Subject: [PATCH 16/20] iio: pressure-core: st: Provide support for the Vdd power supply

From: [email-masked] (Jonathan Cameron)
Date: Sat, 21 Sep 2013 14:03:04 +0100

On 09/16/13 17:02, Lee Jones wrote:
> The power to some of the sensors are controlled by regulators. In most
> cases these are 'always on', but if not they will fail to work until
> the regulator is enabled using the relevant APIs. This patch allows for
> the Vdd power supply to be specified by either platform data or Device
> Tree.
> 
> Signed-off-by: Lee Jones <[email-masked]>

I haven't yet pulled 3.12-rc1 into my togreg branch.  To keep things
clean I'll do a pull request to Greg soon then apply these afterwards
(when a fast forward merge is possible).

> ---
>  drivers/iio/pressure/st_pressure_core.c | 28 ++++++++++++++++++++++++++++
>  include/linux/iio/common/st_sensors.h   |  3 +++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/drivers/iio/pressure/st_pressure_core.c b/drivers/iio/pressure/st_pressure_core.c
> index e879542..c801c80 100644
> --- a/drivers/iio/pressure/st_pressure_core.c
> +++ b/drivers/iio/pressure/st_pressure_core.c
> @@ -23,6 +23,7 @@
>  #include <linux/iio/sysfs.h>
>  #include <linux/iio/trigger.h>
>  #include <linux/iio/buffer.h>
> +#include <linux/regulator/consumer.h>
>  #include <asm/unaligned.h>
>  
>  #include <linux/iio/common/st_sensors.h>
> @@ -313,6 +314,29 @@ static const struct iio_trigger_ops st_press_trigger_ops = {
>  #define ST_PRESS_TRIGGER_OPS NULL
>  #endif
>  
> +void st_press_power_enable(struct iio_dev *indio_dev)
> +{
> +	struct st_sensor_data *pdata = iio_priv(indio_dev);
> +	int err;
> +
> +	/* Regulators not mandatory, but if requested we should enable it. */
> +	pdata->vdd = devm_regulator_get_optional(&indio_dev->dev, "vdd");
> +	if (!IS_ERR(pdata->vdd)) {
> +		err = regulator_enable(pdata->vdd);
> +		if (err != 0)
> +			dev_warn(&indio_dev->dev,
> +				 "Failed to enable specified Vdd supply\n");
> +	}
> +}
> +
> +void st_press_power_disable(struct iio_dev *indio_dev)
> +{
> +	struct st_sensor_data *pdata = iio_priv(indio_dev);
> +
> +	if (!IS_ERR(pdata->vdd))
> +		regulator_disable(pdata->vdd);
> +}
> +
>  int st_press_common_probe(struct iio_dev *indio_dev,
>  				struct st_sensors_platform_data *plat_data)
>  {
> @@ -323,6 +347,8 @@ int st_press_common_probe(struct iio_dev *indio_dev,
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->info = &press_info;
>  
> +	st_press_power_enable(indio_dev);
> +
>  	err = st_sensors_check_device_support(indio_dev,
>  					      ARRAY_SIZE(st_press_sensors),
>  					      st_press_sensors);
> @@ -381,6 +407,8 @@ void st_press_common_remove(struct iio_dev *indio_dev)
>  {
>  	struct st_sensor_data *pdata = iio_priv(indio_dev);
>  
> +	st_press_power_disable(indio_dev);
> +
>  	iio_device_unregister(indio_dev);
>  	if (pdata->get_irq_data_ready(indio_dev) > 0) {
>  		st_sensors_deallocate_trigger(indio_dev);
> diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h
> index e732fda..968b84e 100644
> --- a/include/linux/iio/common/st_sensors.h
> +++ b/include/linux/iio/common/st_sensors.h
> @@ -16,6 +16,7 @@
>  #include <linux/irqreturn.h>
>  #include <linux/iio/trigger.h>
>  #include <linux/bitops.h>
> +#include <linux/regulator/consumer.h>
>  
>  #include <linux/platform_data/st_sensors_pdata.h>
>  
> @@ -201,6 +202,7 @@ struct st_sensors {
>   * @trig: The trigger in use by the core driver.
>   * @sensor: Pointer to the current sensor struct in use.
>   * @current_fullscale: Maximum range of measure by the sensor.
> + * @vdd: Pointer to sensor's Vdd power supply
>   * @enabled: Status of the sensor (false->off, true->on).
>   * @multiread_bit: Use or not particular bit for [I2C/SPI] multiread.
>   * @buffer_data: Data used by buffer part.
> @@ -216,6 +218,7 @@ struct st_sensor_data {
>  	struct iio_trigger *trig;
>  	struct st_sensors *sensor;
>  	struct st_sensor_fullscale_avl *current_fullscale;
> +	struct regulator *vdd;
>  
>  	bool enabled;
>  	bool multiread_bit;
>