node = spi->dev.of_node; > + indio_dev->info = &max11100_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = state->desc->channels; > + indio_dev->num_channels = state->desc->num_chan; Consider setting indio_dev->name= "max11100"; so userspace can identify the type of the device.
> + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi In case you need to resend: 2016-17?
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 38bc319..c32bc7a 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -307,6 +307,15 @@ config MAX1027 To compile this driver as a module, choose M here: the module will be called max1027. +config MAX11100 + tristate "Maxim max11100 ADC driver" + depends on SPI_MASTER + help + Say yes here to build support for Maxim max11100 SPI ADC + + To compile this driver as a module, choose M here: the module will be + called max11100. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index d36c4be..5684369 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -31,6 +31,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o obj-$(CONFIG_LTC2485) += ltc2485.o obj-$(CONFIG_MAX1027) += max1027.o +obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c new file mode 100644 index 0000000..78e2a45 --- /dev/null +++ b/drivers/iio/adc/max11100.c @@ -0,0 +1,187 @@ +/* + * iio/adc/max11100.c + * Maxim max11100 ADC Driver with IIO interface + * + * Copyright (C) 2016 Renesas Electronics Corporation + * Copyright (C) 2016 Jacopo Mondi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/driver.h> + +/* + * LSB is the ADC single digital step + * 1 LSB = (vref_mv / 2 ^ 16) + * + * LSB is used to calculate analog voltage value + * from the number of ADC steps count + * + * Ain = (count * LSB) + */ +#define MAX11100_LSB_DIV (1 << 16) + +struct max11100_state { + const struct max11100_chip_desc *desc; + struct regulator *vref_reg; + struct spi_device *spi; +}; + +static struct iio_chan_spec max11100_channels[] = { + { /* [0] */ + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, +}; + +static struct max11100_chip_desc { + unsigned int num_chan; + const struct iio_chan_spec *channels; +} max11100_desc = { + .num_chan = ARRAY_SIZE(max11100_channels), + .channels = max11100_channels, +}; + +static int max11100_read_single(struct iio_dev *indio_dev, int *val) +{ + int ret; + struct max11100_state *state = iio_priv(indio_dev); + uint8_t buffer[3]; + + ret = spi_read(state->spi, buffer, sizeof(buffer)); + if (ret) { + dev_err(&indio_dev->dev, "SPI transfer failed\n"); + return ret; + } + + /* the first 8 bits sent out from ADC must be 0s */ + if (buffer[0]) { + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); + return -EINVAL; + } + + *val = (buffer[1] << 8) | buffer[2]; + + return 0; +} + +static int max11100_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long info) +{ + int ret, vref_uv; + struct max11100_state *state = iio_priv(indio_dev); + + switch (info) { + case IIO_CHAN_INFO_RAW: + ret = max11100_read_single(indio_dev, val); + if (ret) + return ret; + + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + vref_uv = regulator_get_voltage(state->vref_reg); + if (vref_uv < 0) + /* dummy regulator "get_voltage" returns -EINVAL */ + return -EINVAL; + + *val = vref_uv / 1000; + *val2 = MAX11100_LSB_DIV; + return IIO_VAL_FRACTIONAL; + } + + return -EINVAL; +} + +static const struct iio_info max11100_info = { + .driver_module = THIS_MODULE, + .read_raw = max11100_read_raw, +}; + +static int max11100_probe(struct spi_device *spi) +{ + int ret; + struct iio_dev *indio_dev; + struct max11100_state *state; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state)); + if (!indio_dev) + return -ENOMEM; + + spi_set_drvdata(spi, indio_dev); + + state = iio_priv(indio_dev); + state->spi = spi; + state->desc = &max11100_desc; + + indio_dev->dev.parent = &spi->dev; + indio_dev->dev.of_node = spi->dev.of_node; + indio_dev->info = &max11100_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = state->desc->channels; + indio_dev->num_channels = state->desc->num_chan; + + state->vref_reg = devm_regulator_get(&spi->dev, "vref"); + if (IS_ERR(state->vref_reg)) + return PTR_ERR(state->vref_reg); + + ret = regulator_enable(state->vref_reg); + if (ret) + return ret; + + ret = iio_device_register(indio_dev); + if (ret) + goto disable_regulator; + + return 0; + +disable_regulator: + regulator_disable(state->vref_reg); + + return ret; +} + +static int max11100_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct max11100_state *state = iio_priv(indio_dev); + + regulator_disable(state->vref_reg); + + iio_device_unregister(indio_dev); + + return 0; +} + +static const struct of_device_id max11100_ids[] = { + {.compatible = "maxim,max11100"}, + { }, +}; +MODULE_DEVICE_TABLE(of, max11100_ids); + +static struct spi_driver max11100_driver = { + .driver = { + .name = "max11100", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(max11100_ids), + }, + .probe = max11100_probe, + .remove = max11100_remove, +}; + +module_spi_driver(max11100_driver); + +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); +MODULE_DESCRIPTION("Maxim max11100 ADC Driver"); +MODULE_LICENSE("GPL v2");