i2c: Fix bus-level power management callbacks
There are three issues with the i2c bus type's power management
callbacks at the moment. First, they don't include any hibernate
callbacks, although they should at least include the .restore()
callback (there's no guarantee that the driver will be present in
memory before loading the image kernel and we must restore the
pre-hibernation state of the device). Second, the "legacy"
callbacks are not going to be invoked by the PM core since the bus
type's pm object is not NULL. Finally, the system sleep PM
(ie. suspend/resume) callbacks don't check if the device has been
already suspended at run time, in which case they should skip
suspending it. Also, it looks like the i2c bus type can use the
generic subsystem-level runtime PM callbacks.
For these reasons, rework the system sleep PM callbacks provided by
the i2c bus type to handle hibernation correctly and to invoke the
"legacy" callbacks for drivers that provide them. In addition to
that make the i2c bus type use the generic subsystem-level runtime
PM callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index c2258a5..7c469a6 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -159,82 +159,8 @@
driver->shutdown(client);
}
-#ifdef CONFIG_SUSPEND
-static int i2c_device_pm_suspend(struct device *dev)
-{
- const struct dev_pm_ops *pm;
-
- if (!dev->driver)
- return 0;
- pm = dev->driver->pm;
- if (!pm || !pm->suspend)
- return 0;
- return pm->suspend(dev);
-}
-
-static int i2c_device_pm_resume(struct device *dev)
-{
- const struct dev_pm_ops *pm;
-
- if (!dev->driver)
- return 0;
- pm = dev->driver->pm;
- if (!pm || !pm->resume)
- return 0;
- return pm->resume(dev);
-}
-#else
-#define i2c_device_pm_suspend NULL
-#define i2c_device_pm_resume NULL
-#endif
-
-#ifdef CONFIG_PM_RUNTIME
-static int i2c_device_runtime_suspend(struct device *dev)
-{
- const struct dev_pm_ops *pm;
-
- if (!dev->driver)
- return 0;
- pm = dev->driver->pm;
- if (!pm || !pm->runtime_suspend)
- return 0;
- return pm->runtime_suspend(dev);
-}
-
-static int i2c_device_runtime_resume(struct device *dev)
-{
- const struct dev_pm_ops *pm;
-
- if (!dev->driver)
- return 0;
- pm = dev->driver->pm;
- if (!pm || !pm->runtime_resume)
- return 0;
- return pm->runtime_resume(dev);
-}
-
-static int i2c_device_runtime_idle(struct device *dev)
-{
- const struct dev_pm_ops *pm = NULL;
- int ret;
-
- if (dev->driver)
- pm = dev->driver->pm;
- if (pm && pm->runtime_idle) {
- ret = pm->runtime_idle(dev);
- if (ret)
- return ret;
- }
-
- return pm_runtime_suspend(dev);
-}
-#else
-#define i2c_device_runtime_suspend NULL
-#define i2c_device_runtime_resume NULL
-#define i2c_device_runtime_idle NULL
-#endif
-
-static int i2c_device_suspend(struct device *dev, pm_message_t mesg)
+#ifdef CONFIG_PM_SLEEP
+static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg)
{
struct i2c_client *client = i2c_verify_client(dev);
struct i2c_driver *driver;
@@ -247,7 +173,7 @@
return driver->suspend(client, mesg);
}
-static int i2c_device_resume(struct device *dev)
+static int i2c_legacy_resume(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
struct i2c_driver *driver;
@@ -260,6 +186,104 @@
return driver->resume(client);
}
+static int i2c_device_pm_suspend(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm_runtime_suspended(dev))
+ return 0;
+
+ if (pm)
+ return pm->suspend ? pm->suspend(dev) : 0;
+
+ return i2c_legacy_suspend(dev, PMSG_SUSPEND);
+}
+
+static int i2c_device_pm_resume(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+ int ret;
+
+ if (pm)
+ ret = pm->resume ? pm->resume(dev) : 0;
+ else
+ ret = i2c_legacy_resume(dev);
+
+ if (!ret) {
+ pm_runtime_disable(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+ }
+
+ return ret;
+}
+
+static int i2c_device_pm_freeze(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm_runtime_suspended(dev))
+ return 0;
+
+ if (pm)
+ return pm->freeze ? pm->freeze(dev) : 0;
+
+ return i2c_legacy_suspend(dev, PMSG_FREEZE);
+}
+
+static int i2c_device_pm_thaw(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm_runtime_suspended(dev))
+ return 0;
+
+ if (pm)
+ return pm->thaw ? pm->thaw(dev) : 0;
+
+ return i2c_legacy_resume(dev);
+}
+
+static int i2c_device_pm_poweroff(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm_runtime_suspended(dev))
+ return 0;
+
+ if (pm)
+ return pm->poweroff ? pm->poweroff(dev) : 0;
+
+ return i2c_legacy_suspend(dev, PMSG_HIBERNATE);
+}
+
+static int i2c_device_pm_restore(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+ int ret;
+
+ if (pm)
+ ret = pm->restore ? pm->restore(dev) : 0;
+ else
+ ret = i2c_legacy_resume(dev);
+
+ if (!ret) {
+ pm_runtime_disable(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+ }
+
+ return ret;
+}
+#else /* !CONFIG_PM_SLEEP */
+#define i2c_device_pm_suspend NULL
+#define i2c_device_pm_resume NULL
+#define i2c_device_pm_freeze NULL
+#define i2c_device_pm_thaw NULL
+#define i2c_device_pm_poweroff NULL
+#define i2c_device_pm_restore NULL
+#endif /* !CONFIG_PM_SLEEP */
+
static void i2c_client_dev_release(struct device *dev)
{
kfree(to_i2c_client(dev));
@@ -301,9 +325,15 @@
static const struct dev_pm_ops i2c_device_pm_ops = {
.suspend = i2c_device_pm_suspend,
.resume = i2c_device_pm_resume,
- .runtime_suspend = i2c_device_runtime_suspend,
- .runtime_resume = i2c_device_runtime_resume,
- .runtime_idle = i2c_device_runtime_idle,
+ .freeze = i2c_device_pm_freeze,
+ .thaw = i2c_device_pm_thaw,
+ .poweroff = i2c_device_pm_poweroff,
+ .restore = i2c_device_pm_restore,
+ SET_RUNTIME_PM_OPS(
+ pm_generic_runtime_suspend,
+ pm_generic_runtime_resume,
+ pm_generic_runtime_idle
+ )
};
struct bus_type i2c_bus_type = {
@@ -312,8 +342,6 @@
.probe = i2c_device_probe,
.remove = i2c_device_remove,
.shutdown = i2c_device_shutdown,
- .suspend = i2c_device_suspend,
- .resume = i2c_device_resume,
.pm = &i2c_device_pm_ops,
};
EXPORT_SYMBOL_GPL(i2c_bus_type);
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index b776db7..6e81888 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -30,6 +30,9 @@
extern void __pm_runtime_disable(struct device *dev, bool check_resume);
extern void pm_runtime_allow(struct device *dev);
extern void pm_runtime_forbid(struct device *dev);
+extern int pm_generic_runtime_idle(struct device *dev);
+extern int pm_generic_runtime_suspend(struct device *dev);
+extern int pm_generic_runtime_resume(struct device *dev);
static inline bool pm_children_suspended(struct device *dev)
{
@@ -96,6 +99,10 @@
static inline void device_set_run_wake(struct device *dev, bool enable) {}
static inline bool pm_runtime_suspended(struct device *dev) { return false; }
+static inline int pm_generic_runtime_idle(struct device *dev) { return 0; }
+static inline int pm_generic_runtime_suspend(struct device *dev) { return 0; }
+static inline int pm_generic_runtime_resume(struct device *dev) { return 0; }
+
#endif /* !CONFIG_PM_RUNTIME */
static inline int pm_runtime_get(struct device *dev)