On Fri, 29 Nov 2019 17:53:14 +0100 Marco Felsch <m.felsch@xxxxxxxxxxxxxx> wrote: > The device is always in a low-power state due to the hardware design. It > wakes up upon a conversion request and goes back into the low-power > state. The pm ops are added to disable the device completely and to free > the regulator. Disbaling the device completely should be not that > notable but freeing the regulator is important. Because if it is a shared > power-rail the regulator won't be disabled during suspend-to-ram/disk > and so all devices connected to that rail keeps on. > > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> Looks fine to me, but I'd like to leave it a little longer for Alex and anyone else who is interested to have time to take a look. Thanks, Jonathan > --- > Hi, > > this v3 contains the comments made on [1]. > > [1] https://www.spinics.net/lists/linux-iio/msg48135.html > > Changelog: > v3: > - add resync error check during resume > > v2: > - squash patch 2 & 3 > - call regulator_disable() unconditional during suspend() > - drop dev_err() messages during suspend > - fix error path within resume() > --- > drivers/iio/adc/ad799x.c | 66 ++++++++++++++++++++++++++++++++++++---- > 1 file changed, 60 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c > index f658012baad8..ef013af1aec0 100644 > --- a/drivers/iio/adc/ad799x.c > +++ b/drivers/iio/adc/ad799x.c > @@ -167,6 +167,21 @@ static int ad799x_read_config(struct ad799x_state *st) > } > } > > +static int ad799x_update_config(struct ad799x_state *st, u16 config) > +{ > + int ret; > + > + ret = ad799x_write_config(st, config); > + if (ret < 0) > + return ret; > + ret = ad799x_read_config(st); > + if (ret < 0) > + return ret; > + st->config = ret; > + > + return 0; > +} > + > /** > * ad799x_trigger_handler() bh of trigger launched polling to ring buffer > * > @@ -808,13 +823,9 @@ static int ad799x_probe(struct i2c_client *client, > indio_dev->channels = st->chip_config->channel; > indio_dev->num_channels = chip_info->num_channels; > > - ret = ad799x_write_config(st, st->chip_config->default_config); > - if (ret < 0) > - goto error_disable_vref; > - ret = ad799x_read_config(st); > - if (ret < 0) > + ret = ad799x_update_config(st, st->chip_config->default_config); > + if (ret) > goto error_disable_vref; > - st->config = ret; > > ret = iio_triggered_buffer_setup(indio_dev, NULL, > &ad799x_trigger_handler, NULL); > @@ -864,6 +875,48 @@ static int ad799x_remove(struct i2c_client *client) > return 0; > } > > +static int __maybe_unused ad799x_suspend(struct device *dev) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); > + struct ad799x_state *st = iio_priv(indio_dev); > + > + regulator_disable(st->vref); > + regulator_disable(st->reg); > + > + return 0; > +} > + > +static int __maybe_unused ad799x_resume(struct device *dev) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); > + struct ad799x_state *st = iio_priv(indio_dev); > + int ret; > + > + ret = regulator_enable(st->reg); > + if (ret) { > + dev_err(dev, "Unable to enable vcc regulator\n"); > + return ret; > + } > + ret = regulator_enable(st->vref); > + if (ret) { > + regulator_disable(st->reg); > + dev_err(dev, "Unable to enable vref regulator\n"); > + return ret; > + } > + > + /* resync config */ > + ret = ad799x_update_config(st, st->config); > + if (ret) { > + regulator_disable(st->vref); > + regulator_disable(st->reg); > + return ret; > + } > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(ad799x_pm_ops, ad799x_suspend, ad799x_resume); > + > static const struct i2c_device_id ad799x_id[] = { > { "ad7991", ad7991 }, > { "ad7995", ad7995 }, > @@ -881,6 +934,7 @@ MODULE_DEVICE_TABLE(i2c, ad799x_id); > static struct i2c_driver ad799x_driver = { > .driver = { > .name = "ad799x", > + .pm = &ad799x_pm_ops, > }, > .probe = ad799x_probe, > .remove = ad799x_remove,
