From 1a65017a503362fa21f933b1fdc54c3a4db13dc4 Mon Sep 17 00:00:00 2001 From: Nico Huber Date: Sun, 16 Dec 2018 02:39:28 +0100 Subject: soc/intel/skl/graphics: Implement panel setup Logs from Linux' i915 suggest that not even the FSP/GOP takes proper care of this. The sequence is mostly the same as on older platforms, with a slightly different configuration of the backlight PWM. We light the panel up with 50% PWM duty cycle. This often results in an already rather high perceived brightness, but shouldn't be too blinding. Change-Id: I762a77c8df023a4c14af502af5edfeeb961da1ae Signed-off-by: Nico Huber Reviewed-on: https://review.coreboot.org/c/coreboot/+/30246 Tested-by: build bot (Jenkins) Reviewed-by: Arthur Heymans --- src/soc/intel/skylake/chip.h | 12 ++++++++ src/soc/intel/skylake/graphics.c | 64 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 76 insertions(+) (limited to 'src/soc/intel') diff --git a/src/soc/intel/skylake/chip.h b/src/soc/intel/skylake/chip.h index a537165dd9..9c8e2bfaa9 100644 --- a/src/soc/intel/skylake/chip.h +++ b/src/soc/intel/skylake/chip.h @@ -48,6 +48,18 @@ struct soc_intel_skylake_config { /* Common struct containing soc config data required by common code */ struct soc_intel_common_config common_soc_config; + /* IGD panel configuration */ + unsigned int gpu_pp_up_delay_ms; + unsigned int gpu_pp_down_delay_ms; + unsigned int gpu_pp_cycle_delay_ms; + unsigned int gpu_pp_backlight_on_delay_ms; + unsigned int gpu_pp_backlight_off_delay_ms; + unsigned int gpu_pch_backlight_pwm_hz; + enum { + GPU_BACKLIGHT_POLARITY_HIGH = 0, + GPU_BACKLIGHT_POLARITY_LOW, + } gpu_pch_backlight_polarity; + /* * Interrupt Routing configuration * If bit7 is 1, the interrupt is disabled. diff --git a/src/soc/intel/skylake/graphics.c b/src/soc/intel/skylake/graphics.c index f563c11302..7efc65a591 100644 --- a/src/soc/intel/skylake/graphics.c +++ b/src/soc/intel/skylake/graphics.c @@ -16,9 +16,11 @@ #include #include +#include #include #include #include +#include #include #include #include @@ -32,10 +34,72 @@ uintptr_t fsp_soc_get_igd_bar(void) return graphics_get_memory_base(); } +static void graphics_setup_panel(struct device *dev) +{ + struct soc_intel_skylake_config *conf = dev->chip_info; + struct resource *mmio_res; + uint8_t *base; + u32 reg32; + + if (!conf) + return; + + mmio_res = find_resource(dev, PCI_BASE_ADDRESS_0); + if (!mmio_res || !mmio_res->base) + return; + base = (void *)(uintptr_t)mmio_res->base; + + reg32 = conf->gpu_pp_up_delay_ms * 10 << 16; + reg32 |= conf->gpu_pp_backlight_on_delay_ms * 10; + write32(base + PCH_PP_ON_DELAYS, reg32); + + reg32 = conf->gpu_pp_down_delay_ms * 10 << 16; + reg32 |= conf->gpu_pp_backlight_off_delay_ms * 10; + write32(base + PCH_PP_OFF_DELAYS, reg32); + + reg32 = read32(base + PCH_PP_DIVISOR); + reg32 &= ~0x1f; + reg32 |= (DIV_ROUND_UP(conf->gpu_pp_cycle_delay_ms, 100) + 1) & 0x1f; + write32(base + PCH_PP_DIVISOR, reg32); + + /* 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) { + /* 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_chicken1; + + south_chicken1 = read32(base + SOUTH_CHICKEN1); + if (conf->gpu_pch_backlight_pwm_hz > hz_limit) { + pwm_increment = 16; + south_chicken1 &= ~1; + } else { + pwm_increment = 128; + south_chicken1 |= 1; + } + write32(base + SOUTH_CHICKEN1, south_chicken1); + + pwm_period = 24 * 1000 * 1000 / pwm_increment + / conf->gpu_pch_backlight_pwm_hz; + /* Start with a 50% duty cycle. */ + write32(base + BLC_PWM_PCH_CTL2, + pwm_period << 16 | pwm_period / 2); + + write32(base + BLC_PWM_PCH_CTL1, + !!conf->gpu_pch_backlight_polarity << 29 | + BLM_PCH_PWM_ENABLE); + } +} + void graphics_soc_init(struct device *dev) { u32 ddi_buf_ctl; + graphics_setup_panel(dev); + /* * Enable DDI-A (eDP) 4-lane operation if the link is not up yet. * This will allow the kernel to use 4-lane eDP links properly -- cgit v1.2.3