Some devices need to wait for some milliseconds after reset, so add
post reset delay in the gpio-reset chip.
The post reset delay is optional.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
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)
This driver implements a reset controller device that toggle a gpio
connected to a reset pin of a peripheral IC. The delay between assertion
and de-assertion of the reset signal can be configured via device tree.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Lars Ivar Miljeteig