intel/broadwell: Correct backlight-PWM divider
The PWM-granularity chicken bit in the Wildcat Point and Lynx Point
PCHs has actually the opposite meaning of the one for Sunrise Point
and later. When the bit is set, we get a divider of 16, when it's
unset 128. Flip the bit!
Change-Id: I1dbde1915d8b269c11643a1636565a560eb07334
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39770
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/soc/intel/broadwell/igd.c b/src/soc/intel/broadwell/igd.c
index 37f3871..ecb5417 100644
--- a/src/soc/intel/broadwell/igd.c
+++ b/src/soc/intel/broadwell/igd.c
@@ -348,10 +348,10 @@
south_chicken2 = gtt_read(SOUTH_CHICKEN2);
if (conf->gpu_pch_backlight_pwm_hz > hz_limit) {
pwm_increment = 16;
- south_chicken2 &= ~(1 << 5);
+ south_chicken2 |= 1 << 5;
} else {
pwm_increment = 128;
- south_chicken2 |= 1 << 5;
+ south_chicken2 &= ~(1 << 5);
}
gtt_write(SOUTH_CHICKEN2, south_chicken2);