i2c: Add driver suspend/resume/shutdown support

Driver model updates for the I2C core:

 - Add new suspend(), resume(), and shutdown() methods.  Use them in the
   standard driver model style; document them.

 - Minor doc updates to highlight zero-initialized fields in drivers, and
   the driver model accessors for "clientdata".

If any i2c drivers were previously using the old suspend/resume calls
in "struct driver", they were getting warning messages ... and will
now no longer work.  Other than that, this patch changes no behaviors;
and it lets I2C drivers use conventional PM and shutdown support.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 44 insertions, 21 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 60f6eb194046..9653f7f81561 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -41,49 +41,72 @@ static LIST_HEAD(drivers);
 static DEFINE_MUTEX(core_lists);
 static DEFINE_IDR(i2c_adapter_idr);
 
+
+/* ------------------------------------------------------------------------- */
+
 /* match always succeeds, as we want the probe() to tell if we really accept this match */
 static int i2c_device_match(struct device *dev, struct device_driver *drv)
 {
         return 1;
 }
 
-static int i2c_bus_suspend(struct device * dev, pm_message_t state)
+static int i2c_device_probe(struct device *dev)
 {
-        int rc = 0;
+        return -ENODEV;
+}
 
-        if (dev->driver && dev->driver->suspend)
-                rc = dev->driver->suspend(dev, state);
-        return rc;
+static int i2c_device_remove(struct device *dev)
+{
+        return 0;
 }
 
-static int i2c_bus_resume(struct device * dev)
+static void i2c_device_shutdown(struct device *dev)
 {
-        int rc = 0;
-        
-        if (dev->driver && dev->driver->resume)
-                rc = dev->driver->resume(dev);
-        return rc;
+        struct i2c_driver *driver;
+
+        if (!dev->driver)
+                return;
+        driver = to_i2c_driver(dev->driver);
+        if (driver->shutdown)
+                driver->shutdown(to_i2c_client(dev));
 }
 
-static int i2c_device_probe(struct device *dev)
+static int i2c_device_suspend(struct device * dev, pm_message_t mesg)
 {
-        return -ENODEV;
+        struct i2c_driver *driver;
+
+        if (!dev->driver)
+                return 0;
+        driver = to_i2c_driver(dev->driver);
+        if (!driver->suspend)
+                return 0;
+        return driver->suspend(to_i2c_client(dev), mesg);
 }
 
-static int i2c_device_remove(struct device *dev)
+static int i2c_device_resume(struct device * dev)
 {
-        return 0;
+        struct i2c_driver *driver;
+
+        if (!dev->driver)
+                return 0;
+        driver = to_i2c_driver(dev->driver);
+        if (!driver->resume)
+                return 0;
+        return driver->resume(to_i2c_client(dev));
 }
 
 struct bus_type i2c_bus_type = {
-        .name =         "i2c",
-        .match =        i2c_device_match,
-        .probe =        i2c_device_probe,
-        .remove =       i2c_device_remove,
-        .suspend =      i2c_bus_suspend,
-        .resume =       i2c_bus_resume,
+        .name           = "i2c",
+        .match          = i2c_device_match,
+        .probe          = i2c_device_probe,
+        .remove         = i2c_device_remove,
+        .shutdown       = i2c_device_shutdown,
+        .suspend        = i2c_device_suspend,
+        .resume         = i2c_device_resume,
 };
 
+/* ------------------------------------------------------------------------- */
+
 void i2c_adapter_dev_release(struct device *dev)
 {
         struct i2c_adapter *adap = dev_to_i2c_adapter(dev);