drm/i915/dsi: Add TE handler for dsi cmd mode.

In case of dual link, we get the TE on slave. So clear the TE on slave
DSI IIR.

If we are operating in TE_GATE mode, after we do a frame update, the
transcoder will send the frame data to the panel, after it receives a
TE. Whereas if we are operating in NO_GATE mode then the transcoder will
immediately send the frame data to the panel. We are not dealing with
the periodic command mode here.

v2: Pass only relevant masked bits to the handler (Jani)

v3: Fix the check for cmd mode in TE handler function.

v4: Use intel_handle_vblank instead of drm_handle_vblank (Jani)

v3: Use static on handler func (Jani)
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200924124209.17916-4-vandita.kulkarni@intel.com

drivers/gpu/drm/i915/i915_irq.c

@@ -2254,6 +2254,63 @@ gen8_de_misc_irq_handler(struct drm_i915_private *dev_priv, u32 iir)
 		drm_err(&dev_priv->drm, "Unexpected DE Misc interrupt\n");
 }
 
+static void gen11_dsi_te_interrupt_handler(struct drm_i915_private *dev_priv,
+					   u32 te_trigger)
+{
+	enum pipe pipe = INVALID_PIPE;
+	enum transcoder dsi_trans;
+	enum port port;
+	u32 val, tmp;
+
+	/*
+	 * Incase of dual link, TE comes from DSI_1
+	 * this is to check if dual link is enabled
+	 */
+	val = I915_READ(TRANS_DDI_FUNC_CTL2(TRANSCODER_DSI_0));
+	val &= PORT_SYNC_MODE_ENABLE;
+
+	/*
+	 * if dual link is enabled, then read DSI_0
+	 * transcoder registers
+	 */
+	port = ((te_trigger & DSI1_TE && val) || (te_trigger & DSI0_TE)) ?
+						  PORT_A : PORT_B;
+	dsi_trans = (port == PORT_A) ? TRANSCODER_DSI_0 : TRANSCODER_DSI_1;
+
+	/* Check if DSI configured in command mode */
+	val = I915_READ(DSI_TRANS_FUNC_CONF(dsi_trans));
+	val = val & OP_MODE_MASK;
+
+	if (val != CMD_MODE_NO_GATE && val != CMD_MODE_TE_GATE) {
+		drm_err(&dev_priv->drm, "DSI trancoder not configured in command mode\n");
+		return;
+	}
+
+	/* Get PIPE for handling VBLANK event */
+	val = I915_READ(TRANS_DDI_FUNC_CTL(dsi_trans));
+	switch (val & TRANS_DDI_EDP_INPUT_MASK) {
+	case TRANS_DDI_EDP_INPUT_A_ON:
+		pipe = PIPE_A;
+		break;
+	case TRANS_DDI_EDP_INPUT_B_ONOFF:
+		pipe = PIPE_B;
+		break;
+	case TRANS_DDI_EDP_INPUT_C_ONOFF:
+		pipe = PIPE_C;
+		break;
+	default:
+		drm_err(&dev_priv->drm, "Invalid PIPE\n");
+		return;
+	}
+
+	intel_handle_vblank(dev_priv, pipe);
+
+	/* clear TE in dsi IIR */
+	port = (te_trigger & DSI1_TE) ? PORT_B : PORT_A;
+	tmp = I915_READ(DSI_INTR_IDENT_REG(port));
+	I915_WRITE(DSI_INTR_IDENT_REG(port), tmp);
+}
+
 static irqreturn_t
 gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
 {
@@ -2318,6 +2375,14 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
 				found = true;
 			}
 
+			if (INTEL_GEN(dev_priv) >= 11) {
+				tmp_mask = iir & (DSI0_TE | DSI1_TE);
+				if (tmp_mask) {
+					gen11_dsi_te_interrupt_handler(dev_priv, tmp_mask);
+					found = true;
+				}
+			}
+
 			if (!found)
 				drm_err(&dev_priv->drm,
 					"Unexpected DE Port interrupt\n");