[PATCH 5.15.y 1/2] i2c: acpi: Add i2c_acpi_new_device_by_fwnode() function

[Sasha Levin <sashal@kernel.org>]

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit c537be0bfad6337f2afd618fe252c03217191405 ]

Change i2c_acpi_new_device() into i2c_acpi_new_device_by_fwnode() and
add a static inline wrapper providing the old i2c_acpi_new_device()
behavior.

This is necessary because in some cases we may only have access
to the fwnode / acpi_device and not to the matching physical-node
struct device *.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211203102857.44539-4-hdegoede@redhat.com
Stable-dep-of: a65917d0a22f ("i2c: acpi: Fix adapter reference leak in i2c_acpi_new_device_by_fwnode()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-acpi.c | 17 +++++++++++------
 include/linux/i2c.h         | 17 +++++++++++++----
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 93bd78137ea67..1ee80ada212c3 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -501,8 +501,8 @@ struct notifier_block i2c_acpi_notifier = {
 };
 
 /**
- * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
- * @dev:     Device owning the ACPI resources to get the client from
+ * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource
+ * @fwnode:  fwnode with the ACPI resources to get the client from
  * @index:   Index of ACPI resource to get
  * @info:    describes the I2C device; note this is modified (addr gets set)
  * Context: can sleep
@@ -518,15 +518,20 @@ struct notifier_block i2c_acpi_notifier = {
  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
  */
-struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
-				       struct i2c_board_info *info)
+struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
+						 int index,
+						 struct i2c_board_info *info)
 {
-	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct i2c_acpi_lookup lookup;
 	struct i2c_adapter *adapter;
+	struct acpi_device *adev;
 	LIST_HEAD(resource_list);
 	int ret;
 
+	adev = to_acpi_device_node(fwnode);
+	if (!adev)
+		return ERR_PTR(-ENODEV);
+
 	memset(&lookup, 0, sizeof(lookup));
 	lookup.info = info;
 	lookup.device_handle = acpi_device_handle(adev);
@@ -548,7 +553,7 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 
 	return i2c_new_client_device(adapter, info);
 }
-EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
+EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);
 
 #ifdef CONFIG_ACPI_I2C_OPREGION
 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index b115fb9e2071e..7910dad637d44 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -1038,8 +1038,9 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 			       struct acpi_resource_i2c_serialbus **i2c);
 int i2c_acpi_client_count(struct acpi_device *adev);
 u32 i2c_acpi_find_bus_speed(struct device *dev);
-struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
-				       struct i2c_board_info *info);
+struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
+						 int index,
+						 struct i2c_board_info *info);
 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
 #else
 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
@@ -1055,8 +1056,9 @@ static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
 {
 	return 0;
 }
-static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
-					int index, struct i2c_board_info *info)
+static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
+					struct fwnode_handle *fwnode, int index,
+					struct i2c_board_info *info)
 {
 	return ERR_PTR(-ENODEV);
 }
@@ -1066,4 +1068,11 @@ static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle ha
 }
 #endif /* CONFIG_ACPI */
 
+static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
+						     int index,
+						     struct i2c_board_info *info)
+{
+	return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
+}
+
 #endif /* _LINUX_I2C_H */
-- 
2.53.0