driver core: add dev_groups to all drivers

Add the ability for the driver core to create and remove a list of
attribute groups automatically when the device is bound/unbound from a
specific driver.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Richard Gong <richard.gong@linux.intel.com>
Link: https://lore.kernel.org/r/20190731124349.4474-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/dd.c

@@ -554,9 +554,16 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 			goto probe_failed;
 	}
 
+	if (device_add_groups(dev, drv->dev_groups)) {
+		dev_err(dev, "device_add_groups() failed\n");
+		goto dev_groups_failed;
+	}
+
 	if (test_remove) {
 		test_remove = false;
 
+		device_remove_groups(dev, drv->dev_groups);
+
 		if (dev->bus->remove)
 			dev->bus->remove(dev);
 		else if (drv->remove)
@@ -584,6 +591,11 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		 drv->bus->name, __func__, dev_name(dev), drv->name);
 	goto done;
 
+dev_groups_failed:
+	if (dev->bus->remove)
+		dev->bus->remove(dev);
+	else if (drv->remove)
+		drv->remove(dev);
 probe_failed:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
@@ -1114,6 +1126,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 
 		pm_runtime_put_sync(dev);
 
+		device_remove_groups(dev, drv->dev_groups);
+
 		if (dev->bus && dev->bus->remove)
 			dev->bus->remove(dev);
 		else if (drv->remove)

include/linux/device.h

@@ -262,6 +262,8 @@ enum probe_type {
  * @resume:	Called to bring a device from sleep mode.
  * @groups:	Default attributes that get created by the driver core
  *		automatically.
+ * @dev_groups:	Additional attributes attached to device instance once the
+ *		it is bound to the driver.
  * @pm:		Power management operations of the device which matched
  *		this driver.
  * @coredump:	Called when sysfs entry is written to. The device driver
@@ -296,6 +298,7 @@ struct device_driver {
 	int (*suspend) (struct device *dev, pm_message_t state);
 	int (*resume) (struct device *dev);
 	const struct attribute_group **groups;
+	const struct attribute_group **dev_groups;
 
 	const struct dev_pm_ops *pm;
 	void (*coredump) (struct device *dev);