drm/i915: Enable edp psr error interrupts on hsw

The definitions for the error register should be valid on bdw/skl too,
but there we haven't even enabled DE_MISC handling yet.

Somewhat confusing the the moved register offset on bdw is only for
the _CTL/_AUX register, and that _IIR/IMR stayed where they have been
on bdw.

v2: Fixes from Ville.

v3: From DK
 * Rebased on drm-tip
 * Removed BDW IIR bit definition, looks like an unintentional change that
should be in the following patch.

v4: From DK
 * Don't mask REG_WRITE.

References: bspec/11974 [SRD Interrupt Bit Definition DevHSW]
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Jose Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180405220023.9449-1-dhinakaran.pandiyan@intel.com

drivers/gpu/drm/i915/i915_irq.c

@@ -2452,6 +2452,26 @@ static void ilk_display_irq_handler(struct drm_i915_private *dev_priv,
 		ironlake_rps_change_irq_handler(dev_priv);
 }
 
+static void hsw_edp_psr_irq_handler(struct drm_i915_private *dev_priv)
+{
+	u32 edp_psr_iir = I915_READ(EDP_PSR_IIR);
+
+	if (edp_psr_iir & EDP_PSR_ERROR)
+		DRM_DEBUG_KMS("PSR error\n");
+
+	if (edp_psr_iir & EDP_PSR_PRE_ENTRY) {
+		DRM_DEBUG_KMS("PSR prepare entry in 2 vblanks\n");
+		I915_WRITE(EDP_PSR_IMR, EDP_PSR_PRE_ENTRY);
+	}
+
+	if (edp_psr_iir & EDP_PSR_POST_EXIT) {
+		DRM_DEBUG_KMS("PSR exit completed\n");
+		I915_WRITE(EDP_PSR_IMR, 0);
+	}
+
+	I915_WRITE(EDP_PSR_IIR, edp_psr_iir);
+}
+
 static void ivb_display_irq_handler(struct drm_i915_private *dev_priv,
 				    u32 de_iir)
 {
@@ -2464,6 +2484,9 @@ static void ivb_display_irq_handler(struct drm_i915_private *dev_priv,
 	if (de_iir & DE_ERR_INT_IVB)
 		ivb_err_int_handler(dev_priv);
 
+	if (de_iir & DE_EDP_PSR_INT_HSW)
+		hsw_edp_psr_irq_handler(dev_priv);
+
 	if (de_iir & DE_AUX_CHANNEL_A_IVB)
 		dp_aux_irq_handler(dev_priv);
 
@@ -3348,6 +3371,11 @@ static void ironlake_irq_reset(struct drm_device *dev)
 	if (IS_GEN7(dev_priv))
 		I915_WRITE(GEN7_ERR_INT, 0xffffffff);
 
+	if (IS_HASWELL(dev_priv)) {
+		I915_WRITE(EDP_PSR_IMR, 0xffffffff);
+		I915_WRITE(EDP_PSR_IIR, 0xffffffff);
+	}
+
 	gen5_gt_irq_reset(dev_priv);
 
 	ibx_irq_reset(dev_priv);
@@ -3762,6 +3790,12 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
 			      DE_DP_A_HOTPLUG);
 	}
 
+	if (IS_HASWELL(dev_priv)) {
+		gen3_assert_iir_is_zero(dev_priv, EDP_PSR_IIR);
+		I915_WRITE(EDP_PSR_IMR, 0);
+		display_mask |= DE_EDP_PSR_INT_HSW;
+	}
+
 	dev_priv->irq_mask = ~display_mask;
 
 	ibx_irq_pre_postinstall(dev);

drivers/gpu/drm/i915/i915_reg.h

@@ -4026,6 +4026,13 @@ enum {
 #define   EDP_PSR_TP1_TIME_0us			(3<<4)
 #define   EDP_PSR_IDLE_FRAME_SHIFT		0
 
+/* Bspec claims those aren't shifted but stay at 0x64800 */
+#define EDP_PSR_IMR				_MMIO(0x64834)
+#define EDP_PSR_IIR				_MMIO(0x64838)
+#define   EDP_PSR_ERROR				(1<<2)
+#define   EDP_PSR_POST_EXIT			(1<<1)
+#define   EDP_PSR_PRE_ENTRY			(1<<0)
+
 #define EDP_PSR_AUX_CTL				_MMIO(dev_priv->psr_mmio_base + 0x10)
 #define   EDP_PSR_AUX_CTL_TIME_OUT_MASK		(3 << 26)
 #define   EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK	(0x1f << 20)
@@ -6837,6 +6844,7 @@ enum {
 #define DE_PCH_EVENT_IVB		(1<<28)
 #define DE_DP_A_HOTPLUG_IVB		(1<<27)
 #define DE_AUX_CHANNEL_A_IVB		(1<<26)
+#define DE_EDP_PSR_INT_HSW		(1<<19)
 #define DE_SPRITEC_FLIP_DONE_IVB	(1<<14)
 #define DE_PLANEC_FLIP_DONE_IVB		(1<<13)
 #define DE_PIPEC_VBLANK_IVB		(1<<10)