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-rw-r--r--drivers/iio/dac/mcp4725.c99
1 files changed, 92 insertions, 7 deletions
diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index 5b2dfa0a0d2c..1e9d8f387e00 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -27,12 +27,20 @@
#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;
+ 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)
@@ -87,6 +95,7 @@ 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;
@@ -279,6 +288,28 @@ 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)
@@ -291,7 +322,11 @@ static int mcp4725_read_raw(struct iio_dev *indio_dev,
*val = data->dac_value;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- ret = regulator_get_voltage(data->vdd_reg);
+ 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;
@@ -335,8 +370,9 @@ static int mcp4725_probe(struct i2c_client *client,
struct mcp4725_data *data;
struct iio_dev *indio_dev;
struct mcp4725_platform_data *pdata = dev_get_platdata(&client->dev);
- u8 inbuf[3];
+ u8 inbuf[4];
u8 pd;
+ u8 ref;
int err;
if (!pdata) {
@@ -350,6 +386,26 @@ static int mcp4725_probe(struct i2c_client *client,
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
+ data->id = id->driver_data;
+
+ 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))
@@ -359,6 +415,18 @@ static int mcp4725_probe(struct i2c_client *client,
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->vdd_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;
indio_dev->info = &mcp4725_info;
@@ -366,23 +434,38 @@ static int mcp4725_probe(struct i2c_client *client,
indio_dev->num_channels = 1;
indio_dev->modes = INDIO_DIRECT_MODE;
- /* read current DAC value */
- err = i2c_master_recv(client, inbuf, 3);
+ /* read current DAC value and settings */
+ err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
+
if (err < 0) {
dev_err(&client->dev, "failed to read DAC value");
- goto err_disable_vdd_reg;
+ goto err_disable_vref_reg;
}
pd = (inbuf[0] >> 1) & 0x3;
data->powerdown = pd > 0 ? true : false;
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_vdd_reg;
+ goto err_disable_vref_reg;
return 0;
+err_disable_vref_reg:
+ if (data->vref_reg)
+ regulator_disable(data->vref_reg);
err_disable_vdd_reg:
regulator_disable(data->vdd_reg);
@@ -397,6 +480,8 @@ static int mcp4725_remove(struct i2c_client *client)
iio_device_unregister(indio_dev);
+ if (data->vref_reg)
+ regulator_disable(data->vref_reg);
regulator_disable(data->vdd_reg);
return 0;