Re: [PATCH 3/5] clk: qcom: gdsc: Add support to control associated clks

[Stanimir Varbanov <stanimir.varbanov@linaro.org>]

Hi Rajendra,

Thanks for the patches!

On 03/21/2017 08:15 AM, Rajendra Nayak wrote:
> The devices within a gdsc power domain, quite often have additional
> clocks to be turned on/off along with the power domain itself.
> Add support for this by specifying a list of clk_hw pointers
> per gdsc which would be the clocks turned on/off along with the
> powerdomain on/off callbacks.
> 
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> ---
>  drivers/clk/qcom/gdsc.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++--
>  drivers/clk/qcom/gdsc.h |  8 ++++++++
>  2 files changed, 54 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
> index a4f3580..e9e7442 100644
> --- a/drivers/clk/qcom/gdsc.c
> +++ b/drivers/clk/qcom/gdsc.c
> @@ -12,15 +12,19 @@
>   */
>  
>  #include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <linux/jiffies.h>
>  #include <linux/kernel.h>
>  #include <linux/ktime.h>
> +#include <linux/pm_clock.h>

this is not needed

>  #include <linux/pm_domain.h>
>  #include <linux/regmap.h>
>  #include <linux/reset-controller.h>
>  #include <linux/slab.h>
> +#include "common.h"
>  #include "gdsc.h"
>  
>  #define PWR_ON_MASK		BIT(31)
> @@ -166,6 +170,27 @@ static inline void gdsc_assert_clamp_io(struct gdsc *sc)
>  			   GMEM_CLAMP_IO_MASK, 1);
>  }
>  
> +static int gdsc_clk_enable(struct gdsc *sc)
> +{
> +	int i, ret;
> +
> +	for (i = 0; i < sc->clk_count; i++) {
> +		ret = clk_prepare_enable(sc->clks[i]);
> +		if (ret)
> +			pr_err("Failed to enable clock: %s\n",
> +			       __clk_get_name(sc->clks[i]));
		
I think the error message can be removed. And the already enabled clocks
should be disabled on error.

> +	}
> +	return ret;
> +}
> +
> +static void gdsc_clk_disable(struct gdsc *sc)
> +{
> +	int i;
> +
> +	for (i = 0; i < sc->clk_count; i++)
> +		clk_disable_unprepare(sc->clks[i]);
> +}
> +
>  static int gdsc_enable(struct generic_pm_domain *domain)
>  {
>  	struct gdsc *sc = domain_to_gdsc(domain);
> @@ -193,6 +218,9 @@ static int gdsc_enable(struct generic_pm_domain *domain)
>  	 */
>  	udelay(1);
>  
> +	if (sc->clk_count)
> +		gdsc_clk_enable(sc);

could you add error handling.

> +
>  	/* Turn on HW trigger mode if supported */
>  	if (sc->flags & HW_CTRL) {
>  		ret = gdsc_hwctrl(sc, true);
> @@ -241,6 +269,9 @@ static int gdsc_disable(struct generic_pm_domain *domain)
>  			return ret;
>  	}
>  
> +	if (sc->clk_count)
> +		gdsc_clk_disable(sc);

IMO sc->clk_count check could be moved in gdsc_clk_disable. This is also
valid for all clk_count checks.

> +
>  	if (sc->pwrsts & PWRSTS_OFF)
>  		gdsc_clear_mem_on(sc);
>  
> @@ -254,7 +285,7 @@ static int gdsc_disable(struct generic_pm_domain *domain)
>  	return 0;
>  }
>  
> -static int gdsc_init(struct gdsc *sc)
> +static int gdsc_init(struct device *dev, struct gdsc *sc)
>  {
>  	u32 mask, val;
>  	int on, ret;
> @@ -284,6 +315,19 @@ static int gdsc_init(struct gdsc *sc)
>  	if (on < 0)
>  		return on;
>  
> +	if (sc->clk_count) {
> +		int i;
> +
> +		sc->clks = devm_kcalloc(dev, sc->clk_count, sizeof(*sc->clks),
> +					GFP_KERNEL);
> +		if (!sc->clks)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < sc->clk_count; i++)
> +			sc->clks[i] = devm_clk_hw_get_clk(dev, sc->clk_hws[i],
> +							  NULL);

error handling?

Also I think it will be more readable if you above chunk in separate
function like gdsc_clk_get and call it unconditionally?

> +	}
> +

<snip>

-- 
regards,
Stan