diff --git a/src/mainboard/google/auron/variants/auron_paine/devicetree.cb b/src/mainboard/google/auron/variants/auron_paine/devicetree.cb index b31d82979c..f6ec15a617 100644 --- a/src/mainboard/google/auron/variants/auron_paine/devicetree.cb +++ b/src/mainboard/google/auron/variants/auron_paine/devicetree.cb @@ -9,9 +9,8 @@ chip soc/intel/broadwell # Enable HDMI Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000000" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/google/auron/variants/auron_yuna/devicetree.cb b/src/mainboard/google/auron/variants/auron_yuna/devicetree.cb index 3c00ec954f..db02565b27 100644 --- a/src/mainboard/google/auron/variants/auron_yuna/devicetree.cb +++ b/src/mainboard/google/auron/variants/auron_yuna/devicetree.cb @@ -9,9 +9,8 @@ chip soc/intel/broadwell # Enable HDMI Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000000" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/google/auron/variants/buddy/devicetree.cb b/src/mainboard/google/auron/variants/buddy/devicetree.cb index f75da84eee..e12882f413 100644 --- a/src/mainboard/google/auron/variants/buddy/devicetree.cb +++ b/src/mainboard/google/auron/variants/buddy/devicetree.cb @@ -9,9 +9,8 @@ chip soc/intel/broadwell # Enable HDMI Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000000" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/google/auron/variants/gandof/devicetree.cb b/src/mainboard/google/auron/variants/gandof/devicetree.cb index 118e646ee0..230f5bd009 100644 --- a/src/mainboard/google/auron/variants/gandof/devicetree.cb +++ b/src/mainboard/google/auron/variants/gandof/devicetree.cb @@ -9,9 +9,8 @@ chip soc/intel/broadwell # Enable HDMI Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000000" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/google/auron/variants/lulu/devicetree.cb b/src/mainboard/google/auron/variants/lulu/devicetree.cb index 622ea3488d..1983045983 100644 --- a/src/mainboard/google/auron/variants/lulu/devicetree.cb +++ b/src/mainboard/google/auron/variants/lulu/devicetree.cb @@ -9,9 +9,8 @@ chip soc/intel/broadwell # Enable HDMI Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000000" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/google/auron/variants/samus/devicetree.cb b/src/mainboard/google/auron/variants/samus/devicetree.cb index a6c2feae56..434ecc80b9 100644 --- a/src/mainboard/google/auron/variants/samus/devicetree.cb +++ b/src/mainboard/google/auron/variants/samus/devicetree.cb @@ -9,9 +9,8 @@ chip soc/intel/broadwell # Enable DDI2 Hotplug with 6ms pulse register "gpu_dp_c_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000200" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/purism/librem_bdw/variants/librem13v1/devicetree.cb b/src/mainboard/purism/librem_bdw/variants/librem13v1/devicetree.cb index e713cd2f56..98b5163b5f 100644 --- a/src/mainboard/purism/librem_bdw/variants/librem13v1/devicetree.cb +++ b/src/mainboard/purism/librem_bdw/variants/librem13v1/devicetree.cb @@ -6,9 +6,8 @@ chip soc/intel/broadwell # Enable DDI1 Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000200" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/mainboard/purism/librem_bdw/variants/librem15v2/devicetree.cb b/src/mainboard/purism/librem_bdw/variants/librem15v2/devicetree.cb index 3e83d3fb1a..32c3ed166f 100644 --- a/src/mainboard/purism/librem_bdw/variants/librem15v2/devicetree.cb +++ b/src/mainboard/purism/librem_bdw/variants/librem15v2/devicetree.cb @@ -6,9 +6,8 @@ chip soc/intel/broadwell # Enable DDI1 Hotplug with 6ms pulse register "gpu_dp_b_hotplug" = "0x06" - # Set backlight PWM values for eDP - register "gpu_cpu_backlight" = "0x00000200" - register "gpu_pch_backlight" = "0x04000200" + # Set backlight PWM value for eDP + register "gpu_pch_backlight_pwm_hz" = "200" # Enable Panel and configure power delays register "gpu_panel_port_select" = "1" # eDP diff --git a/src/soc/intel/broadwell/chip.h b/src/soc/intel/broadwell/chip.h index 456a4354ca..18a65857a7 100644 --- a/src/soc/intel/broadwell/chip.h +++ b/src/soc/intel/broadwell/chip.h @@ -117,8 +117,11 @@ struct soc_intel_broadwell_config { u16 gpu_panel_power_backlight_off_delay; /* Panel backlight settings */ - u32 gpu_cpu_backlight; - u32 gpu_pch_backlight; + unsigned int gpu_pch_backlight_pwm_hz; + enum { + GPU_BACKLIGHT_POLARITY_HIGH = 0, + GPU_BACKLIGHT_POLARITY_LOW, + } gpu_pch_backlight_polarity; /* * Graphics CD Clock Frequency diff --git a/src/soc/intel/broadwell/igd.c b/src/soc/intel/broadwell/igd.c index dab2d15750..f4322bf70e 100644 --- a/src/soc/intel/broadwell/igd.c +++ b/src/soc/intel/broadwell/igd.c @@ -335,14 +335,34 @@ static void igd_setup_panel(struct device *dev) gtt_write(PCH_PP_DIVISOR, reg32); } - /* Enable Backlight if needed */ - if (conf->gpu_cpu_backlight) { - gtt_write(BLC_PWM_CPU_CTL2, BLC_PWM2_ENABLE); - gtt_write(BLC_PWM_CPU_CTL, conf->gpu_cpu_backlight); - } - if (conf->gpu_pch_backlight) { - gtt_write(BLC_PWM_PCH_CTL1, BLM_PCH_PWM_ENABLE); - gtt_write(BLC_PWM_PCH_CTL2, conf->gpu_pch_backlight); + /* So far all devices seem to use the PCH PWM function. + The CPU PWM registers are all zero after reset. */ + if (conf->gpu_pch_backlight_pwm_hz) { + /* For Lynx Point-LP: + Reference clock is 24MHz. We can choose either a 16 + or a 128 step increment. Use 16 if we would have less + than 100 steps otherwise. */ + const unsigned int hz_limit = 24 * 1000 * 1000 / 128 / 100; + unsigned int pwm_increment, pwm_period; + u32 south_chicken2; + + south_chicken2 = gtt_read(SOUTH_CHICKEN2); + if (conf->gpu_pch_backlight_pwm_hz > hz_limit) { + pwm_increment = 16; + south_chicken2 &= ~(1 << 5); + } else { + pwm_increment = 128; + south_chicken2 |= 1 << 5; + } + gtt_write(SOUTH_CHICKEN2, south_chicken2); + + pwm_period = 24 * 1000 * 1000 / pwm_increment / conf->gpu_pch_backlight_pwm_hz; + /* Start with a 50% duty cycle. */ + gtt_write(BLC_PWM_PCH_CTL2, pwm_period << 16 | pwm_period / 2); + + gtt_write(BLC_PWM_PCH_CTL1, + (conf->gpu_pch_backlight_polarity == GPU_BACKLIGHT_POLARITY_LOW) << 29 | + BLM_PCH_OVERRIDE_ENABLE | BLM_PCH_PWM_ENABLE); } }