[PATCH v3 1/2] clk: Add consumer APIs for discovering possible parent clocks

[Yuantian Tang]

Hi,

This patch is acked by clock maintainer. If no comments from anyone else, we will merge it in next week.

Thanks,
Yuantian

> -----Original Message-----
> From: Scott Wood [mailto:oss at buserror.net]
> Sent: Thursday, June 16, 2016 2:21 PM
> To: Russell King <linux at armlinux.org.uk>; Michael Turquette
> <mturquette at baylibre.com>; Stephen Boyd <sboyd at codeaurora.org>;
> Viresh Kumar <viresh.kumar at linaro.org>; Rafael J. Wysocki
> <rjw at rjwysocki.net>
> Cc: linux-clk at vger.kernel.org; linux-pm at vger.kernel.org; linuxppc-
> dev at lists.ozlabs.org; Yuantian Tang <yuantian.tang at nxp.com>; Yang-Leo Li
> <leoyang.li at nxp.com>; Xiaofeng Ren <xiaofeng.ren at nxp.com>; Scott Wood
> <scottwood at freescale.com>
> Subject: [PATCH v3 1/2] clk: Add consumer APIs for discovering possible
> parent clocks
> 
> From: Scott Wood <scottwood at freescale.com>
> 
> Commit fc4a05d4b0eb ("clk: Remove unused provider APIs") removed
> __clk_get_num_parents() and clk_hw_get_parent_by_index(), leaving only
> true provider API versions that operate on struct clk_hw.
> 
> qoriq-cpufreq needs these functions in order to determine the options it has
> for calling clk_set_parent() and thus populate the cpufreq table, so revive
> them as legitimate consumer APIs.
> 
> Signed-off-by: Scott Wood <scottwood at freescale.com>
> ---
> v2: Add missing 'static inline' to stub functions.
> 
> v3: no changes
> 
>  drivers/clk/clk.c   | 19 +++++++++++++++++++
>  include/linux/clk.h | 31 +++++++++++++++++++++++++++++++
>  2 files changed, 50 insertions(+)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index d584004..d61a3fe 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -290,6 +290,12 @@ struct clk_hw *__clk_get_hw(struct clk *clk)  }
> EXPORT_SYMBOL_GPL(__clk_get_hw);
> 
> +unsigned int clk_get_num_parents(struct clk *clk) {
> +	return !clk ? 0 : clk->core->num_parents; }
> +EXPORT_SYMBOL_GPL(clk_get_num_parents);
> +
>  unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)  {
>  	return hw->core->num_parents;
> @@ -358,6 +364,19 @@ static struct clk_core
> *clk_core_get_parent_by_index(struct clk_core *core,
>  	return core->parents[index];
>  }
> 
> +struct clk *clk_get_parent_by_index(struct clk *clk, unsigned int
> +index) {
> +	struct clk_core *parent;
> +
> +	if (!clk)
> +		return NULL;
> +
> +	parent = clk_core_get_parent_by_index(clk->core, index);
> +
> +	return !parent ? NULL : parent->hw->clk; }
> +EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
> +
>  struct clk_hw *
>  clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
> { diff --git a/include/linux/clk.h b/include/linux/clk.h index 0df4a51..acd115f
> 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -392,6 +392,26 @@ int clk_set_parent(struct clk *clk, struct clk *parent);
> struct clk *clk_get_parent(struct clk *clk);
> 
>  /**
> + * clk_get_parent_by_index - get a possible parent clock by index
> + * @clk: clock source
> + * @index: index into the array of possible parents of this clock
> + *
> + * Returns struct clk corresponding to the requested possible
> + * parent clock source, or NULL.
> + */
> +struct clk *clk_get_parent_by_index(struct clk *clk,
> +				    unsigned int index);
> +
> +/**
> + * clk_get_num_parents - get number of possible parents
> + * @clk: clock source
> + *
> + * Returns the number of possible parents of this clock,
> + * which can then be enumerated using clk_get_parent_by_index().
> + */
> +unsigned int clk_get_num_parents(struct clk *clk);
> +
> +/**
>   * clk_get_sys - get a clock based upon the device name
>   * @dev_id: device name
>   * @con_id: connection ID
> @@ -461,6 +481,17 @@ static inline struct clk *clk_get_parent(struct clk *clk)
>  	return NULL;
>  }
> 
> +static inline struct clk *clk_get_parent_by_index(struct clk *clk,
> +						  unsigned int index)
> +{
> +	return NULL;
> +}
> +
> +static inline unsigned int clk_get_num_parents(struct clk *clk) {
> +	return 0;
> +}
> +
>  #endif
> 
>  /* clk_prepare_enable helps cases using clk_enable in non-atomic context.
> */
> --
> 2.5.0