Up until now optional functions in the reset API were similar to the non
optional.
This patch corrects that, while maintaining compatibility with existing
drivers.
As suggested here: https://lkml.org/lkml/2016/12/14/502
Signed-off-by: Ramiro Oliveira <[email protected]>
---
drivers/reset/core.c | 21 +++++++++++++++++++--
include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 61 insertions(+), 6 deletions(-)
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 395dc9c..6150e7c 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -135,9 +135,14 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
* @rstc: reset controller
*
* Calling this on a shared reset controller is an error.
+ *
+ * If it's an optional reset it will return 0.
*/
int reset_control_reset(struct reset_control *rstc)
{
+ if (!rstc)
+ return 0;
+
if (WARN_ON(rstc->shared))
return -EINVAL;
@@ -158,9 +163,14 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
*
* For shared reset controls a driver cannot expect the hw's registers and
* internal state to be reset, but must be prepared for this to happen.
+ *
+ * If it's an optional reset it will return 0.
*/
int reset_control_assert(struct reset_control *rstc)
{
+ if (!rstc)
+ return 0;
+
if (!rstc->rcdev->ops->assert)
return -ENOTSUPP;
@@ -180,10 +190,14 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
* reset_control_deassert - deasserts the reset line
* @rstc: reset controller
*
- * After calling this function, the reset is guaranteed to be deasserted.
+ * After calling this function, the reset is guaranteed to be deasserted, if
+ * it's not optional.
*/
int reset_control_deassert(struct reset_control *rstc)
{
+ if (!rstc)
+ return 0;
+
if (!rstc->rcdev->ops->deassert)
return -ENOTSUPP;
@@ -199,11 +213,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
/**
* reset_control_status - returns a negative errno if not supported, a
* positive value if the reset line is asserted, or zero if the reset
- * line is not asserted.
+ * line is not asserted or if the desc is NULL (optional reset).
* @rstc: reset controller
*/
int reset_control_status(struct reset_control *rstc)
{
+ if (!rstc)
+ return 0;
+
if (rstc->rcdev->ops->status)
return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 5daff15..1af1e62 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -138,13 +138,33 @@ static inline struct reset_control *reset_control_get_shared(
static inline struct reset_control *reset_control_get_optional_exclusive(
struct device *dev, const char *id)
{
- return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
+ struct reset_control *desc;
+
+ desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
+
+ if (IS_ERR(desc)) {
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ }
+
+ return desc;
+
}
static inline struct reset_control *reset_control_get_optional_shared(
struct device *dev, const char *id)
{
- return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
+
+ struct reset_control *desc;
+
+ desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
+
+ if (IS_ERR(desc)) {
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ }
+
+ return desc;
}
/**
@@ -273,13 +293,31 @@ static inline struct reset_control *devm_reset_control_get_shared(
static inline struct reset_control *devm_reset_control_get_optional_exclusive(
struct device *dev, const char *id)
{
- return __devm_reset_control_get(dev, id, 0, 0);
+ struct reset_control *desc;
+
+ desc = __devm_reset_control_get(dev, id, 0, 0);
+
+ if (IS_ERR(desc)) {
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ }
+
+ return desc;
}
static inline struct reset_control *devm_reset_control_get_optional_shared(
struct device *dev, const char *id)
{
- return __devm_reset_control_get(dev, id, 0, 1);
+ struct reset_control *desc;
+
+ desc = __devm_reset_control_get(dev, id, 0, 1);
+
+ if (IS_ERR(desc)) {
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ }
+
+ return desc;
}
/**
--
2.10.2
Hi Ramiro,
Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
> Up until now optional functions in the reset API were similar to the non
> optional.
>
> This patch corrects that, while maintaining compatibility with existing
> drivers.
>
> As suggested here: https://lkml.org/lkml/2016/12/14/502
>
> Signed-off-by: Ramiro Oliveira <[email protected]>
> ---
> drivers/reset/core.c | 21 +++++++++++++++++++--
> include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++++++----
> 2 files changed, 61 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 395dc9c..6150e7c 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -135,9 +135,14 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
> * @rstc: reset controller
> *
> * Calling this on a shared reset controller is an error.
> + *
> + * If it's an optional reset it will return 0.
I'd prefer this to explicitly mention that rstc==NULL means this is an
optional reset:
"If rstc is NULL it is an optional reset and the function will just
return 0."
> */
> int reset_control_reset(struct reset_control *rstc)
> {
> + if (!rstc)
> + return 0;
> +
> if (WARN_ON(rstc->shared))
> return -EINVAL;
>
> @@ -158,9 +163,14 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
> *
> * For shared reset controls a driver cannot expect the hw's registers and
> * internal state to be reset, but must be prepared for this to happen.
> + *
> + * If it's an optional reset it will return 0.
Same as above.
> */
> int reset_control_assert(struct reset_control *rstc)
> {
> + if (!rstc)
> + return 0;
> +
> if (!rstc->rcdev->ops->assert)
> return -ENOTSUPP;
>
> @@ -180,10 +190,14 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
> * reset_control_deassert - deasserts the reset line
> * @rstc: reset controller
> *
> - * After calling this function, the reset is guaranteed to be deasserted.
> + * After calling this function, the reset is guaranteed to be deasserted, if
> + * it's not optional.
Same as above.
> */
> int reset_control_deassert(struct reset_control *rstc)
> {
> + if (!rstc)
> + return 0;
> +
> if (!rstc->rcdev->ops->deassert)
> return -ENOTSUPP;
>
> @@ -199,11 +213,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
> /**
> * reset_control_status - returns a negative errno if not supported, a
> * positive value if the reset line is asserted, or zero if the reset
> - * line is not asserted.
> + * line is not asserted or if the desc is NULL (optional reset).
> * @rstc: reset controller
> */
> int reset_control_status(struct reset_control *rstc)
> {
> + if (!rstc)
> + return 0;
> +
> if (rstc->rcdev->ops->status)
> return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
>
> diff --git a/include/linux/reset.h b/include/linux/reset.h
> index 5daff15..1af1e62 100644
> --- a/include/linux/reset.h
> +++ b/include/linux/reset.h
> @@ -138,13 +138,33 @@ static inline struct reset_control *reset_control_get_shared(
> static inline struct reset_control *reset_control_get_optional_exclusive(
> struct device *dev, const char *id)
> {
> - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
> + struct reset_control *desc;
> +
> + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
Note that the __of_reset_control_get stub returns -ENOTSUPP if
CONFIG_RESET_CONTROLLER is disabled.
> + if (IS_ERR(desc)) {
> + if (PTR_ERR(desc) == -ENOENT)
> + return NULL;
> + }
> +
> + return desc;
> +
> }
>
> static inline struct reset_control *reset_control_get_optional_shared(
> struct device *dev, const char *id)
> {
> - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
> +
> + struct reset_control *desc;
> +
> + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
> +
> + if (IS_ERR(desc)) {
> + if (PTR_ERR(desc) == -ENOENT)
> + return NULL;
> + }
With this duplication, I think it might be better to add an int optional
parameter to __of_reset_control_get and let that return NULL if optional
is set and either of_property_match_string or of_parse_phandle_with_args
would cause an -ENOENT return.
The stub could then
return optional ? NULL : ERR_PTR(-EONOENT);
> + return desc;
> }
>
> /**
> @@ -273,13 +293,31 @@ static inline struct reset_control *devm_reset_control_get_shared(
> static inline struct reset_control *devm_reset_control_get_optional_exclusive(
> struct device *dev, const char *id)
> {
> - return __devm_reset_control_get(dev, id, 0, 0);
> + struct reset_control *desc;
> +
> + desc = __devm_reset_control_get(dev, id, 0, 0);
> +
> + if (IS_ERR(desc)) {
> + if (PTR_ERR(desc) == -ENOENT)
> + return NULL;
> + }
Same as for __of_reset_control_get above.
> + return desc;
> }
>
> static inline struct reset_control *devm_reset_control_get_optional_shared(
> struct device *dev, const char *id)
> {
> - return __devm_reset_control_get(dev, id, 0, 1);
> + struct reset_control *desc;
> +
> + desc = __devm_reset_control_get(dev, id, 0, 1);
> +
> + if (IS_ERR(desc)) {
> + if (PTR_ERR(desc) == -ENOENT)
> + return NULL;
> + }
> +
> + return desc;
> }
>
> /**
regards
Philipp
Hello,
On Friday 23 Dec 2016 11:58:57 Philipp Zabel wrote:
> Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
> > Up until now optional functions in the reset API were similar to the non
> > optional.
> >
> > This patch corrects that, while maintaining compatibility with existing
> > drivers.
> >
> > As suggested here: https://lkml.org/lkml/2016/12/14/502
> >
> > Signed-off-by: Ramiro Oliveira <[email protected]>
> > ---
> >
> > drivers/reset/core.c | 21 +++++++++++++++++++--
> > include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++++++----
> > 2 files changed, 61 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> > index 395dc9c..6150e7c 100644
> > --- a/drivers/reset/core.c
> > +++ b/drivers/reset/core.c
> > @@ -135,9 +135,14 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
> > * @rstc: reset controller
> > *
> > * Calling this on a shared reset controller is an error.
> > + *
> > + * If it's an optional reset it will return 0.
>
> I'd prefer this to explicitly mention that rstc==NULL means this is an
> optional reset:
>
> "If rstc is NULL it is an optional reset and the function will just
> return 0."
Maybe we should document in a single place that NULL is a valid value for a
reset_control pointer and will result in the API behaving as a no-op ? If you
want to duplicate the information I'd still prefer talking about no-op than
about "just returning 0".
> > */
> > int reset_control_reset(struct reset_control *rstc)
> > {
> > + if (!rstc)
> > + return 0;
> > +
> > if (WARN_ON(rstc->shared))
> > return -EINVAL;
> >
> > @@ -158,9 +163,14 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
> > *
> > * For shared reset controls a driver cannot expect the hw's registers
> > and
> > * internal state to be reset, but must be prepared for this to happen.
> > + *
> > + * If it's an optional reset it will return 0.
>
> Same as above.
>
> > */
> >
> > int reset_control_assert(struct reset_control *rstc)
> > {
> > + if (!rstc)
> > + return 0;
> > +
> > if (!rstc->rcdev->ops->assert)
> > return -ENOTSUPP;
> >
> > @@ -180,10 +190,14 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
> > * reset_control_deassert - deasserts the reset line
> > * @rstc: reset controller
> > *
> > - * After calling this function, the reset is guaranteed to be deasserted.
> > + * After calling this function, the reset is guaranteed to be deasserted,
> > if
> > + * it's not optional.
>
> Same as above.
>
> > */
> > int reset_control_deassert(struct reset_control *rstc)
> > {
> > + if (!rstc)
> > + return 0;
> > +
> > if (!rstc->rcdev->ops->deassert)
> > return -ENOTSUPP;
> >
> > @@ -199,11 +213,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
> > /**
> > * reset_control_status - returns a negative errno if not supported, a
> > * positive value if the reset line is asserted, or zero if the reset
> > - * line is not asserted.
> > + * line is not asserted or if the desc is NULL (optional reset).
> > * @rstc: reset controller
> > */
> > int reset_control_status(struct reset_control *rstc)
> > {
> > + if (!rstc)
> > + return 0;
> > +
> > if (rstc->rcdev->ops->status)
> > return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
> >
> > diff --git a/include/linux/reset.h b/include/linux/reset.h
> > index 5daff15..1af1e62 100644
> > --- a/include/linux/reset.h
> > +++ b/include/linux/reset.h
> > @@ -138,13 +138,33 @@ static inline struct reset_control
> > *reset_control_get_shared(>
> > static inline struct reset_control *reset_control_get_optional_exclusive(
> > struct device *dev, const char *id)
> > {
> > - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
> > + struct reset_control *desc;
> > +
> > + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
>
> Note that the __of_reset_control_get stub returns -ENOTSUPP if
> CONFIG_RESET_CONTROLLER is disabled.
>
> > + if (IS_ERR(desc)) {
> > + if (PTR_ERR(desc) == -ENOENT)
> > + return NULL;
> > + }
> > +
> > + return desc;
> > +
> > }
> >
> > static inline struct reset_control *reset_control_get_optional_shared(
> > struct device *dev, const char *id)
> > {
> > - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
> > +
> > + struct reset_control *desc;
> > +
> > + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
> > +
> > + if (IS_ERR(desc)) {
> > + if (PTR_ERR(desc) == -ENOENT)
> > + return NULL;
> > + }
>
> With this duplication, I think it might be better to add an int optional
> parameter
What's wrong with bool by the way ? :-)
> to __of_reset_control_get and let that return NULL if optional
> is set and either of_property_match_string or of_parse_phandle_with_args
> would cause an -ENOENT return.
>
> The stub could then
> return optional ? NULL : ERR_PTR(-EONOENT);
>
> > + return desc;
> > }
> >
> > /**
> > @@ -273,13 +293,31 @@ static inline struct reset_control
> > *devm_reset_control_get_shared(
> > static inline struct reset_control
> > *devm_reset_control_get_optional_exclusive(
> > struct device *dev, const char *id)
> > {
> > - return __devm_reset_control_get(dev, id, 0, 0);
> > + struct reset_control *desc;
> > +
> > + desc = __devm_reset_control_get(dev, id, 0, 0);
> > +
> > + if (IS_ERR(desc)) {
> > + if (PTR_ERR(desc) == -ENOENT)
> > + return NULL;
> > + }
>
> Same as for __of_reset_control_get above.
>
> > + return desc;
> > }
> >
> > static inline struct reset_control
> > *devm_reset_control_get_optional_shared(
> > struct device *dev, const char *id)
> > {
> > - return __devm_reset_control_get(dev, id, 0, 1);
> > + struct reset_control *desc;
> > +
> > + desc = __devm_reset_control_get(dev, id, 0, 1);
> > +
> > + if (IS_ERR(desc)) {
> > + if (PTR_ERR(desc) == -ENOENT)
> > + return NULL;
> > + }
> > +
> > + return desc;
> > }
> >
> > /**
--
Regards,
Laurent Pinchart
Hi Laurent,
Am Freitag, den 23.12.2016, 13:23 +0200 schrieb Laurent Pinchart:
> Hello,
>
> On Friday 23 Dec 2016 11:58:57 Philipp Zabel wrote:
> > Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
> > > Up until now optional functions in the reset API were similar to the non
> > > optional.
> > >
> > > This patch corrects that, while maintaining compatibility with existing
> > > drivers.
> > >
> > > As suggested here: https://lkml.org/lkml/2016/12/14/502
> > >
> > > Signed-off-by: Ramiro Oliveira <[email protected]>
> > > ---
> > >
> > > drivers/reset/core.c | 21 +++++++++++++++++++--
> > > include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++++++----
> > > 2 files changed, 61 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> > > index 395dc9c..6150e7c 100644
> > > --- a/drivers/reset/core.c
> > > +++ b/drivers/reset/core.c
> > > @@ -135,9 +135,14 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
> > > * @rstc: reset controller
> > > *
> > > * Calling this on a shared reset controller is an error.
> > > + *
> > > + * If it's an optional reset it will return 0.
> >
> > I'd prefer this to explicitly mention that rstc==NULL means this is an
> > optional reset:
> >
> > "If rstc is NULL it is an optional reset and the function will just
> > return 0."
>
> Maybe we should document in a single place that NULL is a valid value for a
> reset_control pointer and will result in the API behaving as a no-op ? If you
> want to duplicate the information I'd still prefer talking about no-op than
> about "just returning 0".
Does "no-op" implicate the return value 0? Maybe there is a better way
to express "no action, returns 0".
Currently there is no central place for this information, and as long as
the text not much longer than a reference to the central location would
be, I'm fine with duplication.
> > > */
> > > int reset_control_reset(struct reset_control *rstc)
> > > {
> > > + if (!rstc)
> > > + return 0;
> > > +
> > > if (WARN_ON(rstc->shared))
> > > return -EINVAL;
> > >
> > > @@ -158,9 +163,14 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
> > > *
> > > * For shared reset controls a driver cannot expect the hw's registers
> > > and
> > > * internal state to be reset, but must be prepared for this to happen.
> > > + *
> > > + * If it's an optional reset it will return 0.
> >
> > Same as above.
> >
> > > */
> > >
> > > int reset_control_assert(struct reset_control *rstc)
> > > {
> > > + if (!rstc)
> > > + return 0;
> > > +
> > > if (!rstc->rcdev->ops->assert)
> > > return -ENOTSUPP;
> > >
> > > @@ -180,10 +190,14 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
> > > * reset_control_deassert - deasserts the reset line
> > > * @rstc: reset controller
> > > *
> > > - * After calling this function, the reset is guaranteed to be deasserted.
> > > + * After calling this function, the reset is guaranteed to be deasserted,
> > > if
> > > + * it's not optional.
> >
> > Same as above.
> >
> > > */
> > > int reset_control_deassert(struct reset_control *rstc)
> > > {
> > > + if (!rstc)
> > > + return 0;
> > > +
> > > if (!rstc->rcdev->ops->deassert)
> > > return -ENOTSUPP;
> > >
> > > @@ -199,11 +213,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
> > > /**
> > > * reset_control_status - returns a negative errno if not supported, a
> > > * positive value if the reset line is asserted, or zero if the reset
> > > - * line is not asserted.
> > > + * line is not asserted or if the desc is NULL (optional reset).
> > > * @rstc: reset controller
> > > */
> > > int reset_control_status(struct reset_control *rstc)
> > > {
> > > + if (!rstc)
> > > + return 0;
> > > +
> > > if (rstc->rcdev->ops->status)
> > > return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
> > >
> > > diff --git a/include/linux/reset.h b/include/linux/reset.h
> > > index 5daff15..1af1e62 100644
> > > --- a/include/linux/reset.h
> > > +++ b/include/linux/reset.h
> > > @@ -138,13 +138,33 @@ static inline struct reset_control
> > > *reset_control_get_shared(>
> > > static inline struct reset_control *reset_control_get_optional_exclusive(
> > > struct device *dev, const char *id)
> > > {
> > > - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
> > > + struct reset_control *desc;
> > > +
> > > + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
> >
> > Note that the __of_reset_control_get stub returns -ENOTSUPP if
> > CONFIG_RESET_CONTROLLER is disabled.
> >
> > > + if (IS_ERR(desc)) {
> > > + if (PTR_ERR(desc) == -ENOENT)
> > > + return NULL;
> > > + }
> > > +
> > > + return desc;
> > > +
> > > }
> > >
> > > static inline struct reset_control *reset_control_get_optional_shared(
> > > struct device *dev, const char *id)
> > > {
> > > - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
> > > +
> > > + struct reset_control *desc;
> > > +
> > > + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
> > > +
> > > + if (IS_ERR(desc)) {
> > > + if (PTR_ERR(desc) == -ENOENT)
> > > + return NULL;
> > > + }
> >
> > With this duplication, I think it might be better to add an int optional
> > parameter
>
> What's wrong with bool by the way ? :-)
Nothing wrong, it's just that the "exclusive" parameter is already int.
I'd be perfectly fine with using bool for both.
regards
Philipp
Hi Philipp,
On Friday 23 Dec 2016 13:08:54 Philipp Zabel wrote:
> Am Freitag, den 23.12.2016, 13:23 +0200 schrieb Laurent Pinchart:
> > On Friday 23 Dec 2016 11:58:57 Philipp Zabel wrote:
> >> Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
> >>> Up until now optional functions in the reset API were similar to the
> >>> non optional.
> >>>
> >>> This patch corrects that, while maintaining compatibility with
> >>> existing drivers.
> >>>
> >>> As suggested here: https://lkml.org/lkml/2016/12/14/502
> >>>
> >>> Signed-off-by: Ramiro Oliveira <[email protected]>
> >>> ---
> >>>
> >>> drivers/reset/core.c | 21 +++++++++++++++++++--
> >>> include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++----
> >>> 2 files changed, 61 insertions(+), 6 deletions(-)
> >>>
> >>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> >>> index 395dc9c..6150e7c 100644
> >>> --- a/drivers/reset/core.c
> >>> +++ b/drivers/reset/core.c
> >>> @@ -135,9 +135,14 @@
> >>> EXPORT_SYMBOL_GPL(devm_reset_controller_register);
> >>> * @rstc: reset controller
> >>> *
> >>> * Calling this on a shared reset controller is an error.
> >>> + *
> >>> + * If it's an optional reset it will return 0.
> >>
> >> I'd prefer this to explicitly mention that rstc==NULL means this is an
> >> optional reset:
> >>
> >> "If rstc is NULL it is an optional reset and the function will just
> >> return 0."
> >
> > Maybe we should document in a single place that NULL is a valid value for
> > a reset_control pointer and will result in the API behaving as a no-op ?
> > If you want to duplicate the information I'd still prefer talking about
> > no-op than about "just returning 0".
>
> Does "no-op" implicate the return value 0? Maybe there is a better way
> to express "no action, returns 0".
The important point in my opinion is that a NULL argument will result in the
function performing no operation and indicating success exactly like a call
with a non-NULL pointer would. The proposed text makes it sound like a 0
return value is specific to the NULL argument case. This is a detail though.
> Currently there is no central place for this information, and as long as
> the text not much longer than a reference to the central location would
> be, I'm fine with duplication.
>
> >>> */
> >>> int reset_control_reset(struct reset_control *rstc)
> >>> {
> >>> + if (!rstc)
> >>> + return 0;
> >>> +
> >>> if (WARN_ON(rstc->shared))
> >>> return -EINVAL;
--
Regards,
Laurent Pinchart
Hi Laurent and Philipp
On 12/23/2016 4:41 PM, Laurent Pinchart wrote:
> Hi Philipp,
>
> On Friday 23 Dec 2016 13:08:54 Philipp Zabel wrote:
>> Am Freitag, den 23.12.2016, 13:23 +0200 schrieb Laurent Pinchart:
>>> On Friday 23 Dec 2016 11:58:57 Philipp Zabel wrote:
>>>> Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
>>>>> Up until now optional functions in the reset API were similar to the
>>>>> non optional.
>>>>>
>>>>> This patch corrects that, while maintaining compatibility with
>>>>> existing drivers.
>>>>>
>>>>> As suggested here: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2016_12_14_502&d=DgICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=BHEb-RADEOm-lgrwdN4zqtr2BWZMjeocyTkjphE6PrA&m=8s4unvlk7rXGYKdQcMBxpYLmdnROh5aQ_iHU03InFoM&s=oNBgTOo47LBs0JvtJ5Qd_6uVqrcMkWAq1PmNN4qt16g&e=
>>>>>
>>>>> Signed-off-by: Ramiro Oliveira <[email protected]>
>>>>> ---
>>>>>
>>>>> drivers/reset/core.c | 21 +++++++++++++++++++--
>>>>> include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++----
>>>>> 2 files changed, 61 insertions(+), 6 deletions(-)
>>>>>
>>>>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
>>>>> index 395dc9c..6150e7c 100644
>>>>> --- a/drivers/reset/core.c
>>>>> +++ b/drivers/reset/core.c
>>>>> @@ -135,9 +135,14 @@
>>>>> EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>>>>> * @rstc: reset controller
>>>>> *
>>>>> * Calling this on a shared reset controller is an error.
>>>>> + *
>>>>> + * If it's an optional reset it will return 0.
>>>>
>>>> I'd prefer this to explicitly mention that rstc==NULL means this is an
>>>> optional reset:
>>>>
>>>> "If rstc is NULL it is an optional reset and the function will just
>>>> return 0."
>>>
>>> Maybe we should document in a single place that NULL is a valid value for
>>> a reset_control pointer and will result in the API behaving as a no-op ?
>>> If you want to duplicate the information I'd still prefer talking about
>>> no-op than about "just returning 0".
>>
>> Does "no-op" implicate the return value 0? Maybe there is a better way
>> to express "no action, returns 0".
>
> The important point in my opinion is that a NULL argument will result in the
> function performing no operation and indicating success exactly like a call
> with a non-NULL pointer would. The proposed text makes it sound like a 0
> return value is specific to the NULL argument case. This is a detail though.
>
"If rstc is NULL it is an optional reset and the function will just return 0
like any other successful call."
Do you guys think the above message is more explicit?
>> Currently there is no central place for this information, and as long as
>> the text not much longer than a reference to the central location would
>> be, I'm fine with duplication.
>>
>>>>> */
>>>>> int reset_control_reset(struct reset_control *rstc)
>>>>> {
>>>>> + if (!rstc)
>>>>> + return 0;
>>>>> +
>>>>> if (WARN_ON(rstc->shared))
>>>>> return -EINVAL;
>
Hi Philipp
On 12/23/2016 12:08 PM, Philipp Zabel wrote:
> Hi Laurent,
>
> Am Freitag, den 23.12.2016, 13:23 +0200 schrieb Laurent Pinchart:
>> Hello,
>>
>> On Friday 23 Dec 2016 11:58:57 Philipp Zabel wrote:
>>> Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
>>>> Up until now optional functions in the reset API were similar to the non
>>>> optional.
>>>>
>>>> This patch corrects that, while maintaining compatibility with existing
>>>> drivers.
>>>>
>>>> As suggested here: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2016_12_14_502&d=DgICaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=BHEb-RADEOm-lgrwdN4zqtr2BWZMjeocyTkjphE6PrA&m=_0T0di-X6zgDw8ZRLDNk2ExL2EieBiCmAmuxc8OGAg4&s=H5BfD4P5MB85jtyUjDrn6yKu-6ws5srNWNNiFpPL0pQ&e=
>>>>
>>>> Signed-off-by: Ramiro Oliveira <[email protected]>
>>>> ---
>>>>
>>>> drivers/reset/core.c | 21 +++++++++++++++++++--
>>>> include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++++++----
>>>> 2 files changed, 61 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
>>>> index 395dc9c..6150e7c 100644
>>>> --- a/drivers/reset/core.c
>>>> +++ b/drivers/reset/core.c
>>>> @@ -135,9 +135,14 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>>>> * @rstc: reset controller
>>>> *
>>>> * Calling this on a shared reset controller is an error.
>>>> + *
>>>> + * If it's an optional reset it will return 0.
>>>
>>> I'd prefer this to explicitly mention that rstc==NULL means this is an
>>> optional reset:
>>>
>>> "If rstc is NULL it is an optional reset and the function will just
>>> return 0."
>>
>> Maybe we should document in a single place that NULL is a valid value for a
>> reset_control pointer and will result in the API behaving as a no-op ? If you
>> want to duplicate the information I'd still prefer talking about no-op than
>> about "just returning 0".
>
> Does "no-op" implicate the return value 0? Maybe there is a better way
> to express "no action, returns 0".
>
> Currently there is no central place for this information, and as long as
> the text not much longer than a reference to the central location would
> be, I'm fine with duplication.
>
>>>> */
>>>> int reset_control_reset(struct reset_control *rstc)
>>>> {
>>>> + if (!rstc)
>>>> + return 0;
>>>> +
>>>> if (WARN_ON(rstc->shared))
>>>> return -EINVAL;
>>>>
>>>> @@ -158,9 +163,14 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
>>>> *
>>>> * For shared reset controls a driver cannot expect the hw's registers
>>>> and
>>>> * internal state to be reset, but must be prepared for this to happen.
>>>> + *
>>>> + * If it's an optional reset it will return 0.
>>>
>>> Same as above.
>>>
>>>> */
>>>>
>>>> int reset_control_assert(struct reset_control *rstc)
>>>> {
>>>> + if (!rstc)
>>>> + return 0;
>>>> +
>>>> if (!rstc->rcdev->ops->assert)
>>>> return -ENOTSUPP;
>>>>
>>>> @@ -180,10 +190,14 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
>>>> * reset_control_deassert - deasserts the reset line
>>>> * @rstc: reset controller
>>>> *
>>>> - * After calling this function, the reset is guaranteed to be deasserted.
>>>> + * After calling this function, the reset is guaranteed to be deasserted,
>>>> if
>>>> + * it's not optional.
>>>
>>> Same as above.
>>>
>>>> */
>>>> int reset_control_deassert(struct reset_control *rstc)
>>>> {
>>>> + if (!rstc)
>>>> + return 0;
>>>> +
>>>> if (!rstc->rcdev->ops->deassert)
>>>> return -ENOTSUPP;
>>>>
>>>> @@ -199,11 +213,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
>>>> /**
>>>> * reset_control_status - returns a negative errno if not supported, a
>>>> * positive value if the reset line is asserted, or zero if the reset
>>>> - * line is not asserted.
>>>> + * line is not asserted or if the desc is NULL (optional reset).
>>>> * @rstc: reset controller
>>>> */
>>>> int reset_control_status(struct reset_control *rstc)
>>>> {
>>>> + if (!rstc)
>>>> + return 0;
>>>> +
>>>> if (rstc->rcdev->ops->status)
>>>> return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
>>>>
>>>> diff --git a/include/linux/reset.h b/include/linux/reset.h
>>>> index 5daff15..1af1e62 100644
>>>> --- a/include/linux/reset.h
>>>> +++ b/include/linux/reset.h
>>>> @@ -138,13 +138,33 @@ static inline struct reset_control
>>>> *reset_control_get_shared(>
>>>> static inline struct reset_control *reset_control_get_optional_exclusive(
>>>> struct device *dev, const char *id)
>>>> {
>>>> - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
>>>> + struct reset_control *desc;
>>>> +
>>>> + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
>>>
>>> Note that the __of_reset_control_get stub returns -ENOTSUPP if
>>> CONFIG_RESET_CONTROLLER is disabled.
>>>
>>>> + if (IS_ERR(desc)) {
>>>> + if (PTR_ERR(desc) == -ENOENT)
>>>> + return NULL;
>>>> + }
>>>> +
>>>> + return desc;
>>>> +
>>>> }
>>>>
>>>> static inline struct reset_control *reset_control_get_optional_shared(
>>>> struct device *dev, const char *id)
>>>> {
>>>> - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
>>>> +
>>>> + struct reset_control *desc;
>>>> +
>>>> + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
>>>> +
>>>> + if (IS_ERR(desc)) {
>>>> + if (PTR_ERR(desc) == -ENOENT)
>>>> + return NULL;
>>>> + }
>>>
>>> With this duplication, I think it might be better to add an int optional
>>> parameter
>>
>> What's wrong with bool by the way ? :-)
>
> Nothing wrong, it's just that the "exclusive" parameter is already int.
> I'd be perfectly fine with using bool for both.
>
Do you prefer me to keep them both int, or change them to bool?
BRs,
Ramiro
Hi Ramiro,
On Friday 23 Dec 2016 17:19:43 Ramiro Oliveira wrote:
> On 12/23/2016 12:08 PM, Philipp Zabel wrote:
> > Am Freitag, den 23.12.2016, 13:23 +0200 schrieb Laurent Pinchart:
> >> On Friday 23 Dec 2016 11:58:57 Philipp Zabel wrote:
> >>> Am Donnerstag, den 15.12.2016, 18:05 +0000 schrieb Ramiro Oliveira:
> >>>> Up until now optional functions in the reset API were similar to the
> >>>> non
> >>>> optional.
> >>>>
> >>>> This patch corrects that, while maintaining compatibility with existing
> >>>> drivers.
> >>>>
> >>>> As suggested here:
> >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_201
> >>>> 6_12_14_502&d=DgICaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=BHEb-RADEOm-lgrwdN4zqtr
> >>>> 2BWZMjeocyTkjphE6PrA&m=_0T0di-X6zgDw8ZRLDNk2ExL2EieBiCmAmuxc8OGAg4&s=H5
> >>>> BfD4P5MB85jtyUjDrn6yKu-6ws5srNWNNiFpPL0pQ&e=
> >>>>
> >>>> Signed-off-by: Ramiro Oliveira <[email protected]>
> >>>> ---
> >>>>
> >>>> drivers/reset/core.c | 21 +++++++++++++++++++--
> >>>> include/linux/reset.h | 46 +++++++++++++++++++++++++++++++++++++++----
> >>>> 2 files changed, 61 insertions(+), 6 deletions(-)
> >>>>
> >>>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> >>>> index 395dc9c..6150e7c 100644
> >>>> --- a/drivers/reset/core.c
> >>>> +++ b/drivers/reset/core.c
[snip]
> >>>> static inline struct reset_control *reset_control_get_optional_shared(
> >>>> struct device *dev, const char
> >>>> *id)
> >>>> {
> >>>> - return __of_reset_control_get(dev ? dev->of_node : NULL, id,
> >>>> 0, 1);
> >>>> +
> >>>> + struct reset_control *desc;
> >>>> +
> >>>> + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id,
> >>>> 0, 1);
> >>>> +
> >>>> + if (IS_ERR(desc)) {
> >>>> + if (PTR_ERR(desc) == -ENOENT)
> >>>> + return NULL;
> >>>> + }
> >>>
> >>> With this duplication, I think it might be better to add an int optional
> >>> parameter
> >>
> >> What's wrong with bool by the way ? :-)
> >
> > Nothing wrong, it's just that the "exclusive" parameter is already int.
> > I'd be perfectly fine with using bool for both.
>
> Do you prefer me to keep them both int, or change them to bool?
I'd prefer bool myself, it's slightly more explicit.
--
Regards,
Laurent Pinchart