Re: [PATCH v2 3/3] clk: qcom: gdsc: Add support to poll CFG register to check GDSC state

From: Stephen Boyd
Date: Tue Apr 17 2018 - 00:31:02 EST


Quoting Taniya Das (2018-04-09 01:41:46)
> @@ -64,18 +69,43 @@ static int gdsc_hwctrl(struct gdsc *sc, bool en)
> return regmap_update_bits(sc->regmap, sc->gdscr, HW_CONTROL_MASK, val);
> }
>
> +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);
> +
> + return !(val & GDSC_POWER_DOWN_COMPLETE);
> +}
> +
> static int gdsc_poll_status(struct gdsc *sc, unsigned int reg, bool en)
> {
> ktime_t start;
>
> start = ktime_get();
> do {
> - if (gdsc_is_enabled(sc, reg) == en)
> - return 0;
> + if (sc->flags & POLL_CFG_GDSCR) {
> + if (gdsc_is_enabled_by_poll_cfg_reg(sc, en) == en)
> + return 0;
> + } else {
> + if (gdsc_is_enabled(sc, reg) == en)
> + return 0;

Ok, I thought you would bury the is_enabled_by_poll_cfg_reg() stuff into
gdsc_is_enabled() directly. Because that function is used in one more
place than here, in gdsc_init(), to figure out if a GDSC is on at boot
time. The sc->gds_hw_ctrl check should be able to get buried into
gdsc_is_enabled() as well so that the function doesn't have to take a
register at all.

> + }
> } while (ktime_us_delta(ktime_get(), start) < TIMEOUT_US);
>
> - if (gdsc_is_enabled(sc, reg) == en)
> - return 0;
> + if (sc->flags & POLL_CFG_GDSCR) {
> + if (gdsc_is_enabled_by_poll_cfg_reg(sc, en) == en)
> + return 0;
> + } else {
> + if (gdsc_is_enabled(sc, reg) == en)
> + return 0;
> + }

And then this duplicate diff wouldn't happen either.

>
> return -ETIMEDOUT;
> }
> @@ -254,6 +284,7 @@ static int gdsc_disable(struct generic_pm_domain *domain)
> udelay(1);
>
> reg = sc->gds_hw_ctrl ? sc->gds_hw_ctrl : sc->gdscr;
> +

This change shouldn't be here?

> ret = gdsc_poll_status(sc, reg, true);
> if (ret)
> return ret;