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charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Em ter., 20 de jul. de 2021 =C3=A0s 04:22, Alexandru Ardelean escreveu: > > On Mon, Jul 19, 2021 at 6:25 PM Th=C3=A9o Bor=C3=A9m Fabris wrote: > > > > Hi, Alexandru. > > > > Em seg., 19 de jul. de 2021 =C3=A0s 04:33, Alexandru Ardelean > > escreveu: > > > > > > On Sun, Jul 18, 2021 at 11:42 PM Th=C3=A9o Bor=C3=A9m Fabris wrote: > > > > > > > > Add a device managed hook, via devm_add_action_or_reset() and > > > > max5821_regulator_disable(), to disable voltage regulator on device > > > > detach. > > > > Replace iio_device_register() by devm_iio_device_register() and rem= ove > > > > the max5821_remove() function used to unregister the device and dis= able the > > > > voltage regulator. > > > > Remove i2c_set_clientdata() from the probe function, since > > > > i2c_get_clientdata() is not used anymore. > > > > > > Looks good overall. > > > A few comments inline. > > > > > > > > > > > Signed-off-by: Th=C3=A9o Bor=C3=A9m Fabris > > > > --- > > > > drivers/iio/dac/max5821.c | 30 ++++++++++++++++-------------- > > > > 1 file changed, 16 insertions(+), 14 deletions(-) > > > > > > > > diff --git a/drivers/iio/dac/max5821.c b/drivers/iio/dac/max5821.c > > > > index bd6e75699a63..44c04ae70b32 100644 > > > > --- a/drivers/iio/dac/max5821.c > > > > +++ b/drivers/iio/dac/max5821.c > > > > @@ -294,6 +294,13 @@ static const struct iio_info max5821_info =3D = { > > > > .write_raw =3D max5821_write_raw, > > > > }; > > > > > > > > +static void max5821_regulator_disable(void *data) > > > > +{ > > > > + struct regulator *rdata =3D data; > > > > + > > > > + regulator_disable(rdata); > > > > > > This can be simplified a bit: > > > > > > static void max5821_regulator_disable(void *reg) > > > { > > > regulator_disable(reg); > > > } > > > > > > I used to do explicit casting, but then I also figured that it's not = necessary. > > > > > Ok. > > > > > > +} > > > > + > > > > static int max5821_probe(struct i2c_client *client, > > > > const struct i2c_device_id *id) > > > > { > > > > @@ -306,7 +313,6 @@ static int max5821_probe(struct i2c_client *cli= ent, > > > > if (!indio_dev) > > > > return -ENOMEM; > > > > data =3D iio_priv(indio_dev); > > > > - i2c_set_clientdata(client, indio_dev); > > > > data->client =3D client; > > > > mutex_init(&data->lock); > > > > > > > > @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *cl= ient, > > > > goto error_free_reg; > > > > } > > > > > > > > + ret =3D devm_add_action_or_reset(&client->dev, max5821_regu= lator_disable, > > > > + data->vref_reg); > > > > + if (ret) { > > > > + dev_err(&client->dev, > > > > + "Failed to add action to managed regulator:= %d\n", ret); > > > > + goto error_disable_reg; > > > > > > return ret; > > > > > > devm_add_action_or_reset() should call max5821_regulator_disable() in > > > case of error > > > > > Ok. > > > > > > + } > > > > + > > > > ret =3D regulator_get_voltage(data->vref_reg); > > > > if (ret < 0) { > > > > dev_err(&client->dev, > > > > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *cli= ent, > > > > indio_dev->modes =3D INDIO_DIRECT_MODE; > > > > indio_dev->info =3D &max5821_info; > > > > > > > > - return iio_device_register(indio_dev); > > > > + return devm_iio_device_register(&client->dev, indio_dev); > > > > > > > > error_disable_reg: > > > > > > This entire goto block should be removed. > > > The idea of using only devm_ functions is to not have these goto stat= ements. > > > > > I thought the action added via devm_add_action (and devres_add) was cal= led only > > on driver detach, thus the error_disable_reg label would be necessary > > to handle the > > devm_add_action() yes > this is devm_add_action_or_reset() which looks like this: > > static inline int devm_add_action_or_reset(struct device *dev, > void (*action)(void *), void *data) > { > int ret; > > ret =3D devm_add_action(dev, action, data); > if (ret) > action(data); > > return ret; > } > > it can be found in "include/linux/device.h" > > > possible error on regulator_get_voltage. Could you please clarify for > > me when does > > a driver detach happen? > > a driver detach happens when: > * the kmod is unloaded (assuming the driver is running as a kmod) > * manually unbinding the driver from sysfs ; > a quick article about this [it's for USB, but other interfaces use > the same mechanism]: > https://lwn.net/Articles/143397/ > there should be something under /sys/bus/spi/drivers/xxxx/unbind > * when the system powers down (reboots) > * maybe there is some other new method to do this [that I don't know abou= t] > Thank you so much. So, should this goto error_disable_reg be replaced by "regulator_disable(.); return ret;"? ret =3D regulator_get_voltage(data->vref_reg); if (ret < 0) { dev_err(&client->dev, "Failed to get voltage on regulator: %d\n", ret); goto error_disable_reg; } > > > > Thanks for your reply, > > Th=C3=A9o > > > > > > regulator_disable(data->vref_reg); > > > > @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *cl= ient, > > > > return ret; > > > > } > > > > > > > > -static int max5821_remove(struct i2c_client *client) > > > > -{ > > > > - struct iio_dev *indio_dev =3D i2c_get_clientdata(client); > > > > - struct max5821_data *data =3D iio_priv(indio_dev); > > > > - > > > > - iio_device_unregister(indio_dev); > > > > - regulator_disable(data->vref_reg); > > > > - > > > > - return 0; > > > > -} > > > > - > > > > static const struct i2c_device_id max5821_id[] =3D { > > > > { "max5821", ID_MAX5821 }, > > > > { } > > > > @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver =3D { > > > > .pm =3D &max5821_pm_ops, > > > > }, > > > > .probe =3D max5821_probe, > > > > - .remove =3D max5821_remove, > > > > .id_table =3D max5821_id, > > > > }; > > > > module_i2c_driver(max5821_driver); > > > > -- > > > > 2.20.1 > > > >