On 04/12/16 02:19, Brian Masney wrote:
> This patch adds power management support to the isl29028 driver.
>
> Signed-off-by: Brian Masney <masneyb@xxxxxxxxxxxxx>
Hmm. I'm not sure why we need the suspended boolean.
I 'think' it's impossible to have a sysfs read in progress during suspend or resume.
At least I hope it is as a lot of drivers will be broken otherwise :(
Looks like this particular corner is only really present in light sensor drivers...
Jonathan
> ---
> drivers/staging/iio/light/isl29028.c | 59 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
>
> diff --git a/drivers/staging/iio/light/isl29028.c b/drivers/staging/iio/light/isl29028.c
> index 4f819a8..e96a8cb 100644
> --- a/drivers/staging/iio/light/isl29028.c
> +++ b/drivers/staging/iio/light/isl29028.c
> @@ -75,6 +75,7 @@ struct isl29028_chip {
>
> int lux_scale;
> enum isl29028_als_ir_mode als_ir_mode;
> + bool suspended;
> };
>
> static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
> @@ -274,6 +275,12 @@ static int isl29028_write_raw(struct iio_dev *indio_dev,
> int ret = -EINVAL;
>
> mutex_lock(&chip->lock);
> +
> + if (chip->suspended) {
> + ret = -EBUSY;
> + goto write_done;
> + }
> +
> switch (chan->type) {
> case IIO_PROXIMITY:
> if (mask != IIO_CHAN_INFO_SAMP_FREQ) {
> @@ -322,6 +329,8 @@ static int isl29028_write_raw(struct iio_dev *indio_dev,
> dev_err(dev, "Unsupported channel type\n");
> break;
> }
> +
> +write_done:
> mutex_unlock(&chip->lock);
> return ret;
> }
> @@ -335,6 +344,12 @@ static int isl29028_read_raw(struct iio_dev *indio_dev,
> int ret = -EINVAL;
>
> mutex_lock(&chip->lock);
> +
> + if (chip->suspended) {
> + ret = -EBUSY;
> + goto read_done;
> + }
> +
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> case IIO_CHAN_INFO_PROCESSED:
> @@ -374,6 +389,8 @@ static int isl29028_read_raw(struct iio_dev *indio_dev,
> dev_err(dev, "mask value 0x%08lx not supported\n", mask);
> break;
> }
> +
> +read_done:
> mutex_unlock(&chip->lock);
> return ret;
> }
> @@ -437,6 +454,9 @@ static int isl29028_chip_init_and_power_on(struct isl29028_chip *chip)
> ret = isl29028_set_als_scale(chip, chip->lux_scale);
> if (ret < 0)
> dev_err(dev, "setting als scale failed, err = %d\n", ret);
> +
> + chip->suspended = false;
> +
> return ret;
> }
>
> @@ -479,6 +499,7 @@ static int isl29028_probe(struct i2c_client *client,
>
> i2c_set_clientdata(client, indio_dev);
> mutex_init(&chip->lock);
> + chip->suspended = true;
>
> chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
> if (IS_ERR(chip->regmap)) {
> @@ -530,6 +551,43 @@ static int isl29028_probe(struct i2c_client *client,
> return 0;
> }
>
> +static int __maybe_unused isl29028_suspend(struct device *dev)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct isl29028_chip *chip = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&chip->lock);
> +
> + ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
> + if (ret < 0)
> + dev_err(dev, "%s(): Error %d turning off chip\n", __func__,
> + ret);
> +
> + chip->suspended = true;
> +
> + mutex_unlock(&chip->lock);
> +
> + return ret;
> +}
> +
> +static int __maybe_unused isl29028_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct isl29028_chip *chip = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&chip->lock);
> +
> + ret = isl29028_chip_init_and_power_on(chip);
> +
> + mutex_unlock(&chip->lock);
> +
> + return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(isl29028_pm_ops, isl29028_suspend, isl29028_resume);
> +
> static const struct i2c_device_id isl29028_id[] = {
> {"isl29028", 0},
> {}
> @@ -546,6 +604,7 @@ MODULE_DEVICE_TABLE(of, isl29028_of_match);
> static struct i2c_driver isl29028_driver = {
> .driver = {
> .name = "isl29028",
> + .pm = &isl29028_pm_ops,
> .of_match_table = isl29028_of_match,
> },
> .probe = isl29028_probe,
>
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