On 06/14/2013 04:58 PM, Lars-Peter Clausen wrote:
> Add platform_data for the driver which allows to specify whether an external
> reference voltage is used or not. It is not possible to use the return value of
> regulator_get() for this since the regulator framework is able to return a dummy
> regulator in case no regulator has been specified. In this case the driver will
> always get a valid regulator, no matter if it has been specified or not. Also
> make the regulator non-optional if platform_data states that an external
> reference voltage should be used.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Applied to the togreg branch of iio.git
> ---
> drivers/staging/iio/adc/ad7291.c | 38 +++++++++++++++++++++++---------------
> drivers/staging/iio/adc/ad7291.h | 12 ++++++++++++
> 2 files changed, 35 insertions(+), 15 deletions(-)
> create mode 100644 drivers/staging/iio/adc/ad7291.h
>
> diff --git a/drivers/staging/iio/adc/ad7291.c b/drivers/staging/iio/adc/ad7291.c
> index c2709d6..3fc79e5 100644
> --- a/drivers/staging/iio/adc/ad7291.c
> +++ b/drivers/staging/iio/adc/ad7291.c
> @@ -21,6 +21,8 @@
> #include <linux/iio/sysfs.h>
> #include <linux/iio/events.h>
>
> +#include "ad7291.h"
> +
> /*
> * Simplified handling
> *
> @@ -76,7 +78,6 @@
> struct ad7291_chip_info {
> struct i2c_client *client;
> struct regulator *reg;
> - u16 int_vref_mv;
> u16 command;
> u16 c_mask; /* Active voltage channels for events */
> struct mutex state_lock;
> @@ -445,7 +446,15 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
> case IIO_CHAN_INFO_SCALE:
> switch (chan->type) {
> case IIO_VOLTAGE:
> - *val = chip->int_vref_mv;
> + if (chip->reg) {
> + int vref;
> + vref = regulator_get_voltage(chip->reg);
> + if (vref < 0)
> + return vref;
> + *val = vref / 1000;
> + } else {
> + *val = 2500;
> + }
> *val2 = AD7291_BITS;
> return IIO_VAL_FRACTIONAL_LOG2;
> case IIO_TEMP:
> @@ -513,9 +522,10 @@ static const struct iio_info ad7291_info = {
> static int ad7291_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> + struct ad7291_platform_data *pdata = client->dev.platform_data;
> struct ad7291_chip_info *chip;
> struct iio_dev *indio_dev;
> - int ret = 0, voltage_uv = 0;
> + int ret = 0;
>
> indio_dev = iio_device_alloc(sizeof(*chip));
> if (indio_dev == NULL) {
> @@ -524,12 +534,14 @@ static int ad7291_probe(struct i2c_client *client,
> }
> chip = iio_priv(indio_dev);
>
> - chip->reg = regulator_get(&client->dev, "vcc");
> - if (!IS_ERR(chip->reg)) {
> + if (pdata && pdata->use_external_ref) {
> + chip->reg = regulator_get(&client->dev, "vref");
> + if (IS_ERR(chip->reg))
> + goto error_free;
> +
> ret = regulator_enable(chip->reg);
> if (ret)
> goto error_put_reg;
> - voltage_uv = regulator_get_voltage(chip->reg);
> }
>
> mutex_init(&chip->state_lock);
> @@ -542,12 +554,8 @@ static int ad7291_probe(struct i2c_client *client,
> AD7291_T_SENSE_MASK | /* Tsense always enabled */
> AD7291_ALERT_POLARITY; /* set irq polarity low level */
>
> - if (voltage_uv) {
> - chip->int_vref_mv = voltage_uv / 1000;
> + if (pdata && pdata->use_external_ref)
> chip->command |= AD7291_EXT_REF;
> - } else {
> - chip->int_vref_mv = 2500; /* Build-in ref */
> - }
>
> indio_dev->name = id->name;
> indio_dev->channels = ad7291_channels;
> @@ -590,12 +598,12 @@ error_unreg_irq:
> if (client->irq)
> free_irq(client->irq, indio_dev);
> error_disable_reg:
> - if (!IS_ERR(chip->reg))
> + if (chip->reg)
> regulator_disable(chip->reg);
> error_put_reg:
> - if (!IS_ERR(chip->reg))
> + if (chip->reg)
> regulator_put(chip->reg);
> -
> +error_free:
> iio_device_free(indio_dev);
> error_ret:
> return ret;
> @@ -611,7 +619,7 @@ static int ad7291_remove(struct i2c_client *client)
> if (client->irq)
> free_irq(client->irq, indio_dev);
>
> - if (!IS_ERR(chip->reg)) {
> + if (chip->reg) {
> regulator_disable(chip->reg);
> regulator_put(chip->reg);
> }
> diff --git a/drivers/staging/iio/adc/ad7291.h b/drivers/staging/iio/adc/ad7291.h
> new file mode 100644
> index 0000000..bbd89fa
> --- /dev/null
> +++ b/drivers/staging/iio/adc/ad7291.h
> @@ -0,0 +1,12 @@
> +#ifndef __IIO_AD7291_H__
> +#define __IIO_AD7291_H__
> +
> +/**
> + * struct ad7291_platform_data - AD7291 platform data
> + * @use_external_ref: Whether to use an external or internal reference voltage
> + */
> +struct ad7291_platform_data {
> + bool use_external_ref;
> +};
> +
> +#endif
>
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
