gpio_cs5535: disable AUX on output

The AMD CS5535/CS5536 GPIO has two alternate output modes: AUX-1 and AUX-2.
When either AUX is enabled, the cs5535_gpio driver cannot control the
output.

Some BIOS code for the Geode processor enables AUX-1 for GPIO-1, which
configures it as the PC BEEP output.

This patch will disable AUX-1 and AUX-2 when the user enables output.

Signed-of-by: Ben Gardner <gardner.ben@gmail.com>
Cc: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/char/cs5535_gpio.c b/drivers/char/cs5535_gpio.c
index fe6d2407baed..c2d23cae9515 100644
--- a/drivers/char/cs5535_gpio.c
+++ b/drivers/char/cs5535_gpio.c
@@ -104,6 +104,11 @@ static ssize_t cs5535_gpio_write(struct file *file, const char __user *data,
                 for (j = 0; j < ARRAY_SIZE(rm); j++) {
                         if (c == rm[j].on) {
                                 outl(m1, base + rm[j].wr_offset);
+                                /* If enabling output, turn off AUX 1 and AUX 2 */
+                                if (c == 'O') {
+                                        outl(m0, base + 0x10);
+                                        outl(m0, base + 0x14);
+                                }
                                 break;
                         } else if (c == rm[j].off) {
                                 outl(m0, base + rm[j].wr_offset);