[PATCH 09/11] driver core: Add dev_set_drv_sync_state()

[Ulf Hansson]

From: Saravana Kannan <saravanak at google.com>

This can be used by frameworks to set the sync_state() helper functions
for drivers that don't already have them set.

Signed-off-by: Saravana Kannan <saravanak at google.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
---

Note that, I have picked this patch from another series [1] that are about to be
re-freshed.

[1]
https://lore.kernel.org/all/YG6lhT7vuiCNvvDg@kroah.com/

---
 include/linux/device.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/linux/device.h b/include/linux/device.h
index 79e49fe494b7..544523d48cd4 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -955,6 +955,18 @@ static inline bool dev_has_sync_state(struct device *dev)
 	return false;
 }
 
+static inline int dev_set_drv_sync_state(struct device *dev,
+					 void (*fn)(struct device *dev))
+{
+	if (!dev || !dev->driver)
+		return 0;
+	if (dev->driver->sync_state && dev->driver->sync_state != fn)
+		return -EBUSY;
+	if (!dev->driver->sync_state)
+		dev->driver->sync_state = fn;
+	return 0;
+}
+
 static inline void dev_set_removable(struct device *dev,
 				     enum device_removable removable)
 {
-- 
2.43.0