diff options
| author | Arthur Heymans <arthur@aheymans.xyz> | 2016-11-24 13:23:05 +0100 |
|---|---|---|
| committer | Nico Huber <nico.h@gmx.de> | 2016-11-28 19:24:12 +0100 |
| commit | 12bed2608f2f98fd41f6dac9c918123f51e830d4 (patch) | |
| tree | 16cf601292493934479de819916e1482bf8c5910 /src/northbridge/intel/gm45 | |
| parent | ea08ad7188eee27ad03c75ddc679a68737b4b74a (diff) | |
nb/gm45/gma.c: Compute BLC_PWM_CTL value from PWM frequency
This allows to set the backlight PWM frequency and the
duty cycle in the devicetree instead of using a plain BLC_PWM_CTL
value.
Change-Id: I4d9a555ac7ea5605712c1fcda994a6fcabf9acf3
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/17597
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
Diffstat (limited to 'src/northbridge/intel/gm45')
| -rw-r--r-- | src/northbridge/intel/gm45/chip.h | 2 | ||||
| -rw-r--r-- | src/northbridge/intel/gm45/gma.c | 22 |
2 files changed, 22 insertions, 2 deletions
diff --git a/src/northbridge/intel/gm45/chip.h b/src/northbridge/intel/gm45/chip.h index 836d6bb737..a281ee96d9 100644 --- a/src/northbridge/intel/gm45/chip.h +++ b/src/northbridge/intel/gm45/chip.h @@ -26,6 +26,8 @@ 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; + u8 duty_cycle; /* * Maximum PCI mmio size in MiB. diff --git a/src/northbridge/intel/gm45/gma.c b/src/northbridge/intel/gm45/gma.c index 3e9f508b70..37f81c5094 100644 --- a/src/northbridge/intel/gm45/gma.c +++ b/src/northbridge/intel/gm45/gma.c @@ -629,11 +629,25 @@ static u32 get_cdclk(struct device *const dev) } } +static u32 freq_to_blc_pwm_ctl(struct device *const dev, + u16 pwm_freq, u8 duty_perc) +{ + u32 blc_mod; + + blc_mod = get_cdclk(dev) / (128 * pwm_freq); + + if (duty_perc <= 100) + return (blc_mod << 16) | (blc_mod * duty_perc / 100); + else + return (blc_mod << 16) | blc_mod; +} + static void gma_pm_init_post_vbios(struct device *const dev) { const struct northbridge_intel_gm45_config *const conf = dev->chip_info; u32 reg32; + u8 reg8; /* Setup Panel Power On Delays */ reg32 = gtt_read(PP_ON_DELAYS); @@ -661,10 +675,14 @@ static void gma_pm_init_post_vbios(struct device *const dev) /* Enable Backlight */ gtt_write(BLC_PWM_CTL2, (1 << 31)); - if (conf->gfx.backlight == 0) + reg8 = 100; + if (conf->duty_cycle != 0) + reg8 = conf->duty_cycle; + if (conf->pwm_freq == 0) gtt_write(BLC_PWM_CTL, 0x06100610); else - gtt_write(BLC_PWM_CTL, conf->gfx.backlight); + gtt_write(BLC_PWM_CTL, freq_to_blc_pwm_ctl(dev, + conf->pwm_freq, reg8)); } static void gma_func0_init(struct device *dev) |