1 files changed, 160 insertions, 16 deletions

diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index cca935c06f2b..db109f0cdd8c 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -18,6 +18,8 @@
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/delay.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -26,12 +28,20 @@
 
 #define MCP4725_DRV_NAME "mcp4725"
 
+#define MCP472X_REF_VDD			0x00
+#define MCP472X_REF_VREF_UNBUFFERED	0x02
+#define MCP472X_REF_VREF_BUFFERED	0x03
+
 struct mcp4725_data {
 	struct i2c_client *client;
-	u16 vref_mv;
+	int id;
+	unsigned ref_mode;
+	bool vref_buffered;
 	u16 dac_value;
 	bool powerdown;
 	unsigned powerdown_mode;
+	struct regulator *vdd_reg;
+	struct regulator *vref_reg;
 };
 
 static int mcp4725_suspend(struct device *dev)
@@ -86,6 +96,7 @@ static ssize_t mcp4725_store_eeprom(struct device *dev,
 		return 0;
 
 	inoutbuf[0] = 0x60; /* write EEPROM */
+	inoutbuf[0] |= data->ref_mode << 3;
 	inoutbuf[1] = data->dac_value >> 4;
 	inoutbuf[2] = (data->dac_value & 0xf) << 4;
 
@@ -278,18 +289,49 @@ static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
 		return 0;
 }
 
+static int mcp4726_set_cfg(struct iio_dev *indio_dev)
+{
+	struct mcp4725_data *data = iio_priv(indio_dev);
+	u8 outbuf[3];
+	int ret;
+
+	outbuf[0] = 0x40;
+	outbuf[0] |= data->ref_mode << 3;
+	if (data->powerdown)
+		outbuf[0] |= data->powerdown << 1;
+	outbuf[1] = data->dac_value >> 4;
+	outbuf[2] = (data->dac_value & 0xf) << 4;
+
+	ret = i2c_master_send(data->client, outbuf, 3);
+	if (ret < 0)
+		return ret;
+	else if (ret != 3)
+		return -EIO;
+	else
+		return 0;
+}
+
 static int mcp4725_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val, int *val2, long mask)
 {
 	struct mcp4725_data *data = iio_priv(indio_dev);
+	int ret;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		*val = data->dac_value;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
-		*val = data->vref_mv;
+		if (data->ref_mode == MCP472X_REF_VDD)
+			ret = regulator_get_voltage(data->vdd_reg);
+		else
+			ret = regulator_get_voltage(data->vref_reg);
+
+		if (ret < 0)
+			return ret;
+
+		*val = ret / 1000;
 		*val2 = 12;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	}
@@ -323,27 +365,98 @@ static const struct iio_info mcp4725_info = {
 	.driver_module = THIS_MODULE,
 };
 
+#ifdef CONFIG_OF
+static int mcp4725_probe_dt(struct device *dev,
+			    struct mcp4725_platform_data *pdata)
+{
+	struct device_node *np = dev->of_node;
+
+	if (!np)
+		return -ENODEV;
+
+	/* check if is the vref-supply defined */
+	pdata->use_vref = of_property_read_bool(np, "vref-supply");
+	pdata->vref_buffered =
+		of_property_read_bool(np, "microchip,vref-buffered");
+
+	return 0;
+}
+#else
+static int mcp4725_probe_dt(struct device *dev,
+			    struct mcp4725_platform_data *platform_data)
+{
+	return -ENODEV;
+}
+#endif
+
 static int mcp4725_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct mcp4725_data *data;
 	struct iio_dev *indio_dev;
-	struct mcp4725_platform_data *platform_data = client->dev.platform_data;
-	u8 inbuf[3];
+	struct mcp4725_platform_data *pdata, pdata_dt;
+	u8 inbuf[4];
 	u8 pd;
+	u8 ref;
 	int err;
 
-	if (!platform_data || !platform_data->vref_mv) {
-		dev_err(&client->dev, "invalid platform data");
-		return -EINVAL;
-	}
-
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (indio_dev == NULL)
 		return -ENOMEM;
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
+	data->id = id->driver_data;
+	pdata = dev_get_platdata(&client->dev);
+
+	if (!pdata) {
+		err = mcp4725_probe_dt(&client->dev, &pdata_dt);
+		if (err) {
+			dev_err(&client->dev,
+				"invalid platform or devicetree data");
+			return err;
+		}
+		pdata = &pdata_dt;
+	}
+
+	if (data->id == MCP4725 && pdata->use_vref) {
+		dev_err(&client->dev,
+			"external reference is unavailable on MCP4725");
+		return -EINVAL;
+	}
+
+	if (!pdata->use_vref && pdata->vref_buffered) {
+		dev_err(&client->dev,
+			"buffering is unavailable on the internal reference");
+		return -EINVAL;
+	}
+
+	if (!pdata->use_vref)
+		data->ref_mode = MCP472X_REF_VDD;
+	else
+		data->ref_mode = pdata->vref_buffered ?
+			MCP472X_REF_VREF_BUFFERED :
+			MCP472X_REF_VREF_UNBUFFERED;
+
+	data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
+	if (IS_ERR(data->vdd_reg))
+		return PTR_ERR(data->vdd_reg);
+
+	err = regulator_enable(data->vdd_reg);
+	if (err)
+		return err;
+
+	if (pdata->use_vref) {
+		data->vref_reg = devm_regulator_get(&client->dev, "vref");
+		if (IS_ERR(data->vref_reg)) {
+			err = PTR_ERR(data->vref_reg);
+			goto err_disable_vdd_reg;
+		}
+
+		err = regulator_enable(data->vref_reg);
+		if (err)
+			goto err_disable_vdd_reg;
+	}
 
 	indio_dev->dev.parent = &client->dev;
 	indio_dev->name = id->name;
@@ -352,25 +465,56 @@ static int mcp4725_probe(struct i2c_client *client,
 	indio_dev->num_channels = 1;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	data->vref_mv = platform_data->vref_mv;
+	/* read current DAC value and settings */
+	err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
 
-	/* read current DAC value */
-	err = i2c_master_recv(client, inbuf, 3);
 	if (err < 0) {
 		dev_err(&client->dev, "failed to read DAC value");
-		return err;
+		goto err_disable_vref_reg;
 	}
 	pd = (inbuf[0] >> 1) & 0x3;
 	data->powerdown = pd > 0 ? true : false;
-	data->powerdown_mode = pd ? pd - 1 : 2; /* largest register to gnd */
+	data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
 	data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
+	if (data->id == MCP4726)
+		ref = (inbuf[3] >> 3) & 0x3;
+
+	if (data->id == MCP4726 && ref != data->ref_mode) {
+		dev_info(&client->dev,
+			"voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
+			data->ref_mode, ref, data->ref_mode);
+		err = mcp4726_set_cfg(indio_dev);
+		if (err < 0)
+			goto err_disable_vref_reg;
+	}
+ 
+	err = iio_device_register(indio_dev);
+	if (err)
+		goto err_disable_vref_reg;
+
+	return 0;
+
+err_disable_vref_reg:
+	if (data->vref_reg)
+		regulator_disable(data->vref_reg);
 
-	return iio_device_register(indio_dev);
+err_disable_vdd_reg:
+	regulator_disable(data->vdd_reg);
+
+	return err;
 }
 
 static int mcp4725_remove(struct i2c_client *client)
 {
-	iio_device_unregister(i2c_get_clientdata(client));
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct mcp4725_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	if (data->vref_reg)
+		regulator_disable(data->vref_reg);
+	regulator_disable(data->vdd_reg);
+
 	return 0;
 }