[PATCH v2 4/8] iio: sx9324: Add precharge internal resistance setting

[Gwendal Grignou <gwendal@chromium.org>]

Add ability to set the precharge internal resistance from the device
tree.
Fix the default value for the register that set the resistance:
it has to be 0x10.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes since v1:
- Suffix field with kOhms unit.

 drivers/iio/proximity/sx9324.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/iio/proximity/sx9324.c b/drivers/iio/proximity/sx9324.c
index 1dfa19426c210..95de5d9f8eacb 100644
--- 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_RSVD	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
 
@@ -893,6 +894,15 @@ 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-kohms",
+				&raw);
+		reg_def->def &= ~SX9324_REG_AFE_CTRL8_RESFILTIN_MASK;
+		reg_def->def |= FIELD_PREP(SX9324_REG_AFE_CTRL8_RESFILTIN_MASK,
+					   raw / 2);
+		break;
+
 	case SX9324_REG_ADV_CTRL5:
 		ret = device_property_read_u32(dev, "semtech,startup-sensor",
 					       &start);
-- 
2.35.1.894.gb6a874cedc-goog