drm/i915/icl: compute the combo PHY (DPLL) HDMI registers

HDMI mode DPLL programming on ICL is the same as CNL, so just reuse
the CNL code.

v2:
 - Properly detect HDMI crtcs.
 - Rebase after changes to the cnl function (clock * 1000).
v3:
 - Add a comment to clarify why we treat 38.4 as 19.2 (James).

Reviewed-by: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328215803.13835-5-paulo.r.zanoni@intel.com

1 files changed, 36 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index 14f5414ceab2..a1c2bd10a72e 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -2218,6 +2218,7 @@ cnl_ddi_calculate_wrpll(int clock,
                         struct skl_wrpll_params *wrpll_params)
 {
         u32 afe_clock = clock * 5;
+        uint32_t ref_clock;
         u32 dco_min = 7998000;
         u32 dco_max = 10000000;
         u32 dco_mid = (dco_min + dco_max) / 2;
@@ -2250,8 +2251,17 @@ cnl_ddi_calculate_wrpll(int clock,
 
         cnl_wrpll_get_multipliers(best_div, &pdiv, &qdiv, &kdiv);
 
-        cnl_wrpll_params_populate(wrpll_params, best_dco,
-                                  dev_priv->cdclk.hw.ref, pdiv, qdiv, kdiv);
+        ref_clock = dev_priv->cdclk.hw.ref;
+
+        /*
+         * For ICL, the spec states: if reference frequency is 38.4, use 19.2
+         * because the DPLL automatically divides that by 2.
+         */
+        if (IS_ICELAKE(dev_priv) && ref_clock == 38400)
+                ref_clock = 19200;
+
+        cnl_wrpll_params_populate(wrpll_params, best_dco, ref_clock, pdiv, qdiv,
+                                  kdiv);
 
         return true;
 }
@@ -2403,7 +2413,30 @@ static bool icl_calc_dpll_state(struct intel_crtc_state *crtc_state,
                                 struct intel_encoder *encoder, int clock,
                                 struct intel_dpll_hw_state *pll_state)
 {
-        /* TODO */
+        struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+        uint32_t cfgcr0, cfgcr1;
+        struct skl_wrpll_params pll_params = { 0 };
+        bool ret;
+
+        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI))
+                ret = cnl_ddi_calculate_wrpll(clock, dev_priv, &pll_params);
+        else
+                ret = false; /* TODO */
+
+        if (!ret)
+                return false;
+
+        cfgcr0 = DPLL_CFGCR0_DCO_FRACTION(pll_params.dco_fraction) |
+                 pll_params.dco_integer;
+
+        cfgcr1 = DPLL_CFGCR1_QDIV_RATIO(pll_params.qdiv_ratio) |
+                 DPLL_CFGCR1_QDIV_MODE(pll_params.qdiv_mode) |
+                 DPLL_CFGCR1_KDIV(pll_params.kdiv) |
+                 DPLL_CFGCR1_PDIV(pll_params.pdiv) |
+                 DPLL_CFGCR1_CENTRAL_FREQ_8400;
+
+        pll_state->cfgcr0 = cfgcr0;
+        pll_state->cfgcr1 = cfgcr1;
         return true;
 }