Re: [PATCH v1] clk: Add devm_clk_{prepare,enable,prepare_enable}

Russell King - ARM Linux admin
2019-11-25T13:31:13Z

On Mon, Nov 25, 2019 at 02:16:17PM +0100, Marc Gonzalez wrote:
> On 25/11/2019 13:52, Russell King - ARM Linux admin wrote:
>
> > On Mon, Nov 25, 2019 at 01:46:51PM +0100, Marc Gonzalez wrote:
> >
> >> On 15/07/2019 17:34, Marc Gonzalez wrote:
> >>
> >>> Provide devm variants for automatic resource release on device removal.
> >>> probe() error-handling is simpler, and remove is no longer required.
> >>>
> >>> Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
> >>> ---
> >>> Documentation/driver-model/devres.rst | 3 +++
> >>> drivers/clk/clk.c | 24 ++++++++++++++++++++++++
> >>> include/linux/clk.h | 8 ++++++++
> >>> 3 files changed, 35 insertions(+)
> >>>
> >>> diff --git a/Documentation/driver-model/devres.rst b/Documentation/driver-model/devres.rst
> >>> index 1b6ced8e4294..9357260576ef 100644
> >>> --- a/Documentation/driver-model/devres.rst
> >>> +++ b/Documentation/driver-model/devres.rst
> >>> @@ -253,6 +253,9 @@ CLOCK
> >>> devm_clk_hw_register()
> >>> devm_of_clk_add_hw_provider()
> >>> devm_clk_hw_register_clkdev()
> >>> + devm_clk_prepare()
> >>> + devm_clk_enable()
> >>> + devm_clk_prepare_enable()
> >>>
> >>> DMA
> >>> dmaenginem_async_device_register()
> >>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> >>> index c0990703ce54..5e85548357c0 100644
> >>> --- a/drivers/clk/clk.c
> >>> +++ b/drivers/clk/clk.c
> >>> @@ -914,6 +914,18 @@ int clk_prepare(struct clk *clk)
> >>> }
> >>> EXPORT_SYMBOL_GPL(clk_prepare);
> >>>
> >>> +static void unprepare(void *clk)
> >>> +{
> >>> + clk_unprepare(clk);
> >>> +}
> >>> +
> >>> +int devm_clk_prepare(struct device *dev, struct clk *clk)
> >>> +{
> >>> + int rc = clk_prepare(clk);
> >>> + return rc ? : devm_add_action_or_reset(dev, unprepare, clk);
> >>> +}
> >>> +EXPORT_SYMBOL_GPL(devm_clk_prepare);
> >>> +
> >>> static void clk_core_disable(struct clk_core *core)
> >>> {
> >>> lockdep_assert_held(&enable_lock);
> >>> @@ -1136,6 +1148,18 @@ int clk_enable(struct clk *clk)
> >>> }
> >>> EXPORT_SYMBOL_GPL(clk_enable);
> >>>
> >>> +static void disable(void *clk)
> >>> +{
> >>> + clk_disable(clk);
> >>> +}
> >>> +
> >>> +int devm_clk_enable(struct device *dev, struct clk *clk)
> >>> +{
> >>> + int rc = clk_enable(clk);
> >>> + return rc ? : devm_add_action_or_reset(dev, disable, clk);
> >>> +}
> >>> +EXPORT_SYMBOL_GPL(devm_clk_enable);
> >>> +
> >>> static int clk_core_prepare_enable(struct clk_core *core)
> >>> {
> >>> int ret;
> >>> diff --git a/include/linux/clk.h b/include/linux/clk.h
> >>> index 3c096c7a51dc..d09b5207e3f1 100644
> >>> --- a/include/linux/clk.h
> >>> +++ b/include/linux/clk.h
> >>> @@ -895,6 +895,14 @@ static inline void clk_restore_context(void) {}
> >>>
> >>> #endif
> >>>
> >>> +int devm_clk_prepare(struct device *dev, struct clk *clk);
> >>> +int devm_clk_enable(struct device *dev, struct clk *clk);
> >>> +static inline int devm_clk_prepare_enable(struct device *dev, struct clk *clk)
> >>> +{
> >>> + int rc = devm_clk_prepare(dev, clk);
> >>> + return rc ? : devm_clk_enable(dev, clk);
> >>> +}
> >>> +
> >>> /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
> >>> static inline int clk_prepare_enable(struct clk *clk)
> >>> {
> >>
> >> Thoughts? Comments?
> >
> > These are part of the clk API rather than the CCF API, and belong in
> > drivers/clk/clk-devres.c.
>
> I'm totally confused.
>
> Are you saying that a hypothetical devm_clk_prepare() function should not be
> implemented in the same file as the "raw" clk_prepare() ?

The clk API and CCF are two different things. I look after the clk API.
The CCF is an implementation of the clk API. Do not introduce clk API
code in files that are CCF specific.

--
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