Commit 121643c2 authored by Satheeshakrishna M's avatar Satheeshakrishna M Committed by Daniel Vetter

drm/i915/skl: CD clock back calculation for SKL

Determine programmed cd clock for SKL.

v2: Fix the LCPLL1 enable warning logic

v3: Rebase over the hsw pll rework.

v4: Rebase on top of the per-platform split (Damien)

v5: Modified as per review comments from Paulo
Reviewed-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: default avatarSatheeshakrishna M <satheeshakrishna.m@intel.com>
Signed-off-by: default avatarDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 429d47d5
......@@ -1259,6 +1259,54 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder)
}
}
static int skl_get_cdclk_freq(struct drm_i915_private *dev_priv)
{
uint32_t lcpll1 = I915_READ(LCPLL1_CTL);
uint32_t cdctl = I915_READ(CDCLK_CTL);
uint32_t linkrate;
if (!(lcpll1 & LCPLL_PLL_ENABLE)) {
WARN(1, "LCPLL1 not enabled\n");
return 24000; /* 24MHz is the cd freq with NSSC ref */
}
if ((cdctl & CDCLK_FREQ_SEL_MASK) == CDCLK_FREQ_540)
return 540000;
linkrate = (I915_READ(DPLL_CTRL1) &
DPLL_CRTL1_LINK_RATE_MASK(SKL_DPLL0)) >> 1;
if (linkrate == DPLL_CRTL1_LINK_RATE_2160 ||
linkrate == DPLL_CRTL1_LINK_RATE_1080) {
/* vco 8640 */
switch (cdctl & CDCLK_FREQ_SEL_MASK) {
case CDCLK_FREQ_450_432:
return 432000;
case CDCLK_FREQ_337_308:
return 308570;
case CDCLK_FREQ_675_617:
return 617140;
default:
WARN(1, "Unknown cd freq selection\n");
}
} else {
/* vco 8100 */
switch (cdctl & CDCLK_FREQ_SEL_MASK) {
case CDCLK_FREQ_450_432:
return 450000;
case CDCLK_FREQ_337_308:
return 337500;
case CDCLK_FREQ_675_617:
return 675000;
default:
WARN(1, "Unknown cd freq selection\n");
}
}
/* error case, do as if DPLL0 isn't enabled */
return 24000;
}
static int bdw_get_cdclk_freq(struct drm_i915_private *dev_priv)
{
uint32_t lcpll = I915_READ(LCPLL_CTL);
......@@ -1300,6 +1348,9 @@ int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
{
struct drm_device *dev = dev_priv->dev;
if (IS_SKYLAKE(dev))
return skl_get_cdclk_freq(dev_priv);
if (IS_BROADWELL(dev))
return bdw_get_cdclk_freq(dev_priv);
......@@ -1368,19 +1419,25 @@ void intel_ddi_pll_init(struct drm_device *dev)
hsw_shared_dplls_init(dev_priv);
/* The LCPLL register should be turned on by the BIOS. For now let's
* just check its state and print errors in case something is wrong.
* Don't even try to turn it on.
*/
DRM_DEBUG_KMS("CDCLK running at %dKHz\n",
intel_ddi_get_cdclk_freq(dev_priv));
if (val & LCPLL_CD_SOURCE_FCLK)
DRM_ERROR("CDCLK source is not LCPLL\n");
if (IS_SKYLAKE(dev)) {
if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
DRM_ERROR("LCPLL1 is disabled\n");
} else {
/*
* The LCPLL register should be turned on by the BIOS. For now
* let's just check its state and print errors in case
* something is wrong. Don't even try to turn it on.
*/
if (val & LCPLL_CD_SOURCE_FCLK)
DRM_ERROR("CDCLK source is not LCPLL\n");
if (val & LCPLL_PLL_DISABLE)
DRM_ERROR("LCPLL is disabled\n");
if (val & LCPLL_PLL_DISABLE)
DRM_ERROR("LCPLL is disabled\n");
}
}
void intel_ddi_prepare_link_retrain(struct drm_encoder *encoder)
......
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