ARM: OMAP3xxx: CPUIdle: simplify the PER next-state code

The OMAP3xxx CPUIdle driver contains some code to place a lower bound
on the PER powerdomain's power state.  Convert this code to a data-driven
implementation to remove branches and to improve readability.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 22590db..cba6945 100644 (file)
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -36,40 +36,53 @@
 
 /* Mach specific information to be recorded in the C-state driver_data */
 struct omap3_idle_statedata {
-       u32 mpu_state;
-       u32 core_state;
+       u8 mpu_state;
+       u8 core_state;
+       u8 per_min_state;
 };
 
 static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
 
+/*
+ * Prevent PER OFF if CORE is not in RETention or OFF as this would
+ * disable PER wakeups completely.
+ */
 static struct omap3_idle_statedata omap3_idle_data[] = {
        {
                .mpu_state = PWRDM_POWER_ON,
                .core_state = PWRDM_POWER_ON,
+               /* In C1 do not allow PER state lower than CORE state */
+               .per_min_state = PWRDM_POWER_ON,
        },
        {
                .mpu_state = PWRDM_POWER_ON,
                .core_state = PWRDM_POWER_ON,
+               .per_min_state = PWRDM_POWER_RET,
        },
        {
                .mpu_state = PWRDM_POWER_RET,
                .core_state = PWRDM_POWER_ON,
+               .per_min_state = PWRDM_POWER_RET,
        },
        {
                .mpu_state = PWRDM_POWER_OFF,
                .core_state = PWRDM_POWER_ON,
+               .per_min_state = PWRDM_POWER_RET,
        },
        {
                .mpu_state = PWRDM_POWER_RET,
                .core_state = PWRDM_POWER_RET,
+               .per_min_state = PWRDM_POWER_OFF,
        },
        {
                .mpu_state = PWRDM_POWER_OFF,
                .core_state = PWRDM_POWER_RET,
+               .per_min_state = PWRDM_POWER_OFF,
        },
        {
                .mpu_state = PWRDM_POWER_OFF,
                .core_state = PWRDM_POWER_OFF,
+               .per_min_state = PWRDM_POWER_OFF,
        },
 };
 
@@ -209,10 +222,9 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
                               struct cpuidle_driver *drv,
                               int index)
 {
-       int new_state_idx;
-       u32 core_next_state, per_next_state = 0, per_saved_state = 0;
+       int new_state_idx, ret;
+       u8 per_next_state, per_saved_state;
        struct omap3_idle_statedata *cx;
-       int ret;
 
        /*
         * Use only C1 if CAM is active.
@@ -233,25 +245,13 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
 
        /* Program PER state */
        cx = &omap3_idle_data[new_state_idx];
-       core_next_state = cx->core_state;
-       per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
-       if (new_state_idx == 0) {
-               /* In C1 do not allow PER state lower than CORE state */
-               if (per_next_state < core_next_state)
-                       per_next_state = core_next_state;
-       } else {
-               /*
-                * Prevent PER OFF if CORE is not in RETention or OFF as this
-                * would disable PER wakeups completely.
-                */
-               if ((per_next_state == PWRDM_POWER_OFF) &&
-                   (core_next_state > PWRDM_POWER_RET))
-                       per_next_state = PWRDM_POWER_RET;
-       }
 
-       /* Are we changing PER target state? */
-       if (per_next_state != per_saved_state)
+       per_next_state = pwrdm_read_next_pwrst(per_pd);
+       per_saved_state = per_next_state;
+       if (per_next_state < cx->per_min_state) {
+               per_next_state = cx->per_min_state;
                pwrdm_set_next_pwrst(per_pd, per_next_state);
+       }
 
        ret = omap3_enter_idle(dev, drv, new_state_idx);