pxa_gpio_mode() is a universal call that fiddles with the GAFR
(gpio alternate function register.) GAFR does not exist on PXA3
CPUs, but instead the alternate functions are controlled via the
MFP support code.
Platforms are expected to configure the MFP according to their
needs in their platform support code rather than drivers. We
extend this idea to the GAFR, and make the gpio_direction_*()
functions purely operate on the GPIO level.
This means platform support code is entirely responsible for
configuring the GPIOs alternate functions on all PXA CPU types.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The default value passed through to pxa_gpio_mode() is lost
due to a missing GPIO_DFLT_HIGH mask for nonzero values. The enclosed
patch fixes this programming error.
Signed-off-by: Bill Gatliff <bgat@billgatliff.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It's been pointed out that output GPIOs should have an initial value, to
avoid signal glitching ... among other things, it can be some time before
a driver is ready. This patch corrects that oversight, fixing
- documentation
- platforms supporting the GPIO interface
- users of that call (just one for now, others are pending)
There's only one user of this call for now since most platforms are still
using non-generic GPIO setup code, which in most cases already couples the
initial value with its "set output mode" request.
Note that most platforms are clear about the hardware letting the output
value be set before the pin direction is changed, but the s3c241x docs are
vague on that topic ... so those chips might not avoid the glitches.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Acked-by: Milan Svoboda <msvoboda@ra.rockwell.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on the discussion last december (http://lkml.org/lkml/2006/12/20/242),
this patch:
- moves the PXA_LAST_GPIO check into pxa_gpio_mode
- fixes comment and includes in gpio.h
- replaces the gpio_set/get_value macros with inline
functions and adds a non-inline version to avoid
code explosion when gpio is not a constant.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
