MLK-11395-1: reset: register gpio-reset driver in arch_initcall

It's a little bit late to register gpio-reset driver at module_init
time, because gpio-reset provides reset control via gpio for other
devices which are mostly probed at module_init time too.  And it
becomes even worse, when the gpio comes from IO expander on I2C bus,
e.g. pca953x.  In that case, gpio-reset needs to be ready before I2C
bus driver which is generally ready at subsys_initcall time.  Let's
register gpio-reset driver in arch_initcall() to have it ready early
enough.

The defer probe mechanism is not used here, because a reset controller
driver should be reasonably registered early than other devices.  More
importantly, defer probe doe not help in some nasty cases, e.g. the
gpio-pca953x device itself needs a reset from gpio-reset driver start
working.

[shawn.guo: cherry-pick commit 7153f05108ef from imx_3.10.y]
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
(cherry picked from commit 11e3543010d4ed50db78a5fc809f24c89e8c6e30)

diff --git a/drivers/reset/gpio-reset.c b/drivers/reset/gpio-reset.c
index 5d2515a..4cb9929 100644 (file)
--- a/drivers/reset/gpio-reset.c
+++ b/drivers/reset/gpio-reset.c
@@ -165,7 +165,17 @@ static struct platform_driver gpio_reset_driver = {
        },
 };
 
-module_platform_driver(gpio_reset_driver);
+static int __init gpio_reset_init(void)
+{
+       return platform_driver_register(&gpio_reset_driver);
+}
+arch_initcall(gpio_reset_init);
+
+static void __exit gpio_reset_exit(void)
+{
+       platform_driver_unregister(&gpio_reset_driver);
+}
+module_exit(gpio_reset_exit);
 
 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
 MODULE_DESCRIPTION("gpio reset controller");