[PATCHv2] amba: support pm ops

[Rabin Vincent]

Support pm_ops in the AMBA bus, required to allow drivers to use runtime pm.
The implementation of AMBA bus pm ops is based on the platform bus
implementation.

Signed-off-by: Rabin Vincent <rabin.vincent at stericsson.com>
---
v2: Base the implementation on the platform bus instead of the generic ops,
    implementation all the functions platform does and with the same behaviour.
    Also continue to support the legacy operations so that this patch doesn't
    need to modify all the drivers and thus becomes easier to merge.

 drivers/amba/bus.c       |  329 ++++++++++++++++++++++++++++++++++++++++++----
 include/linux/amba/bus.h |    2 +
 2 files changed, 308 insertions(+), 23 deletions(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index ca96b0a..7bc7762 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -13,12 +13,12 @@
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/pm.h>
 #include <linux/amba/bus.h>
 
 #include <asm/irq.h>
 #include <asm/sizes.h>
 
-#define to_amba_device(d)	container_of(d, struct amba_device, dev)
 #define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
 
 static struct amba_id *
@@ -57,26 +57,6 @@ static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
 #define amba_uevent NULL
 #endif
 
-static int amba_suspend(struct device *dev, pm_message_t state)
-{
-	struct amba_driver *drv = to_amba_driver(dev->driver);
-	int ret = 0;
-
-	if (dev->driver && drv->suspend)
-		ret = drv->suspend(to_amba_device(dev), state);
-	return ret;
-}
-
-static int amba_resume(struct device *dev)
-{
-	struct amba_driver *drv = to_amba_driver(dev->driver);
-	int ret = 0;
-
-	if (dev->driver && drv->resume)
-		ret = drv->resume(to_amba_device(dev));
-	return ret;
-}
-
 #define amba_attr_func(name,fmt,arg...)					\
 static ssize_t name##_show(struct device *_dev,				\
 			   struct device_attribute *attr, char *buf)	\
@@ -102,6 +82,310 @@ static struct device_attribute amba_dev_attrs[] = {
 	__ATTR_NULL,
 };
 
+#ifdef CONFIG_PM_SLEEP
+
+static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
+{
+	struct amba_driver *adrv = to_amba_driver(dev->driver);
+	struct amba_device *adev = to_amba_device(dev);
+	int ret = 0;
+
+	if (dev->driver && adrv->suspend)
+		ret = adrv->suspend(adev, mesg);
+
+	return ret;
+}
+
+static int amba_legacy_resume(struct device *dev)
+{
+	struct amba_driver *adrv = to_amba_driver(dev->driver);
+	struct amba_device *adev = to_amba_device(dev);
+	int ret = 0;
+
+	if (dev->driver && adrv->resume)
+		ret = adrv->resume(adev);
+
+	return ret;
+}
+
+static int amba_pm_prepare(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (drv && drv->pm && drv->pm->prepare)
+		ret = drv->pm->prepare(dev);
+
+	return ret;
+}
+
+static void amba_pm_complete(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+
+	if (drv && drv->pm && drv->pm->complete)
+		drv->pm->complete(dev);
+}
+
+#else /* !CONFIG_PM_SLEEP */
+
+#define amba_pm_prepare		NULL
+#define amba_pm_complete		NULL
+
+#endif /* !CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_SUSPEND
+
+static int amba_pm_suspend(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->suspend)
+			ret = drv->pm->suspend(dev);
+	} else {
+		ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
+	}
+
+	return ret;
+}
+
+static int amba_pm_suspend_noirq(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->suspend_noirq)
+			ret = drv->pm->suspend_noirq(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_resume(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->resume)
+			ret = drv->pm->resume(dev);
+	} else {
+		ret = amba_legacy_resume(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_resume_noirq(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->resume_noirq)
+			ret = drv->pm->resume_noirq(dev);
+	}
+
+	return ret;
+}
+
+#else /* !CONFIG_SUSPEND */
+
+#define amba_pm_suspend		NULL
+#define amba_pm_resume		NULL
+#define amba_pm_suspend_noirq	NULL
+#define amba_pm_resume_noirq	NULL
+
+#endif /* !CONFIG_SUSPEND */
+
+#ifdef CONFIG_HIBERNATION
+
+static int amba_pm_freeze(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->freeze)
+			ret = drv->pm->freeze(dev);
+	} else {
+		ret = amba_legacy_suspend(dev, PMSG_FREEZE);
+	}
+
+	return ret;
+}
+
+static int amba_pm_freeze_noirq(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->freeze_noirq)
+			ret = drv->pm->freeze_noirq(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_thaw(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->thaw)
+			ret = drv->pm->thaw(dev);
+	} else {
+		ret = amba_legacy_resume(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_thaw_noirq(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->thaw_noirq)
+			ret = drv->pm->thaw_noirq(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_poweroff(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->poweroff)
+			ret = drv->pm->poweroff(dev);
+	} else {
+		ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
+	}
+
+	return ret;
+}
+
+static int amba_pm_poweroff_noirq(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->poweroff_noirq)
+			ret = drv->pm->poweroff_noirq(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_restore(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->restore)
+			ret = drv->pm->restore(dev);
+	} else {
+		ret = amba_legacy_resume(dev);
+	}
+
+	return ret;
+}
+
+static int amba_pm_restore_noirq(struct device *dev)
+{
+	struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->restore_noirq)
+			ret = drv->pm->restore_noirq(dev);
+	}
+
+	return ret;
+}
+
+#else /* !CONFIG_HIBERNATION */
+
+#define amba_pm_freeze		NULL
+#define amba_pm_thaw		NULL
+#define amba_pm_poweroff		NULL
+#define amba_pm_restore		NULL
+#define amba_pm_freeze_noirq	NULL
+#define amba_pm_thaw_noirq		NULL
+#define amba_pm_poweroff_noirq	NULL
+#define amba_pm_restore_noirq	NULL
+
+#endif /* !CONFIG_HIBERNATION */
+
+static const struct dev_pm_ops amba_pm = {
+	.prepare	= amba_pm_prepare,
+	.complete	= amba_pm_complete,
+	.suspend	= amba_pm_suspend,
+	.resume		= amba_pm_resume,
+	.freeze		= amba_pm_freeze,
+	.thaw		= amba_pm_thaw,
+	.poweroff	= amba_pm_poweroff,
+	.restore	= amba_pm_restore,
+	.suspend_noirq	= amba_pm_suspend_noirq,
+	.resume_noirq	= amba_pm_resume_noirq,
+	.freeze_noirq	= amba_pm_freeze_noirq,
+	.thaw_noirq	= amba_pm_thaw_noirq,
+	.poweroff_noirq	= amba_pm_poweroff_noirq,
+	.restore_noirq	= amba_pm_restore_noirq,
+	SET_RUNTIME_PM_OPS(
+		pm_generic_runtime_suspend,
+		pm_generic_runtime_resume,
+		pm_generic_runtime_idle
+	)
+};
+
 /*
  * Primecells are part of the Advanced Microcontroller Bus Architecture,
  * so we call the bus "amba".
@@ -111,8 +395,7 @@ struct bus_type amba_bustype = {
 	.dev_attrs	= amba_dev_attrs,
 	.match		= amba_match,
 	.uevent		= amba_uevent,
-	.suspend	= amba_suspend,
-	.resume		= amba_resume,
+	.pm		= &amba_pm,
 };
 
 static int __init amba_init(void)
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index a0ccf28..1849975 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -58,6 +58,8 @@ enum amba_vendor {
 
 extern struct bus_type amba_bustype;
 
+#define to_amba_device(d)	container_of(d, struct amba_device, dev)
+
 #define amba_get_drvdata(d)	dev_get_drvdata(&d->dev)
 #define amba_set_drvdata(d,p)	dev_set_drvdata(&d->dev, p)
 
-- 
1.7.2.dirty