i2c: acpi: export i2c_acpi_find_adapter_by_handle

This allows drivers to lookup i2c adapters on ACPI based systems similar to
of_get_i2c_adapter_by_node() with DT based systems.

Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/i2c-core-acpi.c

@@ -337,14 +337,15 @@ static int i2c_acpi_find_match_device(struct device *dev, void *data)
 	return ACPI_COMPANION(dev) == data;
 }
 
-static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 {
 	struct device *dev;
 
 	dev = bus_find_device(&i2c_bus_type, NULL, handle,
 			      i2c_acpi_find_match_adapter);
 	return dev ? i2c_verify_adapter(dev) : NULL;
 }
+EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 
 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 {

include/linux/i2c.h

@@ -14,6 +14,7 @@
 #ifndef _LINUX_I2C_H
 #define _LINUX_I2C_H
 
+#include <linux/acpi.h>		/* for acpi_handle */
 #include <linux/mod_devicetable.h>
 #include <linux/device.h>	/* for struct device */
 #include <linux/sched.h>	/* for completion */
@@ -981,6 +982,7 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 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_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
 #else
 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 					     struct acpi_resource_i2c_serialbus **i2c)
@@ -996,6 +998,10 @@ static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
 {
 	return NULL;
 }
+static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+{
+	return NULL;
+}
 #endif /* CONFIG_ACPI */
 
 #endif /* _LINUX_I2C_H */