Re: [PATCH v3 6/7] iio: light: al3320a implement suspend support

[Jonathan Cameron <jic23@kernel.org>]

On Sat,  1 Feb 2020 19:00:23 +0100
David Heidelberg <david@ixit.cz> wrote:

> AL3320a is fairly simple chip, so for suspend is enough to disable and
> later enable it again.
> 
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>  drivers/iio/light/al3320a.c | 31 ++++++++++++++++++++++++++-----
>  1 file changed, 26 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/light/al3320a.c b/drivers/iio/light/al3320a.c
> index 613830b7df6e..d99f9d139b5f 100644
> --- a/drivers/iio/light/al3320a.c
> +++ b/drivers/iio/light/al3320a.c
> @@ -7,6 +7,9 @@
>   * IIO driver for AL3320A (7-bit I2C slave address 0x1C).
>   *
>   * TODO: interrupt support, thresholds
> + * When the driver will get support for interrupt handling, then interrupt
> + * will need to be disabled before turning sensor OFF in order to avoid
> + * potential races with the interrupt handling.
>   */
>  
>  #include <linux/module.h>
> @@ -84,13 +87,19 @@ static const struct attribute_group al3320a_attribute_group = {
>  	.attrs = al3320a_attributes,
>  };
>  
> +static int al3320a_set_pwr(struct i2c_client *client, bool pwr)
> +{
> +	u8 val = pwr ? AL3320A_CONFIG_ENABLE : AL3320A_CONFIG_DISABLE;
> +	return i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG, val);
> +}
> +

One blank line is almost always enough.

> +
>  static int al3320a_init(struct al3320a_data *data)
>  {
>  	int ret;
>  
> -	/* power on */
> -	ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG,
> -					AL3320A_CONFIG_ENABLE);
> +	ret = al3320a_set_pwr(data->client, true);
> +
>  	if (ret < 0)
>  		return ret;
>  
> @@ -208,10 +217,21 @@ static int al3320a_probe(struct i2c_client *client,
>  
>  static int al3320a_remove(struct i2c_client *client)
>  {
> -	return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG,
> -					 AL3320A_CONFIG_DISABLE);
> +	return al3320a_set_pwr(client, false);
> +}
> +
> +static int __maybe_unused al3320a_suspend(struct device *dev)
> +{
> +	return al3320a_set_pwr(to_i2c_client(dev), false);
> +}
> +
> +static int __maybe_unused al3320a_resume(struct device *dev)
> +{
> +	return al3320a_set_pwr(to_i2c_client(dev), true);
>  }
>  
> +SIMPLE_DEV_PM_OPS(al3320a_pm_ops, al3320a_suspend, al3320a_resume);
> +
>  static const struct i2c_device_id al3320a_id[] = {
>  	{"al3320a", 0},
>  	{}
> @@ -221,6 +241,7 @@ MODULE_DEVICE_TABLE(i2c, al3320a_id);
>  static struct i2c_driver al3320a_driver = {
>  	.driver = {
>  		.name = AL3320A_DRV_NAME,
> +		.pm = &al3320a_pm_ops,
>  	},
>  	.probe		= al3320a_probe,
>  	.remove		= al3320a_remove,