From: Matt Roper <matthew.d.roper@xxxxxxxxx> DG1 always uses a 38.4 MHz rawclk rather than the 19.2/24 MHz frequencies on CNP+. Note that register bits associated with this frequency confusingly use 37 for the divider field rather than 38 as you might expect. For simplicity, let's just assume that this 38.4 MHz frequency will hold true for other future platforms with "fake" PCH south displays and that the CNP-style behavior will remain for other platforms with a real PCH. Bspec: 49950 Bspec: 49309 Cc: Aditya Swarup <aditya.swarup@xxxxxxxxx> Cc: Clinton Taylor <Clinton.A.Taylor@xxxxxxxxx> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_cdclk.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c index 45f7f33d11447..3aea30ba9f743 100644 --- a/drivers/gpu/drm/i915/display/intel_cdclk.c +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c @@ -2673,6 +2673,18 @@ void intel_update_cdclk(struct drm_i915_private *dev_priv) DIV_ROUND_UP(dev_priv->cdclk.hw.cdclk, 1000)); } +static int dg1_rawclk(struct drm_i915_private *dev_priv) +{ + /* + * DG1 always uses a 38.4 MHz rawclk. The bspec tells us + * "Program Numerator=2, Denominator=4, Divider=37 decimal." + */ + I915_WRITE(PCH_RAWCLK_FREQ, + CNP_RAWCLK_DEN(4) | CNP_RAWCLK_DIV(37) | ICP_RAWCLK_NUM(2)); + + return 38400; +} + static int cnp_rawclk(struct drm_i915_private *dev_priv) { u32 rawclk; @@ -2781,7 +2793,9 @@ u32 intel_read_rawclk(struct drm_i915_private *dev_priv) { u32 freq; - if (INTEL_PCH_TYPE(dev_priv) >= PCH_CNP) + if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1) + freq = dg1_rawclk(dev_priv); + else if (INTEL_PCH_TYPE(dev_priv) >= PCH_CNP) freq = cnp_rawclk(dev_priv); else if (HAS_PCH_SPLIT(dev_priv)) freq = pch_rawclk(dev_priv); -- 2.26.2 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx