[PATCH v4 3/3] i2c: Extend i2c_device_get_match_data() to support i2c sysfs

[Biju Das <biju.das.jz@xxxxxxxxxxxxxx>]

Extend i2c_device_get_match_data() to i2c sysfs interface by changing
i2c_of_match_device_sysfs() to non-static and call this function as a
fallback for i2c_get_match_data_helper().

Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Suggested-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v4:
 * split from patch #2
 * Added space after of_device_id for i2c_of_match_device_sysfs()
 * Added const parameter for struct i2c_client, to prevent overriding it's
   pointer.
 * Moved declaration from public i2c.h->i2c-core.h
---
 drivers/i2c/i2c-core-base.c | 16 +++++++++++++++-
 drivers/i2c/i2c-core-of.c   |  5 +++--
 drivers/i2c/i2c-core.h      |  9 +++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 2436f23e63af..d002c5a1cc84 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -131,11 +131,25 @@ static const void *i2c_device_get_match_data(const struct device *dev)
 	/* TODO: use i2c_verify_client() when it accepts const pointer */
 	const struct i2c_client *client = (dev->type == &i2c_client_type) ?
 					  to_i2c_client(dev) : NULL;
+	const void *data;
 
 	if (!client || !dev->driver)
 		return NULL;
 
-	return i2c_get_match_data_helper(client);
+	data = i2c_get_match_data_helper(client);
+	if (data)
+		return data;
+
+	if (dev->driver->of_match_table) {
+		const struct of_device_id *match;
+
+		match = i2c_of_match_device_sysfs(dev->driver->of_match_table,
+						  client);
+		if (match)
+			return match->data;
+	}
+
+	return data;
 }
 
 const void *i2c_get_match_data(const struct i2c_client *client)
diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index a6c407d36800..179b3486904a 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -113,9 +113,9 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
 	of_node_put(bus);
 }
 
-static const struct of_device_id*
+const struct of_device_id *
 i2c_of_match_device_sysfs(const struct of_device_id *matches,
-				  struct i2c_client *client)
+			  const struct i2c_client *client)
 {
 	const char *name;
 
@@ -141,6 +141,7 @@ i2c_of_match_device_sysfs(const struct of_device_id *matches,
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(i2c_of_match_device_sysfs);
 
 const struct of_device_id
 *i2c_of_match_device(const struct of_device_id *matches,
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 1247e6e6e975..e4d397b67989 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -82,8 +82,17 @@ static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) {
 
 #ifdef CONFIG_OF
 void of_i2c_register_devices(struct i2c_adapter *adap);
+const struct of_device_id *
+i2c_of_match_device_sysfs(const struct of_device_id *matches,
+			  const struct i2c_client *client);
 #else
 static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
+static inline const struct of_device_id *
+i2c_of_match_device_sysfs(const struct of_device_id *matches,
+			  const struct i2c_client *client)
+{
+	return NULL;
+}
 #endif
 extern struct notifier_block i2c_of_notifier;
 
-- 
2.25.1