Hi Jonathan, On Sat, 22 Oct 2016 19:18:06 +0100 Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On 18/10/16 18:43, Tomas Novotny wrote: > > From: Tomas Novotny <tomas@xxxxxxxxxx> > > > > MCP47x6 chip supports selection of a voltage reference (VDD, VREF buffered > > or unbuffered). MCP4725 doesn't have this feature thus the eventual setting > > is ignored and user is warned. > > > > The setting is stored only in the volatile memory of the chip. You need to > > manually store it to the EEPROM of the chip via 'store_eeprom' sysfs entry. > > > > Signed-off-by: Tomas Novotny <tomas@xxxxxxxxxx> > Something odd happened and this patch wouldn't apply without some manual > intervention. > > Please check the result in the testing branch of iio.git. It was a whitespace fix. The result is correct. Thanks for the reviews and for taking this series, Tomas > Thanks, > > Jonathan > > --- > > drivers/iio/dac/mcp4725.c | 97 ++++++++++++++++++++++++++++++++++++++--- > > include/linux/iio/dac/mcp4725.h | 11 +++++ > > 2 files changed, 102 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c > > index e481f38..83d431f 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); > > > > @@ -396,6 +479,8 @@ 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 7c062e8..628b2cf 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_ */ > > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html