i2c: boardinfo: Annotate code used in init phase only

Annotate two places in boardinfo code:
- __i2c_first_dynamic_bus_num is set in init phase. Annotate it as
  __ro_after_init to prevent later changes.
- i2c_register_board_info() is used in init phase only, so annotate it
  as __init, allowing to free the memory after init phase.
  This is safe, see comment: "done in board-specific init code near
  arch_initcall() time"

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Author: hkallweit

drivers/i2c/i2c-boardinfo.c

@@ -22,7 +22,7 @@ EXPORT_SYMBOL_GPL(__i2c_board_lock);
 LIST_HEAD(__i2c_board_list);
 EXPORT_SYMBOL_GPL(__i2c_board_list);
 
-int __i2c_first_dynamic_bus_num;
+int __i2c_first_dynamic_bus_num __ro_after_init;
 EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
 
 
@@ -48,7 +48,7 @@ EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
  * The board info passed can safely be __initdata, but be careful of embedded
  * pointers (for platform_data, functions, etc) since that won't be copied.
  */
-int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len)
+int __init i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len)
 {
 	int status;
 

include/linux/i2c.h

@@ -499,7 +499,7 @@ static inline struct i2c_client *i2c_verify_client(struct device *dev)
  * Modules for add-on boards must use other calls.
  */
 #ifdef CONFIG_I2C_BOARDINFO
-int
+int __init
 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 			unsigned n);
 #else