diff mbox

[7/9] PM / Runtime: Add generic clock manipulation rountines for runtime PM

Message ID 201104170142.10723.rjw@sisk.pl (mailing list archive)
State Not Applicable
Headers show

Commit Message

Rafael Wysocki April 16, 2011, 11:42 p.m. UTC
From: Rafael J. Wysocki <rjw@sisk.pl>

Many different platforms and subsystems may want to disable device
clocks during suspend and enable them during resume which is going to
be done in a very similar way in all those cases.  For this reason,
provide generic routines for the manipulation of device clocks during
suspend and resume.

Convert the ARM shmobile platform to using the new routines.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 arch/arm/mach-shmobile/pm_runtime.c |  139 +--------------------------
 drivers/base/power/Makefile         |    1 
 drivers/base/power/clock_ops.c      |  179 ++++++++++++++++++++++++++++++++++++
 include/linux/pm_runtime.h          |   27 +++++
 kernel/power/Kconfig                |    4 
 5 files changed, 216 insertions(+), 134 deletions(-)


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Comments

Mark Brown April 19, 2011, 10:58 a.m. UTC | #1
On Sun, Apr 17, 2011 at 01:42:10AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Many different platforms and subsystems may want to disable device
> clocks during suspend and enable them during resume which is going to
> be done in a very similar way in all those cases.  For this reason,
> provide generic routines for the manipulation of device clocks during
> suspend and resume.

> Convert the ARM shmobile platform to using the new routines.

I've had similar thoughts with respect to the regulator API - I'd been
thinking of dealing with this by adding a notifier which subsystems
could build upon, in much the same way as already exists for the system
ssuspend and resume events.
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Rafael Wysocki April 19, 2011, 9:35 p.m. UTC | #2
On Tuesday, April 19, 2011, Mark Brown wrote:
> On Sun, Apr 17, 2011 at 01:42:10AM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > 
> > Many different platforms and subsystems may want to disable device
> > clocks during suspend and enable them during resume which is going to
> > be done in a very similar way in all those cases.  For this reason,
> > provide generic routines for the manipulation of device clocks during
> > suspend and resume.
> 
> > Convert the ARM shmobile platform to using the new routines.
> 
> I've had similar thoughts with respect to the regulator API - I'd been
> thinking of dealing with this by adding a notifier which subsystems
> could build upon, in much the same way as already exists for the system
> ssuspend and resume events.

Well, I generally avoid using notifiers, because they lead to big functions
that carry out many different tasks.

That said, I think consolidation and reduction of duplicate code is all good,
this way or another. :-)

Thanks,
Rafael
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Mark Brown April 20, 2011, 11:57 a.m. UTC | #3
On Tue, Apr 19, 2011 at 11:35:34PM +0200, Rafael J. Wysocki wrote:
> On Tuesday, April 19, 2011, Mark Brown wrote:

> > I've had similar thoughts with respect to the regulator API - I'd been
> > thinking of dealing with this by adding a notifier which subsystems
> > could build upon, in much the same way as already exists for the system
> > ssuspend and resume events.

> Well, I generally avoid using notifiers, because they lead to big functions
> that carry out many different tasks.

> That said, I think consolidation and reduction of duplicate code is all good,
> this way or another. :-)

Well, if you're comfortable with adding explicit regulator API hooks in
the code directly then I can just do that - I'd been thinking notifiers
since they mean you don't have to worry about what's going on with it
but if you're happy with making it explicit that's fine by me also.
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diff mbox

Patch

Index: linux-2.6/drivers/base/power/clock_ops.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/base/power/clock_ops.c
@@ -0,0 +1,179 @@ 
+/*
+ * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
+ *
+ * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Jinzai Solution Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+
+#ifdef CONFIG_PM_RUNTIME
+
+struct pm_runtime_data {
+	struct clk *clk;
+	unsigned int clock_active:1;
+	unsigned int clock_enabled:1;
+};
+
+static struct pm_runtime_data *__to_prd(struct device *dev)
+{
+	return dev ? dev->power.subsys_data : NULL;
+}
+
+int pm_runtime_clock_add(struct device *dev)
+{
+	struct pm_runtime_data *prd;
+
+	prd = kzalloc(sizeof(*prd), GFP_KERNEL);
+	if (!prd) {
+		dev_err(dev, "unable to allocate memory for runtime PM\n");
+		return -ENOMEM;
+	}
+
+	dev->power.subsys_data = prd;
+	return 0;
+}
+
+void pm_runtime_clock_remove(struct device *dev)
+{
+	struct pm_runtime_data *prd = __to_prd(dev);
+
+	if (!prd)
+		return;
+
+	if (prd->clk) {
+		if (prd->clock_enabled)
+			clk_disable(prd->clk);
+
+		if (prd->clock_active)
+			clk_put(prd->clk);
+	}
+
+	kfree(prd);
+}
+
+static void pm_runtime_clock_init(struct device *dev,
+				  struct pm_runtime_data *prd)
+{
+	prd->clk = clk_get(dev, NULL);
+	if (!IS_ERR(prd->clk)) {
+		prd->clock_active = true;
+		dev_info(dev, "clock managed by runtime PM\n");
+	}
+}
+
+int pm_runtime_clock_suspend(struct device *dev)
+{
+	struct pm_runtime_data *prd = __to_prd(dev);
+
+	dev_dbg(dev, "%s()\n", __func__);
+
+	if (prd) {
+		if (!prd->clk) {
+			dev_err(dev, "clock is not ready for runtime PM\n");
+			pm_runtime_clock_init(dev, prd);
+		}
+
+		if (prd->clock_active) {
+			clk_disable(prd->clk);
+			prd->clock_enabled = false;
+		}
+	}
+
+	return 0;
+}
+
+int pm_runtime_clock_resume(struct device *dev)
+{
+	struct pm_runtime_data *prd = __to_prd(dev);
+
+	dev_dbg(dev, "%s()\n", __func__);
+
+	if (prd) {
+		if (!prd->clk)
+			pm_runtime_clock_init(dev, prd);
+
+		if (prd->clock_active) {
+			clk_enable(prd->clk);
+			prd->clock_enabled = true;
+		}
+	}
+
+	return 0;
+}
+
+static int pm_runtime_clock_notify(struct notifier_block *nb,
+				   unsigned long action, void *data)
+{
+	struct pm_domain_notifier_block *pdnb;
+	struct device *dev = data;
+
+	dev_dbg(dev, "%s() %ld\n", __func__, action);
+
+	pdnb = container_of(nb, struct pm_domain_notifier_block, nb);
+
+	switch (action) {
+	case BUS_NOTIFY_BIND_DRIVER:
+		dev->pwr_domain = pdnb->pwr_domain;
+		pm_runtime_clock_add(dev);
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		dev->pwr_domain = NULL;
+		pm_runtime_clock_remove(dev);
+		break;
+	}
+
+	return 0;
+}
+
+#else /* !CONFIG_PM_RUNTIME */
+
+static int pm_runtime_clock_notify(struct notifier_block *nb,
+				   unsigned long action, void *data)
+{
+	struct device *dev = data;
+	struct clk *clk;
+
+	dev_dbg(dev, "%s() %ld\n", __func__, action);
+
+	switch (action) {
+	case BUS_NOTIFY_BIND_DRIVER:
+		clk = clk_get(dev, NULL);
+		if (!IS_ERR(clk)) {
+			clk_enable(clk);
+			clk_put(clk);
+			dev_info(dev, "runtime PM disabled, clock forced on\n");
+		}
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		clk = clk_get(dev, NULL);
+		if (!IS_ERR(clk)) {
+			clk_disable(clk);
+			clk_put(clk);
+			dev_info(dev, "runtime PM disabled, clock forced off\n");
+		}
+		break;
+	}
+
+	return 0;
+}
+
+#endif /* !CONFIG_PM_RUNTIME */
+
+void pm_runtim_clock_add_notifier(struct bus_type *bus,
+				  struct pm_domain_notifier_block *pdnb)
+{
+	if (!bus || !pdnb)
+		return;
+
+	pdnb->nb.notifier_call = pm_runtime_clock_notify;
+	bus_register_notifier(bus, &pdnb->nb);
+}
Index: linux-2.6/kernel/power/Kconfig
===================================================================
--- linux-2.6.orig/kernel/power/Kconfig
+++ linux-2.6/kernel/power/Kconfig
@@ -229,3 +229,7 @@  config PM_OPP
 	  representing individual voltage domains and provides SOC
 	  implementations a ready to use framework to manage OPPs.
 	  For more information, read <file:Documentation/power/opp.txt>
+
+config PM_RUNTIME_CLK
+	def_bool y
+	depends on PM_RUNTIME && HAVE_CLK
Index: linux-2.6/drivers/base/power/Makefile
===================================================================
--- linux-2.6.orig/drivers/base/power/Makefile
+++ linux-2.6/drivers/base/power/Makefile
@@ -3,6 +3,7 @@  obj-$(CONFIG_PM_SLEEP)	+= main.o wakeup.
 obj-$(CONFIG_PM_RUNTIME)	+= runtime.o
 obj-$(CONFIG_PM_TRACE_RTC)	+= trace.o
 obj-$(CONFIG_PM_OPP)	+= opp.o
+obj-$(CONFIG_HAVE_CLK)	+= clock_ops.o
 
 ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
 ccflags-$(CONFIG_PM_VERBOSE)   += -DDEBUG
Index: linux-2.6/include/linux/pm_runtime.h
===================================================================
--- linux-2.6.orig/include/linux/pm_runtime.h
+++ linux-2.6/include/linux/pm_runtime.h
@@ -245,4 +245,31 @@  static inline void pm_runtime_dont_use_a
 	__pm_runtime_use_autosuspend(dev, false);
 }
 
+struct pm_domain_notifier_block {
+	struct notifier_block nb;
+	struct dev_power_domain *pwr_domain;
+};
+
+#ifdef CONFIG_PM_RUNTIME_CLK
+extern int pm_runtime_clock_add(struct device *dev);
+extern void pm_runtime_clock_remove(struct device *dev);
+extern int pm_runtime_clock_suspend(struct device *dev);
+extern int pm_runtime_clock_resume(struct device *dev);
+#else
+static inline pm_runtime_clock_add(struct device *dev) { return -EINVAL; }
+static inline pm_runtime_clock_remove(struct device *dev) {}
+#define pm_runtime_clock_suspend	NULL
+#define pm_runtime_clock_resume		NULL
+#endif
+
+#ifdef CONFIG_HAVE_CLK
+extern void pm_runtim_clock_add_notifier(struct bus_type *bus,
+					 struct pm_domain_notifier_block *pdnb);
+#else
+static inline void pm_runtim_clock_add_notifier(struct bus_type *bus,
+					 struct pm_domain_notifier_block *pdnb);
+{
+}
+#endif
+
 #endif
Index: linux-2.6/arch/arm/mach-shmobile/pm_runtime.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shmobile/pm_runtime.c
+++ linux-2.6/arch/arm/mach-shmobile/pm_runtime.c
@@ -21,70 +21,6 @@ 
 #include <linux/slab.h>
 
 #ifdef CONFIG_PM_RUNTIME
-#define BIT_ONCE 0
-#define BIT_ACTIVE 1
-#define BIT_CLK_ENABLED 2
-
-struct pm_runtime_data {
-	unsigned long flags;
-	struct clk *clk;
-};
-
-static struct pm_runtime_data *__to_prd(struct device *dev)
-{
-	return dev ? dev->power.subsys_data : NULL;
-}
-
-static void platform_pm_runtime_init(struct device *dev,
-				     struct pm_runtime_data *prd)
-{
-	if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags)) {
-		prd->clk = clk_get(dev, NULL);
-		if (!IS_ERR(prd->clk)) {
-			set_bit(BIT_ACTIVE, &prd->flags);
-			dev_info(dev, "clocks managed by runtime pm\n");
-		}
-	}
-}
-
-static void platform_pm_runtime_bug(struct device *dev,
-				    struct pm_runtime_data *prd)
-{
-	if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags))
-		dev_err(dev, "runtime pm suspend before resume\n");
-}
-
-static int default_platform_runtime_suspend(struct device *dev)
-{
-	struct pm_runtime_data *prd = __to_prd(dev);
-
-	dev_dbg(dev, "%s()\n", __func__);
-
-	platform_pm_runtime_bug(dev, prd);
-
-	if (prd && test_bit(BIT_ACTIVE, &prd->flags)) {
-		clk_disable(prd->clk);
-		clear_bit(BIT_CLK_ENABLED, &prd->flags);
-	}
-
-	return 0;
-}
-
-static int default_platform_runtime_resume(struct device *dev)
-{
-	struct pm_runtime_data *prd = __to_prd(dev);
-
-	dev_dbg(dev, "%s()\n", __func__);
-
-	platform_pm_runtime_init(dev, prd);
-
-	if (prd && test_bit(BIT_ACTIVE, &prd->flags)) {
-		clk_enable(prd->clk);
-		set_bit(BIT_CLK_ENABLED, &prd->flags);
-	}
-
-	return 0;
-}
 
 static int default_platform_runtime_idle(struct device *dev)
 {
@@ -95,86 +31,21 @@  static int default_platform_runtime_idle
 static struct dev_power_domain default_power_domain = {
 	.ops = {
 		USE_PLATFORM_PM_SLEEP_OPS,
-		.runtime_suspend = default_platform_runtime_suspend,
-		.runtime_resume = default_platform_runtime_resume,
+		.runtime_suspend = pm_runtime_clock_suspend,
+		.runtime_resume = pm_runtime_clock_resume,
 		.runtime_idle = default_platform_runtime_idle,
 	},
 };
 
-static int platform_bus_notify(struct notifier_block *nb,
-			       unsigned long action, void *data)
-{
-	struct device *dev = data;
-	struct pm_runtime_data *prd;
-
-	dev_dbg(dev, "platform_bus_notify() %ld !\n", action);
-
-	switch (action) {
-	case BUS_NOTIFY_BIND_DRIVER:
-		prd = kzalloc(sizeof(*prd), GFP_KERNEL);
-		if (prd) {
-			dev->power.subsys_data = prd;
-			dev->pwr_domain = &default_power_domain;
-		} else {
-			dev_err(dev, "unable to alloc memory for runtime pm\n");
-		}
-		break;
-	case BUS_NOTIFY_UNBOUND_DRIVER:
-		prd = __to_prd(dev);
-		if (prd) {
-			if (test_bit(BIT_CLK_ENABLED, &prd->flags))
-				clk_disable(prd->clk);
-
-			if (test_bit(BIT_ACTIVE, &prd->flags))
-				clk_put(prd->clk);
-		}
-		break;
-	}
-
-	return 0;
-}
-
-#else /* CONFIG_PM_RUNTIME */
-
-static int platform_bus_notify(struct notifier_block *nb,
-			       unsigned long action, void *data)
-{
-	struct device *dev = data;
-	struct clk *clk;
-
-	dev_dbg(dev, "platform_bus_notify() %ld !\n", action);
-
-	switch (action) {
-	case BUS_NOTIFY_BIND_DRIVER:
-		clk = clk_get(dev, NULL);
-		if (!IS_ERR(clk)) {
-			clk_enable(clk);
-			clk_put(clk);
-			dev_info(dev, "runtime pm disabled, clock forced on\n");
-		}
-		break;
-	case BUS_NOTIFY_UNBOUND_DRIVER:
-		clk = clk_get(dev, NULL);
-		if (!IS_ERR(clk)) {
-			clk_disable(clk);
-			clk_put(clk);
-			dev_info(dev, "runtime pm disabled, clock forced off\n");
-		}
-		break;
-	}
-
-	return 0;
-}
-
 #endif /* CONFIG_PM_RUNTIME */
 
-static struct notifier_block platform_bus_notifier = {
-	.notifier_call = platform_bus_notify
+static struct pm_domain_notifier_block platform_bus_notifier = {
+	.pwr_domain = &default_power_domain,
 };
 
 static int __init sh_pm_runtime_init(void)
 {
-	bus_register_notifier(&platform_bus_type, &platform_bus_notifier);
+	pm_runtim_clock_add_notifier(&platform_bus_type, &platform_bus_notifier);
 	return 0;
 }
 core_initcall(sh_pm_runtime_init);