diff options
Diffstat (limited to 'drivers/clk/qcom/gdsc.c')
| -rw-r--r-- | drivers/clk/qcom/gdsc.c | 58 |
1 files changed, 45 insertions, 13 deletions
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 288186cce0ae..a4f3580587b7 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -63,11 +63,26 @@ static int gdsc_hwctrl(struct gdsc *sc, bool en) return regmap_update_bits(sc->regmap, sc->gdscr, HW_CONTROL_MASK, val); } +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; + } while (ktime_us_delta(ktime_get(), start) < TIMEOUT_US); + + if (gdsc_is_enabled(sc, reg) == en) + return 0; + + return -ETIMEDOUT; +} + static int gdsc_toggle_logic(struct gdsc *sc, bool en) { int ret; u32 val = en ? 0 : SW_COLLAPSE_MASK; - ktime_t start; unsigned int status_reg = sc->gdscr; ret = regmap_update_bits(sc->regmap, sc->gdscr, SW_COLLAPSE_MASK, val); @@ -100,16 +115,7 @@ static int gdsc_toggle_logic(struct gdsc *sc, bool en) udelay(1); } - start = ktime_get(); - do { - if (gdsc_is_enabled(sc, status_reg) == en) - return 0; - } while (ktime_us_delta(ktime_get(), start) < TIMEOUT_US); - - if (gdsc_is_enabled(sc, status_reg) == en) - return 0; - - return -ETIMEDOUT; + return gdsc_poll_status(sc, status_reg, en); } static inline int gdsc_deassert_reset(struct gdsc *sc) @@ -188,8 +194,20 @@ static int gdsc_enable(struct generic_pm_domain *domain) udelay(1); /* Turn on HW trigger mode if supported */ - if (sc->flags & HW_CTRL) - return gdsc_hwctrl(sc, true); + if (sc->flags & HW_CTRL) { + ret = gdsc_hwctrl(sc, true); + if (ret) + return ret; + /* + * Wait for the GDSC to go through a power down and + * up cycle. In case a firmware ends up polling status + * bits for the gdsc, it might read an 'on' status before + * the GDSC can finish the power cycle. + * We wait 1us before returning to ensure the firmware + * can't immediately poll the status bits. + */ + udelay(1); + } return 0; } @@ -204,9 +222,23 @@ static int gdsc_disable(struct generic_pm_domain *domain) /* Turn off HW trigger mode if supported */ if (sc->flags & HW_CTRL) { + unsigned int reg; + ret = gdsc_hwctrl(sc, false); if (ret < 0) return ret; + /* + * Wait for the GDSC to go through a power down and + * up cycle. In case we end up polling status + * bits for the gdsc before the power cycle is completed + * it might read an 'on' status wrongly. + */ + udelay(1); + + reg = sc->gds_hw_ctrl ? sc->gds_hw_ctrl : sc->gdscr; + ret = gdsc_poll_status(sc, reg, true); + if (ret) + return ret; } if (sc->pwrsts & PWRSTS_OFF) |