iio: sx9324: Add precharge internal resistance setting

Add ability to set the precharge internal resistance from the device
tree.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220429220144.1476049-5-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 ed9fb17..28e2672 100644 (file)
--- a/drivers/iio/proximity/sx9324.c
+++ b/drivers/iio/proximity/sx9324.c
@@ -72,6 +72,7 @@
 #define SX9324_REG_AFE_CTRL8           0x2c
 #define SX9324_REG_AFE_CTRL8_RESERVED  0x10
 #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_1   0x08
 
@@ -909,6 +910,18 @@ sx9324_get_default_reg(struct device *dev, int idx,
                reg_def->def |= FIELD_PREP(SX9324_REG_AFE_CTRL4_RESOLUTION_MASK,
                                           raw);
                break;
+       case SX9324_REG_AFE_CTRL8:
+               ret = device_property_read_u32(dev,
+                               "semtech,input-precharge-resistor-ohms",
+                               &raw);
+               if (ret)
+                       break;
+
+               reg_def->def &= ~SX9324_REG_AFE_CTRL8_RESFILTIN_MASK;
+               reg_def->def |= FIELD_PREP(SX9324_REG_AFE_CTRL8_RESFILTIN_MASK,
+                                          raw / 2000);
+               break;
+
        case SX9324_REG_ADV_CTRL5:
                ret = device_property_read_u32(dev, "semtech,startup-sensor",
                                               &start);