drm/i915: Actually read out DPLL0 vco on skl from hardware
Currently we're trying to guess which lcpll vco frequency is used
use based on the cdclk. That doesn't work for cdclk==540 since
both vco frequencies can generate a 540 Mhz output. Let's stop
guessing and just read the actual vco frequency from the
hardware.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-6-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 78f3918..27b4b88 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5471,31 +5471,35 @@
}
}
-static const struct skl_cdclk_entry {
- unsigned int freq;
- unsigned int vco;
-} skl_cdclk_frequencies[] = {
- { .freq = 308570, .vco = 8640 },
- { .freq = 337500, .vco = 8100 },
- { .freq = 432000, .vco = 8640 },
- { .freq = 450000, .vco = 8100 },
- { .freq = 540000, .vco = 8100 },
- { .freq = 617140, .vco = 8640 },
- { .freq = 675000, .vco = 8100 },
-};
-
-unsigned int skl_cdclk_get_vco(unsigned int freq)
+static void
+skl_dpll0_update(struct drm_i915_private *dev_priv)
{
- unsigned int i;
+ u32 val;
- for (i = 0; i < ARRAY_SIZE(skl_cdclk_frequencies); i++) {
- const struct skl_cdclk_entry *e = &skl_cdclk_frequencies[i];
-
- if (e->freq == freq)
- return e->vco;
+ val = I915_READ(LCPLL1_CTL);
+ if ((val & LCPLL_PLL_ENABLE) == 0) {
+ dev_priv->skl_vco_freq = 0;
+ return;
}
- return 8100;
+ val = I915_READ(DPLL_CTRL1);
+
+ switch (val & DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0)) {
+ case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810, SKL_DPLL0):
+ case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1350, SKL_DPLL0):
+ case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1620, SKL_DPLL0):
+ case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2700, SKL_DPLL0):
+ dev_priv->skl_vco_freq = 8100;
+ break;
+ case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1080, SKL_DPLL0):
+ case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2160, SKL_DPLL0):
+ dev_priv->skl_vco_freq = 8640;
+ break;
+ default:
+ MISSING_CASE(val & DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0));
+ dev_priv->skl_vco_freq = 0;
+ break;
+ }
}
static void
@@ -6540,43 +6544,40 @@
static int skylake_get_display_clock_speed(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
- uint32_t lcpll1 = I915_READ(LCPLL1_CTL);
- uint32_t cdctl = I915_READ(CDCLK_CTL);
- uint32_t linkrate;
+ uint32_t cdctl;
- if (!(lcpll1 & LCPLL_PLL_ENABLE))
+ skl_dpll0_update(dev_priv);
+
+ if (dev_priv->skl_vco_freq == 0)
return 24000; /* 24MHz is the cd freq with NSSC ref */
- if ((cdctl & CDCLK_FREQ_SEL_MASK) == CDCLK_FREQ_540)
- return 540000;
+ cdctl = I915_READ(CDCLK_CTL);
- linkrate = (I915_READ(DPLL_CTRL1) &
- DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0)) >> 1;
-
- if (linkrate == DPLL_CTRL1_LINK_RATE_2160 ||
- linkrate == DPLL_CTRL1_LINK_RATE_1080) {
- /* vco 8640 */
+ if (dev_priv->skl_vco_freq == 8640) {
switch (cdctl & CDCLK_FREQ_SEL_MASK) {
case CDCLK_FREQ_450_432:
return 432000;
case CDCLK_FREQ_337_308:
return 308570;
+ case CDCLK_FREQ_540:
+ return 540000;
case CDCLK_FREQ_675_617:
return 617140;
default:
- WARN(1, "Unknown cd freq selection\n");
+ MISSING_CASE(cdctl & CDCLK_FREQ_SEL_MASK);
}
} 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_540:
+ return 540000;
case CDCLK_FREQ_675_617:
return 675000;
default:
- WARN(1, "Unknown cd freq selection\n");
+ MISSING_CASE(cdctl & CDCLK_FREQ_SEL_MASK);
}
}