ARM: OMAP2: Add functions to save and restore clock/dpll context en-masse.

The clock/dpll registers are in the WKUP power domain. Under both RTC-only
suspend and hibernation, these registers are lost.

Signed-off-by: Russ Dill <Russ.Dill@ti.com>
[j-keerthy@ti.com] ported to 3.14 with quite a bit of rework
Signed-off-by: Keerthy <j-keerthy@ti.com>

3 files changed, 42 insertions, 0 deletions

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 939533da93a..5c1b9fad04d 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -73,6 +73,11 @@ struct clk_hw;
  *		Called with enable_lock held.  This function must not
  *		sleep.
  *
+ * @save_context: Save the context of the clock in prepration for poweroff.
+ *
+ * @restore_context: Restore the context of the clock after a restoration
+ *		of power.
+ *
  * @recalc_rate	Recalculate the rate of this clock, by querying hardware. The
  * 		parent rate is an input parameter.  It is up to the caller to
  * 		ensure that the prepare_mutex is held across this call.
@@ -148,6 +153,8 @@ struct clk_ops {
 	void		(*disable)(struct clk_hw *hw);
 	int		(*is_enabled)(struct clk_hw *hw);
 	void		(*disable_unused)(struct clk_hw *hw);
+	int	(*save_context)(struct clk_hw *hw);
+	void	(*restore_context)(struct clk_hw *hw);
 	unsigned long	(*recalc_rate)(struct clk_hw *hw,
 					unsigned long parent_rate);
 	long		(*round_rate)(struct clk_hw *hw, unsigned long,
@@ -313,6 +320,7 @@ struct clk_divider {
 	u8		flags;
 	const struct clk_div_table	*table;
 	spinlock_t	*lock;
+	u32		context;
 };
 
 #define CLK_DIVIDER_ONE_BASED		BIT(0)
@@ -360,6 +368,7 @@ struct clk_mux {
 	u8		shift;
 	u8		flags;
 	spinlock_t	*lock;
+	u8		saved_parent;
 };
 
 #define CLK_MUX_INDEX_ONE		BIT(0)
@@ -570,5 +579,7 @@ static inline void clk_writel(u32 val, u32 __iomem *reg)
 
 #endif	/* platform dependent I/O accessors */
 
+void clk_dflt_restore_context(struct clk_hw *hw);
+
 #endif /* CONFIG_COMMON_CLK */
 #endif /* CLK_PROVIDER_H */
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 0dd91148165..e88a9275cfe 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -293,6 +293,23 @@ struct clk *clk_get_parent(struct clk *clk);
  */
 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
 
+/**
+ * clks_save_context - save clock context for poweroff
++ *
+ * Saves the context of the clock register for powerstates in which the
+ * contents of the registers will be lost. Occurs deep within the suspend
+ * code so locking is not necessary.
+ */
+int clks_save_context(void);
+
+/**
++ * clks_restore_context - restore clock context after poweroff
+ *
+ * This occurs with all clocks enabled. Occurs deep within the resume code
+ * so locking is not necessary.
+ */
+void clks_restore_context(void);
+
 #else /* !CONFIG_HAVE_CLK */
 
 static inline struct clk *clk_get(struct device *dev, const char *id)
@@ -341,6 +358,13 @@ static inline struct clk *clk_get_parent(struct clk *clk)
 	return NULL;
 }
 
+static inline int clks_save_context(void)
+{
+	return 0;
+}
+
+static inline void clks_restore_context(void) {}
+
 #endif
 
 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index 845f640302a..f411764a8b7 100644
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -148,6 +148,7 @@ struct clk_hw_omap {
 	const char		*clkdm_name;
 	struct clockdomain	*clkdm;
 	const struct clk_hw_omap_ops	*ops;
+	u32			context;
 };
 
 /*
@@ -318,6 +319,12 @@ static inline void of_ti_clk_allow_autoidle_all(void) { }
 static inline void of_ti_clk_deny_autoidle_all(void) { }
 #endif
 
+int omap3_noncore_dpll_save_context(struct clk_hw *hw);
+void omap3_noncore_dpll_restore_context(struct clk_hw *hw);
+
+int omap3_core_dpll_save_context(struct clk_hw *hw);
+void omap3_core_dpll_restore_context(struct clk_hw *hw);
+
 extern const struct clk_hw_omap_ops clkhwops_omap2xxx_dpll;
 extern const struct clk_hw_omap_ops clkhwops_omap2430_i2chs_wait;
 extern const struct clk_hw_omap_ops clkhwops_omap3_dpll;