cs5535-gpio: add AMD CS5535/CS5536 GPIO driver support

This creates a CS5535/CS5536 GPIO driver which uses a gpio_chip backend
(allowing GPIO users to use the generic GPIO API if desired) while also
allowing architecture-specific users directly (via the cs5535_gpio_*
functions).

Tested on an OLPC machine.  Some Leemotes also use CS5536 (with a mips
cpu), which is why this is in drivers/gpio rather than arch/x86.
Currently, it conflicts with older geode GPIO support; once MFGPT support
is reworked to also be more generic, the older geode code will be removed.

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: David Brownell <david-b@pacbell.net>
Reviewed-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 2ad0128c63c6..df4b82d1348e 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -174,6 +174,16 @@ config GPIO_ADP5520
 
 comment "PCI GPIO expanders:"
 
+config GPIO_CS5535
+        tristate "AMD CS5535/CS5536 GPIO support"
+        depends on PCI && !CS5535_GPIO && !MGEODE_LX
+        help
+          The AMD CS5535 and CS5536 southbridges support 28 GPIO pins that
+          can be used for quite a number of things.  The CS5535/6 is found on
+          AMD Geode and Lemote Yeeloong devices.
+
+          If unsure, say N.
+
 config GPIO_BT8XX
         tristate "BT8XX GPIO abuser"
         depends on PCI && VIDEO_BT848=n