ARM: OMAP4: suspend: Add MPUSS power domain RETENTION support

This patch adds MPUSS(MPU Sub System) power domain
CSWR(Close Switch Retention) support to system wide suspend.
For MPUSS power domain to hit retention(CSWR or OSWR), both
CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
since CPU power domain CSWR is not supported by hardware

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
index 9c1c12b..f9bb2b3 100644
--- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
@@ -66,6 +66,7 @@
 };
 
 static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
+static struct powerdomain *mpuss_pd;
 
 /*
  * Program the wakeup routine address for the CPU0 and CPU1
@@ -140,6 +141,13 @@
  * of OMAP4 MPUSS subsystem
  * @cpu : CPU ID
  * @power_state: Low power state.
+ *
+ * MPUSS states for the context save:
+ * save_state =
+ *	0 - Nothing lost and no need to save: MPUSS INACTIVE
+ *	1 - CPUx L1 and logic lost: MPUSS CSWR
+ *	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
+ *	3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
  */
 int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
 {
@@ -169,6 +177,7 @@
 		return -ENXIO;
 	}
 
+	pwrdm_clear_all_prev_pwrst(mpuss_pd);
 	clear_cpu_prev_pwrst(cpu);
 	set_cpu_next_pwrst(cpu, power_state);
 	set_cpu_wakeup_addr(cpu, virt_to_phys(omap4_cpu_resume));
@@ -268,6 +277,13 @@
 	/* Initialise CPU1 power domain state to ON */
 	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
 
+	mpuss_pd = pwrdm_lookup("mpu_pwrdm");
+	if (!mpuss_pd) {
+		pr_err("Failed to lookup MPUSS power domain\n");
+		return -ENODEV;
+	}
+	pwrdm_clear_all_prev_pwrst(mpuss_pd);
+
 	/* Save device type on scratchpad for low level code to use */
 	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
 		__raw_writel(1, sar_base + OMAP_TYPE_OFFSET);