diff options
| author | Alisa-Dariana Roman <alisadariana@gmail.com> | 2024-05-14 15:02:19 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2024-06-04 19:53:05 +0100 |
| commit | 2b12a52b298f41ec581efc3047792c0535dd615c (patch) | |
| tree | 0ca7a34fff5691cfdf0ad2f9a37226a2ff69ff1c | |
| parent | ecec83a236db6b0966d790fd582884b510ee11a3 (diff) | |
| download | linux-2b12a52b298f41ec581efc3047792c0535dd615c.tar.gz linux-2b12a52b298f41ec581efc3047792c0535dd615c.zip | |
iio: adc: ad7192: Add aincom supply
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@analog.com>
Link: https://lore.kernel.org/r/20240514120222.56488-4-alisa.roman@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
| -rw-r--r-- | drivers/iio/adc/ad7192.c | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c index ace81e3817a1..7160929d32c9 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 +744,24 @@ 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: + /* + * Only applies to pseudo-differential inputs. + * AINCOM voltage has to be converted to "raw" units. + */ + 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 +1068,7 @@ 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 +1084,35 @@ 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)) { + if (PTR_ERR(aincom) != -ENODEV) + return dev_err_probe(&spi->dev, PTR_ERR(aincom), + "Failed to get AINCOM supply\n"); + + 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 / MILLI; + } + st->avdd = devm_regulator_get(&spi->dev, "avdd"); if (IS_ERR(st->avdd)) return PTR_ERR(st->avdd); |