linux-kernel - Re: [PATCH 1/3] clk: qcom: gdsc: add collapse-bit helper

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Date:   Fri, 20 May 2022 14:50:17 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Johan Hovold <johan+linaro@...nel.org>
Cc:     Bjorn Andersson <bjorn.andersson@...aro.org>,
        Andy Gross <agross@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, linux-arm-msm@...r.kernel.org,
        linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] clk: qcom: gdsc: add collapse-bit helper

On Fri, 20 May 2022 at 13:10, Johan Hovold <johan+linaro@...nel.org> wrote:
>
> Add a helper for updating the SW_COLLAPSE bit during initialisation and
> state updates.
>


> Note that the update during initialisation was relying on the
> SW_COLLAPSE bit not having been set earlier rather than passing in zero
> explicitly to clear the collapse vote.

I think this part deserves a separate commit with proper Fixes: tag.

>
> Signed-off-by: Johan Hovold <johan+linaro@...nel.org>
> ---
>  drivers/clk/qcom/gdsc.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
> index 44520efc6c72..c676416e685f 100644
> --- a/drivers/clk/qcom/gdsc.c
> +++ b/drivers/clk/qcom/gdsc.c
> @@ -132,10 +132,24 @@ static int gdsc_poll_status(struct gdsc *sc, enum gdsc_status status)
>         return -ETIMEDOUT;
>  }
>
> +static int gdsc_update_collapse_bit(struct gdsc *sc, bool val)
> +{
> +       u32 reg, mask;
> +       int ret;
> +
> +       reg = sc->gdscr;
> +       mask = SW_COLLAPSE_MASK;
> +
> +       ret = regmap_update_bits(sc->regmap, reg, mask, val ? mask : 0);
> +       if (ret)
> +               return ret;
> +
> +       return 0;
> +}
> +
>  static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
>  {
>         int ret;
> -       u32 val = (status == GDSC_ON) ? 0 : SW_COLLAPSE_MASK;
>
>         if (status == GDSC_ON && sc->rsupply) {
>                 ret = regulator_enable(sc->rsupply);
> @@ -143,9 +157,7 @@ static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
>                         return ret;
>         }
>
> -       ret = regmap_update_bits(sc->regmap, sc->gdscr, SW_COLLAPSE_MASK, val);
> -       if (ret)
> -               return ret;
> +       ret = gdsc_update_collapse_bit(sc, status == GDSC_OFF);
>
>         /* If disabling votable gdscs, don't poll on status */
>         if ((sc->flags & VOTABLE) && status == GDSC_OFF) {
> @@ -425,8 +437,7 @@ static int gdsc_init(struct gdsc *sc)
>                  * If a Votable GDSC is ON, make sure we have a Vote.
>                  */
>                 if (sc->flags & VOTABLE) {
> -                       ret = regmap_update_bits(sc->regmap, sc->gdscr,
> -                                                SW_COLLAPSE_MASK, val);
> +                       ret = gdsc_update_collapse_bit(sc, false);
>                         if (ret)
>                                 return ret;
>                 }
> --
> 2.35.1
>


-- 
With best wishes
Dmitry