[PATCH v4 7/7] iio: accel: adxl345: Add spi-3wire option

[Lothar Rubusch <l.rubusch@xxxxxxxxx>]

Add a setup function implementation to the spi module to enable
spi-3wire as option when specified in the device-tree.

Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx>
---
 drivers/iio/accel/adxl345.h     |  1 +
 drivers/iio/accel/adxl345_spi.c | 12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/accel/adxl345.h b/drivers/iio/accel/adxl345.h
index 620a2e0f0..55a72ca38 100644
--- a/drivers/iio/accel/adxl345.h
+++ b/drivers/iio/accel/adxl345.h
@@ -36,6 +36,7 @@
 #define ADXL345_DATA_FORMAT_8G		2
 #define ADXL345_DATA_FORMAT_16G		3
 #define ADXL345_DATA_FORMAT_MSK		~((u8) BIT(6)) /* ignore spi-3wire */
+#define ADXL345_DATA_FORMAT_SPI_3WIRE	BIT(6)
 
 #define ADXL345_DEVID			0xE5
 
diff --git a/drivers/iio/accel/adxl345_spi.c b/drivers/iio/accel/adxl345_spi.c
index 1c0513bd3..f145d5c1d 100644
--- a/drivers/iio/accel/adxl345_spi.c
+++ b/drivers/iio/accel/adxl345_spi.c
@@ -20,6 +20,16 @@ static const struct regmap_config adxl345_spi_regmap_config = {
 	.read_flag_mask = BIT(7) | BIT(6),
 };
 
+static int adxl345_spi_setup(struct device *dev, struct regmap *regmap)
+{
+	struct spi_device *spi = container_of(dev, struct spi_device, dev);
+
+	if (spi->mode & SPI_3WIRE)
+		return regmap_write(regmap, ADXL345_REG_DATA_FORMAT,
+				    ADXL345_DATA_FORMAT_SPI_3WIRE);
+	return 0;
+}
+
 static int adxl345_spi_probe(struct spi_device *spi)
 {
 	struct regmap *regmap;
@@ -33,7 +43,7 @@ static int adxl345_spi_probe(struct spi_device *spi)
 	if (IS_ERR(regmap))
 		return dev_err_probe(&spi->dev, PTR_ERR(regmap), "Error initializing regmap\n");
 
-	return adxl345_core_probe(&spi->dev, regmap, NULL);
+	return adxl345_core_probe(&spi->dev, regmap, adxl345_spi_setup);
 }
 
 static const struct adxl345_chip_info adxl345_spi_info = {
-- 
2.25.1