ARM: 6758/1: amba: support pm ops

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.
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/amba/bus.c

@@ -13,12 +13,13 @@
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.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 const struct amba_id *
@@ -57,26 +58,6 @@ 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 +83,320 @@ 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 */
+
+#ifdef CONFIG_PM
+
+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
+	)
+};
+
+#define AMBA_PM (&amba_pm)
+
+#else /* !CONFIG_PM */
+
+#define AMBA_PM	NULL
+
+#endif /* !CONFIG_PM */
+
 /*
  * Primecells are part of the Advanced Microcontroller Bus Architecture,
  * so we call the bus "amba".
@@ -111,8 +406,7 @@ 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)

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)