[PATCH 4/5] ARM: DRA7: PM: cpuidle MPU CSWR support

[Tony Lindgren]

From: Santosh Shilimkar <santosh.shilimkar at ti.com>

Add DRA74/72 CPUIDLE support.

This patch adds MPUSS low power states in cpuidle.

        C1 - CPU0 WFI + CPU1 WFI + MPU ON
        C2 - CPU0 RET + CPU1 RET + MPU CSWR

Tested on DRA74/72-EVM for C1 and C2 states.

NOTE: DRA7 does not do voltage scaling as part of retention transition
and has Mercury which speeds up transition paths - Latency numbers are
based on measurements done by toggling GPIOs.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
[ j-keerthy at ti.com rework on 3.14]
Signed-off-by: Keerthy <j-keerthy at ti.com>
[nm at ti.com: updates based on profiling]
[tony at atomide.com: dropped CPUIDLE_FLAG_TIME_VALID no longer used]
Signed-off-by: Nishanth Menon <nm at ti.com>
---
 arch/arm/mach-omap2/cpuidle44xx.c | 80 ++++++++++++++++++++++++++++++++++++++-
 arch/arm/mach-omap2/pm44xx.c      |  2 +-
 2 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -21,6 +21,7 @@
 #include "common.h"
 #include "pm.h"
 #include "prm.h"
+#include "soc.h"
 #include "clockdomain.h"
 
 #define MAX_CPUS	2
@@ -30,6 +31,7 @@ struct idle_statedata {
 	u32 cpu_state;
 	u32 mpu_logic_state;
 	u32 mpu_state;
+	u32 mpu_state_vote;
 };
 
 static struct idle_statedata omap4_idle_data[] = {
@@ -50,12 +52,26 @@ static struct idle_statedata omap4_idle_data[] = {
 	},
 };
 
+static struct idle_statedata dra7_idle_data[] = {
+	{
+		.cpu_state = PWRDM_POWER_ON,
+		.mpu_state = PWRDM_POWER_ON,
+		.mpu_logic_state = PWRDM_POWER_ON,
+	},
+	{
+		.cpu_state = PWRDM_POWER_RET,
+		.mpu_state = PWRDM_POWER_RET,
+		.mpu_logic_state = PWRDM_POWER_RET,
+	},
+};
+
 static struct powerdomain *mpu_pd, *cpu_pd[MAX_CPUS];
 static struct clockdomain *cpu_clkdm[MAX_CPUS];
 
 static atomic_t abort_barrier;
 static bool cpu_done[MAX_CPUS];
 static struct idle_statedata *state_ptr = &omap4_idle_data[0];
+static DEFINE_RAW_SPINLOCK(mpu_lock);
 
 /* Private functions */
 
@@ -77,6 +93,32 @@ static int omap_enter_idle_simple(struct cpuidle_device *dev,
 	return index;
 }
 
+static int omap_enter_idle_smp(struct cpuidle_device *dev,
+			       struct cpuidle_driver *drv,
+			       int index)
+{
+	struct idle_statedata *cx = state_ptr + index;
+	unsigned long flag;
+
+	raw_spin_lock_irqsave(&mpu_lock, flag);
+	cx->mpu_state_vote++;
+	if (cx->mpu_state_vote == num_online_cpus()) {
+		pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
+		omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
+	}
+	raw_spin_unlock_irqrestore(&mpu_lock, flag);
+
+	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
+
+	raw_spin_lock_irqsave(&mpu_lock, flag);
+	if (cx->mpu_state_vote == num_online_cpus())
+		omap_set_pwrdm_state(mpu_pd, PWRDM_POWER_ON);
+	cx->mpu_state_vote--;
+	raw_spin_unlock_irqrestore(&mpu_lock, flag);
+
+	return index;
+}
+
 static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 			struct cpuidle_driver *drv,
 			int index)
@@ -220,6 +262,32 @@ static struct cpuidle_driver omap4_idle_driver = {
 	.safe_state_index = 0,
 };
 
+static struct cpuidle_driver dra7_idle_driver = {
+	.name				= "dra7_idle",
+	.owner				= THIS_MODULE,
+	.states = {
+		{
+			/* C1 - CPU0 ON + CPU1 ON + MPU ON */
+			.exit_latency = 2 + 2,
+			.target_residency = 5,
+			.enter = omap_enter_idle_simple,
+			.name = "C1",
+			.desc = "CPUx WFI, MPUSS ON"
+		},
+		{
+			/* C2 - CPU0 RET + CPU1 RET + MPU CSWR */
+			.exit_latency = 48 + 60,
+			.target_residency = 100,
+			.flags = CPUIDLE_FLAG_TIMER_STOP,
+			.enter = omap_enter_idle_smp,
+			.name = "C2",
+			.desc = "CPUx CSWR, MPUSS CSWR",
+		},
+	},
+	.state_count = ARRAY_SIZE(dra7_idle_data),
+	.safe_state_index = 0,
+};
+
 /* Public functions */
 
 /**
@@ -230,6 +298,16 @@ static struct cpuidle_driver omap4_idle_driver = {
  */
 int __init omap4_idle_init(void)
 {
+	struct cpuidle_driver *idle_driver;
+
+	if (soc_is_dra7xx()) {
+		state_ptr = &dra7_idle_data[0];
+		idle_driver = &dra7_idle_driver;
+	} else {
+		state_ptr = &omap4_idle_data[0];
+		idle_driver = &omap4_idle_driver;
+	}
+
 	mpu_pd = pwrdm_lookup("mpu_pwrdm");
 	cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
 	cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
@@ -244,5 +322,5 @@ int __init omap4_idle_init(void)
 	/* Configure the broadcast timer on each cpu */
 	on_each_cpu(omap_setup_broadcast_timer, NULL, 1);
 
-	return cpuidle_register(&omap4_idle_driver, cpu_online_mask);
+	return cpuidle_register(idle_driver, cpu_online_mask);
 }
diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
--- a/arch/arm/mach-omap2/pm44xx.c
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -287,7 +287,7 @@ int __init omap4_pm_init(void)
 	/* Overwrite the default cpu_do_idle() */
 	arm_pm_idle = omap_default_idle;
 
-	if (cpu_is_omap44xx())
+	if (cpu_is_omap44xx() || soc_is_dra7xx())
 		omap4_idle_init();
 
 err2:
-- 
2.9.3