ARM: OMAP2+: Add functions to save and restore clockdomain context en-masse.

This is used to support suspend modes like RTC-only and hibernate where
the state of the registers controlling clockdomains is lost.
Signed-off-by: Russ Dill <Russ.Dill@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/clockdomain.c

@@ -1307,3 +1307,49 @@ int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
 	return 0;
 }
 
+/**
+ * _clkdm_save_context - save the context for the control of this clkdm
+ *
+ * Due to a suspend or hibernation operation, the state of the registers
+ * controlling this clkdm will be lost, save their context.
+ */
+static int _clkdm_save_context(struct clockdomain *clkdm, void *ununsed)
+{
+	if (!arch_clkdm || !arch_clkdm->clkdm_save_context)
+		return -EINVAL;
+
+	return arch_clkdm->clkdm_save_context(clkdm);
+}
+
+/**
+ * _clkdm_restore_context - restore context for control of this clkdm
+ *
+ * Restore the register values for this clockdomain.
+ */
+static int _clkdm_restore_context(struct clockdomain *clkdm, void *ununsed)
+{
+	if (!arch_clkdm || !arch_clkdm->clkdm_restore_context)
+		return -EINVAL;
+
+	return arch_clkdm->clkdm_restore_context(clkdm);
+}
+
+/**
+ * clkdm_save_context - Saves the context for each registered clkdm
+ *
+ * Save the context for each registered clockdomain.
+ */
+void clkdm_save_context(void)
+{
+	clkdm_for_each(_clkdm_save_context, NULL);
+}
+
+/**
+ * clkdm_restore_context - Restores the context for each registered clkdm
+ *
+ * Restore the context for each registered clockdomain.
+ */
+void clkdm_restore_context(void)
+{
+	clkdm_for_each(_clkdm_restore_context, NULL);
+}

arch/arm/mach-omap2/clockdomain.h

@@ -141,6 +141,7 @@ struct clockdomain {
 	int usecount;
 	int forcewake_count;
 	struct list_head node;
+	u32 context;
 };
 
 /**
@@ -159,6 +160,8 @@ struct clockdomain {
  * @clkdm_deny_idle: Disable hw supervised idle transitions for clock domain
  * @clkdm_clk_enable: Put the clkdm in right state for a clock enable
  * @clkdm_clk_disable: Put the clkdm in right state for a clock disable
+ * @clkdm_save_context: Save the current clkdm context
+ * @clkdm_restore_context: Restore the clkdm context
  */
 struct clkdm_ops {
 	int	(*clkdm_add_wkdep)(struct clockdomain *clkdm1, struct clockdomain *clkdm2);
@@ -175,6 +178,8 @@ struct clkdm_ops {
 	void	(*clkdm_deny_idle)(struct clockdomain *clkdm);
 	int	(*clkdm_clk_enable)(struct clockdomain *clkdm);
 	int	(*clkdm_clk_disable)(struct clockdomain *clkdm);
+	int	(*clkdm_save_context)(struct clockdomain *clkdm);
+	int	(*clkdm_restore_context)(struct clockdomain *clkdm);
 };
 
 int clkdm_register_platform_funcs(struct clkdm_ops *co);
@@ -214,6 +219,9 @@ int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk);
 int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh);
 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh);
 
+void clkdm_save_context(void);
+void clkdm_restore_context(void);
+
 extern void __init omap242x_clockdomains_init(void);
 extern void __init omap243x_clockdomains_init(void);
 extern void __init omap3xxx_clockdomains_init(void);

arch/arm/mach-omap2/cm33xx.c

@@ -72,6 +72,17 @@ static inline u32 am33xx_cm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
 	return v;
 }
 
+static inline u32 am33xx_cm_read_reg_bits(u16 inst, s16 idx, u32 mask)
+{
+	u32 v;
+
+	v = am33xx_cm_read_reg(inst, idx);
+	v &= mask;
+	v >>= __ffs(mask);
+
+	return v;
+}
+
 /**
  * _clkctrl_idlest - read a CM_*_CLKCTRL register; mask & shift IDLEST bitfield
  * @inst: CM instance register offset (*_INST macro)
@@ -338,6 +349,46 @@ static u32 am33xx_cm_xlate_clkctrl(u8 part, u16 inst, u16 offset)
 	return cm_base.pa + inst + offset;
 }
 
+/**
+ * am33xx_clkdm_save_context - Save the clockdomain transition context
+ * @clkdm: The clockdomain pointer whose context needs to be saved
+ *
+ * Save the clockdomain transition context.
+ */
+static int am33xx_clkdm_save_context(struct clockdomain *clkdm)
+{
+	clkdm->context = am33xx_cm_read_reg_bits(clkdm->cm_inst,
+						 clkdm->clkdm_offs,
+						 AM33XX_CLKTRCTRL_MASK);
+
+	return 0;
+}
+
+/**
+ * am33xx_restore_save_context - Restore the clockdomain transition context
+ * @clkdm: The clockdomain pointer whose context needs to be restored
+ *
+ * Restore the clockdomain transition context.
+ */
+static int am33xx_clkdm_restore_context(struct clockdomain *clkdm)
+{
+	switch (clkdm->context) {
+	case OMAP34XX_CLKSTCTRL_DISABLE_AUTO:
+		am33xx_clkdm_deny_idle(clkdm);
+		break;
+	case OMAP34XX_CLKSTCTRL_FORCE_SLEEP:
+		am33xx_clkdm_sleep(clkdm);
+		break;
+	case OMAP34XX_CLKSTCTRL_FORCE_WAKEUP:
+		am33xx_clkdm_wakeup(clkdm);
+		break;
+	case OMAP34XX_CLKSTCTRL_ENABLE_AUTO:
+		am33xx_clkdm_allow_idle(clkdm);
+		break;
+	}
+	return 0;
+}
+
 struct clkdm_ops am33xx_clkdm_operations = {
 	.clkdm_sleep		= am33xx_clkdm_sleep,
 	.clkdm_wakeup		= am33xx_clkdm_wakeup,
@@ -345,6 +396,8 @@ struct clkdm_ops am33xx_clkdm_operations = {
 	.clkdm_deny_idle	= am33xx_clkdm_deny_idle,
 	.clkdm_clk_enable	= am33xx_clkdm_clk_enable,
 	.clkdm_clk_disable	= am33xx_clkdm_clk_disable,
+	.clkdm_save_context	= am33xx_clkdm_save_context,
+	.clkdm_restore_context	= am33xx_clkdm_restore_context,
 };
 
 static const struct cm_ll_data am33xx_cm_ll_data = {

arch/arm/mach-omap2/cminst44xx.c

@@ -481,6 +481,47 @@ static u32 omap4_cminst_xlate_clkctrl(u8 part, u16 inst, u16 offset)
 	return _cm_bases[part].pa + inst + offset;
 }
 
+/**
+ * omap4_clkdm_save_context - Save the clockdomain modulemode context
+ * @clkdm: The clockdomain pointer whose context needs to be saved
+ *
+ * Save the clockdomain modulemode context.
+ */
+static int omap4_clkdm_save_context(struct clockdomain *clkdm)
+{
+	clkdm->context = omap4_cminst_read_inst_reg(clkdm->prcm_partition,
+						    clkdm->cm_inst,
+						    clkdm->clkdm_offs +
+						    OMAP4_CM_CLKSTCTRL);
+	clkdm->context &= OMAP4430_MODULEMODE_MASK;
+	return 0;
+}
+
+/**
+ * omap4_clkdm_restore_context - Restore the clockdomain modulemode context
+ * @clkdm: The clockdomain pointer whose context needs to be restored
+ *
+ * Restore the clockdomain modulemode context.
+ */
+static int omap4_clkdm_restore_context(struct clockdomain *clkdm)
+{
+	switch (clkdm->context) {
+	case OMAP34XX_CLKSTCTRL_DISABLE_AUTO:
+		omap4_clkdm_deny_idle(clkdm);
+		break;
+	case OMAP34XX_CLKSTCTRL_FORCE_SLEEP:
+		omap4_clkdm_sleep(clkdm);
+		break;
+	case OMAP34XX_CLKSTCTRL_FORCE_WAKEUP:
+		omap4_clkdm_wakeup(clkdm);
+		break;
+	case OMAP34XX_CLKSTCTRL_ENABLE_AUTO:
+		omap4_clkdm_allow_idle(clkdm);
+		break;
+	}
+	return 0;
+}
+
 struct clkdm_ops omap4_clkdm_operations = {
 	.clkdm_add_wkdep	= omap4_clkdm_add_wkup_sleep_dep,
 	.clkdm_del_wkdep	= omap4_clkdm_del_wkup_sleep_dep,
@@ -496,6 +537,8 @@ struct clkdm_ops omap4_clkdm_operations = {
 	.clkdm_deny_idle	= omap4_clkdm_deny_idle,
 	.clkdm_clk_enable	= omap4_clkdm_clk_enable,
 	.clkdm_clk_disable	= omap4_clkdm_clk_disable,
+	.clkdm_save_context	= omap4_clkdm_save_context,
+	.clkdm_restore_context	= omap4_clkdm_restore_context,
 };
 
 struct clkdm_ops am43xx_clkdm_operations = {