drm/i915/cnl: DDI - PLL mapping

One of the steps for PLL (un)initialization is to (un)map
the correspondent DDI that is actually using that PLL.

So, let's do this step following the places already stablished
and used so far, although spec put this as part of PLL
initialization sequences.

v2: Use proper prefix on bits names as suggested by Ander.
v3: Add missed "~". Without that the logic was inverted
    so we were disabling interrupts.
    Credits-to: Clinton
    Credits-to: Art
v4: Spec is getting updated to do DDI -> PLL mapping
    and clock on in 2 separated reg writes. (Paulo)
    Also update bits definitions to use space
    (1 << 1) instead of (1<<1). (Paulo)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Art Runyan <arthur.j.runyan@intel.com>
Cc: Clint Taylor <clinton.a.taylor@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Kahola, Mika <mika.kahola@intel.com>
Cc: Ander Conselvan De Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Kahola, Mika <mika.kahola@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1497047175-27250-5-git-send-email-rodrigo.vivi@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -8134,6 +8134,15 @@ enum {
 #define DPLL_CFGCR1(id)	_MMIO_PIPE((id) - SKL_DPLL1, _DPLL1_CFGCR1, _DPLL2_CFGCR1)
 #define DPLL_CFGCR2(id)	_MMIO_PIPE((id) - SKL_DPLL1, _DPLL1_CFGCR2, _DPLL2_CFGCR2)
 
+/*
+ * CNL Clocks
+ */
+#define DPCLKA_CFGCR0				_MMIO(0x6C200)
+#define  DPCLKA_CFGCR0_DDI_CLK_OFF(port)	(1 << ((port)+10))
+#define  DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port)	(3 << ((port)*2))
+#define  DPCLKA_CFGCR0_DDI_CLK_SEL_SHIFT(port)	((port)*2)
+#define  DPCLKA_CFGCR0_DDI_CLK_SEL(pll, port)	((pll) << ((port)*2))
+
 /* BXT display engine PLL */
 #define BXT_DE_PLL_CTL			_MMIO(0x6d000)
 #define   BXT_DE_PLL_RATIO(x)		(x)	/* {60,65,100} * 19.2MHz */

drivers/gpu/drm/i915/intel_ddi.c

@@ -1621,13 +1621,27 @@ static void intel_ddi_clk_select(struct intel_encoder *encoder,
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	enum port port = intel_ddi_get_encoder_port(encoder);
+	uint32_t val;
 
 	if (WARN_ON(!pll))
 		return;
 
-	if (IS_GEN9_BC(dev_priv)) {
-		uint32_t val;
+	if (IS_CANNONLAKE(dev_priv)) {
+		/* Configure DPCLKA_CFGCR0 to map the DPLL to the DDI. */
+		val = I915_READ(DPCLKA_CFGCR0);
+		val |= DPCLKA_CFGCR0_DDI_CLK_SEL(pll->id, port);
+		I915_WRITE(DPCLKA_CFGCR0, val);
 
+		/*
+		 * Configure DPCLKA_CFGCR0 to turn on the clock for the DDI.
+		 * This step and the step before must be done with separate
+		 * register writes.
+		 */
+		val = I915_READ(DPCLKA_CFGCR0);
+		val &= ~(DPCLKA_CFGCR0_DDI_CLK_OFF(port) |
+			 DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port));
+		I915_WRITE(DPCLKA_CFGCR0, val);
+	} else if (IS_GEN9_BC(dev_priv)) {
 		/* DDI -> PLL mapping  */
 		val = I915_READ(DPLL_CTRL2);
 
@@ -1767,7 +1781,10 @@ static void intel_ddi_post_disable(struct intel_encoder *intel_encoder,
 	if (dig_port)
 		intel_display_power_put(dev_priv, dig_port->ddi_io_power_domain);
 
-	if (IS_GEN9_BC(dev_priv))
+	if (IS_CANNONLAKE(dev_priv))
+		I915_WRITE(DPCLKA_CFGCR0, I915_READ(DPCLKA_CFGCR0) |
+			   DPCLKA_CFGCR0_DDI_CLK_OFF(port));
+	else if (IS_GEN9_BC(dev_priv))
 		I915_WRITE(DPLL_CTRL2, (I915_READ(DPLL_CTRL2) |
 					DPLL_CTRL2_DDI_CLK_OFF(port)));
 	else if (INTEL_GEN(dev_priv) < 9)