iio: sx9324: Add Setting for internal analog gain

Based on device tree setting, set the internal analog gain.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220429220144.1476049-9-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/proximity/sx9324.c b/drivers/iio/proximity/sx9324.c
index 926a0da..7f367f6 100644 (file)
--- a/drivers/iio/proximity/sx9324.c
+++ b/drivers/iio/proximity/sx9324.c
@@ -79,6 +79,7 @@
 #define SX9324_REG_AFE_CTRL8_RESFILTIN_4KOHM 0x02
 #define SX9324_REG_AFE_CTRL8_RESFILTIN_MASK GENMASK(3, 0)
 #define SX9324_REG_AFE_CTRL9           0x2d
+#define SX9324_REG_AFE_CTRL9_AGAIN_MASK                        GENMASK(3, 0)
 #define SX9324_REG_AFE_CTRL9_AGAIN_1   0x08
 
 #define SX9324_REG_PROX_CTRL0          0x30
@@ -941,6 +942,27 @@ sx9324_get_default_reg(struct device *dev, int idx,
                                           raw / 2000);
                break;
 
+       case SX9324_REG_AFE_CTRL9:
+               ret = device_property_read_u32(dev,
+                               "semtech,input-analog-gain", &raw);
+               if (ret)
+                       break;
+               /*
+                * The analog gain has the following setting:
+                * +---------+----------------+----------------+
+                * | dt(raw) | physical value | register value |
+                * +---------+----------------+----------------+
+                * |  0      |      x1.247    |      6         |
+                * |  1      |      x1        |      8         |
+                * |  2      |      x0.768    |     11         |
+                * |  3      |      x0.552    |     15         |
+                * +---------+----------------+----------------+
+                */
+               reg_def->def &= ~SX9324_REG_AFE_CTRL9_AGAIN_MASK;
+               reg_def->def |= FIELD_PREP(SX9324_REG_AFE_CTRL9_AGAIN_MASK,
+                                          6 + raw * (raw + 3) / 2);
+               break;
+
        case SX9324_REG_ADV_CTRL5:
                ret = device_property_read_u32(dev, "semtech,startup-sensor",
                                               &start);