linux-kernel - Re: [PATCH 3/3] clk: qcom: gdsc: Add support to poll CFG register to check GDSC state

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Date:   Mon, 9 Apr 2018 14:11:42 +0530
From:   Taniya Das <tdas@...eaurora.org>
To:     Stephen Boyd <sboyd@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...eaurora.org>
Cc:     Andy Gross <andy.gross@...aro.org>,
        David Brown <david.brown@...aro.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Odelu Kukatla <okukatla@...eaurora.org>,
        Amit Nischal <anischal@...eaurora.org>,
        linux-arm-msm@...r.kernel.org, linux-soc@...r.kernel.org,
        linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] clk: qcom: gdsc: Add support to poll CFG register to
 check GDSC state

Hello Stephen,

Thanks for the review comments.

On 4/6/2018 10:10 PM, Stephen Boyd wrote:
> Quoting Taniya Das (2018-04-02 03:45:45)
>> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
>> index e89584e..e0c83ba 100644
>> --- a/drivers/clk/qcom/gdsc.c
>> +++ b/drivers/clk/qcom/gdsc.c
>> @@ -83,6 +88,38 @@ static int gdsc_poll_status(struct gdsc *sc, unsigned int reg, bool en)
>>          return -ETIMEDOUT;
>>   }
>>
>> +static int gdsc_is_enabled_by_poll_cfg_reg(struct gdsc *sc, bool en)
>> +{
>> +       u32 val;
>> +       int ret;
>> +
>> +       ret = regmap_read(sc->regmap, sc->gdscr + CFG_GDSCR_OFFSET, &val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       if (en)
>> +               return !!(val & GDSC_POWER_UP_COMPLETE);
>> +       else
>> +               return !(val & GDSC_POWER_DOWN_COMPLETE);
> 
> Make this into
> 
> 	if (en)
> 		return ...
> 
> 	return ...
> 

Will fix this in the next series.

>> +}
>> +
>> +static int gdsc_poll_cfg_status(struct gdsc *sc, bool en)
>> +{
>> +       ktime_t start = ktime_get();
>> +       ktime_t timeout =
>> +               (sc->flags & GDS_TIMEOUT) ? TIMEOUT_US_GDS : TIMEOUT_US;
>> +
>> +       do {
>> +               if (gdsc_is_enabled_by_poll_cfg_reg(sc, en) == en)
>> +                       return 0;
>> +       } while (ktime_us_delta(ktime_get(), start) < timeout);
>> +
>> +       if (gdsc_is_enabled_by_poll_cfg_reg(sc, en) == en)
>> +               return 0;
>> +
>> +       return -ETIMEDOUT;
>> +}
>> +
>>   static int gdsc_toggle_logic(struct gdsc *sc, bool en)
>>   {
>>          int ret;
>> @@ -106,6 +143,9 @@ static int gdsc_toggle_logic(struct gdsc *sc, bool en)
>>                  return 0;
>>          }
>>
>> +       if (sc->flags & POLL_CFG_GDSCR)
>> +               return gdsc_poll_cfg_status(sc, en);
>> +
>>          if (sc->gds_hw_ctrl) {
>>                  status_reg = sc->gds_hw_ctrl;
>>                  /*
>> @@ -258,8 +298,12 @@ static int gdsc_disable(struct generic_pm_domain *domain)
>>                   */
>>                  udelay(1);
>>
>> -               reg = sc->gds_hw_ctrl ? sc->gds_hw_ctrl : sc->gdscr;
>> -               ret = gdsc_poll_status(sc, reg, true);
>> +               if (sc->flags & POLL_CFG_GDSCR) {
>> +                       ret = gdsc_poll_cfg_status(sc, true);
>> +               } else {
>> +                       reg = sc->gds_hw_ctrl ? sc->gds_hw_ctrl : sc->gdscr;
>> +                       ret = gdsc_poll_status(sc, reg, true);
>> +               }
> 
> Maybe this can be pushed into the gdsc_poll_status() function so that
> we can keep the "how do we poll status bit" logic in one place.
> 

Yes, I will push the logic in the gdsc_poll_status() in the next series.

>>                  if (ret)
>>                          return ret;
>>          }

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