diff options
Diffstat (limited to 'src/drivers')
| -rw-r--r-- | src/drivers/intel/gma/Kconfig | 16 | ||||
| -rw-r--r-- | src/drivers/intel/gma/vbt.c | 3 |
2 files changed, 18 insertions, 1 deletions
diff --git a/src/drivers/intel/gma/Kconfig b/src/drivers/intel/gma/Kconfig index 9c0f22783c..23290d56f4 100644 --- a/src/drivers/intel/gma/Kconfig +++ b/src/drivers/intel/gma/Kconfig @@ -2,6 +2,7 @@ ## This file is part of the coreboot project. ## ## Copyright 2013 Google Inc. +## Copyright 2016-2017 secunet Security Networks AG ## ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by @@ -37,6 +38,21 @@ config INTEL_GMA_ACPI bool default n +config INTEL_GMA_SSC_ALTERNATE_REF + bool + default n + help + Set when the SSC reference clock for LVDS runs at a different fre- + quency than the general display reference clock. + + To be set by northbridge or mainboard Kconfig. For most platforms, + there is no choice, i.e. for i945 and gm45 the SSC reference always + differs from the display reference clock (i945: 66Mhz SSC vs. 48MHz + DREF; gm45: 100MHz SSC vs. 96Mhz DREF), for Nehalem and newer, it's + the same frequency for SSC/non-SSC (120MHz). The only, currently + supported platform with a choice seems to be Pineview, where the + alternative is 100MHz vs. the default 96MHz. + config GFX_GMA_CPU string default "Skylake" if SOC_INTEL_SKYLAKE diff --git a/src/drivers/intel/gma/vbt.c b/src/drivers/intel/gma/vbt.c index 0d76afee48..d8dd9301a7 100644 --- a/src/drivers/intel/gma/vbt.c +++ b/src/drivers/intel/gma/vbt.c @@ -2,6 +2,7 @@ * This file is part of the coreboot project. * * Copyright (C) 2013, 2014 Vladimir Serbinenko + * Copyright (C) 2017 secunet Security Networks AG * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -59,7 +60,7 @@ static size_t generate_vbt(const struct i915_gpu_controller_info *const conf, genfeat->flexaim = 1; genfeat->download_ext_vbt = 1; genfeat->enable_ssc = conf->use_spread_spectrum_clock; - genfeat->ssc_freq = !conf->link_frequency_270_mhz; + genfeat->ssc_freq = IS_ENABLED(CONFIG_INTEL_GMA_SSC_ALTERNATE_REF); genfeat->rsvd10 = 0x4; genfeat->legacy_monitor_detect = 1; genfeat->int_crt_support = 1; |