Re: [PATCH 2/3] iio: magnetometer: mmc35240: Add PM sleep support

[Jonathan Cameron <jic23@kernel.org>]

On 15/04/15 12:02, Daniel Baluta wrote:
> We rely on regmap to save the state of the registers at suspend,
> and then we do an explicit sync at resume.
> 
> Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
This looks fine to me.
> ---
>  drivers/iio/magnetometer/mmc35240.c | 35 +++++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c
> index c46c1f7..4c76938 100644
> --- a/drivers/iio/magnetometer/mmc35240.c
> +++ b/drivers/iio/magnetometer/mmc35240.c
> @@ -17,6 +17,7 @@
>  #include <linux/i2c.h>
>  #include <linux/delay.h>
>  #include <linux/regmap.h>
> +#include <linux/pm.h>
>  
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> @@ -454,6 +455,39 @@ static int mmc35240_remove(struct i2c_client *client)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int mmc35240_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct mmc35240_data *data = iio_priv(indio_dev);
> +
> +	regcache_cache_only(data->regmap, true);
> +
> +	return 0;
> +}
> +
> +static int mmc35240_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct mmc35240_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	regcache_mark_dirty(data->regmap);
> +	ret = regcache_sync_region(data->regmap, MMC35240_REG_CTRL0,
> +				   MMC35240_REG_CTRL1);
> +	if (ret < 0)
> +		dev_err(dev, "Failed to restore control registers\n");
> +
> +	regcache_cache_only(data->regmap, false);
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops mmc35240_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(mmc35240_suspend, mmc35240_resume)
> +};
> +
>  static const struct i2c_device_id mmc35240_id[] = {
>  	{"MMC35240", 0},
>  	{}
> @@ -463,6 +497,7 @@ MODULE_DEVICE_TABLE(i2c, mmc35240_id);
>  static struct i2c_driver mmc35240_driver = {
>  	.driver = {
>  		.name = MMC35240_DRV_NAME,
> +		.pm = &mmc35240_pm_ops,
>  	},
>  	.probe		= mmc35240_probe,
>  	.remove		= mmc35240_remove,
>