Merge branch 'topic/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...

[karo-tx-linux.git] / drivers / clk / qcom / gdsc.c

diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
index 288186cce0ae420d499cf995636320bb0a9203d5..a4f3580587b7e121d25bcffefc1d50074127e103 100644 (file)
--- 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)