ARM: OMAP: SMS: save/restore of SMS_SYSCONFIG for off-mode

The SMS_SYSCONFIG register gets reset in off mode, added a
save/restore mechanism for that.
Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@digia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/pm34xx.c

@@ -399,6 +399,7 @@ static void omap_sram_idle(void)
 			omap3_core_restore_context();
 			omap3_prcm_restore_context();
 			omap3_sram_restore_context();
+			omap2_sms_restore_context();
 		}
 		if (per_next_state < PWRDM_POWER_ON) {
 			per_prev_state =

arch/arm/mach-omap2/sdrc.c

@@ -37,11 +37,37 @@ static struct omap_sdrc_params *sdrc_init_params_cs0, *sdrc_init_params_cs1;
 void __iomem *omap2_sdrc_base;
 void __iomem *omap2_sms_base;
 
+struct omap2_sms_regs {
+	u32	sms_sysconfig;
+};
+
+static struct omap2_sms_regs sms_context;
+
 /* SDRC_POWER register bits */
 #define SDRC_POWER_EXTCLKDIS_SHIFT		3
 #define SDRC_POWER_PWDENA_SHIFT			2
 #define SDRC_POWER_PAGEPOLICY_SHIFT		0
 
+/**
+ * omap2_sms_save_context - Save SMS registers
+ *
+ * Save SMS registers that need to be restored after off mode.
+ */
+void omap2_sms_save_context(void)
+{
+	sms_context.sms_sysconfig = sms_read_reg(SMS_SYSCONFIG);
+}
+
+/**
+ * omap2_sms_restore_context - Restore SMS registers
+ *
+ * Restore SMS registers that need to be Restored after off mode.
+ */
+void omap2_sms_restore_context(void)
+{
+	sms_write_reg(sms_context.sms_sysconfig, SMS_SYSCONFIG);
+}
+
 /**
  * omap2_sdrc_get_params - return SDRC register values for a given clock rate
  * @r: SDRC clock rate (in Hz)
@@ -132,4 +158,5 @@ void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
 	l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
 		(1 << SDRC_POWER_PAGEPOLICY_SHIFT);
 	sdrc_write_reg(l, SDRC_POWER);
+	omap2_sms_save_context();
 }

arch/arm/plat-omap/include/plat/sdrc.h

@@ -120,6 +120,8 @@ void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
 int omap2_sdrc_get_params(unsigned long r,
 			  struct omap_sdrc_params **sdrc_cs0,
 			  struct omap_sdrc_params **sdrc_cs1);
+void omap2_sms_save_context(void);
+void omap2_sms_restore_context(void);
 
 #ifdef CONFIG_ARCH_OMAP2