drm/i915: State readout and cross-checking for ddi_pll_sel

To make things a bit more manageable extract a new function for
reading out common ddi port state. This means a bit of duplication
between encoders and the core since both look at the same registers,
but doesn't seem worth to make a fuzz about.

We can also remove the state readout code in intel_ddi_setup_hw_pll_state.
That code is only called from the hardware take over and not the cross
check code, and only after the crtc state is reconstructed. So we can
rely on an accurate value of crtc->config.ddi_pll_sel already.

Compared to the old code also trust the hw state more and don't
special-case port A - we want to cross-check the actual-state, not
bake in our own assumptions about how this is supposed to all be
linked up.

v2: Make use of the read-out ddi_pll_sel in intel_ddi_clock_get.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[imre: rebased on patchset version w/o pch/crt/fdi refactoring]
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -5794,6 +5794,7 @@ enum punit_power_well {
 #define  TRANS_DDI_FUNC_ENABLE		(1<<31)
 /* Those bits are ignored by pipe EDP since it can only connect to DDI A */
 #define  TRANS_DDI_PORT_MASK		(7<<28)
+#define  TRANS_DDI_PORT_SHIFT		28
 #define  TRANS_DDI_SELECT_PORT(x)	((x)<<28)
 #define  TRANS_DDI_PORT_NONE		(0<<28)
 #define  TRANS_DDI_MODE_SELECT_MASK	(7<<24)

drivers/gpu/drm/i915/intel_ddi.c

@@ -612,11 +612,10 @@ static void intel_ddi_clock_get(struct intel_encoder *encoder,
 				struct intel_crtc_config *pipe_config)
 {
 	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
-	enum port port = intel_ddi_get_encoder_port(encoder);
 	int link_clock = 0;
 	u32 val, pll;
 
-	val = I915_READ(PORT_CLK_SEL(port));
+	val = pipe_config->ddi_pll_sel;
 	switch (val & PORT_CLK_SEL_MASK) {
 	case PORT_CLK_SEL_LCPLL_810:
 		link_clock = 81000;
@@ -1113,40 +1112,6 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
 	return false;
 }
 
-static uint32_t intel_ddi_get_crtc_pll(struct drm_i915_private *dev_priv,
-				       enum pipe pipe)
-{
-	uint32_t temp, ret;
-	enum port port = I915_MAX_PORTS;
-	enum transcoder cpu_transcoder = intel_pipe_to_cpu_transcoder(dev_priv,
-								      pipe);
-	int i;
-
-	if (cpu_transcoder == TRANSCODER_EDP) {
-		port = PORT_A;
-	} else {
-		temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
-		temp &= TRANS_DDI_PORT_MASK;
-
-		for (i = PORT_B; i <= PORT_E; i++)
-			if (temp == TRANS_DDI_SELECT_PORT(i))
-				port = i;
-	}
-
-	if (port == I915_MAX_PORTS) {
-		WARN(1, "Pipe %c enabled on an unknown port\n",
-		     pipe_name(pipe));
-		ret = PORT_CLK_SEL_NONE;
-	} else {
-		ret = I915_READ(PORT_CLK_SEL(port));
-		DRM_DEBUG_KMS("Pipe %c connected to port %c using clock "
-			      "0x%08x\n", pipe_name(pipe), port_name(port),
-			      ret);
-	}
-
-	return ret;
-}
-
 void intel_ddi_setup_hw_pll_state(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1165,9 +1130,6 @@ void intel_ddi_setup_hw_pll_state(struct drm_device *dev)
 			continue;
 		}
 
-		intel_crtc->config.ddi_pll_sel = intel_ddi_get_crtc_pll(dev_priv,
-								 pipe);
-
 		switch (intel_crtc->config.ddi_pll_sel) {
 		case PORT_CLK_SEL_WRPLL1:
 			dev_priv->ddi_plls.wrpll1_refcount++;

drivers/gpu/drm/i915/intel_display.c

@@ -7570,6 +7570,35 @@ static int haswell_crtc_mode_set(struct drm_crtc *crtc,
 	return 0;
 }
 
+static void haswell_get_ddi_port_state(struct intel_crtc *crtc,
+				       struct intel_crtc_config *pipe_config)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum port port;
+	uint32_t tmp;
+
+	tmp = I915_READ(TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder));
+
+	port = (tmp & TRANS_DDI_PORT_MASK) >> TRANS_DDI_PORT_SHIFT;
+
+	pipe_config->ddi_pll_sel = I915_READ(PORT_CLK_SEL(port));
+	/*
+	 * Haswell has only FDI/PCH transcoder A. It is which is connected to
+	 * DDI E. So just check whether this pipe is wired to DDI E and whether
+	 * the PCH transcoder is on.
+	 */
+	if ((port == PORT_E) && I915_READ(LPT_TRANSCONF) & TRANS_ENABLE) {
+		pipe_config->has_pch_encoder = true;
+
+		tmp = I915_READ(FDI_RX_CTL(PIPE_A));
+		pipe_config->fdi_lanes = ((FDI_DP_PORT_WIDTH_MASK & tmp) >>
+					  FDI_DP_PORT_WIDTH_SHIFT) + 1;
+
+		ironlake_get_fdi_m_n_config(crtc, pipe_config);
+	}
+}
+
 static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 				    struct intel_crtc_config *pipe_config)
 {
@@ -7615,22 +7644,7 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	if (!(tmp & PIPECONF_ENABLE))
 		return false;
 
-	/*
-	 * Haswell has only FDI/PCH transcoder A. It is which is connected to
-	 * DDI E. So just check whether this pipe is wired to DDI E and whether
-	 * the PCH transcoder is on.
-	 */
-	tmp = I915_READ(TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder));
-	if ((tmp & TRANS_DDI_PORT_MASK) == TRANS_DDI_SELECT_PORT(PORT_E) &&
-	    I915_READ(LPT_TRANSCONF) & TRANS_ENABLE) {
-		pipe_config->has_pch_encoder = true;
-
-		tmp = I915_READ(FDI_RX_CTL(PIPE_A));
-		pipe_config->fdi_lanes = ((FDI_DP_PORT_WIDTH_MASK & tmp) >>
-					  FDI_DP_PORT_WIDTH_SHIFT) + 1;
-
-		ironlake_get_fdi_m_n_config(crtc, pipe_config);
-	}
+	haswell_get_ddi_port_state(crtc, pipe_config);
 
 	intel_get_pipe_timings(crtc, pipe_config);
 
@@ -10409,6 +10423,8 @@ intel_pipe_config_compare(struct drm_device *dev,
 
 	PIPE_CONF_CHECK_I(double_wide);
 
+	PIPE_CONF_CHECK_X(ddi_pll_sel);
+
 	PIPE_CONF_CHECK_I(shared_dpll);
 	PIPE_CONF_CHECK_X(dpll_hw_state.dpll);
 	PIPE_CONF_CHECK_X(dpll_hw_state.dpll_md);