staging: iio: ad7780: add filter reading to ad778x

This patch adds the new feature of reading the filter odr value for
ad778x chips. This value is stored in the chip's state struct whenever a
read or write call is performed on the chip's driver.

This feature requires sharing SAMP_FREQ. Since the ad717x does not have
a filter option, the driver only shares the relevant info mask for the
ad778x family.

Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
index abb30c1..ae329bf 100644 (file)
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -42,7 +42,8 @@
 #define AD7780_GAIN_MIDPOINT   64
 #define AD7780_FILTER_MIDPOINT 13350
 
-static const unsigned int ad778x_gain[2] = { 1, 128 };
+static const unsigned int ad778x_gain[2]      = { 1, 128 };
+static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
 
 struct ad7780_chip_info {
        struct iio_chan_spec    channel;
@@ -58,6 +59,7 @@ struct ad7780_state {
        struct gpio_desc                *gain_gpio;
        struct gpio_desc                *filter_gpio;
        unsigned int                    gain;
+       unsigned int                    odr;
        unsigned int                    int_vref_mv;
 
        struct ad_sigma_delta sd;
@@ -120,6 +122,9 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
        case IIO_CHAN_INFO_OFFSET:
                *val = -(1 << (chan->scan_type.realbits - 1));
                return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *val = st->odr;
+               return IIO_VAL_INT;
        default:
                break;
        }
@@ -162,6 +167,7 @@ static int ad7780_write_raw(struct iio_dev *indio_dev,
                        val = 0;
                else
                        val = 1;
+               st->odr = ad778x_odr_avail[val];
                gpiod_set_value(st->filter_gpio, val);
                break;
        default:
@@ -181,8 +187,10 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
            ((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
                return -EIO;
 
-       if (chip_info->is_ad778x)
+       if (chip_info->is_ad778x) {
                st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
+               st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
+       }
 
        return 0;
 }
@@ -194,17 +202,19 @@ static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
 };
 
 #define AD7780_CHANNEL(bits, wordsize) \
+       AD_SD_CHANNEL(1, 0, 0, bits, 32, wordsize - bits)
+#define AD7170_CHANNEL(bits, wordsize) \
        AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, wordsize - bits)
 
 static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
        [ID_AD7170] = {
-               .channel = AD7780_CHANNEL(12, 24),
+               .channel = AD7170_CHANNEL(12, 24),
                .pattern = AD7170_PATTERN,
                .pattern_mask = AD7170_PATTERN_MASK,
                .is_ad778x = false,
        },
        [ID_AD7171] = {
-               .channel = AD7780_CHANNEL(16, 24),
+               .channel = AD7170_CHANNEL(16, 24),
                .pattern = AD7170_PATTERN,
                .pattern_mask = AD7170_PATTERN_MASK,
                .is_ad778x = false,