ARM: OMAP2+: prm44xx: Introduce context save/restore for am43 PRCM IO

index acb9593..0a4aa90 100644
@@ -57,6 +57,13 @@
 	.reconfigure_io_chain	= &omap44xx_prm_reconfigure_io_chain,
 };
 
+struct omap_prm_irq_context {
+	unsigned long irq_enable;
+	unsigned long pm_ctrl;
+};
+
+static struct omap_prm_irq_context omap_prm_context;
+
 /*
  * omap44xx_prm_reset_src_map - map from bits in the PRM_RSTST
  *   hardware register (which are specific to OMAP44xx SoCs) to reset

@@ -689,6 +696,28 @@ struct pwrdm_ops omap4_pwrdm_operations = {
 
 static int omap44xx_prm_late_init(void);
 
+void prm_save_context(void)
+{
+	omap_prm_context.irq_enable =
+			omap4_prm_read_inst_reg(AM43XX_PRM_OCP_SOCKET_INST,
+						omap4_prcm_irq_setup.mask);
+
+	omap_prm_context.pm_ctrl =
+			omap4_prm_read_inst_reg(AM43XX_PRM_DEVICE_INST,
+						omap4_prcm_irq_setup.pm_ctrl);
+}
+
+void prm_restore_context(void)
+{
+	omap4_prm_write_inst_reg(omap_prm_context.irq_enable,
+				 OMAP4430_PRM_OCP_SOCKET_INST,
+				 omap4_prcm_irq_setup.mask);
+
+	omap4_prm_write_inst_reg(omap_prm_context.pm_ctrl,
+				 AM43XX_PRM_DEVICE_INST,
+				 omap4_prcm_irq_setup.pm_ctrl);
+}
+
 /*
  * XXX document
  */

index 0a4aa90..5478c71 100644
@@ -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 */
 

@@ -718,6 +720,22 @@ 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
  */

@@ -738,6 +756,7 @@ void prm_restore_context(void)
 
 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;

@@ -759,6 +778,12 @@ 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);
 }