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 remove
the max5821_remove() function used to unregister the device and disable the
voltage regulator.
Remove i2c_set_clientdata() from the probe function, since
i2c_get_clientdata() is not used anymore.
Signed-off-by: Théo Borém Fabris <[email protected]>
---
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 = {
.write_raw = max5821_write_raw,
};
+static void max5821_regulator_disable(void *data)
+{
+ struct regulator *rdata = data;
+
+ regulator_disable(rdata);
+}
+
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 *client,
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
- i2c_set_clientdata(client, indio_dev);
data->client = client;
mutex_init(&data->lock);
@@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
goto error_free_reg;
}
+ ret = devm_add_action_or_reset(&client->dev, max5821_regulator_disable,
+ data->vref_reg);
+ if (ret) {
+ dev_err(&client->dev,
+ "Failed to add action to managed regulator: %d\n", ret);
+ goto error_disable_reg;
+ }
+
ret = regulator_get_voltage(data->vref_reg);
if (ret < 0) {
dev_err(&client->dev,
@@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &max5821_info;
- return iio_device_register(indio_dev);
+ return devm_iio_device_register(&client->dev, indio_dev);
error_disable_reg:
regulator_disable(data->vref_reg);
@@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
return ret;
}
-static int max5821_remove(struct i2c_client *client)
-{
- struct iio_dev *indio_dev = i2c_get_clientdata(client);
- struct max5821_data *data = iio_priv(indio_dev);
-
- iio_device_unregister(indio_dev);
- regulator_disable(data->vref_reg);
-
- return 0;
-}
-
static const struct i2c_device_id max5821_id[] = {
{ "max5821", ID_MAX5821 },
{ }
@@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
.pm = &max5821_pm_ops,
},
.probe = max5821_probe,
- .remove = max5821_remove,
.id_table = max5821_id,
};
module_i2c_driver(max5821_driver);
--
2.20.1
On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris <[email protected]> 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 remove
> the max5821_remove() function used to unregister the device and disable 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: Théo Borém Fabris <[email protected]>
> ---
> 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 = {
> .write_raw = max5821_write_raw,
> };
>
> +static void max5821_regulator_disable(void *data)
> +{
> + struct regulator *rdata = 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.
> +}
> +
> 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 *client,
> if (!indio_dev)
> return -ENOMEM;
> data = iio_priv(indio_dev);
> - i2c_set_clientdata(client, indio_dev);
> data->client = client;
> mutex_init(&data->lock);
>
> @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
> goto error_free_reg;
> }
>
> + ret = devm_add_action_or_reset(&client->dev, max5821_regulator_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
> + }
> +
> ret = regulator_get_voltage(data->vref_reg);
> if (ret < 0) {
> dev_err(&client->dev,
> @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &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 statements.
> regulator_disable(data->vref_reg);
> @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
> return ret;
> }
>
> -static int max5821_remove(struct i2c_client *client)
> -{
> - struct iio_dev *indio_dev = i2c_get_clientdata(client);
> - struct max5821_data *data = iio_priv(indio_dev);
> -
> - iio_device_unregister(indio_dev);
> - regulator_disable(data->vref_reg);
> -
> - return 0;
> -}
> -
> static const struct i2c_device_id max5821_id[] = {
> { "max5821", ID_MAX5821 },
> { }
> @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
> .pm = &max5821_pm_ops,
> },
> .probe = max5821_probe,
> - .remove = max5821_remove,
> .id_table = max5821_id,
> };
> module_i2c_driver(max5821_driver);
> --
> 2.20.1
>
Hi, Alexandru.
Em seg., 19 de jul. de 2021 às 04:33, Alexandru Ardelean
<[email protected]> escreveu:
>
> On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris <[email protected]> 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 remove
> > the max5821_remove() function used to unregister the device and disable 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: Théo Borém Fabris <[email protected]>
> > ---
> > 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 = {
> > .write_raw = max5821_write_raw,
> > };
> >
> > +static void max5821_regulator_disable(void *data)
> > +{
> > + struct regulator *rdata = 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 *client,
> > if (!indio_dev)
> > return -ENOMEM;
> > data = iio_priv(indio_dev);
> > - i2c_set_clientdata(client, indio_dev);
> > data->client = client;
> > mutex_init(&data->lock);
> >
> > @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
> > goto error_free_reg;
> > }
> >
> > + ret = devm_add_action_or_reset(&client->dev, max5821_regulator_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 = regulator_get_voltage(data->vref_reg);
> > if (ret < 0) {
> > dev_err(&client->dev,
> > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
> > indio_dev->modes = INDIO_DIRECT_MODE;
> > indio_dev->info = &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 statements.
>
I thought the action added via devm_add_action (and devres_add) was called only
on driver detach, thus the error_disable_reg label would be necessary
to handle the
possible error on regulator_get_voltage. Could you please clarify for
me when does
a driver detach happen?
Thanks for your reply,
Théo
> > regulator_disable(data->vref_reg);
> > @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
> > return ret;
> > }
> >
> > -static int max5821_remove(struct i2c_client *client)
> > -{
> > - struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > - struct max5821_data *data = iio_priv(indio_dev);
> > -
> > - iio_device_unregister(indio_dev);
> > - regulator_disable(data->vref_reg);
> > -
> > - return 0;
> > -}
> > -
> > static const struct i2c_device_id max5821_id[] = {
> > { "max5821", ID_MAX5821 },
> > { }
> > @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
> > .pm = &max5821_pm_ops,
> > },
> > .probe = max5821_probe,
> > - .remove = max5821_remove,
> > .id_table = max5821_id,
> > };
> > module_i2c_driver(max5821_driver);
> > --
> > 2.20.1
> >
On Mon, Jul 19, 2021 at 6:25 PM Théo Borém Fabris <[email protected]> wrote:
>
> Hi, Alexandru.
>
> Em seg., 19 de jul. de 2021 às 04:33, Alexandru Ardelean
> <[email protected]> escreveu:
> >
> > On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris <[email protected]> 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 remove
> > > the max5821_remove() function used to unregister the device and disable 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: Théo Borém Fabris <[email protected]>
> > > ---
> > > 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 = {
> > > .write_raw = max5821_write_raw,
> > > };
> > >
> > > +static void max5821_regulator_disable(void *data)
> > > +{
> > > + struct regulator *rdata = 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 *client,
> > > if (!indio_dev)
> > > return -ENOMEM;
> > > data = iio_priv(indio_dev);
> > > - i2c_set_clientdata(client, indio_dev);
> > > data->client = client;
> > > mutex_init(&data->lock);
> > >
> > > @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
> > > goto error_free_reg;
> > > }
> > >
> > > + ret = devm_add_action_or_reset(&client->dev, max5821_regulator_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 = regulator_get_voltage(data->vref_reg);
> > > if (ret < 0) {
> > > dev_err(&client->dev,
> > > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
> > > indio_dev->modes = INDIO_DIRECT_MODE;
> > > indio_dev->info = &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 statements.
> >
> I thought the action added via devm_add_action (and devres_add) was called 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 = 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 about]
>
> Thanks for your reply,
> Théo
>
> > > regulator_disable(data->vref_reg);
> > > @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
> > > return ret;
> > > }
> > >
> > > -static int max5821_remove(struct i2c_client *client)
> > > -{
> > > - struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > > - struct max5821_data *data = iio_priv(indio_dev);
> > > -
> > > - iio_device_unregister(indio_dev);
> > > - regulator_disable(data->vref_reg);
> > > -
> > > - return 0;
> > > -}
> > > -
> > > static const struct i2c_device_id max5821_id[] = {
> > > { "max5821", ID_MAX5821 },
> > > { }
> > > @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
> > > .pm = &max5821_pm_ops,
> > > },
> > > .probe = max5821_probe,
> > > - .remove = max5821_remove,
> > > .id_table = max5821_id,
> > > };
> > > module_i2c_driver(max5821_driver);
> > > --
> > > 2.20.1
> > >
> From: Alexandru Ardelean <[email protected]>
> Sent: Tuesday, July 20, 2021 9:23 AM
> To: Théo Borém Fabris <[email protected]>
> Cc: Jonathan Cameron <[email protected]>; Lars-Peter Clausen
> <[email protected]>; linux-iio <[email protected]>; LKML
> <[email protected]>
> Subject: Re: [PATCH] iio: dac: max5821: convert device register to
> device managed function
>
> On Mon, Jul 19, 2021 at 6:25 PM Théo Borém Fabris <[email protected]>
> wrote:
> >
> > Hi, Alexandru.
> >
> > Em seg., 19 de jul. de 2021 às 04:33, Alexandru Ardelean
> > <[email protected]> escreveu:
> > >
> > > On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris
> <[email protected]> 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
> remove
> > > > the max5821_remove() function used to unregister the device
> and disable 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: Théo Borém Fabris <[email protected]>
> > > > ---
> > > > 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
> = {
> > > > .write_raw = max5821_write_raw,
> > > > };
> > > >
> > > > +static void max5821_regulator_disable(void *data)
> > > > +{
> > > > + struct regulator *rdata = 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
> *client,
> > > > if (!indio_dev)
> > > > return -ENOMEM;
> > > > data = iio_priv(indio_dev);
> > > > - i2c_set_clientdata(client, indio_dev);
> > > > data->client = client;
> > > > mutex_init(&data->lock);
> > > >
> > > > @@ -331,6 +337,14 @@ static int max5821_probe(struct
> i2c_client *client,
> > > > goto error_free_reg;
> > > > }
> > > >
> > > > + ret = devm_add_action_or_reset(&client->dev,
> max5821_regulator_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 = regulator_get_voltage(data->vref_reg);
> > > > if (ret < 0) {
> > > > dev_err(&client->dev,
> > > > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client
> *client,
> > > > indio_dev->modes = INDIO_DIRECT_MODE;
> > > > indio_dev->info = &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
> statements.
> > >
> > I thought the action added via devm_add_action (and devres_add)
> was called 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 = 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://urldefense.com/v3/__https://lwn.net/Articles/143397/__;!!A
> 3Ni8CS0y2Y!rw-
> qxijVlohZWCG9q_wWFPGASqW7JWcfS48uJSwY8coKiBPoA9Z0G2WSCZ
> clCw$
> 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
> about]
If the device get's deleted with 'device_del()'...
- Nuno Sá
Em ter., 20 de jul. de 2021 às 04:22, Alexandru Ardelean
<[email protected]> escreveu:
>
> On Mon, Jul 19, 2021 at 6:25 PM Théo Borém Fabris <[email protected]> wrote:
> >
> > Hi, Alexandru.
> >
> > Em seg., 19 de jul. de 2021 às 04:33, Alexandru Ardelean
> > <[email protected]> escreveu:
> > >
> > > On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris <[email protected]> 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 remove
> > > > the max5821_remove() function used to unregister the device and disable 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: Théo Borém Fabris <[email protected]>
> > > > ---
> > > > 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 = {
> > > > .write_raw = max5821_write_raw,
> > > > };
> > > >
> > > > +static void max5821_regulator_disable(void *data)
> > > > +{
> > > > + struct regulator *rdata = 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 *client,
> > > > if (!indio_dev)
> > > > return -ENOMEM;
> > > > data = iio_priv(indio_dev);
> > > > - i2c_set_clientdata(client, indio_dev);
> > > > data->client = client;
> > > > mutex_init(&data->lock);
> > > >
> > > > @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
> > > > goto error_free_reg;
> > > > }
> > > >
> > > > + ret = devm_add_action_or_reset(&client->dev, max5821_regulator_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 = regulator_get_voltage(data->vref_reg);
> > > > if (ret < 0) {
> > > > dev_err(&client->dev,
> > > > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
> > > > indio_dev->modes = INDIO_DIRECT_MODE;
> > > > indio_dev->info = &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 statements.
> > >
> > I thought the action added via devm_add_action (and devres_add) was called 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 = 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 about]
>
Thank you so much.
So, should this goto error_disable_reg be replaced by
"regulator_disable(.); return ret;"?
ret = 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,
> > Théo
> >
> > > > regulator_disable(data->vref_reg);
> > > > @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
> > > > return ret;
> > > > }
> > > >
> > > > -static int max5821_remove(struct i2c_client *client)
> > > > -{
> > > > - struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > > > - struct max5821_data *data = iio_priv(indio_dev);
> > > > -
> > > > - iio_device_unregister(indio_dev);
> > > > - regulator_disable(data->vref_reg);
> > > > -
> > > > - return 0;
> > > > -}
> > > > -
> > > > static const struct i2c_device_id max5821_id[] = {
> > > > { "max5821", ID_MAX5821 },
> > > > { }
> > > > @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
> > > > .pm = &max5821_pm_ops,
> > > > },
> > > > .probe = max5821_probe,
> > > > - .remove = max5821_remove,
> > > > .id_table = max5821_id,
> > > > };
> > > > module_i2c_driver(max5821_driver);
> > > > --
> > > > 2.20.1
> > > >
On Wed, Jul 21, 2021 at 3:11 AM Théo Borém Fabris <[email protected]> wrote:
>
> Em ter., 20 de jul. de 2021 às 04:22, Alexandru Ardelean
> <[email protected]> escreveu:
> >
> > On Mon, Jul 19, 2021 at 6:25 PM Théo Borém Fabris <[email protected]> wrote:
> > >
> > > Hi, Alexandru.
> > >
> > > Em seg., 19 de jul. de 2021 às 04:33, Alexandru Ardelean
> > > <[email protected]> escreveu:
> > > >
> > > > On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris <[email protected]> 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 remove
> > > > > the max5821_remove() function used to unregister the device and disable 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: Théo Borém Fabris <[email protected]>
> > > > > ---
> > > > > 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 = {
> > > > > .write_raw = max5821_write_raw,
> > > > > };
> > > > >
> > > > > +static void max5821_regulator_disable(void *data)
> > > > > +{
> > > > > + struct regulator *rdata = 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 *client,
> > > > > if (!indio_dev)
> > > > > return -ENOMEM;
> > > > > data = iio_priv(indio_dev);
> > > > > - i2c_set_clientdata(client, indio_dev);
> > > > > data->client = client;
> > > > > mutex_init(&data->lock);
> > > > >
> > > > > @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
> > > > > goto error_free_reg;
> > > > > }
> > > > >
> > > > > + ret = devm_add_action_or_reset(&client->dev, max5821_regulator_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 = regulator_get_voltage(data->vref_reg);
> > > > > if (ret < 0) {
> > > > > dev_err(&client->dev,
> > > > > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
> > > > > indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > indio_dev->info = &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 statements.
> > > >
> > > I thought the action added via devm_add_action (and devres_add) was called 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 = 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 about]
> >
> Thank you so much.
>
> So, should this goto error_disable_reg be replaced by
> "regulator_disable(.); return ret;"?
> ret = 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;
> }
This is sufficient:
[ No extra regulator_disable() is required; regulator_disable() gets
called via max5821_regulator_disable() on the error path ]
ret = devm_add_action_or_reset(&client->dev, max5821_regulator_disable,
data->vref_reg);
if (ret) {
dev_err(&client->dev,
"Failed to add action to managed regulator: %d\n", ret);
return ret;
}
>
> > >
> > > Thanks for your reply,
> > > Théo
> > >
> > > > > regulator_disable(data->vref_reg);
> > > > > @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
> > > > > return ret;
> > > > > }
> > > > >
> > > > > -static int max5821_remove(struct i2c_client *client)
> > > > > -{
> > > > > - struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > > > > - struct max5821_data *data = iio_priv(indio_dev);
> > > > > -
> > > > > - iio_device_unregister(indio_dev);
> > > > > - regulator_disable(data->vref_reg);
> > > > > -
> > > > > - return 0;
> > > > > -}
> > > > > -
> > > > > static const struct i2c_device_id max5821_id[] = {
> > > > > { "max5821", ID_MAX5821 },
> > > > > { }
> > > > > @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
> > > > > .pm = &max5821_pm_ops,
> > > > > },
> > > > > .probe = max5821_probe,
> > > > > - .remove = max5821_remove,
> > > > > .id_table = max5821_id,
> > > > > };
> > > > > module_i2c_driver(max5821_driver);
> > > > > --
> > > > > 2.20.1
> > > > >
Thank you, Alexandru and Numo, for your help. I have submitted the
second version.
Théo
Em qua., 21 de jul. de 2021 às 04:23, Alexandru Ardelean
<[email protected]> escreveu:
>
> On Wed, Jul 21, 2021 at 3:11 AM Théo Borém Fabris <[email protected]> wrote:
> >
> > Em ter., 20 de jul. de 2021 às 04:22, Alexandru Ardelean
> > <[email protected]> escreveu:
> > >
> > > On Mon, Jul 19, 2021 at 6:25 PM Théo Borém Fabris <[email protected]> wrote:
> > > >
> > > > Hi, Alexandru.
> > > >
> > > > Em seg., 19 de jul. de 2021 às 04:33, Alexandru Ardelean
> > > > <[email protected]> escreveu:
> > > > >
> > > > > On Sun, Jul 18, 2021 at 11:42 PM Théo Borém Fabris <[email protected]> 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 remove
> > > > > > the max5821_remove() function used to unregister the device and disable 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: Théo Borém Fabris <[email protected]>
> > > > > > ---
> > > > > > 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 = {
> > > > > > .write_raw = max5821_write_raw,
> > > > > > };
> > > > > >
> > > > > > +static void max5821_regulator_disable(void *data)
> > > > > > +{
> > > > > > + struct regulator *rdata = 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 *client,
> > > > > > if (!indio_dev)
> > > > > > return -ENOMEM;
> > > > > > data = iio_priv(indio_dev);
> > > > > > - i2c_set_clientdata(client, indio_dev);
> > > > > > data->client = client;
> > > > > > mutex_init(&data->lock);
> > > > > >
> > > > > > @@ -331,6 +337,14 @@ static int max5821_probe(struct i2c_client *client,
> > > > > > goto error_free_reg;
> > > > > > }
> > > > > >
> > > > > > + ret = devm_add_action_or_reset(&client->dev, max5821_regulator_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 = regulator_get_voltage(data->vref_reg);
> > > > > > if (ret < 0) {
> > > > > > dev_err(&client->dev,
> > > > > > @@ -346,7 +360,7 @@ static int max5821_probe(struct i2c_client *client,
> > > > > > indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > > indio_dev->info = &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 statements.
> > > > >
> > > > I thought the action added via devm_add_action (and devres_add) was called 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 = 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 about]
> > >
> > Thank you so much.
> >
> > So, should this goto error_disable_reg be replaced by
> > "regulator_disable(.); return ret;"?
> > ret = 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;
> > }
>
>
> This is sufficient:
> [ No extra regulator_disable() is required; regulator_disable() gets
> called via max5821_regulator_disable() on the error path ]
>
> ret = devm_add_action_or_reset(&client->dev, max5821_regulator_disable,
> data->vref_reg);
> if (ret) {
> dev_err(&client->dev,
> "Failed to add action to managed regulator: %d\n", ret);
> return ret;
> }
>
> >
> > > >
> > > > Thanks for your reply,
> > > > Théo
> > > >
> > > > > > regulator_disable(data->vref_reg);
> > > > > > @@ -356,17 +370,6 @@ static int max5821_probe(struct i2c_client *client,
> > > > > > return ret;
> > > > > > }
> > > > > >
> > > > > > -static int max5821_remove(struct i2c_client *client)
> > > > > > -{
> > > > > > - struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > > > > > - struct max5821_data *data = iio_priv(indio_dev);
> > > > > > -
> > > > > > - iio_device_unregister(indio_dev);
> > > > > > - regulator_disable(data->vref_reg);
> > > > > > -
> > > > > > - return 0;
> > > > > > -}
> > > > > > -
> > > > > > static const struct i2c_device_id max5821_id[] = {
> > > > > > { "max5821", ID_MAX5821 },
> > > > > > { }
> > > > > > @@ -386,7 +389,6 @@ static struct i2c_driver max5821_driver = {
> > > > > > .pm = &max5821_pm_ops,
> > > > > > },
> > > > > > .probe = max5821_probe,
> > > > > > - .remove = max5821_remove,
> > > > > > .id_table = max5821_id,
> > > > > > };
> > > > > > module_i2c_driver(max5821_driver);
> > > > > > --
> > > > > > 2.20.1
> > > > > >