OMAP3: PM: CPUidle: Add new lower-latency C1 state

This patch introduces a new C state which allows MPU to go to WFI but keeps
the core domain active. This offers a much better wakeup latency (3us vs
10s of us for the current C1) at the cost of a higher power consumption.

Signed-off-by: Peter 'p2' De Schrijver <peter.de-schrijver@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/cpuidle34xx.c

@@ -25,8 +25,9 @@
 #include <linux/cpuidle.h>
 
 #include <plat/prcm.h>
-#include <plat/powerdomain.h>
 #include <plat/irqs.h>
+#include <plat/powerdomain.h>
+#include <plat/clockdomain.h>
 #include <plat/control.h>
 #include <plat/serial.h>
 
@@ -34,13 +35,14 @@
 
 #ifdef CONFIG_CPU_IDLE
 
-#define OMAP3_MAX_STATES 7
+#define OMAP3_MAX_STATES 8
 #define OMAP3_STATE_C1 1 /* C1 - MPU WFI + Core active */
-#define OMAP3_STATE_C2 2 /* C2 - MPU CSWR + Core active */
-#define OMAP3_STATE_C3 3 /* C3 - MPU OFF + Core active */
-#define OMAP3_STATE_C4 4 /* C4 - MPU RET + Core RET */
-#define OMAP3_STATE_C5 5 /* C5 - MPU OFF + Core RET */
-#define OMAP3_STATE_C6 6 /* C6 - MPU OFF + Core OFF */
+#define OMAP3_STATE_C2 2 /* C2 - MPU WFI + Core inactive */
+#define OMAP3_STATE_C3 3 /* C3 - MPU CSWR + Core inactive */
+#define OMAP3_STATE_C4 4 /* C4 - MPU OFF + Core iactive */
+#define OMAP3_STATE_C5 5 /* C5 - MPU RET + Core RET */
+#define OMAP3_STATE_C6 6 /* C6 - MPU OFF + Core RET */
+#define OMAP3_STATE_C7 7 /* C7 - MPU OFF + Core OFF */
 
 struct omap3_processor_cx {
 	u8 valid;
@@ -64,6 +66,20 @@ static int omap3_idle_bm_check(void)
 	return 0;
 }
 
+static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
+				struct clockdomain *clkdm)
+{
+	omap2_clkdm_allow_idle(clkdm);
+	return 0;
+}
+
+static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
+				struct clockdomain *clkdm)
+{
+	omap2_clkdm_deny_idle(clkdm);
+	return 0;
+}
+
 /**
  * omap3_enter_idle - Programs OMAP3 to enter the specified state
  * @dev: cpuidle device
@@ -100,9 +116,19 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
 	if (omap_irq_pending())
 		goto return_sleep_time;
 
+	if (cx->type == OMAP3_STATE_C1) {
+		pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
+		pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
+	}
+
 	/* Execute ARM wfi */
 	omap_sram_idle();
 
+	if (cx->type == OMAP3_STATE_C1) {
+		pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
+		pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
+	}
+
 return_sleep_time:
 	getnstimeofday(&ts_postidle);
 	ts_idle = timespec_sub(ts_postidle, ts_preidle);
@@ -141,79 +167,90 @@ DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
 /* omap3_init_power_states - Initialises the OMAP3 specific C states.
  *
  * Below is the desciption of each C state.
- *	C1 . MPU WFI + Core active
- *	C2 . MPU CSWR + Core active
- *	C3 . MPU OFF + Core active
- *	C4 . MPU CSWR + Core CSWR
- *	C5 . MPU OFF + Core CSWR
- *	C6 . MPU OFF + Core OFF
+ * 	C1 . MPU WFI + Core active
+ *	C2 . MPU WFI + Core inactive
+ *	C3 . MPU CSWR + Core inactive
+ *	C4 . MPU OFF + Core inactive
+ *	C5 . MPU CSWR + Core CSWR
+ *	C6 . MPU OFF + Core CSWR
+ *	C7 . MPU OFF + Core OFF
  */
 void omap_init_power_states(void)
 {
 	/* C1 . MPU WFI + Core active */
 	omap3_power_states[OMAP3_STATE_C1].valid = 1;
 	omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
-	omap3_power_states[OMAP3_STATE_C1].sleep_latency = 10;
-	omap3_power_states[OMAP3_STATE_C1].wakeup_latency = 10;
-	omap3_power_states[OMAP3_STATE_C1].threshold = 30;
+	omap3_power_states[OMAP3_STATE_C1].sleep_latency = 2;
+	omap3_power_states[OMAP3_STATE_C1].wakeup_latency = 2;
+	omap3_power_states[OMAP3_STATE_C1].threshold = 5;
 	omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
 	omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
 	omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
 
-	/* C2 . MPU CSWR + Core active */
+	/* C2 . MPU WFI + Core inactive */
 	omap3_power_states[OMAP3_STATE_C2].valid = 1;
 	omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
-	omap3_power_states[OMAP3_STATE_C2].sleep_latency = 50;
-	omap3_power_states[OMAP3_STATE_C2].wakeup_latency = 50;
-	omap3_power_states[OMAP3_STATE_C2].threshold = 300;
-	omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_RET;
+	omap3_power_states[OMAP3_STATE_C2].sleep_latency = 10;
+	omap3_power_states[OMAP3_STATE_C2].wakeup_latency = 10;
+	omap3_power_states[OMAP3_STATE_C2].threshold = 30;
+	omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
 	omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
-	omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID |
-				CPUIDLE_FLAG_CHECK_BM;
+	omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID;
 
-	/* C3 . MPU OFF + Core active */
+	/* C3 . MPU CSWR + Core inactive */
 	omap3_power_states[OMAP3_STATE_C3].valid = 1;
 	omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
-	omap3_power_states[OMAP3_STATE_C3].sleep_latency = 1500;
-	omap3_power_states[OMAP3_STATE_C3].wakeup_latency = 1800;
-	omap3_power_states[OMAP3_STATE_C3].threshold = 4000;
-	omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C3].sleep_latency = 50;
+	omap3_power_states[OMAP3_STATE_C3].wakeup_latency = 50;
+	omap3_power_states[OMAP3_STATE_C3].threshold = 300;
+	omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_RET;
 	omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
 	omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID |
 				CPUIDLE_FLAG_CHECK_BM;
 
-	/* C4 . MPU CSWR + Core CSWR*/
+	/* C4 . MPU OFF + Core inactive */
 	omap3_power_states[OMAP3_STATE_C4].valid = 1;
 	omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
-	omap3_power_states[OMAP3_STATE_C4].sleep_latency = 2500;
-	omap3_power_states[OMAP3_STATE_C4].wakeup_latency = 7500;
-	omap3_power_states[OMAP3_STATE_C4].threshold = 12000;
-	omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_RET;
-	omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_RET;
+	omap3_power_states[OMAP3_STATE_C4].sleep_latency = 1500;
+	omap3_power_states[OMAP3_STATE_C4].wakeup_latency = 1800;
+	omap3_power_states[OMAP3_STATE_C4].threshold = 4000;
+	omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_ON;
 	omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
 				CPUIDLE_FLAG_CHECK_BM;
 
-	/* C5 . MPU OFF + Core CSWR */
+	/* C5 . MPU CSWR + Core CSWR*/
 	omap3_power_states[OMAP3_STATE_C5].valid = 1;
 	omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
-	omap3_power_states[OMAP3_STATE_C5].sleep_latency = 3000;
-	omap3_power_states[OMAP3_STATE_C5].wakeup_latency = 8500;
-	omap3_power_states[OMAP3_STATE_C5].threshold = 15000;
-	omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C5].sleep_latency = 2500;
+	omap3_power_states[OMAP3_STATE_C5].wakeup_latency = 7500;
+	omap3_power_states[OMAP3_STATE_C5].threshold = 12000;
+	omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_RET;
 	omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
 	omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
 				CPUIDLE_FLAG_CHECK_BM;
 
-	/* C6 . MPU OFF + Core OFF */
+	/* C6 . MPU OFF + Core CSWR */
 	omap3_power_states[OMAP3_STATE_C6].valid = 1;
 	omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
-	omap3_power_states[OMAP3_STATE_C6].sleep_latency = 10000;
-	omap3_power_states[OMAP3_STATE_C6].wakeup_latency = 30000;
-	omap3_power_states[OMAP3_STATE_C6].threshold = 300000;
+	omap3_power_states[OMAP3_STATE_C6].sleep_latency = 3000;
+	omap3_power_states[OMAP3_STATE_C6].wakeup_latency = 8500;
+	omap3_power_states[OMAP3_STATE_C6].threshold = 15000;
 	omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
-	omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_RET;
 	omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
 				CPUIDLE_FLAG_CHECK_BM;
+
+	/* C7 . MPU OFF + Core OFF */
+	omap3_power_states[OMAP3_STATE_C7].valid = 1;
+	omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
+	omap3_power_states[OMAP3_STATE_C7].sleep_latency = 10000;
+	omap3_power_states[OMAP3_STATE_C7].wakeup_latency = 30000;
+	omap3_power_states[OMAP3_STATE_C7].threshold = 300000;
+	omap3_power_states[OMAP3_STATE_C7].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C7].core_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C7].flags = CPUIDLE_FLAG_TIME_VALID |
+				CPUIDLE_FLAG_CHECK_BM;
 }
 
 struct cpuidle_driver omap3_idle_driver = {