iio: light: apds9960: Add proximity and gesture offset calibration

Proximity and gesture offset registers perform offset correction to
improve cross-talk performance. Added `calibbias` to the proximity
and gesture channels.
Provided facility to set calibbias based on the channel number.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
Link: https://patch.msgid.link/20240804134212.51682-2-abhashkumarjha123@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/light/apds9960.c b/drivers/iio/light/apds9960.c
index e9e65130b6f9116d88054d6e07c52b63ff32f7eb..3c14e4c30805e1b596ef2380f94e6aa3e92082b1 100644 (file)
--- a/drivers/iio/light/apds9960.c
+++ b/drivers/iio/light/apds9960.c
@@ -146,6 +146,25 @@ struct apds9960_data {
 
        /* gesture buffer */
        u8 buffer[4]; /* 4 8-bit channels */
+
+       /* calibration value buffer */
+       int calibbias[5];
+};
+
+enum {
+       APDS9960_CHAN_PROXIMITY,
+       APDS9960_CHAN_GESTURE_UP,
+       APDS9960_CHAN_GESTURE_DOWN,
+       APDS9960_CHAN_GESTURE_LEFT,
+       APDS9960_CHAN_GESTURE_RIGHT,
+};
+
+static const unsigned int apds9960_offset_regs[][2] = {
+       [APDS9960_CHAN_PROXIMITY] = {APDS9960_REG_POFFSET_UR, APDS9960_REG_POFFSET_DL},
+       [APDS9960_CHAN_GESTURE_UP] = {APDS9960_REG_GOFFSET_U, 0},
+       [APDS9960_CHAN_GESTURE_DOWN] = {APDS9960_REG_GOFFSET_D, 0},
+       [APDS9960_CHAN_GESTURE_LEFT] = {APDS9960_REG_GOFFSET_L, 0},
+       [APDS9960_CHAN_GESTURE_RIGHT] = {APDS9960_REG_GOFFSET_R, 0},
 };
 
 static const struct reg_default apds9960_reg_defaults[] = {
@@ -255,6 +274,7 @@ static const struct iio_event_spec apds9960_als_event_spec[] = {
 
 #define APDS9960_GESTURE_CHANNEL(_dir, _si) { \
        .type = IIO_PROXIMITY, \
+       .info_mask_separate = BIT(IIO_CHAN_INFO_CALIBBIAS), \
        .channel = _si + 1, \
        .scan_index = _si, \
        .indexed = 1, \
@@ -282,7 +302,8 @@ static const struct iio_chan_spec apds9960_channels[] = {
        {
                .type = IIO_PROXIMITY,
                .address = APDS9960_REG_PDATA,
-               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                       BIT(IIO_CHAN_INFO_CALIBBIAS),
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
                .channel = 0,
                .indexed = 0,
@@ -316,6 +337,28 @@ static const struct iio_chan_spec apds9960_channels[] = {
        APDS9960_INTENSITY_CHANNEL(BLUE),
 };
 
+static int apds9960_set_calibbias(struct apds9960_data *data,
+               struct iio_chan_spec const *chan, int calibbias)
+{
+       int ret, i;
+
+       if (calibbias < S8_MIN || calibbias > S8_MAX)
+               return -EINVAL;
+
+       guard(mutex)(&data->lock);
+       for (i = 0; i < 2; i++) {
+               if (apds9960_offset_regs[chan->channel][i] == 0)
+                       break;
+
+               ret = regmap_write(data->regmap, apds9960_offset_regs[chan->channel][i], calibbias);
+               if (ret < 0)
+                       return ret;
+       }
+       data->calibbias[chan->channel] = calibbias;
+
+       return 0;
+}
+
 /* integration time in us */
 static const int apds9960_int_time[][2] = {
        { 28000, 246},
@@ -531,6 +574,12 @@ static int apds9960_read_raw(struct iio_dev *indio_dev,
                }
                mutex_unlock(&data->lock);
                break;
+       case IIO_CHAN_INFO_CALIBBIAS:
+               mutex_lock(&data->lock);
+               *val = data->calibbias[chan->channel];
+               ret = IIO_VAL_INT;
+               mutex_unlock(&data->lock);
+               break;
        }
 
        return ret;
@@ -564,6 +613,10 @@ static int apds9960_write_raw(struct iio_dev *indio_dev,
                default:
                        return -EINVAL;
                }
+       case IIO_CHAN_INFO_CALIBBIAS:
+               if (val2 != 0)
+                       return -EINVAL;
+               return apds9960_set_calibbias(data, chan, val);
        default:
                return -EINVAL;
        }