diff options
| -rw-r--r-- | drivers/iio/dac/mcp4725.c | 99 | ||||
| -rw-r--r-- | include/linux/iio/dac/mcp4725.h | 11 |
2 files changed, 103 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; diff --git a/include/linux/iio/dac/mcp4725.h b/include/linux/iio/dac/mcp4725.h index 7c062e8d2a48..628b2cf54c50 100644 --- a/include/linux/iio/dac/mcp4725.h +++ b/include/linux/iio/dac/mcp4725.h @@ -9,7 +9,18 @@ #ifndef IIO_DAC_MCP4725_H_ #define IIO_DAC_MCP4725_H_ +/** + * struct mcp4725_platform_data - MCP4725/6 DAC specific data. + * @use_vref: Whether an external reference voltage on Vref pin should be used. + * Additional vref-supply must be specified when used. + * @vref_buffered: Controls buffering of the external reference voltage. + * + * Vref related settings are available only on MCP4756. See + * Documentation/devicetree/bindings/iio/dac/mcp4725.txt for more information. + */ struct mcp4725_platform_data { + bool use_vref; + bool vref_buffered; }; #endif /* IIO_DAC_MCP4725_H_ */ |