[PATCH 0/4] clk: clk: Add functions to save/restore clock context en-masse

[PATCH 0/4] clk: clk: Add functions to save/restore clock context en-masse

[Keerthy]

Deep enough power saving mode can result into losing context of the clock
registers also, and they need to be restored once coming back from the power
saving mode. Hence add functions to save/restore clock context.

Tested for DS0 on am437x-gp-evm

Based on top of linux-next

Keerthy (2):
  clk: clk: Add clk_dflt_restore
  soc: ti: pm33xx: Save/restore clk context based on enable_off_mode
    setting

Russ Dill (2):
  clk: clk: Add functions to save/restore clock context en-masse
  clk: ti: Add functions to save/restore clk context

 arch/arm/mach-omap2/pm33xx-core.c    |  15 +++++
 drivers/clk/clk.c                    |  93 ++++++++++++++++++++++++++
 drivers/clk/ti/clock.h               |   2 +
 drivers/clk/ti/divider.c             |  36 ++++++++++
 drivers/clk/ti/dpll.c                |   6 ++
 drivers/clk/ti/dpll3xxx.c            | 124 +++++++++++++++++++++++++++++++++++
 drivers/clk/ti/gate.c                |   3 +
 drivers/clk/ti/mux.c                 |  29 ++++++++
 drivers/soc/ti/pm33xx.c              |  13 ++++
 include/linux/clk-provider.h         |   9 +++
 include/linux/clk.h                  |  25 +++++++
 include/linux/clk/ti.h               |   6 ++
 include/linux/platform_data/pm33xx.h |   1 +
 13 files changed, 362 insertions(+)

-- 
1.9.1

[PATCH 1/4] clk: clk: Add functions to save/restore clock context en-masse

[Keerthy]

From: Russ Dill <Russ.Dill@ti.com>

Deep enough power saving mode can result into losing context of the clock
registers also, and they need to be restored once coming back from the power
saving mode. Hence add functions to save/restore clock context.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Russ Dill <Russ.Dill@ti.com>
---
 drivers/clk/clk.c            | 74 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/clk-provider.h |  7 +++++
 include/linux/clk.h          | 25 +++++++++++++++
 3 files changed, 106 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index a24a6af..7347e06 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -910,6 +910,80 @@ static int clk_core_enable_lock(struct clk_core *core)
 	return ret;
 }
 
+static int _clk_save_context(struct clk_core *clk)
+{
+	struct clk_core *child;
+	int ret = 0;
+
+	hlist_for_each_entry(child, &clk->children, child_node) {
+		ret = _clk_save_context(child);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (clk->ops && clk->ops->save_context)
+		ret = clk->ops->save_context(clk->hw);
+
+	return ret;
+}
+
+static void _clk_restore_context(struct clk_core *clk)
+{
+	struct clk_core *child;
+
+	if (clk->ops && clk->ops->restore_context)
+		clk->ops->restore_context(clk->hw);
+
+	hlist_for_each_entry(child, &clk->children, child_node)
+		_clk_restore_context(child);
+}
+
+/**
+ * clk_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.  Returns 0 on success.
+ */
+int clk_save_context(void)
+{
+	struct clk_core *clk;
+	int ret;
+
+	hlist_for_each_entry(clk, &clk_root_list, child_node) {
+		ret = _clk_save_context(clk);
+		if (ret < 0)
+			return ret;
+	}
+
+	hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
+		ret = _clk_save_context(clk);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(clk_save_context);
+
+/**
+ * clk_restore_context - restore clock context after poweroff
+ *
+ * Restore the saved clock context upon resume.
+ *
+ */
+void clk_restore_context(void)
+{
+	struct clk_core *clk;
+
+	hlist_for_each_entry(clk, &clk_root_list, child_node)
+		_clk_restore_context(clk);
+
+	hlist_for_each_entry(clk, &clk_orphan_list, child_node)
+		_clk_restore_context(clk);
+}
+EXPORT_SYMBOL_GPL(clk_restore_context);
+
 /**
  * clk_enable - ungate a clock
  * @clk: the clk being ungated
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index b7cfa03..7f30d62 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -106,6 +106,11 @@ struct clk_rate_request {
  *		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.
@@ -201,6 +206,8 @@ 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 rate,
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 0dbd088..70a2662 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -596,6 +596,23 @@ int __must_check clk_bulk_enable(int num_clks,
  */
 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
 
+/**
+ * clk_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 clk_save_context(void);
+
+/**
+ * clk_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 clk_restore_context(void);
+
 #else /* !CONFIG_HAVE_CLK */
 
 static inline struct clk *clk_get(struct device *dev, const char *id)
@@ -695,6 +712,14 @@ static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
 {
 	return NULL;
 }
+
+static inline int clk_save_context(void)
+{
+	return 0;
+}
+
+static inline void clk_restore_context(void) {}
+
 #endif
 
 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
-- 
1.9.1

[PATCH 2/4] clk: clk: Add clk_dflt_restore

[Keerthy]

The default restore context function enables or disables
the clock based on the enable_count. This is done in cases
where the clock context is lost and based on the enable_count
the clock either needs to be enabled/disabled. This particularly
helps restore the state of gate clocks.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 drivers/clk/clk.c            | 19 +++++++++++++++++++
 include/linux/clk-provider.h |  2 ++
 2 files changed, 21 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 7347e06..c201b8b 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -910,6 +910,25 @@ static int clk_core_enable_lock(struct clk_core *core)
 	return ret;
 }
 
+/**
+ * clk_dflt_restore_context - restore context for poweroff
+ * @hw: the clk_hw pointer of clock whose state is to be restored
+ *
+ * The default restore context function enables or disables
+ * the clock based on the enable_count. This is done in cases
+ * where the clock context is lost and based on the enable_count
+ * the clock either needs to be enabled/disabled. This particularly
+ * helps restore the state of gate clocks.
+ */
+void clk_dflt_restore_context(struct clk_hw *hw)
+{
+	if (hw->clk->core->enable_count)
+		hw->clk->core->ops->enable(hw);
+	else
+		hw->clk->core->ops->disable(hw);
+}
+EXPORT_SYMBOL_GPL(clk_dflt_restore_context);
+
 static int _clk_save_context(struct clk_core *clk)
 {
 	struct clk_core *child;
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 7f30d62..3e0c61a 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -992,5 +992,7 @@ 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 */
-- 
1.9.1

Re: [PATCH 2/4] clk: clk: Add clk_dflt_restore

[Tero Kristo]

On 19/06/18 07:28, Keerthy wrote:
> The default restore context function enables or disables
> the clock based on the enable_count. This is done in cases
> where the clock context is lost and based on the enable_count
> the clock either needs to be enabled/disabled. This particularly
> helps restore the state of gate clocks.
> 
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
>   drivers/clk/clk.c            | 19 +++++++++++++++++++
>   include/linux/clk-provider.h |  2 ++
>   2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 7347e06..c201b8b 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -910,6 +910,25 @@ static int clk_core_enable_lock(struct clk_core *core)
>   	return ret;
>   }
>   
> +/**
> + * clk_dflt_restore_context - restore context for poweroff
> + * @hw: the clk_hw pointer of clock whose state is to be restored
> + *
> + * The default restore context function enables or disables
> + * the clock based on the enable_count. This is done in cases
> + * where the clock context is lost and based on the enable_count
> + * the clock either needs to be enabled/disabled. This particularly
> + * helps restore the state of gate clocks.
> + */
> +void clk_dflt_restore_context(struct clk_hw *hw)

I think the name of this function is wrong, it should be 
clk_gate_restore_context, as only gate clocks are ever going to be using 
this afaics.

-Tero

> +{
> +	if (hw->clk->core->enable_count)
> +		hw->clk->core->ops->enable(hw);
> +	else
> +		hw->clk->core->ops->disable(hw);
> +}
> +EXPORT_SYMBOL_GPL(clk_dflt_restore_context);
> +
>   static int _clk_save_context(struct clk_core *clk)
>   {
>   	struct clk_core *child;
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index 7f30d62..3e0c61a 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -992,5 +992,7 @@ 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 */
> 

--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH 2/4] clk: clk: Add clk_dflt_restore

[J, KEERTHY]

On 6/19/2018 11:36 AM, Tero Kristo wrote:
> On 19/06/18 07:28, Keerthy wrote:
>> The default restore context function enables or disables
>> the clock based on the enable_count. This is done in cases
>> where the clock context is lost and based on the enable_count
>> the clock either needs to be enabled/disabled. This particularly
>> helps restore the state of gate clocks.
>>
>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> ---
>>   drivers/clk/clk.c            | 19 +++++++++++++++++++
>>   include/linux/clk-provider.h |  2 ++
>>   2 files changed, 21 insertions(+)
>>
>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>> index 7347e06..c201b8b 100644
>> --- a/drivers/clk/clk.c
>> +++ b/drivers/clk/clk.c
>> @@ -910,6 +910,25 @@ static int clk_core_enable_lock(struct clk_core 
>> *core)
>>       return ret;
>>   }
>> +/**
>> + * clk_dflt_restore_context - restore context for poweroff
>> + * @hw: the clk_hw pointer of clock whose state is to be restored
>> + *
>> + * The default restore context function enables or disables
>> + * the clock based on the enable_count. This is done in cases
>> + * where the clock context is lost and based on the enable_count
>> + * the clock either needs to be enabled/disabled. This particularly
>> + * helps restore the state of gate clocks.
>> + */
>> +void clk_dflt_restore_context(struct clk_hw *hw)
> 
> I think the name of this function is wrong, it should be 
> clk_gate_restore_context, as only gate clocks are ever going to be using 
> this afaics.

Okay. Yes this applies to gate clocks. I will fix this.

> 
> -Tero
> 
>> +{
>> +    if (hw->clk->core->enable_count)
>> +        hw->clk->core->ops->enable(hw);
>> +    else
>> +        hw->clk->core->ops->disable(hw);
>> +}
>> +EXPORT_SYMBOL_GPL(clk_dflt_restore_context);
>> +
>>   static int _clk_save_context(struct clk_core *clk)
>>   {
>>       struct clk_core *child;
>> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
>> index 7f30d62..3e0c61a 100644
>> --- a/include/linux/clk-provider.h
>> +++ b/include/linux/clk-provider.h
>> @@ -992,5 +992,7 @@ 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 */
>>
> 
> -- 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. 
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

[PATCH 3/4] clk: ti: Add functions to save/restore clk context

[Keerthy]

From: Russ Dill <Russ.Dill@ti.com>

SoCs like AM43XX lose clock registers context during RTC-only
suspend. Hence add functions to save/restore the clock registers
context.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Russ Dill <Russ.Dill@ti.com>
---
 drivers/clk/ti/clock.h    |   2 +
 drivers/clk/ti/divider.c  |  36 ++++++++++++++
 drivers/clk/ti/dpll.c     |   6 +++
 drivers/clk/ti/dpll3xxx.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/ti/gate.c     |   3 ++
 drivers/clk/ti/mux.c      |  29 +++++++++++
 include/linux/clk/ti.h    |   6 +++
 7 files changed, 206 insertions(+)

diff --git a/drivers/clk/ti/clock.h b/drivers/clk/ti/clock.h
index b582780..26fbdf2 100644
--- a/drivers/clk/ti/clock.h
+++ b/drivers/clk/ti/clock.h
@@ -24,6 +24,7 @@ struct clk_omap_divider {
 	u8			flags;
 	s8			latch;
 	const struct clk_div_table	*table;
+	u32		context;
 };
 
 #define to_clk_omap_divider(_hw) container_of(_hw, struct clk_omap_divider, hw)
@@ -36,6 +37,7 @@ struct clk_omap_mux {
 	u8			shift;
 	s8			latch;
 	u8			flags;
+	u8			saved_parent;
 };
 
 #define to_clk_omap_mux(_hw) container_of(_hw, struct clk_omap_mux, hw)
diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
index aaa277d..4418e0d 100644
--- a/drivers/clk/ti/divider.c
+++ b/drivers/clk/ti/divider.c
@@ -268,10 +268,46 @@ static int ti_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
 	return 0;
 }
 
+/**
+ * clk_divider_save_context - Save the divider value
+ * @hw: pointer  struct clk_hw
+ *
+ * Save the divider value
+ */
+static int clk_divider_save_context(struct clk_hw *hw)
+{
+	struct clk_omap_divider *divider = to_clk_omap_divider(hw);
+	u32 val;
+
+	val = ti_clk_ll_ops->clk_readl(&divider->reg) >> divider->shift;
+	divider->context = val & div_mask(divider);
+
+	return 0;
+}
+
+/**
+ * clk_divider_restore_context - restore the saved the divider value
+ * @hw: pointer  struct clk_hw
+ *
+ * Restore the saved the divider value
+ */
+static void clk_divider_restore_context(struct clk_hw *hw)
+{
+	struct clk_omap_divider *divider = to_clk_omap_divider(hw);
+	u32 val;
+
+	val = ti_clk_ll_ops->clk_readl(&divider->reg);
+	val &= ~(div_mask(divider) << divider->shift);
+	val |= divider->context << divider->shift;
+	ti_clk_ll_ops->clk_writel(val, &divider->reg);
+}
+
 const struct clk_ops ti_clk_divider_ops = {
 	.recalc_rate = ti_clk_divider_recalc_rate,
 	.round_rate = ti_clk_divider_round_rate,
 	.set_rate = ti_clk_divider_set_rate,
+	.save_context = clk_divider_save_context,
+	.restore_context = clk_divider_restore_context,
 };
 
 static struct clk *_register_divider(struct device *dev, const char *name,
diff --git a/drivers/clk/ti/dpll.c b/drivers/clk/ti/dpll.c
index 7d33ca9..b1c4d8a 100644
--- a/drivers/clk/ti/dpll.c
+++ b/drivers/clk/ti/dpll.c
@@ -39,6 +39,8 @@
 	.set_rate_and_parent	= &omap3_noncore_dpll_set_rate_and_parent,
 	.determine_rate	= &omap4_dpll_regm4xen_determine_rate,
 	.get_parent	= &omap2_init_dpll_parent,
+	.save_context	= &omap3_core_dpll_save_context,
+	.restore_context = &omap3_core_dpll_restore_context,
 };
 #else
 static const struct clk_ops dpll_m4xen_ck_ops = {};
@@ -62,6 +64,8 @@
 	.set_rate_and_parent	= &omap3_noncore_dpll_set_rate_and_parent,
 	.determine_rate	= &omap3_noncore_dpll_determine_rate,
 	.get_parent	= &omap2_init_dpll_parent,
+	.save_context	= &omap3_noncore_dpll_save_context,
+	.restore_context = &omap3_noncore_dpll_restore_context,
 };
 
 static const struct clk_ops dpll_no_gate_ck_ops = {
@@ -72,6 +76,8 @@
 	.set_parent	= &omap3_noncore_dpll_set_parent,
 	.set_rate_and_parent	= &omap3_noncore_dpll_set_rate_and_parent,
 	.determine_rate	= &omap3_noncore_dpll_determine_rate,
+	.save_context	= &omap3_noncore_dpll_save_context,
+	.restore_context = &omap3_noncore_dpll_restore_context
 };
 #else
 static const struct clk_ops dpll_core_ck_ops = {};
diff --git a/drivers/clk/ti/dpll3xxx.c b/drivers/clk/ti/dpll3xxx.c
index 4534de2..44b6b64 100644
--- a/drivers/clk/ti/dpll3xxx.c
+++ b/drivers/clk/ti/dpll3xxx.c
@@ -782,6 +782,130 @@ unsigned long omap3_clkoutx2_recalc(struct clk_hw *hw,
 	return rate;
 }
 
+/**
+ * omap3_core_dpll_save_context - Save the m and n values of the divider
+ * @hw: pointer  struct clk_hw
+ *
+ * Before the dpll registers are lost save the last rounded rate m and n
+ * and the enable mask.
+ */
+int omap3_core_dpll_save_context(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *dd;
+	u32 v;
+
+	dd = clk->dpll_data;
+
+	v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
+	clk->context = (v & dd->enable_mask) >> __ffs(dd->enable_mask);
+
+	if (clk->context == DPLL_LOCKED) {
+		v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
+		dd->last_rounded_m = (v & dd->mult_mask) >>
+						__ffs(dd->mult_mask);
+		dd->last_rounded_n = ((v & dd->div1_mask) >>
+						__ffs(dd->div1_mask)) + 1;
+	}
+
+	return 0;
+}
+
+/**
+ * omap3_core_dpll_restore_context - restore the m and n values of the divider
+ * @hw: pointer  struct clk_hw
+ *
+ * Restore the last rounded rate m and n
+ * and the enable mask.
+ */
+void omap3_core_dpll_restore_context(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	const struct dpll_data *dd;
+	u32 v;
+
+	dd = clk->dpll_data;
+
+	if (clk->context == DPLL_LOCKED) {
+		_omap3_dpll_write_clken(clk, 0x4);
+		_omap3_wait_dpll_status(clk, 0);
+
+		v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
+		v &= ~(dd->mult_mask | dd->div1_mask);
+		v |= dd->last_rounded_m << __ffs(dd->mult_mask);
+		v |= (dd->last_rounded_n - 1) << __ffs(dd->div1_mask);
+		ti_clk_ll_ops->clk_writel(v, &dd->mult_div1_reg);
+
+		_omap3_dpll_write_clken(clk, DPLL_LOCKED);
+		_omap3_wait_dpll_status(clk, 1);
+	} else {
+		_omap3_dpll_write_clken(clk, clk->context);
+	}
+}
+
+/**
+ * omap3_non_core_dpll_save_context - Save the m and n values of the divider
+ * @hw: pointer  struct clk_hw
+ *
+ * Before the dpll registers are lost save the last rounded rate m and n
+ * and the enable mask.
+ */
+int omap3_noncore_dpll_save_context(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *dd;
+	u32 v;
+
+	dd = clk->dpll_data;
+
+	v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
+	clk->context = (v & dd->enable_mask) >> __ffs(dd->enable_mask);
+
+	if (clk->context == DPLL_LOCKED) {
+		v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
+		dd->last_rounded_m = (v & dd->mult_mask) >>
+						__ffs(dd->mult_mask);
+		dd->last_rounded_n = ((v & dd->div1_mask) >>
+						__ffs(dd->div1_mask)) + 1;
+	}
+
+	return 0;
+}
+
+/**
+ * omap3_core_dpll_restore_context - restore the m and n values of the divider
+ * @hw: pointer  struct clk_hw
+ *
+ * Restore the last rounded rate m and n
+ * and the enable mask.
+ */
+void omap3_noncore_dpll_restore_context(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	const struct dpll_data *dd;
+	u32 ctrl, mult_div1;
+
+	dd = clk->dpll_data;
+
+	ctrl = ti_clk_ll_ops->clk_readl(&dd->control_reg);
+	mult_div1 = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
+
+	if (clk->context == ((ctrl & dd->enable_mask) >>
+			     __ffs(dd->enable_mask)) &&
+	    dd->last_rounded_m == ((mult_div1 & dd->mult_mask) >>
+				   __ffs(dd->mult_mask)) &&
+	    dd->last_rounded_n == ((mult_div1 & dd->div1_mask) >>
+				   __ffs(dd->div1_mask)) + 1) {
+		/* nothing to be done */
+		return;
+	}
+
+	if (clk->context == DPLL_LOCKED)
+		omap3_noncore_dpll_program(clk, 0);
+	else
+		_omap3_dpll_write_clken(clk, clk->context);
+}
+
 /* OMAP3/4 non-CORE DPLL clkops */
 const struct clk_hw_omap_ops clkhwops_omap3_dpll = {
 	.allow_idle	= omap3_dpll_allow_idle,
diff --git a/drivers/clk/ti/gate.c b/drivers/clk/ti/gate.c
index 935b2de..2453b36 100644
--- a/drivers/clk/ti/gate.c
+++ b/drivers/clk/ti/gate.c
@@ -33,6 +33,7 @@
 	.init		= &omap2_init_clk_clkdm,
 	.enable		= &omap2_clkops_enable_clkdm,
 	.disable	= &omap2_clkops_disable_clkdm,
+	.restore_context = clk_dflt_restore_context,
 };
 
 const struct clk_ops omap_gate_clk_ops = {
@@ -40,6 +41,7 @@
 	.enable		= &omap2_dflt_clk_enable,
 	.disable	= &omap2_dflt_clk_disable,
 	.is_enabled	= &omap2_dflt_clk_is_enabled,
+	.restore_context = clk_dflt_restore_context,
 };
 
 static const struct clk_ops omap_gate_clk_hsdiv_restore_ops = {
@@ -47,6 +49,7 @@
 	.enable		= &omap36xx_gate_clk_enable_with_hsdiv_restore,
 	.disable	= &omap2_dflt_clk_disable,
 	.is_enabled	= &omap2_dflt_clk_is_enabled,
+	.restore_context = clk_dflt_restore_context,
 };
 
 /**
diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c
index 69a4308..5749b2b 100644
--- a/drivers/clk/ti/mux.c
+++ b/drivers/clk/ti/mux.c
@@ -91,10 +91,39 @@ static int ti_clk_mux_set_parent(struct clk_hw *hw, u8 index)
 	return 0;
 }
 
+/**
+ * clk_mux_save_context - Save the parent selcted in the mux
+ * @hw: pointer  struct clk_hw
+ *
+ * Save the parent mux value.
+ */
+static int clk_mux_save_context(struct clk_hw *hw)
+{
+	struct clk_omap_mux *mux = to_clk_omap_mux(hw);
+
+	mux->saved_parent = ti_clk_mux_get_parent(hw);
+	return 0;
+}
+
+/**
+ * clk_mux_restore_context - Restore the parent in the mux
+ * @hw: pointer  struct clk_hw
+ *
+ * Restore the saved parent mux value.
+ */
+static void clk_mux_restore_context(struct clk_hw *hw)
+{
+	struct clk_omap_mux *mux = to_clk_omap_mux(hw);
+
+	ti_clk_mux_set_parent(hw, mux->saved_parent);
+}
+
 const struct clk_ops ti_clk_mux_ops = {
 	.get_parent = ti_clk_mux_get_parent,
 	.set_parent = ti_clk_mux_set_parent,
 	.determine_rate = __clk_mux_determine_rate,
+	.save_context = clk_mux_save_context,
+	.restore_context = clk_mux_restore_context,
 };
 
 static struct clk *_register_mux(struct device *dev, const char *name,
diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index a8faa38..c1b13bb 100644
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -159,6 +159,7 @@ struct clk_hw_omap {
 	const char		*clkdm_name;
 	struct clockdomain	*clkdm;
 	const struct clk_hw_omap_ops	*ops;
+	u32			context;
 };
 
 /*
@@ -293,6 +294,11 @@ struct ti_clk_features {
 
 void ti_clk_setup_features(struct ti_clk_features *features);
 const struct ti_clk_features *ti_clk_get_features(void);
+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;
 
-- 
1.9.1

[PATCH 4/4] soc: ti: pm33xx: Save/restore clk context based on enable_off_mode setting

[Keerthy]

Save/restore clk context based on enable_off_mode setting.
The context needs to be saved at the very end of suspend path
and restored at the beginning of resume path.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 arch/arm/mach-omap2/pm33xx-core.c    | 15 +++++++++++++++
 drivers/soc/ti/pm33xx.c              | 13 +++++++++++++
 include/linux/platform_data/pm33xx.h |  1 +
 3 files changed, 29 insertions(+)

diff --git a/arch/arm/mach-omap2/pm33xx-core.c b/arch/arm/mach-omap2/pm33xx-core.c
index 9b3755a..29f848f 100644
--- a/arch/arm/mach-omap2/pm33xx-core.c
+++ b/arch/arm/mach-omap2/pm33xx-core.c
@@ -37,6 +37,20 @@ static int __init am43xx_map_scu(void)
 	return 0;
 }
 
+static int am43xx_check_off_mode_enable(void)
+{
+	/*
+	 * Check for am437x-sk-evm which due to HW design cannot support
+	 * this mode reliably.
+	 */
+	if (of_machine_is_compatible("ti,am437x-sk-evm") && enable_off_mode) {
+		pr_warn("WARNING: This platform does not support off-mode, entering DeepSleep suspend.\n");
+		return 0;
+	}
+
+	return enable_off_mode;
+}
+
 static int amx3_common_init(void)
 {
 	gfx_pwrdm = pwrdm_lookup("gfx_pwrdm");
@@ -161,6 +175,7 @@ static struct am33xx_pm_sram_addr *amx3_get_sram_addrs(void)
 	.init = am43xx_suspend_init,
 	.soc_suspend = am43xx_suspend,
 	.get_sram_addrs = amx3_get_sram_addrs,
+	.check_off_mode_enable = am43xx_check_off_mode_enable,
 };
 
 static struct am33xx_pm_platform_data *am33xx_pm_get_pdata(void)
diff --git a/drivers/soc/ti/pm33xx.c b/drivers/soc/ti/pm33xx.c
index 652739c..e749b8d 100644
--- a/drivers/soc/ti/pm33xx.c
+++ b/drivers/soc/ti/pm33xx.c
@@ -6,6 +6,7 @@
  *	Vaibhav Bedia, Dave Gerlach
  */
 
+#include <linux/clk.h>
 #include <linux/cpu.h>
 #include <linux/err.h>
 #include <linux/genalloc.h>
@@ -52,6 +53,14 @@ static int am33xx_pm_suspend(suspend_state_t suspend_state)
 {
 	int i, ret = 0;
 
+	/*
+	 * For RTC only mode with DDR in selfresh we need to save
+	 * clocks context at the very end
+	 */
+	if (suspend_state == PM_SUSPEND_MEM &&
+	    pm_ops->check_off_mode_enable())
+		clk_save_context();
+
 	ret = pm_ops->soc_suspend((unsigned long)suspend_state,
 				  am33xx_do_wfi_sram);
 
@@ -77,6 +86,10 @@ static int am33xx_pm_suspend(suspend_state_t suspend_state)
 		}
 	}
 
+	if (suspend_state == PM_SUSPEND_MEM &&
+	    pm_ops->check_off_mode_enable())
+		clk_restore_context();
+
 	return ret;
 }
 
diff --git a/include/linux/platform_data/pm33xx.h b/include/linux/platform_data/pm33xx.h
index f9bed2a..36f7007 100644
--- a/include/linux/platform_data/pm33xx.h
+++ b/include/linux/platform_data/pm33xx.h
@@ -25,6 +25,7 @@ struct am33xx_pm_platform_data {
 	int	(*init)(void);
 	int	(*soc_suspend)(unsigned int state, int (*fn)(unsigned long));
 	struct  am33xx_pm_sram_addr *(*get_sram_addrs)(void);
+	int (*check_off_mode_enable)(void);
 };
 
 struct am33xx_pm_sram_data {
-- 
1.9.1