linux/arch
David Brownell 28735a7253 [PATCH] gpio_direction_output() needs an initial value
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>
2007-03-16 19:25:04 -07:00
..
alpha [PATCH] Dynamic kernel command-line: alpha 2007-02-12 09:48:37 -08:00
arm [PATCH] gpio_direction_output() needs an initial value 2007-03-16 19:25:04 -07:00
arm26 [PATCH] arch/arm26/kernel/entry.S: remove dead code 2007-03-01 14:53:35 -08:00
avr32 [PATCH] gpio_direction_output() needs an initial value 2007-03-16 19:25:04 -07:00
cris [PATCH] fix memory leak in dma_declare_coherent_memory() 2007-03-01 14:53:39 -08:00
frv [PATCH] FRV: No ZONE_DMA 2007-03-01 14:53:36 -08:00
h8300 [PATCH] Declare init_irq_proc before we use it. 2007-02-19 14:21:50 -08:00
i386 Disable NMI watchdog by default properly 2007-03-14 17:53:43 -07:00
ia64 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2007-03-09 22:00:51 -08:00
m32r Various typo fixes. 2007-02-17 19:07:33 +01:00
m68k [PATCH] Declare init_irq_proc before we use it. 2007-02-19 14:21:50 -08:00
m68knommu [PATCH] m68knommu: remove local_bh_count 2007-03-06 18:08:38 -08:00
mips [MIPS] kspd: ioctl needs a translation entry. 2007-03-13 16:59:31 +00:00
parisc [PARISC] clocksource: Move update_cr16_clocksource later in boot 2007-02-26 22:21:22 -05:00
powerpc [PATCH] pasemi trivial iomem annotations 2007-03-14 15:27:50 -07:00
ppc mv643xx_eth: Place explicit port number in mv643xx_eth_platform_data 2007-03-06 06:14:54 -05:00
s390 [PATCH] appldata build fix 2007-03-14 15:27:48 -07:00
sh sh: Kill off I/O cruft for R7780RP. 2007-03-05 20:19:57 +09:00
sh64 [PATCH] sysctl: remove insert_at_head from register_sysctl 2007-02-14 08:09:59 -08:00
sparc [PATCH] sparc: nr_free_pages() is unsigned long 2007-03-14 15:27:50 -07:00
sparc64 [SPARC64]: Add missing HPAGE_MASK masks on address parameters. 2007-03-12 22:55:39 -07:00
um [PATCH] stacktrace doesn't work on uml 2007-03-14 15:27:49 -07:00
v850 kbuild: Replace remaining "depends" with "depends on" 2007-02-17 19:05:24 +01:00
x86_64 Disable NMI watchdog by default properly 2007-03-14 17:53:43 -07:00
xtensa [PATCH] Dynamic kernel command-line: xtensa 2007-02-12 09:48:39 -08:00