[PATCH 02/14] ARM: OMAP2: Add functions to save and restore clockdomain context en-masse.

From: Keerthy
Date: Wed Apr 11 2018 - 23:55:19 EST


From: Russ Dill <Russ.Dill@xxxxxx>

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@xxxxxx>
Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
Signed-off-by: Keerthy <j-keerthy@xxxxxx>
---
arch/arm/mach-omap2/clockdomain.c | 46 +++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/clockdomain.h | 8 ++++++
arch/arm/mach-omap2/cm33xx.c | 53 +++++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/cminst44xx.c | 43 +++++++++++++++++++++++++++++++
4 files changed, 150 insertions(+)

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index b79b1ca..0906380 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/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);
+}
diff --git a/arch/arm/mach-omap2/clockdomain.h b/arch/arm/mach-omap2/clockdomain.h
index 24667a5..c7d0953 100644
--- a/arch/arm/mach-omap2/clockdomain.h
+++ b/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_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
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);
diff --git a/arch/arm/mach-omap2/cm33xx.c b/arch/arm/mach-omap2/cm33xx.c
index 1cc0247..084d454 100644
--- a/arch/arm/mach-omap2/cm33xx.c
+++ b/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 = {
diff --git a/arch/arm/mach-omap2/cminst44xx.c b/arch/arm/mach-omap2/cminst44xx.c
index 7deefee..c11ac49 100644
--- a/arch/arm/mach-omap2/cminst44xx.c
+++ b/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 = {
--
1.9.1