spi: core and gpio expanders use subsys_init

Make the SPI external GPIO expander drivers register themselves at
subsys_initcall() time when they're statically linked, and make the SPI
core do its driver model initialization earlier so that's safe.

SOC-integrated GPIOs are available starting very early -- often before
initcalls start to run, or earily in arch_initcall() at latest -- so this
improves consistency, letting more subsystems rely on GPIOs being usable
by their own subsys_initcall() code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpio/max7301.c b/drivers/gpio/max7301.c
index 39c795a..1b5ad97 100644
--- a/drivers/gpio/max7301.c
+++ b/drivers/gpio/max7301.c
@@ -325,13 +325,15 @@ static int __init max7301_init(void)
 {
 	return spi_register_driver(&max7301_driver);
 }
+/* register after spi postcore initcall and before
+ * subsys initcalls that may rely on these GPIOs
+ */
+subsys_initcall(max7301_init);
 
 static void __exit max7301_exit(void)
 {
 	spi_unregister_driver(&max7301_driver);
 }
-
-module_init(max7301_init);
 module_exit(max7301_exit);
 
 MODULE_AUTHOR("Juergen Beisert");