| Message ID | 1484757053-7102-2-git-send-email-jacopo+renesas@jmondi.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
> Add iio driver for Maxim MAX11100 single-channel ADC. minor comments, maybe Jonathan can fix it up when taking this... > 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 | 192 +++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 202 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..b738ecf > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,192 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016-17 Renesas Electronics Corporation > + * Copyright (C) 2016-17 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/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; > + > + /* > + * DMA (thus cache coherency maintenance) requires the > + * transfer buffers to live in their own cache lines. > + */ > + u8 buffer[3] ____cacheline_aligned; > +}; > + > +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, > +}; for just one supported chip, this is more complicated than necessary... > + > +static int max11100_read_single(struct iio_dev *indio_dev, int *val) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + > + ret = spi_read(state->spi, state->buffer, sizeof(state->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 (state->buffer[0]) { > + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); > + return -EINVAL; > + } > + > + *val = (state->buffer[1] << 8) | state->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->name = "max11100"; > + 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); should be the other way around, first _unregister(), then regulator_disable() reverse order as in _probe() > + > + 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"); >
Hi Peter, On 19/01/2017 19:15, Peter Meerwald-Stadler wrote: > >> Add iio driver for Maxim MAX11100 single-channel ADC. > > minor comments, maybe Jonathan can fix it up when taking this... > >> +struct max11100_state { >> + const struct max11100_chip_desc *desc; >> + struct regulator *vref_reg; >> + struct spi_device *spi; >> + >> + /* >> + * DMA (thus cache coherency maintenance) requires the >> + * transfer buffers to live in their own cache lines. >> + */ >> + u8 buffer[3] ____cacheline_aligned; >> +}; >> + >> +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, >> +}; > > for just one supported chip, this is more complicated than necessary... > I can get rid of this, yes, but it's much nicer than hard-coding those values in indio_dev fields ;) >> + >> +static int max11100_read_single(struct iio_dev *indio_dev, int *val) >> +{ >> + int ret; >> + struct max11100_state *state = iio_priv(indio_dev); >> + >> + ret = spi_read(state->spi, state->buffer, sizeof(state->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 (state->buffer[0]) { >> + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); >> + return -EINVAL; >> + } >> + >> + *val = (state->buffer[1] << 8) | state->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->name = "max11100"; >> + 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); > > should be the other way around, first _unregister(), then > regulator_disable() > > reverse order as in _probe() > Yeah, that's right... Let's see, I can send v6 with no issues, or Jonathan can do that if he prefers to. Just let me know :) Thanks j >> + >> + 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 19/01/17 21:47, jacopo mondi wrote: > Hi Peter, > > On 19/01/2017 19:15, Peter Meerwald-Stadler wrote: >> >>> Add iio driver for Maxim MAX11100 single-channel ADC. >> >> minor comments, maybe Jonathan can fix it up when taking this... >> >>> +struct max11100_state { >>> + const struct max11100_chip_desc *desc; >>> + struct regulator *vref_reg; >>> + struct spi_device *spi; >>> + >>> + /* >>> + * DMA (thus cache coherency maintenance) requires the >>> + * transfer buffers to live in their own cache lines. >>> + */ >>> + u8 buffer[3] ____cacheline_aligned; >>> +}; >>> + >>> +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, >>> +}; >> >> for just one supported chip, this is more complicated than necessary... >> > > I can get rid of this, yes, but it's much nicer than hard-coding > those values in indio_dev fields ;) It's abstraction for something that doesn't need to be abstracted. Adds a few lines of code that needs checking for no gain. Hence it's gone. >>> + >>> +static int max11100_read_single(struct iio_dev *indio_dev, int *val) >>> +{ >>> + int ret; >>> + struct max11100_state *state = iio_priv(indio_dev); >>> + >>> + ret = spi_read(state->spi, state->buffer, sizeof(state->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 (state->buffer[0]) { >>> + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); >>> + return -EINVAL; >>> + } >>> + >>> + *val = (state->buffer[1] << 8) | state->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->name = "max11100"; >>> + 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); >> >> should be the other way around, first _unregister(), then >> regulator_disable() >> >> reverse order as in _probe() >> > > Yeah, that's right... Fixed up. > > Let's see, I can send v6 with no issues, or Jonathan can do that if he prefers to. > Just let me know :) I'll do it as minor stuff. Applied with changes as above to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > > Thanks > j > > >>> + >>> + 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"); >>> >> >
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..b738ecf --- /dev/null +++ b/drivers/iio/adc/max11100.c @@ -0,0 +1,192 @@ +/* + * iio/adc/max11100.c + * Maxim max11100 ADC Driver with IIO interface + * + * Copyright (C) 2016-17 Renesas Electronics Corporation + * Copyright (C) 2016-17 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/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; + + /* + * DMA (thus cache coherency maintenance) requires the + * transfer buffers to live in their own cache lines. + */ + u8 buffer[3] ____cacheline_aligned; +}; + +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); + + ret = spi_read(state->spi, state->buffer, sizeof(state->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 (state->buffer[0]) { + dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); + return -EINVAL; + } + + *val = (state->buffer[1] << 8) | state->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->name = "max11100"; + 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");