AINCOM should actually be a supply. AINx inputs are referenced to AINCOM in pseudo-differential operation mode. AINCOM voltage represents the offset of corresponding channels. Signed-off-by: Alisa-Dariana Roman <alisa.roman@xxxxxxxxxx> --- drivers/iio/adc/ad7192.c | 41 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 39 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c index ace81e3817a1..3e797ff48086 100644 --- a/drivers/iio/adc/ad7192.c +++ b/drivers/iio/adc/ad7192.c @@ -20,6 +20,7 @@ #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/property.h> +#include <linux/units.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> @@ -186,6 +187,7 @@ struct ad7192_state { struct regulator *vref; struct clk *mclk; u16 int_vref_mv; + u32 aincom_mv; u32 fclk; u32 mode; u32 conf; @@ -742,10 +744,19 @@ static int ad7192_read_raw(struct iio_dev *indio_dev, *val = -(1 << (chan->scan_type.realbits - 1)); else *val = 0; + switch (chan->type) { + case IIO_VOLTAGE: + if (st->aincom_mv && !chan->differential) + *val += DIV_ROUND_CLOSEST_ULL((u64)st->aincom_mv * NANO, + st->scale_avail[gain][1]); + return IIO_VAL_INT; /* Kelvin to Celsius */ - if (chan->type == IIO_TEMP) + case IIO_TEMP: *val -= 273 * ad7192_get_temp_scale(unipolar); - return IIO_VAL_INT; + return IIO_VAL_INT; + default: + return -EINVAL; + } case IIO_CHAN_INFO_SAMP_FREQ: *val = DIV_ROUND_CLOSEST(ad7192_get_f_adc(st), 1024); return IIO_VAL_INT; @@ -1052,6 +1063,7 @@ static int ad7192_probe(struct spi_device *spi) { struct ad7192_state *st; struct iio_dev *indio_dev; + struct regulator *aincom; int ret; if (!spi->irq) { @@ -1067,6 +1079,31 @@ static int ad7192_probe(struct spi_device *spi) mutex_init(&st->lock); + /* + * Regulator aincom is optional to maintain compatibility with older DT. + * Newer firmware should provide a zero volt fixed supply if wired to + * ground. + */ + aincom = devm_regulator_get_optional(&spi->dev, "aincom"); + if (IS_ERR(aincom)) { + st->aincom_mv = 0; + } else { + ret = regulator_enable(aincom); + if (ret) + return dev_err_probe(&spi->dev, ret, + "Failed to enable specified AINCOM supply\n"); + + ret = devm_add_action_or_reset(&spi->dev, ad7192_reg_disable, aincom); + if (ret) + return ret; + + ret = regulator_get_voltage(aincom); + if (ret < 0) + return dev_err_probe(&spi->dev, ret, + "Device tree error, AINCOM voltage undefined\n"); + st->aincom_mv = ret / 1000; + } + st->avdd = devm_regulator_get(&spi->dev, "avdd"); if (IS_ERR(st->avdd)) return PTR_ERR(st->avdd); -- 2.34.1