drm/i915: Add display hotplug event on Ironlake

Enable display hotplug irqs from Ibex Peak (PCH).
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_drv.h

@@ -214,6 +214,8 @@ typedef struct drm_i915_private {
 	u32 gt_irq_mask_reg;
 	u32 gt_irq_enable_reg;
 	u32 de_irq_enable_reg;
+	u32 pch_irq_mask_reg;
+	u32 pch_irq_enable_reg;
 
 	u32 hotplug_supported_mask;
 	struct work_struct hotplug_work;

drivers/gpu/drm/i915/i915_irq.c

@@ -270,19 +270,24 @@ irqreturn_t igdng_irq_handler(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	int ret = IRQ_NONE;
-	u32 de_iir, gt_iir;
-	u32 new_de_iir, new_gt_iir;
+	u32 de_iir, gt_iir, pch_iir;
+	u32 new_de_iir, new_gt_iir, new_pch_iir;
 	struct drm_i915_master_private *master_priv;
 
 	de_iir = I915_READ(DEIIR);
 	gt_iir = I915_READ(GTIIR);
+	pch_iir = I915_READ(SDEIIR);
 
 	for (;;) {
-		if (de_iir == 0 && gt_iir == 0)
+		if (de_iir == 0 && gt_iir == 0 && pch_iir == 0)
 			break;
 
 		ret = IRQ_HANDLED;
 
+		/* should clear PCH hotplug event before clear CPU irq */
+		I915_WRITE(SDEIIR, pch_iir);
+		new_pch_iir = I915_READ(SDEIIR);
+
 		I915_WRITE(DEIIR, de_iir);
 		new_de_iir = I915_READ(DEIIR);
 		I915_WRITE(GTIIR, gt_iir);
@@ -305,8 +310,15 @@ irqreturn_t igdng_irq_handler(struct drm_device *dev)
 		if (de_iir & DE_GSE)
 			ironlake_opregion_gse_intr(dev);
 
+		/* check event from PCH */
+		if ((de_iir & DE_PCH_EVENT) &&
+			(pch_iir & SDE_HOTPLUG_MASK)) {
+			queue_work(dev_priv->wq, &dev_priv->hotplug_work);
+		}
+
 		de_iir = new_de_iir;
 		gt_iir = new_gt_iir;
+		pch_iir = new_pch_iir;
 	}
 
 	return ret;
@@ -1003,14 +1015,21 @@ static void igdng_irq_preinstall(struct drm_device *dev)
 	I915_WRITE(GTIMR, 0xffffffff);
 	I915_WRITE(GTIER, 0x0);
 	(void) I915_READ(GTIER);
+
+	/* south display irq */
+	I915_WRITE(SDEIMR, 0xffffffff);
+	I915_WRITE(SDEIER, 0x0);
+	(void) I915_READ(SDEIER);
 }
 
 static int igdng_irq_postinstall(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	/* enable kind of interrupts always enabled */
-	u32 display_mask = DE_MASTER_IRQ_CONTROL | DE_GSE /*| DE_PCH_EVENT */;
+	u32 display_mask = DE_MASTER_IRQ_CONTROL | DE_GSE | DE_PCH_EVENT;
 	u32 render_mask = GT_USER_INTERRUPT;
+	u32 hotplug_mask = SDE_CRT_HOTPLUG | SDE_PORTB_HOTPLUG |
+			   SDE_PORTC_HOTPLUG | SDE_PORTD_HOTPLUG;
 
 	dev_priv->irq_mask_reg = ~display_mask;
 	dev_priv->de_irq_enable_reg = display_mask;
@@ -1030,6 +1049,14 @@ static int igdng_irq_postinstall(struct drm_device *dev)
 	I915_WRITE(GTIER, dev_priv->gt_irq_enable_reg);
 	(void) I915_READ(GTIER);
 
+	dev_priv->pch_irq_mask_reg = ~hotplug_mask;
+	dev_priv->pch_irq_enable_reg = hotplug_mask;
+
+	I915_WRITE(SDEIIR, I915_READ(SDEIIR));
+	I915_WRITE(SDEIMR, dev_priv->pch_irq_mask_reg);
+	I915_WRITE(SDEIER, dev_priv->pch_irq_enable_reg);
+	(void) I915_READ(SDEIER);
+
 	return 0;
 }
 

drivers/gpu/drm/i915/i915_reg.h

@@ -2126,6 +2126,7 @@
 #define SDE_PORTC_HOTPLUG       (1 << 9)
 #define SDE_PORTB_HOTPLUG       (1 << 8)
 #define SDE_SDVOB_HOTPLUG       (1 << 6)
+#define SDE_HOTPLUG_MASK	(0xf << 8)
 
 #define SDEISR  0xc4000
 #define SDEIMR  0xc4004