ARM: OMAP2+: prm44xx: Inroduce cpu_pm notifiers for context save/restore

Inroduce cpu_pm notifiers for context save/restore. This will be
needed for am43xx family in case of rtc only mode with ddr in
self-refresh.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index 18b4955ff755ea42a8d7b85b921615ae4e57befe..7b95729e83594d330e4f0d5e3205a05b4d0751e1 100644 (file)
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -12,6 +12,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/cpu_pm.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
@@ -30,6 +31,7 @@
 #include "prcm44xx.h"
 #include "prminst44xx.h"
 #include "powerdomain.h"
+#include "pm.h"
 
 /* Static data */
 
@@ -768,6 +770,22 @@ void prm_restore_context(void)
                                 omap4_prcm_irq_setup.pm_ctrl);
 }
 
+static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
+{
+       switch (cmd) {
+       case CPU_CLUSTER_PM_ENTER:
+               if (enable_off_mode)
+                       prm_save_context();
+               break;
+       case CPU_CLUSTER_PM_EXIT:
+               if (enable_off_mode)
+                       prm_restore_context();
+               break;
+       }
+
+       return NOTIFY_OK;
+}
+
 /*
  * XXX document
  */
@@ -788,6 +806,7 @@ static const struct omap_prcm_init_data *prm_init_data;
 
 int __init omap44xx_prm_init(const struct omap_prcm_init_data *data)
 {
+       static struct notifier_block nb;
        omap_prm_base_init();
 
        prm_init_data = data;
@@ -809,6 +828,12 @@ int __init omap44xx_prm_init(const struct omap_prcm_init_data *data)
                omap4_prcm_irq_setup.mask = AM43XX_PRM_IRQENABLE_MPU_OFFSET;
        }
 
+       /* Only AM43XX can lose prm context during rtc-ddr suspend */
+       if (soc_is_am43xx()) {
+               nb.notifier_call = cpu_notifier;
+               cpu_pm_register_notifier(&nb);
+       }
+
        return prm_register(&omap44xx_prm_ll_data);
 }