[PATCH 2/4] iio: dac: mcp4922: get and enable vdd regulator

[Nicolas Frattaroli <frattaroli.nicolas@gmail.com>]

The MCP4922 family of chips has a vdd power input, which we
model in our device tree binding for it. The driver should get
and enable the vdd regulator as is appropriate.

Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
---
 drivers/iio/dac/mcp4922.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/dac/mcp4922.c b/drivers/iio/dac/mcp4922.c
index da4327624d45..0b9458cbbcff 100644
--- a/drivers/iio/dac/mcp4922.c
+++ b/drivers/iio/dac/mcp4922.c
@@ -31,6 +31,7 @@ struct mcp4922_state {
 	unsigned int value[MCP4922_NUM_CHANNELS];
 	unsigned int vref_mv;
 	struct regulator *vref_reg;
+	struct regulator *vdd_reg;
 	u8 mosi[2] __aligned(IIO_DMA_MINALIGN);
 };
 
@@ -148,10 +149,23 @@ static int mcp4922_probe(struct spi_device *spi)
 	if (ret < 0) {
 		dev_err(&spi->dev, "Failed to read vref regulator: %d\n",
 				ret);
-		goto error_disable_reg;
+		goto error_disable_vref_reg;
 	}
 	state->vref_mv = ret / 1000;
 
+	state->vdd_reg = devm_regulator_get(&spi->dev, "vdd");
+	if (IS_ERR(state->vdd_reg)) {
+		ret = dev_err_probe(&spi->dev, PTR_ERR(state->vdd_reg),
+				    "vdd regulator not specified\n");
+		goto error_disable_vref_reg;
+	}
+	ret = regulator_enable(state->vdd_reg);
+	if (ret) {
+		dev_err(&spi->dev, "Failed to enable vdd regulator: %d\n",
+			ret);
+		goto error_disable_vref_reg;
+	}
+
 	spi_set_drvdata(spi, indio_dev);
 	id = spi_get_device_id(spi);
 	indio_dev->info = &mcp4922_info;
@@ -167,12 +181,13 @@ static int mcp4922_probe(struct spi_device *spi)
 	if (ret) {
 		dev_err(&spi->dev, "Failed to register iio device: %d\n",
 				ret);
-		goto error_disable_reg;
+		goto error_disable_vdd_reg;
 	}
 
 	return 0;
-
-error_disable_reg:
+error_disable_vdd_reg:
+	regulator_disable(state->vdd_reg);
+error_disable_vref_reg:
 	regulator_disable(state->vref_reg);
 
 	return ret;
@@ -185,6 +200,7 @@ static void mcp4922_remove(struct spi_device *spi)
 
 	iio_device_unregister(indio_dev);
 	state = iio_priv(indio_dev);
+	regulator_disable(state->vdd_reg);
 	regulator_disable(state->vref_reg);
 }
 
-- 
2.40.0