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Message-ID: <20170207035151.GA18296@dtor-ws>
Date: Mon, 6 Feb 2017 19:51:51 -0800
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Stephen Boyd <sboyd@...eaurora.org>
Cc: Russell King - ARM Linux <linux@...linux.org.uk>,
Guenter Roeck <linux@...ck-us.net>,
Michael Turquette <mturquette@...libre.com>,
Viresh Kumar <viresh.kumar@...aro.org>,
Andy Shevchenko <andy.shevchenko@...il.com>,
linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] clk: add more managed APIs
On Mon, Jan 30, 2017 at 04:57:13PM -0800, Dmitry Torokhov wrote:
> When converting a driver to managed resources it is desirable to be able to
> manage all resources in the same fashion. This change allows managing clock
> prepared and enabled state in the same way we manage many other resources.
>
> This adds the following managed APIs:
>
> - devm_clk_prepare()/devm_clk_unprepare();
> - devm_clk_prepare_enable()/devm_clk_disable_unprepare().
>
> Reviewed-by: Guenter Roeck <linux@...ck-us.net>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
It would be awesome if we could get it into 4.11...
> ---
>
> v3: adjusted commit message, added Guenter's reviewed-by
> v2: dropped devm_clk_enable() and devm_clk_disable()
>
> drivers/clk/clk-devres.c | 98 +++++++++++++++++++++++++++++++---------------
> include/linux/clk.h | 68 ++++++++++++++++++++++++++++++++
> 2 files changed, 134 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
> index 3a218c3a06ae..2ff94ffe11d3 100644
> --- a/drivers/clk/clk-devres.c
> +++ b/drivers/clk/clk-devres.c
> @@ -9,30 +9,20 @@
> #include <linux/export.h>
> #include <linux/gfp.h>
>
> -static void devm_clk_release(struct device *dev, void *res)
> +static int devm_clk_create_devres(struct device *dev, struct clk *clk,
> + void (*release)(struct device *, void *))
> {
> - clk_put(*(struct clk **)res);
> -}
> + struct clk **ptr;
>
> -struct clk *devm_clk_get(struct device *dev, const char *id)
> -{
> - struct clk **ptr, *clk;
> -
> - ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
> + ptr = devres_alloc(release, sizeof(*ptr), GFP_KERNEL);
> if (!ptr)
> - return ERR_PTR(-ENOMEM);
> + return -ENOMEM;
>
> - clk = clk_get(dev, id);
> - if (!IS_ERR(clk)) {
> - *ptr = clk;
> - devres_add(dev, ptr);
> - } else {
> - devres_free(ptr);
> - }
> + *ptr = clk;
> + devres_add(dev, ptr);
>
> - return clk;
> + return 0;
> }
> -EXPORT_SYMBOL(devm_clk_get);
>
> static int devm_clk_match(struct device *dev, void *res, void *data)
> {
> @@ -44,31 +34,75 @@ static int devm_clk_match(struct device *dev, void *res, void *data)
> return *c == data;
> }
>
> -void devm_clk_put(struct device *dev, struct clk *clk)
> +#define DEFINE_DEVM_CLK_DESTROY_OP(destroy_op) \
> +static void devm_##destroy_op##_release(struct device *dev, void *res) \
> +{ \
> + destroy_op(*(struct clk **)res); \
> +} \
> + \
> +void devm_##destroy_op(struct device *dev, struct clk *clk) \
> +{ \
> + WARN_ON(devres_release(dev, devm_##destroy_op##_release, \
> + devm_clk_match, clk)); \
> +} \
> +EXPORT_SYMBOL(devm_##destroy_op)
> +
> +#define DEFINE_DEVM_CLK_OP(create_op, destroy_op) \
> +DEFINE_DEVM_CLK_DESTROY_OP(destroy_op); \
> +int devm_##create_op(struct device *dev, struct clk *clk) \
> +{ \
> + int error; \
> + \
> + error = create_op(clk); \
> + if (error) \
> + return error; \
> + \
> + error = devm_clk_create_devres(dev, clk, \
> + devm_##destroy_op##_release); \
> + if (error) { \
> + destroy_op(clk); \
> + return error; \
> + } \
> + \
> + return 0; \
> +} \
> +EXPORT_SYMBOL(devm_##create_op)
> +
> +DEFINE_DEVM_CLK_DESTROY_OP(clk_put);
> +DEFINE_DEVM_CLK_OP(clk_prepare, clk_unprepare);
> +DEFINE_DEVM_CLK_OP(clk_prepare_enable, clk_disable_unprepare);
> +
> +struct clk *devm_clk_get(struct device *dev, const char *id)
> {
> - int ret;
> + struct clk *clk;
> + int error;
>
> - ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
> + clk = clk_get(dev, id);
> + if (!IS_ERR(clk)) {
> + error = devm_clk_create_devres(dev, clk, devm_clk_put_release);
> + if (error) {
> + clk_put(clk);
> + return ERR_PTR(error);
> + }
> + }
>
> - WARN_ON(ret);
> + return clk;
> }
> -EXPORT_SYMBOL(devm_clk_put);
> +EXPORT_SYMBOL(devm_clk_get);
>
> struct clk *devm_get_clk_from_child(struct device *dev,
> struct device_node *np, const char *con_id)
> {
> - struct clk **ptr, *clk;
> -
> - ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
> - if (!ptr)
> - return ERR_PTR(-ENOMEM);
> + struct clk *clk;
> + int error;
>
> clk = of_clk_get_by_name(np, con_id);
> if (!IS_ERR(clk)) {
> - *ptr = clk;
> - devres_add(dev, ptr);
> - } else {
> - devres_free(ptr);
> + error = devm_clk_create_devres(dev, clk, devm_clk_put_release);
> + if (error) {
> + clk_put(clk);
> + return ERR_PTR(error);
> + }
> }
>
> return clk;
> diff --git a/include/linux/clk.h b/include/linux/clk.h
> index e9d36b3e49de..413dc8f636bd 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -267,6 +267,29 @@ struct clk *devm_get_clk_from_child(struct device *dev,
> struct device_node *np, const char *con_id);
>
> /**
> + * devm_clk_prepare - prepare clock source as a managed resource
> + * @dev: device owning the resource
> + * @clk: clock source
> + *
> + * This prepares the clock source for use.
> + *
> + * Must not be called from within atomic context.
> + */
> +int devm_clk_prepare(struct device *dev, struct clk *clk);
> +
> +/**
> + * devm_clk_unprepare - undo preparation of a managed clock source
> + * @dev: device used to prepare the clock
> + * @clk: clock source
> + *
> + * This undoes preparation of a clock, previously prepared with a call
> + * to devm_clk_pepare().
> + *
> + * Must not be called from within atomic context.
> + */
> +void devm_clk_unprepare(struct device *dev, struct clk *clk);
> +
> +/**
> * clk_enable - inform the system when the clock source should be running.
> * @clk: clock source
> *
> @@ -295,6 +318,28 @@ int clk_enable(struct clk *clk);
> void clk_disable(struct clk *clk);
>
> /**
> + * devm_clk_prepare_enable - prepare and enable a managed clock source
> + * @dev: device owning the clock source
> + * @clk: clock source
> + *
> + * This prepares the clock source for use and enables it.
> + *
> + * Must not be called from within atomic context.
> + */
> +int devm_clk_prepare_enable(struct device *dev, struct clk *clk);
> +
> +/**
> + * devm_clk_disable_unprepare - disable and undo preparation of a managed clock
> + * @dev: device used to prepare and enable the clock
> + * @clk: clock source
> + *
> + * This disables and undoes a previously prepared clock.
> + *
> + * Must not be called from within atomic context.
> + */
> +void devm_clk_disable_unprepare(struct device *dev, struct clk *clk);
> +
> +/**
> * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
> * This is only valid once the clock source has been enabled.
> * @clk: clock source
> @@ -460,6 +505,17 @@ static inline void clk_put(struct clk *clk) {}
>
> static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
>
> +static inline int devm_clk_prepare(struct device *dev, struct clk *clk)
> +{
> + might_sleep();
> + return 0;
> +}
> +
> +static inline void devm_clk_unprepare(struct device *dev, struct clk *clk)
> +{
> + might_sleep();
> +}
> +
> static inline int clk_enable(struct clk *clk)
> {
> return 0;
> @@ -467,6 +523,18 @@ static inline int clk_enable(struct clk *clk)
>
> static inline void clk_disable(struct clk *clk) {}
>
> +static inline int devm_clk_prepare_enable(struct device *dev, struct clk *clk)
> +{
> + might_sleep();
> + return 0;
> +}
> +
> +static inline void devm_clk_disable_unprepare(struct device *dev,
> + struct clk *clk)
> +{
> + might_sleep();
> +}
> +
> static inline unsigned long clk_get_rate(struct clk *clk)
> {
> return 0;
--
Dmitry
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