On Wed, 17 Apr 2024 20:00:52 +0300
Alisa-Dariana Roman <alisadariana@xxxxxxxxx> wrote:
> AINCOM should actually be a supply. AINx inputs are referenced to AINCOM
> in pseduo-differential operation mode. AINCOM voltage represets the
> offset of corresponding channels.
>
> Signed-off-by: Alisa-Dariana Roman <alisa.roman@xxxxxxxxxx>
One request inline to make my life easier :)
Otherwise, I noticed a subset of what Andy picked up on so won't
repeat his comments!
Thanks,
Jonathan
> ---
> drivers/iio/adc/ad7192.c | 37 +++++++++++++++++++++++++++++++++++--
> 1 file changed, 35 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
> index fe8dbb68a8ba..8d56cf889973 100644
> --- a/drivers/iio/adc/ad7192.c
> +++ b/drivers/iio/adc/ad7192.c
> @@ -186,6 +186,7 @@ struct ad7192_state {
> struct regulator *vref;
> struct clk *mclk;
> u16 int_vref_mv;
> + u32 aincom_mv;
> u32 fclk;
> u32 mode;
> u32 conf;
> @@ -742,10 +743,19 @@ 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 * 1000000000,
> + 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 +1062,7 @@ 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 +1078,27 @@ static int ad7192_probe(struct spi_device *spi)
>
> mutex_init(&st->lock);
>
As we are going around again, could you do me a favour and add a comment
here along the lines of.
/*
* aincom is optional to maintain compatibility with older DT.
* Newer firmware should provide a zero volt fixed supply if
* this is wired to ground.
*/
Aim being to discourage this getting cut and paste into other drivers
that support the common voltage from the start!
> + aincom = devm_regulator_get_optional(&spi->dev, "aincom");
> + if (!IS_ERR(aincom)) {
> + ret = regulator_enable(aincom);
> + if (ret) {
> + dev_err(&spi->dev, "Failed to enable specified AINCOM supply\n");
> + return ret;
> + }
> +
> + 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;
> + } else {
> + st->aincom_mv = 0;
> + }
> +
> st->avdd = devm_regulator_get(&spi->dev, "avdd");
> if (IS_ERR(st->avdd))
> return PTR_ERR(st->avdd);
> @@ -1113,6 +1145,7 @@ static int ad7192_probe(struct spi_device *spi)
> st->int_vref_mv = ret / 1000;
>
> st->chip_info = spi_get_device_match_data(spi);
> +
> indio_dev->name = st->chip_info->name;
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->channels = st->chip_info->channels;
