1 files changed, 44 insertions, 35 deletions

diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 22590dbe8f1..80392fca86c 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -36,40 +36,66 @@
 
 /* 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;
+	u8 flags;
 };
 
 static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
 
+/*
+ * Possible flag bits for struct omap3_idle_statedata.flags:
+ *
+ * OMAP_CPUIDLE_CX_NO_CLKDM_IDLE: don't allow the MPU clockdomain to go
+ *    inactive.  This in turn prevents the MPU DPLL from entering autoidle
+ *    mode, so wakeup latency is greatly reduced, at the cost of additional
+ *    energy consumption.  This also prevents the CORE clockdomain from
+ *    entering idle.
+ */
+#define OMAP_CPUIDLE_CX_NO_CLKDM_IDLE		BIT(0)
+
+/*
+ * 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,
+		.flags = OMAP_CPUIDLE_CX_NO_CLKDM_IDLE,
 	},
 	{
 		.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,
 	},
 };
 
@@ -80,27 +106,25 @@ static int __omap3_enter_idle(struct cpuidle_device *dev,
 				int index)
 {
 	struct omap3_idle_statedata *cx = &omap3_idle_data[index];
-	u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
 
 	local_fiq_disable();
 
-	pwrdm_set_next_pwrst(mpu_pd, mpu_state);
-	pwrdm_set_next_pwrst(core_pd, core_state);
-
 	if (omap_irq_pending() || need_resched())
 		goto return_sleep_time;
 
 	/* Deny idle for C1 */
-	if (index == 0) {
+	if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) {
 		clkdm_deny_idle(mpu_pd->pwrdm_clkdms[0]);
-		clkdm_deny_idle(core_pd->pwrdm_clkdms[0]);
+	} else {
+		pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
+		pwrdm_set_next_pwrst(core_pd, cx->core_state);
 	}
 
 	/*
 	 * Call idle CPU PM enter notifier chain so that
 	 * VFP context is saved.
 	 */
-	if (mpu_state == PWRDM_POWER_OFF)
+	if (cx->mpu_state == PWRDM_POWER_OFF)
 		cpu_pm_enter();
 
 	/* Execute ARM wfi */
@@ -110,17 +134,15 @@ static int __omap3_enter_idle(struct cpuidle_device *dev,
 	 * Call idle CPU PM enter notifier chain to restore
 	 * VFP context.
 	 */
-	if (pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
+	if (cx->mpu_state == PWRDM_POWER_OFF &&
+	    pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
 		cpu_pm_exit();
 
 	/* Re-allow idle for C1 */
-	if (index == 0) {
+	if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE)
 		clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]);
-		clkdm_allow_idle(core_pd->pwrdm_clkdms[0]);
-	}
 
 return_sleep_time:
-
 	local_fiq_enable();
 
 	return index;
@@ -185,7 +207,7 @@ static int next_valid_state(struct cpuidle_device *dev,
 	 * Start search from the next (lower) state.
 	 */
 	for (idx = index - 1; idx >= 0; idx--) {
-		cx =  &omap3_idle_data[idx];
+		cx = &omap3_idle_data[idx];
 		if ((cx->mpu_state >= mpu_deepest_state) &&
 		    (cx->core_state >= core_deepest_state)) {
 			next_index = idx;
@@ -209,10 +231,9 @@ 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 +254,13 @@ 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);