[pm-core][PATCH v3 13/21] OMAP4: suspend: Add MPUSS RET and OFF support

[Santosh Shilimkar <santosh.shilimkar@ti.com>]

This patch adds MPUSS(MPU Sub System) RET and OFF mode support
to suspend path. For both MPUSS RET and OFF support, CPUs are
programmed to OFF state.

Only MPUSS RET and OFF supported at this point of time. CORE RET
will be added subsequently.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
---
 arch/arm/mach-omap2/omap4-mpuss-lowpower.c |    6 ++-
 arch/arm/mach-omap2/pm44xx.c               |   67 ++++++++++++++++++++++++++--
 2 files changed, 68 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-omap2/omap4-mpuss-lowpower.c b/arch/arm/mach-omap2/omap4-mpuss-lowpower.c
index 026c955..7348d29 100644
--- a/arch/arm/mach-omap2/omap4-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap4-mpuss-lowpower.c
@@ -25,7 +25,7 @@
  *	ON(Inactive)	OFF		ON(Inactive)
  *	OFF		OFF		CSWR
  *	OFF		OFF		OSWR (*TBD)
- *	OFF		OFF		OFF* (*TBD)
+ *	OFF		OFF		OFF
  *	----------------------------------------------
  *
  * Note: CPU0 is the master core and it is the last CPU to go down
@@ -293,6 +293,7 @@ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
 	 * Check MPUSS next state and save GIC if needed
 	 * GIC lost during MPU OFF and OSWR
 	 */
+	pwrdm_clear_all_prev_pwrst(mpuss_pd);
 	if (pwrdm_read_next_pwrst(mpuss_pd) == PWRDM_POWER_OFF) {
 		omap_wakeupgen_save();
 		gic_save_context();
@@ -414,6 +415,9 @@ int __init omap4_mpuss_init(void)
 		return -ENODEV;
 	}
 
+	/* Clear CPU previous power domain state */
+	pwrdm_clear_all_prev_pwrst(mpuss_pd);
+
 	/*
 	 * Find out how many interrupts are supported.
 	 * OMAP4 supports max of 128 SPIs where as GIC can support
diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
index 4f932f3..051461c 100644
--- a/arch/arm/mach-omap2/pm44xx.c
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -1,8 +1,9 @@
 /*
  * OMAP4 Power Management Routines
  *
- * Copyright (C) 2010 Texas Instruments, Inc.
+ * Copyright (C) 2010-2011 Texas Instruments, Inc.
  * Rajendra Nayak <rnayak@ti.com>
+ * Santosh Shilimkar <santosh.shilimkar@ti.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -35,7 +36,48 @@ static LIST_HEAD(pwrst_list);
 #ifdef CONFIG_SUSPEND
 static int omap4_pm_suspend(void)
 {
-	do_wfi();
+	struct power_state *pwrst;
+	int state, ret = 0;
+	u32 cpu_id = smp_processor_id();
+
+	/* Save current powerdomain state */
+	list_for_each_entry(pwrst, &pwrst_list, node) {
+		pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
+	}
+
+	/* Set targeted power domain states by suspend */
+	list_for_each_entry(pwrst, &pwrst_list, node) {
+		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
+	}
+
+	/*
+	 * For MPUSS to hit power domain retention(CSWR or OSWR),
+	 * CPU0 and CPU1 power domain needs to be in OFF or DORMANT
+	 * state. For MPUSS to reach off-mode. CPU0 and CPU1 power domain
+	 * should be in off state.
+	 * Only master CPU followes suspend path. All other CPUs follow
+	 * cpu-hotplug path in system wide suspend. On OMAP4, CPU power
+	 * domain CSWR is not supported by hardware.
+	 * More details can be found in OMAP4430 TRM section 4.3.4.2.
+	 */
+	omap4_enter_lowpower(cpu_id, PWRDM_POWER_OFF);
+
+	/* Restore next powerdomain state */
+	list_for_each_entry(pwrst, &pwrst_list, node) {
+		state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
+		if (state > pwrst->next_state) {
+			pr_info("Powerdomain (%s) didn't enter "
+			       "target state %d\n",
+			       pwrst->pwrdm->name, pwrst->next_state);
+			ret = -1;
+		}
+		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
+	}
+	if (ret)
+		pr_err("Could not enter target state in pm_suspend\n");
+	else
+		pr_err("Successfully put all powerdomains to target state\n");
+
 	return 0;
 }
 
@@ -98,14 +140,31 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 	if (!pwrdm->pwrsts)
 		return 0;
 
+	/*
+	 * Skip CPU0 and CPU1 power domains. CPU1 is programmed
+	 * through hotplug path and CPU0 explicitly programmed
+	 * further down in the code path
+	 */
+	if ((!strcmp(pwrdm->name, "cpu0_pwrdm")) ||
+		(!strcmp(pwrdm->name, "cpu1_pwrdm")))
+		return 0;
+
+	/*
+	 * FIXME: Remove this check when core retention is supported
+	 * Only MPUSS power domain is added in the list.
+	 */
+	if (strcmp(pwrdm->name, "mpu_pwrdm"))
+		return 0;
+
 	pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
 	if (!pwrst)
 		return -ENOMEM;
+
 	pwrst->pwrdm = pwrdm;
-	pwrst->next_state = PWRDM_POWER_ON;
+	pwrst->next_state = PWRDM_POWER_OFF;
 	list_add(&pwrst->node, &pwrst_list);
 
-	return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);
+	return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
 }
 
 /**
-- 
1.6.0.4