From c2e46420cc934af77391a52e7e5330b5a7e2b1f5 Mon Sep 17 00:00:00 2001 From: Nico Huber Date: Mon, 23 Mar 2020 01:22:49 +0100 Subject: nb/intel/haswell: Implement proper backlight PWM config Further backport the backlight-PWM handling from Skylake. Beside configuring the PWM frequency in Hz, we also use the PCH's logic for the brightness setting via BLM_PCH_OVERRIDE_ENABLE. Linux would toggle it anyway and that might confuse our ASL code. We assume that the 183Hz value that was set before for Slippy variants was overridden by Linux with the 200Hz VBT value, like it was for the Broadwell Chromebooks. So we set 200Hz for them in the devicetrees. The calculated value for the T440p of 220Hz seems sane and also matches the VBT. Change-Id: I17dfe1a3610d5e2918c617cf5d10896692fdccb3 Signed-off-by: Nico Huber Reviewed-on: https://review.coreboot.org/c/coreboot/+/39769 Tested-by: build bot (Jenkins) Reviewed-by: Angel Pons --- src/drivers/intel/gma/i915_reg.h | 1 + 1 file changed, 1 insertion(+) (limited to 'src/drivers/intel') diff --git a/src/drivers/intel/gma/i915_reg.h b/src/drivers/intel/gma/i915_reg.h index e0bf1427c5..38ea72a6f9 100644 --- a/src/drivers/intel/gma/i915_reg.h +++ b/src/drivers/intel/gma/i915_reg.h @@ -3580,6 +3580,7 @@ #define SOUTH_CHICKEN2 0xc2004 #define FDI_MPHY_IOSFSB_RESET_STATUS (1<<13) #define FDI_MPHY_IOSFSB_RESET_CTL (1<<12) +#define LPT_PWM_GRANULARITY (1<<5) #define DPLS_EDP_PPS_FIX_DIS (1<<0) #define _FDI_RXA_CHICKEN 0xc200c -- cgit v1.2.3