iio: adc: ad7192: Add fast settling support

Add fast settling mode support for AD7193.

Add two new device specific attributes: oversampling_ratio and
oversampling_ratio_available.

For AD7193 the user can set the average factor by writing to
oversampling_ratio. The possible values are exposed when reading
oversampling_ratio_available.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Link: https://lore.kernel.org/r/20231010124927.143343-4-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index fe47ef43b3d7990f623cac30f3251fd44864dcf0..954093ee0fbdac792120a48e2f6dfd8f8e0c5236 100644 (file)
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -60,6 +60,8 @@
 #define AD7192_MODE_SEL_MASK   GENMASK(23, 21) /* Operation Mode Select Mask */
 #define AD7192_MODE_STA_MASK   BIT(20) /* Status Register transmission Mask */
 #define AD7192_MODE_CLKSRC_MASK        GENMASK(19, 18) /* Clock Source Select Mask */
+#define AD7192_MODE_AVG_MASK   GENMASK(17, 16)
+                 /* Fast Settling Filter Average Select Mask (AD7193 only) */
 #define AD7192_MODE_SINC3      BIT(15) /* SINC3 Filter Select */
 #define AD7192_MODE_ENPAR      BIT(13) /* Parity Enable */
 #define AD7192_MODE_CLKDIV     BIT(12) /* Clock divide by 2 (AD7190/2 only)*/
@@ -185,6 +187,7 @@ struct ad7192_state {
        u32                             mode;
        u32                             conf;
        u32                             scale_avail[8][2];
+       u32                             oversampling_ratio_avail[4];
        u8                              gpocon;
        u8                              clock_sel;
        struct mutex                    lock;   /* protect sensor state */
@@ -462,6 +465,11 @@ static int ad7192_setup(struct iio_dev *indio_dev, struct device_node *np)
                st->scale_avail[i][0] = scale_uv;
        }
 
+       st->oversampling_ratio_avail[0] = 1;
+       st->oversampling_ratio_avail[1] = 2;
+       st->oversampling_ratio_avail[2] = 8;
+       st->oversampling_ratio_avail[3] = 16;
+
        return 0;
 }
 
@@ -531,15 +539,21 @@ static ssize_t ad7192_set(struct device *dev,
        return ret ? ret : len;
 }
 
-static int ad7192_compute_f_order(bool sinc3_en, bool chop_en)
+static int ad7192_compute_f_order(struct ad7192_state *st, bool sinc3_en, bool chop_en)
 {
-       if (!chop_en)
+       u8 avg_factor_selected, oversampling_ratio;
+
+       avg_factor_selected = FIELD_GET(AD7192_MODE_AVG_MASK, st->mode);
+
+       if (!avg_factor_selected && !chop_en)
                return 1;
 
+       oversampling_ratio = st->oversampling_ratio_avail[avg_factor_selected];
+
        if (sinc3_en)
-               return AD7192_SYNC3_FILTER;
+               return AD7192_SYNC3_FILTER + oversampling_ratio - 1;
 
-       return AD7192_SYNC4_FILTER;
+       return AD7192_SYNC4_FILTER + oversampling_ratio - 1;
 }
 
 static int ad7192_get_f_order(struct ad7192_state *st)
@@ -549,13 +563,13 @@ static int ad7192_get_f_order(struct ad7192_state *st)
        sinc3_en = FIELD_GET(AD7192_MODE_SINC3, st->mode);
        chop_en = FIELD_GET(AD7192_CONF_CHOP, st->conf);
 
-       return ad7192_compute_f_order(sinc3_en, chop_en);
+       return ad7192_compute_f_order(st, sinc3_en, chop_en);
 }
 
 static int ad7192_compute_f_adc(struct ad7192_state *st, bool sinc3_en,
                                bool chop_en)
 {
-       unsigned int f_order = ad7192_compute_f_order(sinc3_en, chop_en);
+       unsigned int f_order = ad7192_compute_f_order(st, sinc3_en, chop_en);
 
        return DIV_ROUND_CLOSEST(st->fclk,
                                 f_order * FIELD_GET(AD7192_MODE_RATE_MASK, st->mode));
@@ -753,6 +767,9 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
                *val = ad7192_get_3db_filter_freq(st);
                *val2 = 1000;
                return IIO_VAL_FRACTIONAL;
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               *val = st->oversampling_ratio_avail[FIELD_GET(AD7192_MODE_AVG_MASK, st->mode)];
+               return IIO_VAL_INT;
        }
 
        return -EINVAL;
@@ -810,6 +827,23 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
                ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
                break;
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               ret = -EINVAL;
+               mutex_lock(&st->lock);
+               for (i = 0; i < ARRAY_SIZE(st->oversampling_ratio_avail); i++)
+                       if (val == st->oversampling_ratio_avail[i]) {
+                               ret = 0;
+                               tmp = st->mode;
+                               st->mode &= ~AD7192_MODE_AVG_MASK;
+                               st->mode |= FIELD_PREP(AD7192_MODE_AVG_MASK, i);
+                               if (tmp == st->mode)
+                                       break;
+                               ad_sd_write_reg(&st->sd, AD7192_REG_MODE,
+                                               3, st->mode);
+                               break;
+                       }
+               mutex_unlock(&st->lock);
+               break;
        default:
                ret = -EINVAL;
        }
@@ -830,6 +864,8 @@ static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
                return IIO_VAL_INT_PLUS_MICRO;
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               return IIO_VAL_INT;
        default:
                return -EINVAL;
        }
@@ -849,6 +885,12 @@ static int ad7192_read_avail(struct iio_dev *indio_dev,
                /* Values are stored in a 2D matrix  */
                *length = ARRAY_SIZE(st->scale_avail) * 2;
 
+               return IIO_AVAIL_LIST;
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               *vals = (int *)st->oversampling_ratio_avail;
+               *type = IIO_VAL_INT;
+               *length = ARRAY_SIZE(st->oversampling_ratio_avail);
+
                return IIO_AVAIL_LIST;
        }
 
@@ -896,7 +938,7 @@ static const struct iio_info ad7195_info = {
 };
 
 #define __AD719x_CHANNEL(_si, _channel1, _channel2, _address, _type, \
-       _mask_type_av, _ext_info) \
+       _mask_all, _mask_type_av, _mask_all_av, _ext_info) \
        { \
                .type = (_type), \
                .differential = ((_channel2) == -1 ? 0 : 1), \
@@ -908,8 +950,10 @@ static const struct iio_info ad7195_info = {
                        BIT(IIO_CHAN_INFO_OFFSET), \
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
                .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
-                       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
+                       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \
+                       (_mask_all), \
                .info_mask_shared_by_type_available = (_mask_type_av), \
+               .info_mask_shared_by_all_available = (_mask_all_av), \
                .ext_info = (_ext_info), \
                .scan_index = (_si), \
                .scan_type = { \
@@ -921,15 +965,26 @@ static const struct iio_info ad7195_info = {
        }
 
 #define AD719x_DIFF_CHANNEL(_si, _channel1, _channel2, _address) \
-       __AD719x_CHANNEL(_si, _channel1, _channel2, _address, IIO_VOLTAGE, \
-               BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
+       __AD719x_CHANNEL(_si, _channel1, _channel2, _address, IIO_VOLTAGE, 0, \
+               BIT(IIO_CHAN_INFO_SCALE), 0, ad7192_calibsys_ext_info)
 
 #define AD719x_CHANNEL(_si, _channel1, _address) \
-       __AD719x_CHANNEL(_si, _channel1, -1, _address, IIO_VOLTAGE, \
-               BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
+       __AD719x_CHANNEL(_si, _channel1, -1, _address, IIO_VOLTAGE, 0, \
+               BIT(IIO_CHAN_INFO_SCALE), 0, ad7192_calibsys_ext_info)
 
 #define AD719x_TEMP_CHANNEL(_si, _address) \
-       __AD719x_CHANNEL(_si, 0, -1, _address, IIO_TEMP, 0, NULL)
+       __AD719x_CHANNEL(_si, 0, -1, _address, IIO_TEMP, 0, 0, 0, NULL)
+
+#define AD7193_DIFF_CHANNEL(_si, _channel1, _channel2, _address) \
+       __AD719x_CHANNEL(_si, _channel1, _channel2, _address, \
+               IIO_VOLTAGE, \
+               BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+               BIT(IIO_CHAN_INFO_SCALE), \
+               BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+               ad7192_calibsys_ext_info)
+
+#define AD7193_CHANNEL(_si, _channel1, _address) \
+       AD7193_DIFF_CHANNEL(_si, _channel1, -1, _address)
 
 static const struct iio_chan_spec ad7192_channels[] = {
        AD719x_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M),
@@ -944,20 +999,20 @@ static const struct iio_chan_spec ad7192_channels[] = {
 };
 
 static const struct iio_chan_spec ad7193_channels[] = {
-       AD719x_DIFF_CHANNEL(0, 1, 2, AD7193_CH_AIN1P_AIN2M),
-       AD719x_DIFF_CHANNEL(1, 3, 4, AD7193_CH_AIN3P_AIN4M),
-       AD719x_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M),
-       AD719x_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M),
+       AD7193_DIFF_CHANNEL(0, 1, 2, AD7193_CH_AIN1P_AIN2M),
+       AD7193_DIFF_CHANNEL(1, 3, 4, AD7193_CH_AIN3P_AIN4M),
+       AD7193_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M),
+       AD7193_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M),
        AD719x_TEMP_CHANNEL(4, AD7193_CH_TEMP),
-       AD719x_DIFF_CHANNEL(5, 2, 2, AD7193_CH_AIN2P_AIN2M),
-       AD719x_CHANNEL(6, 1, AD7193_CH_AIN1),
-       AD719x_CHANNEL(7, 2, AD7193_CH_AIN2),
-       AD719x_CHANNEL(8, 3, AD7193_CH_AIN3),
-       AD719x_CHANNEL(9, 4, AD7193_CH_AIN4),
-       AD719x_CHANNEL(10, 5, AD7193_CH_AIN5),
-       AD719x_CHANNEL(11, 6, AD7193_CH_AIN6),
-       AD719x_CHANNEL(12, 7, AD7193_CH_AIN7),
-       AD719x_CHANNEL(13, 8, AD7193_CH_AIN8),
+       AD7193_DIFF_CHANNEL(5, 2, 2, AD7193_CH_AIN2P_AIN2M),
+       AD7193_CHANNEL(6, 1, AD7193_CH_AIN1),
+       AD7193_CHANNEL(7, 2, AD7193_CH_AIN2),
+       AD7193_CHANNEL(8, 3, AD7193_CH_AIN3),
+       AD7193_CHANNEL(9, 4, AD7193_CH_AIN4),
+       AD7193_CHANNEL(10, 5, AD7193_CH_AIN5),
+       AD7193_CHANNEL(11, 6, AD7193_CH_AIN6),
+       AD7193_CHANNEL(12, 7, AD7193_CH_AIN7),
+       AD7193_CHANNEL(13, 8, AD7193_CH_AIN8),
        IIO_CHAN_SOFT_TIMESTAMP(14),
 };