Re: [PATCH v2 8/8] reset: Add driver for gpio-controlled reset pins

[Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

Hi Russell,

Am Donnerstag, den 14.02.2013, 10:56 +0000 schrieb Russell King - ARM
Linux:
> On Wed, Feb 13, 2013 at 06:34:32PM +0100, Philipp Zabel wrote:
> > Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> 
> Just be aware that PXA has a "gpio reset" facility which is used for SoC
> reset - see arch/arm/mach-pxa/reset.c
> 
> The use of gpio-reset would be ambiguous... or maybe PXA's usage could be
> combined somehow with this?

thank you for pointing this out. The PXA gpio reset code is used for
system/board reset and fiddles with the reset line to trigger all
possible types of reset without needing configuration. The code I
suggest is targeted at resetting peripheral devices, like I2C and SPI
ICs with a reset line connected via GPIO, and it has to be configured
for either active-high or active-low GPIOs. Should this be combined?
I wonder if it would be worth the effort to make the PXA gpio reset go
through this reset API, as there isn't even a struct device that would
be the reset "consumer".

In fact, I don't even think most drivers that currently implement gpio
resets themselves would gain much from switching to another level of
abstraction, unless the SoC already has an on-chip reset controller
anyway - in which case this would mostly increase overall consistency.

regards
Philipp