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

Stephen Boyd
2018-04-06T16:40:08Z

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 ...

> +}
> +
> +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.

> if (ret)
> return ret;
> }