Currently the CCF doesnt have any interface with the system when it
goes into suspend state. This patch, on similar lines of syscore,
adds clk_suspend/clk_resume functions before system enters suspend state
Also there are suspend/resume hooks added for the clock driver
Acked-by: Olivier Bideau <olivier.bideau@xxxxxx>
Acked-by: Patrice Chotard <patrice.chotard@xxxxxx>
Signed-off-by: Pankaj Dev <pankaj.dev@xxxxxx>
---
drivers/clk/clk.c | 194 ++++++++++++++++++++++++++++++++++++++++++
include/linux/clk-provider.h | 21 +++++
include/linux/clk.h | 23 +++++
kernel/kexec.c | 6 ++
kernel/power/hibernate.c | 16 ++++
kernel/power/suspend.c | 7 ++
6 files changed, 267 insertions(+), 0 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 237f23f..3e3b1d7 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2811,6 +2811,200 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
}
EXPORT_SYMBOL_GPL(clk_notifier_unregister);
+#ifdef CONFIG_PM_SLEEP
+int __clk_resume(struct clk_core *clk)
+{
+ int ret = 0;
+ u8 p_index;
+ unsigned long rate, parent_rate = 0;
+
+ /* restore parent */
+ if (clk->ops->set_parent) {
+ p_index = clk_fetch_parent_index(clk, clk->parent);
+
+ if (p_index != clk->ops->get_parent(clk->hw))
+ ret = clk->ops->set_parent(clk->hw, p_index);
+
+ if (ret) {
+ pr_err("%s: Fail to set parent %s\n",
+ __func__, clk->name);
+ goto out;
+ }
+ }
+
+ /* restore rate */
+ if (clk->ops->set_rate) {
+ if (clk->parent)
+ parent_rate = clk->parent->rate;
+
+ rate = clk->ops->recalc_rate(clk->hw, parent_rate);
+
+ if (rate != clk->rate)
+ ret = clk->ops->set_rate(clk->hw, clk->rate,
+ parent_rate);
+
+ if (ret) {
+ pr_err("%s: Fail to set rate %s\n",
+ __func__, clk->name);
+ goto out;
+ }
+ }
+
+ /* restore prepare status */
+ if (clk->ops->prepare && clk->prepare_count) {
+ if (clk->ops->is_prepared) {
+ if (!clk->ops->is_prepared(clk->hw))
+ ret = clk->ops->prepare(clk->hw);
+ } else {
+ ret = clk->ops->prepare(clk->hw);
+ }
+ if (ret) {
+ pr_err("%s: Fail to prepare %s\n",
+ __func__, clk->name);
+ goto out;
+ }
+ }
+
+ /* restore enable status */
+ if (clk->ops->enable && clk->enable_count) {
+ if (clk->ops->is_enabled) {
+ if (!clk->ops->is_enabled(clk->hw))
+ ret = clk->ops->enable(clk->hw);
+ } else {
+ ret = clk->ops->enable(clk->hw);
+ }
+ if (ret) {
+ pr_err("%s: Fail to enable %s\n",
+ __func__, clk->name);
+ goto out;
+ }
+ }
+ if (clk->ops->disable && !clk->enable_count) {
+ if (clk->ops->is_enabled) {
+ if (clk->ops->is_enabled(clk->hw))
+ clk->ops->disable(clk->hw);
+ } else {
+ clk->ops->disable(clk->hw);
+ }
+ }
+
+ /* restore unprepare status */
+ if (clk->ops->unprepare && !clk->prepare_count) {
+ if (clk->ops->is_prepared) {
+ if (!clk->ops->is_prepared(clk->hw))
+ clk->ops->unprepare(clk->hw);
+ } else {
+ clk->ops->unprepare(clk->hw);
+ }
+ }
+
+out:
+ return ret;
+}
+
+static int _clk_resume(struct clk_core *clk)
+{
+ struct clk_core *child;
+ int ret = 0;
+
+ if (!clk)
+ return 0;
+
+ if (clk->ops->resume)
+ ret = clk->ops->resume(clk->hw);
+ else
+ ret = __clk_resume(clk);
+
+ if (ret)
+ return ret;
+
+ hlist_for_each_entry(child, &clk->children, child_node) {
+ ret = _clk_resume(child);
+ if (ret)
+ return ret;
+ }
+
+ return ret;
+}
+
+void clk_resume(void)
+{
+ struct clk_core *clk;
+
+ hlist_for_each_entry(clk, &clk_root_list, child_node)
+ _clk_resume(clk);
+
+ hlist_for_each_entry(clk, &clk_orphan_list, child_node)
+ _clk_resume(clk);
+}
+
+int __clk_suspend(struct clk_core *clk)
+{
+ /* Currently, Nothing to do. Could be used in future */
+ return 0;
+}
+
+static int _clk_suspend(struct clk_core *clk)
+{
+ struct clk *child;
+ int ret = 0;
+
+ if (!clk)
+ return 0;
+
+ hlist_for_each_entry(child, &clk->children, child_node) {
+ ret = _clk_suspend(child);
+ if (ret)
+ return ret;
+ }
+
+ if (clk->ops->suspend)
+ return clk->ops->suspend(clk->hw);
+
+ return __clk_suspend(clk);
+}
+
+int clk_suspend(void)
+{
+ struct clk_core *clk, *clkerr;
+ int ret;
+
+ hlist_for_each_entry(clk, &clk_root_list, child_node) {
+ ret = _clk_suspend(clk);
+ if (ret) {
+ /* Call resume of suspended clocks if error */
+ hlist_for_each_entry(clkerr, &clk_root_list,
+ child_node) {
+ if (clkerr == clk)
+ goto out;
+ _clk_resume(clkerr);
+ }
+ goto out;
+ }
+ }
+
+ hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
+ ret = _clk_suspend(clk);
+ if (ret) {
+ /* Call resume of suspended clocks if error */
+ hlist_for_each_entry(clkerr, &clk_root_list,
+ child_node)
+ _clk_resume(clkerr);
+ hlist_for_each_entry(clkerr, &clk_orphan_list,
+ child_node) {
+ if (clkerr == clk)
+ goto out;
+ _clk_resume(clkerr);
+ }
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+#endif
+
#ifdef CONFIG_OF
/**
* struct of_clk_provider - Clock provider registration structure
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 5591ea7..ec6438d 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -151,6 +151,18 @@ struct dentry;
* prepare_lock held. Returns 0 on success, -EERROR otherwise.
*
*
+ * @suspend: Called (if defined) when the system is about to enter
+ * Suspend. Framework defined __clk_suspend is called, if
+ * this callback is not defined. Optionally the driver could
+ * also call __clk_suspend inside this callback.
+ * Returns 0 on success, -EERROR otherwise.
+ *
+ * @resume: Called (if defined) when the system is about to exit
+ * Suspend. Framework defined __clk_resume is called, if
+ * this callback is not defined. Optionally the driver could
+ * also call __clk_resume inside this callback.
+ * Returns 0 on success, -EERROR otherwise.
+ *
* The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow
* implementations to split any work between atomic (enable) and sleepable
* (prepare) contexts. If enabling a clock requires code that might sleep,
@@ -194,6 +206,10 @@ struct clk_ops {
int (*set_phase)(struct clk_hw *hw, int degrees);
void (*init)(struct clk_hw *hw);
int (*debug_init)(struct clk_hw *hw, struct dentry *dentry);
+#ifdef CONFIG_PM_SLEEP
+ int (*suspend)(struct clk_hw *hw);
+ int (*resume)(struct clk_hw *hw);
+#endif
};
/**
@@ -596,6 +612,11 @@ static inline void __clk_hw_set_clk(struct clk_hw *dst, struct clk_hw *src)
dst->core = src->core;
}
+#ifdef CONFIG_PM_SLEEP
+int __clk_suspend(struct clk_core *clk);
+int __clk_resume(struct clk_core *clk);
+#endif
+
/*
* FIXME clock api without lock protection
*/
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 68c16a6..5e6a636 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -394,6 +394,23 @@ struct clk *clk_get_parent(struct clk *clk);
*/
struct clk *clk_get_sys(const char *dev_id, const char *con_id);
+#ifdef CONFIG_PM_SLEEP
+/**
+ * clk_suspend - Called by the suspend framework before entering System Suspend
+ *
+ * Returns success (0) or negative errno
+ * Called with Interrupts disabled
+ */
+int clk_suspend(void);
+
+/**
+ * clk_resume - Called by the suspend framework after exiting System Suspend
+ *
+ * Called with Interrupts disabled
+ */
+void clk_resume(void);
+#endif
+
#else /* !CONFIG_HAVE_CLK */
static inline struct clk *clk_get(struct device *dev, const char *id)
@@ -447,6 +464,12 @@ static inline struct clk *clk_get_parent(struct clk *clk)
return NULL;
}
+#ifdef CONFIG_PM_SLEEP
+static inline int clk_suspend(void) {}
+
+static inline void clk_resume(void) {}
+#endif
+
#endif
/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 38c25b1..28bce76 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -36,6 +36,7 @@
#include <linux/syscore_ops.h>
#include <linux/compiler.h>
#include <linux/hugetlb.h>
+#include <linux/clk.h>
#include <asm/page.h>
#include <asm/uaccess.h>
@@ -2724,6 +2725,9 @@ int kernel_kexec(void)
error = syscore_suspend();
if (error)
goto Enable_irqs;
+ error = clk_suspend();
+ if (error)
+ goto Resume_syscore;
} else
#endif
{
@@ -2746,6 +2750,8 @@ int kernel_kexec(void)
#ifdef CONFIG_KEXEC_JUMP
if (kexec_image->preserve_context) {
+ clk_resume();
+ Resume_syscore:
syscore_resume();
Enable_irqs:
local_irq_enable();
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 2329daa..f9b45ff 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -30,6 +30,7 @@
#include <linux/genhd.h>
#include <linux/ktime.h>
#include <trace/events/power.h>
+#include <linux/clk.h>
#include "power.h"
@@ -292,6 +293,12 @@ static int create_image(int platform_mode)
goto Enable_irqs;
}
+ error = clk_suspend();
+ if (error) {
+ pr_err("PM: Clocks Suspend failed aborting hibernation\n");
+ goto Power_up;
+ }
+
if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
goto Power_up;
@@ -310,6 +317,7 @@ static int create_image(int platform_mode)
platform_leave(platform_mode);
+ clk_resume();
Power_up:
syscore_resume();
@@ -442,6 +450,10 @@ static int resume_target_kernel(bool platform_mode)
if (error)
goto Enable_irqs;
+ error = clk_suspend();
+ if (error)
+ goto Resume_syscore;
+
save_processor_state();
error = restore_highmem();
if (!error) {
@@ -467,6 +479,8 @@ static int resume_target_kernel(bool platform_mode)
restore_processor_state();
touch_softlockup_watchdog();
+ clk_resume();
+ Resume_syscore:
syscore_resume();
Enable_irqs:
@@ -556,6 +570,7 @@ int hibernation_platform_enter(void)
local_irq_disable();
syscore_suspend();
+ clk_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
goto Power_up;
@@ -566,6 +581,7 @@ int hibernation_platform_enter(void)
while (1);
Power_up:
+ clk_resume();
syscore_resume();
local_irq_enable();
enable_nonboot_cpus();
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index b7d6b3a..3a9abb7 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -28,6 +28,7 @@
#include <linux/ftrace.h>
#include <trace/events/power.h>
#include <linux/compiler.h>
+#include <linux/clk.h>
#include "power.h"
@@ -349,6 +350,10 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
error = syscore_suspend();
if (!error) {
+ error = clk_suspend();
+ if (error)
+ goto Resume_syscore;
+
*wakeup = pm_wakeup_pending();
if (!(suspend_test(TEST_CORE) || *wakeup)) {
trace_suspend_resume(TPS("machine_suspend"),
@@ -358,6 +363,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
state, false);
events_check_enabled = false;
}
+ clk_resume();
+Resume_syscore:
syscore_resume();
}
--
1.7.5.4
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