[PATCH 03/12] ARM: normalize clk API for older platforms

Sekhar Nori
2017-07-21T08:05:51Z

Hi Arnd,

On Thursday 20 July 2017 09:20 PM, Arnd Bergmann wrote:
> Six ARM platforms still provide their own variant of the clk API
> rather than using the generic COMMON_CLK API. This generally works,
> but it causes some link errors with drivers using the clk_set_rate,
> clk_get_parent, clk_set_parent or clk_round_rate functions when
> a platform lacks those interfaces.
>
> OMAP1 implements the whole set already, but davinci, ep93xx, mmp,
> sa1100 and w90x900 all lack at least one of the functions.
>
> This adds empty stub implementations for each of them, and I
> don't even try to do something useful here but instead just
> print a WARN() message to make it obvious what is going on
> if they ever end up being called.
>
> The drivers that call these won't be used on these platforms
> (otherwise we'd get a link error today), so the added code is harmless
> bloat and will warn about accidental use.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> arch/arm/mach-davinci/clock.c | 6 ++++++
> arch/arm/mach-ep93xx/clock.c | 21 +++++++++++++++++++++
> arch/arm/mach-mmp/clock.c | 22 ++++++++++++++++++++++
> arch/arm/mach-sa1100/clock.c | 29 +++++++++++++++++++++++++++++
> arch/arm/mach-w90x900/clock.c | 29 +++++++++++++++++++++++++++++
> 5 files changed, 107 insertions(+)
>
> diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
> index f5dce9b4e617..89586779526c 100644
> --- a/arch/arm/mach-davinci/clock.c
> +++ b/arch/arm/mach-davinci/clock.c
> @@ -218,6 +218,12 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
> }
> EXPORT_SYMBOL(clk_set_parent);
>
> +struct clk *clk_get_parent(struct clk *clk)
> +{
> + return clk->parent;
> +}
> +EXPORT_SYMBOL(clk_get_parent);

For mach-davinci change:

Acked-by: Sekhar Nori <nsekhar@ti.com>

> +
> int clk_register(struct clk *clk)
> {
> if (clk == NULL || IS_ERR(clk))
> diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c
> index 39ef3b613912..c1c91fc6e178 100644
> --- a/arch/arm/mach-ep93xx/clock.c
> +++ b/arch/arm/mach-ep93xx/clock.c
> @@ -323,6 +323,27 @@ unsigned long clk_get_rate(struct clk *clk)
> }
> EXPORT_SYMBOL(clk_get_rate);
>
> +long clk_round_rate(struct clk *clk, unsigned long rate)
> +{
> + WARN_ON(clk);
> + return 0;
> +}
> +EXPORT_SYMBOL(clk_round_rate);

Its probably better to WARN_ON_ONCE(). Also, since NULL clk is valid, it
should be probably be WARN_ON_ONCE(1).

Thanks,
Sekhar