diff options
| author | Brian Masney <bmasney@redhat.com> | 2026-09-08 13:47:18 -0400 |
|---|---|---|
| committer | Bjorn Andersson <bjorn.andersson@oss.qualcomm.com> | 2026-09-23 18:24:30 -0500 |
| commit | ecf877ef7c5c737b0ae874eb9521e88ab8a03a0a (patch) | |
| tree | 4c8187d6f47ea7aba7e8fddd43df3241e05fe40e /include/linux | |
| parent | 8d0ae69b7c8af642264e57ca61e0c1cced7de436 (diff) | |
driver: core: add subsys_driver() macro
Add a new macro subsys_driver() to eliminate some boilerplate code in
drivers that need to register earlier in the boot at the subsys_initcall
level.
Signed-off-by: Brian Masney <bmasney@redhat.com>
Assisted-by: Claude:claude-opus-4-8
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Tested-by: Pankaj Patil <pankaj.patil@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260908-subsys_initcall-v1-1-cbccf4cd4288@redhat.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/device/driver.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h index 768a1334c0a1..29fbc01ef06f 100644 --- a/include/linux/device/driver.h +++ b/include/linux/device/driver.h @@ -297,4 +297,35 @@ static int __init __driver##_init(void) \ } \ device_initcall(__driver##_init); +/** + * subsys_driver() - Helper macro for drivers that don't do anything special + * in init/exit but have to register earlier, at subsys_initcall level, when + * built in. This eliminates a lot of boilerplate. Each driver may only use + * this macro once, and calling it replaces the init/exit boilerplate. + * + * @__driver: driver name + * @__register: register function for this driver type + * @__unregister: unregister function for this driver type + * @...: Additional arguments to be passed to __register and __unregister. + * + * This is meant to be a direct parallel of module_driver() above, but with + * the init call promoted to subsys_initcall() for built-in drivers so they + * are available earlier during boot. When built as a module subsys_initcall() + * collapses to module_init() and the normal module init/exit paths are used. + * + * Use this macro to construct bus specific macros for registering drivers, + * and do not use it on its own. + */ +#define subsys_driver(__driver, __register, __unregister, ...) \ +static int __init __driver##_init(void) \ +{ \ + return __register(&(__driver), ##__VA_ARGS__); \ +} \ +subsys_initcall(__driver##_init) \ +static void __exit __driver##_exit(void) \ +{ \ + __unregister(&(__driver), ##__VA_ARGS__); \ +} \ +module_exit(__driver##_exit) + #endif /* _DEVICE_DRIVER_H_ */ |