Re: [PATCH v3] clk: Add PWM clock driver

[Philipp Zabel <p.zabel@pengutronix.de>]

Hi Janusz,

Am Freitag, den 12.12.2014, 09:58 +0100 schrieb Janusz Użycki:
> Hi Philipp,
> 
> It moved .enable to .prepare which can sleep and it works
> without any bug.
> The dirty fix:
>   const struct clk_ops clk_pwm_ops = {
> -       .enable = clk_pwm_enable,
> -       .disable = clk_pwm_disable,
> +       .prepare = clk_pwm_enable,
> +       .unprepare = clk_pwm_disable,
>          .recalc_rate = clk_pwm_recalc_rate,
>   };
> 
> What do you think about?

Thanks! Since the pwm API does not give any guarantees that
pwm_enable/disable may be called from atomic context, I think this
change is correct. The PWM documentation says:

   "Currently the PWM core does not enforce any locking to pwm_enable(),
    pwm_disable() and pwm_config(), so the calling context is currently
    driver specific. This is an issue derived from the former barebone
    API and should be fixed soon."

clk_enable should support reentrancy, but calling clk_prepare_enable
inside a clk_enable callback is not going to work.

regards
Philipp