[PATCH 04/10] clk: implement parent pass through functions

Uwe Kleine-König
2011-04-18T09:25:04Z

On Fri, Apr 15, 2011 at 09:08:09PM +0200, Sascha Hauer wrote:
> A common case for clocks is that certain operations are not implemented
> and shall be passed through to the parent. Add convenience functions
> for this purpose
>
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
> ---
> drivers/clk/clk.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/clk.h | 9 ++++++
> 2 files changed, 86 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 264c809..7e2c182 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -171,3 +171,80 @@ struct clk_ops clk_fixed_ops = {
> .get_rate = clk_fixed_get_rate,
> };
> EXPORT_SYMBOL_GPL(clk_fixed_ops);
> +
> +int clk_parent_prepare(struct clk *clk)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return -ENOSYS;
> +
> + return clk_prepare(parent);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_prepare);
> +
> +void clk_parent_unprepare(struct clk *clk)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return;
> +
> + clk_unprepare(parent);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_unprepare);
> +
> +int clk_parent_enable(struct clk *clk)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return 0;
Do you really want to return 0 here? IMHO something is fishy if a clock
has .enable = clk_parent_enable but has no parent.

> +
> + return clk_enable(parent);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_enable);
> +
> +void clk_parent_disable(struct clk *clk)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return;
> +
> + clk_disable(parent);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_disable);
> +
> +unsigned long clk_parent_get_rate(struct clk *clk)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return 0;
> +
> + return clk_get_rate(parent);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_get_rate);
> +
> +long clk_parent_round_rate(struct clk *clk, unsigned long rate)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return -ENOSYS;
> +
> + return clk_round_rate(parent, rate);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_round_rate);
> +
> +int clk_parent_set_rate(struct clk *clk, unsigned long rate)
> +{
> + struct clk *parent = clk_get_parent(clk);
> +
> + if (IS_ERR(parent))
> + return -ENOSYS;
> +
> + return clk_set_rate(parent, rate);
> +}
> +EXPORT_SYMBOL_GPL(clk_parent_set_rate);
> diff --git a/include/linux/clk.h b/include/linux/clk.h
> index d2f0db0..d014341 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -171,6 +171,15 @@ extern struct clk_ops clk_fixed_ops;
> #define DEFINE_CLK_FIXED(name, r) \
> struct clk_fixed name = INIT_CLK_FIXED(name, r)
>
> +/* generic pass-through-to-parent functions */
> +int clk_parent_prepare(struct clk *clk);
> +void clk_parent_unprepare(struct clk *clk);
> +int clk_parent_enable(struct clk *clk);
> +void clk_parent_disable(struct clk *clk);
> +unsigned long clk_parent_get_rate(struct clk *clk);
> +long clk_parent_round_rate(struct clk *clk, unsigned long rate);
> +int clk_parent_set_rate(struct clk *clk, unsigned long rate);
> +
Technically they don't need to depend on USE_COMMON_STRUCT_CLK.

> #else /* !CONFIG_USE_COMMON_STRUCT_CLK */
>
> /*
> --
> 1.7.4.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | http://www.pengutronix.de/ |