erebion/coreboot
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

UPSTREAM: nb/intel/gm45: Set display backlight according to EDID string

Browse source 
Add some known good values for some thinkpads displays.

Known good means that at this pwm frequency the display is evenly lit
on all duty cycles, the display makes minimal to no noise at lower
duty cycles and the display does not flicker. This values differs from
vendor (which uses an obviously wrong display clock  (190MHz instead
of 320MHz) resulting in frequency more than 60% off the intended
value.

TESTED on Thinkpad X200 with edid ascii string in list and removed
from list to see if notice message is shown.

BUG=none
BRANCH=none
TEST=none

Change-Id: I6df100df0f80ce479ace6ee2c1d59114c17f1a7a
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 20cb85fa98
Original-Change-Id: Id7bc0d453fac31e806852206ba2c895720b2c843
Original-Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Original-Reviewed-on: https://review.coreboot.org/19500
Original-Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://chromium-review.googlesource.com/496055
This commit is contained in:
Arthur Heymans 2017-04-29 14:31:32 +02:00 • committed by chrome-bot
commit 2c1234c057
9 changed files with 147 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/northbridge/intel/gm45/chip.h
View file

@ -26,7 +26,7 @@ struct northbridge_intel_gm45_config {
u16 gpu_panel_power_backlight_off_delay; /* Tx time sequence */
u8 gpu_panel_power_cycle_delay; /* T4 time sequence */
struct i915_gpu_controller_info gfx;
u16 pwm_freq;
u16 default_pwm_freq;
u8 duty_cycle;
/*

7
src/northbridge/intel/gm45/gm45.h
View file

@ -436,6 +436,13 @@ u32 decode_igd_gtt_size(u32 gsm);
void init_iommu(void);
struct blc_pwm_t {
char ascii_string[13];
int pwm_freq; /* In Hz */
};
int get_blc_values(const struct blc_pwm_t **entries);
#if ENV_RAMSTAGE && !defined(__SIMPLE_DEVICE__)
#include <device/device.h>

38
src/northbridge/intel/gm45/gma.c
View file

@ -653,12 +653,16 @@ static u32 freq_to_blc_pwm_ctl(struct device *const dev,
return (blc_mod << 16) | blc_mod;
}
static void gma_pm_init_post_vbios(struct device *const dev)
static void gma_pm_init_post_vbios(struct device *const dev,
const char *edid_ascii_string)
{
const struct northbridge_intel_gm45_config *const conf = dev->chip_info;
u32 reg32;
u8 reg8;
const struct blc_pwm_t *blc_pwm;
int blc_array_len, i;
u16 pwm_freq = 0;
/* Setup Panel Power On Delays */
reg32 = gtt_read(PP_ON_DELAYS);
@ -689,11 +693,35 @@ static void gma_pm_init_post_vbios(struct device *const dev)
reg8 = 100;
if (conf->duty_cycle != 0)
reg8 = conf->duty_cycle;
if (conf->pwm_freq == 0)
blc_array_len = get_blc_values(&blc_pwm);
if (conf->default_pwm_freq != 0)
pwm_freq = conf->default_pwm_freq;
/* Find EDID string and pwm freq in lookup table */
for (i = 0; i < blc_array_len; i++) {
if (!strncmp(blc_pwm[i].ascii_string, edid_ascii_string,
strlen(blc_pwm[i].ascii_string))) {
pwm_freq = blc_pwm[i].pwm_freq;
printk(BIOS_DEBUG, "Found EDID string: %s in lookup table, pwm: %dHz\n",
blc_pwm[i].ascii_string, pwm_freq);
break;
}
}
if (i == blc_array_len)
printk(BIOS_NOTICE, "Your panels EDID `%s` wasn't found in the"
"lookup table.\n You may have issues with your panels"
"backlight.\n If you want to help improving coreboot"
"please report: this EDID string\n and the result"
"of `intel_read read BLC_PWM_CTL`"
"(from intel-gpu-tools)\n while running vendor BIOS\n",
edid_ascii_string);
if (pwm_freq == 0)
gtt_write(BLC_PWM_CTL, 0x06100610);
else
gtt_write(BLC_PWM_CTL, freq_to_blc_pwm_ctl(dev,
conf->pwm_freq, reg8));
gtt_write(BLC_PWM_CTL, freq_to_blc_pwm_ctl(dev, pwm_freq,
reg8));
}
static void gma_func0_init(struct device *dev)
@ -726,7 +754,7 @@ static void gma_func0_init(struct device *dev)
decode_edid(edid_data_lvds, sizeof(edid_data_lvds), &edid_lvds);
/* Post VBIOS init */
gma_pm_init_post_vbios(dev);
gma_pm_init_post_vbios(dev, edid_lvds.ascii_string);
if (IS_ENABLED(CONFIG_MAINBOARD_DO_NATIVE_VGA_INIT))
gma_ngi(dev, &edid_lvds);