drm/i915/chv: Preliminary interrupt support for Cherryview

CHV has the Gen8 master interrupt register, as well as Gen8
GT/PCU interrupt registers.

The display block is based on VLV, with the main difference
of adding pipe C.

v2: Rewrite the order of operations to make more sense
    Don't bail out if MASTER_CTL register doesn't show an interrupt,
    as display interrupts aren't reported there.

v3: Rebase on top of Egbert Eich's hpd irq handling rework by using
the relevant port hotplug logic like for vlv.

v4: Rebase on top of Ben's gt irq #define refactoring.

v5: Squash in gen8_gt_irq_handler refactoring from Zhao Yakui
<yakui.zhao@intel.com>

v6: Adapt to upstream changes, dev_priv->irq_received is gone.

v7: Enable 3 the commented-out 3 pipe support.

v8: Rebase on top of Paulo's irq setup rework, use the renamed macros from
upstream.

v9: Grab irq_lock around i915_enable_pipestat()

FIXME: There's probably some potential for more shared code between bdw and chv.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v2)
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
[danvet: Drop the unnecessary cast Jani spotted.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -1703,6 +1703,95 @@ out:
 	return ret;
 }
 
+static irqreturn_t cherryview_irq_handler(int irq, void *arg)
+{
+	struct drm_device *dev = (struct drm_device *) arg;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 master_ctl, iir;
+	irqreturn_t ret = IRQ_NONE;
+	unsigned int pipes = 0;
+
+	master_ctl = I915_READ(GEN8_MASTER_IRQ);
+
+	I915_WRITE(GEN8_MASTER_IRQ, 0);
+
+	ret = gen8_gt_irq_handler(dev, dev_priv, master_ctl);
+
+	iir = I915_READ(VLV_IIR);
+
+	if (iir & (I915_DISPLAY_PIPE_A_VBLANK_INTERRUPT | I915_DISPLAY_PIPE_A_EVENT_INTERRUPT))
+		pipes |= 1 << 0;
+	if (iir & (I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT | I915_DISPLAY_PIPE_B_EVENT_INTERRUPT))
+		pipes |= 1 << 1;
+	if (iir & (I915_DISPLAY_PIPE_C_VBLANK_INTERRUPT | I915_DISPLAY_PIPE_C_EVENT_INTERRUPT))
+		pipes |= 1 << 2;
+
+	if (pipes) {
+		u32 pipe_stats[I915_MAX_PIPES] = {};
+		unsigned long irqflags;
+		int pipe;
+
+		spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+		for_each_pipe(pipe) {
+			unsigned int reg;
+
+			if (!(pipes & (1 << pipe)))
+				continue;
+
+			reg = PIPESTAT(pipe);
+			pipe_stats[pipe] = I915_READ(reg);
+
+			/*
+			 * Clear the PIPE*STAT regs before the IIR
+			 */
+			if (pipe_stats[pipe] & 0x8000ffff) {
+				if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
+					DRM_DEBUG_DRIVER("pipe %c underrun\n",
+							 pipe_name(pipe));
+				I915_WRITE(reg, pipe_stats[pipe]);
+			}
+		}
+		spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+
+		for_each_pipe(pipe) {
+			if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS)
+				drm_handle_vblank(dev, pipe);
+
+			if (pipe_stats[pipe] & PLANE_FLIP_DONE_INT_STATUS_VLV) {
+				intel_prepare_page_flip(dev, pipe);
+				intel_finish_page_flip(dev, pipe);
+			}
+		}
+
+		if (pipe_stats[0] & PIPE_GMBUS_INTERRUPT_STATUS)
+			gmbus_irq_handler(dev);
+
+		ret = IRQ_HANDLED;
+	}
+
+	/* Consume port.  Then clear IIR or we'll miss events */
+	if (iir & I915_DISPLAY_PORT_INTERRUPT) {
+		u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);
+
+		I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status);
+
+		DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
+				 hotplug_status);
+		if (hotplug_status & HOTPLUG_INT_STATUS_I915)
+			queue_work(dev_priv->wq,
+				   &dev_priv->hotplug_work);
+
+		ret = IRQ_HANDLED;
+	}
+
+	I915_WRITE(VLV_IIR, iir);
+
+	I915_WRITE(GEN8_MASTER_IRQ, DE_MASTER_IRQ_CONTROL);
+	POSTING_READ(GEN8_MASTER_IRQ);
+
+	return ret;
+}
+
 static void ibx_irq_handler(struct drm_device *dev, u32 pch_iir)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -2974,6 +3063,37 @@ static void gen8_irq_preinstall(struct drm_device *dev)
 	gen8_irq_reset(dev);
 }
 
+static void cherryview_irq_preinstall(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int pipe;
+
+	I915_WRITE(GEN8_MASTER_IRQ, 0);
+	POSTING_READ(GEN8_MASTER_IRQ);
+
+	GEN8_IRQ_RESET_NDX(GT, 0);
+	GEN8_IRQ_RESET_NDX(GT, 1);
+	GEN8_IRQ_RESET_NDX(GT, 2);
+	GEN8_IRQ_RESET_NDX(GT, 3);
+
+	GEN5_IRQ_RESET(GEN8_PCU_);
+
+	POSTING_READ(GEN8_PCU_IIR);
+
+	I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK_CHV);
+
+	I915_WRITE(PORT_HOTPLUG_EN, 0);
+	I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
+
+	for_each_pipe(pipe)
+		I915_WRITE(PIPESTAT(pipe), 0xffff);
+
+	I915_WRITE(VLV_IMR, 0xffffffff);
+	I915_WRITE(VLV_IER, 0x0);
+	I915_WRITE(VLV_IIR, 0xffffffff);
+	POSTING_READ(VLV_IIR);
+}
+
 static void ibx_hpd_irq_setup(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3291,6 +3411,50 @@ static int gen8_irq_postinstall(struct drm_device *dev)
 	return 0;
 }
 
+static int cherryview_irq_postinstall(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 enable_mask = I915_DISPLAY_PORT_INTERRUPT |
+		I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
+		I915_DISPLAY_PIPE_A_VBLANK_INTERRUPT |
+		I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
+		I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT |
+		I915_DISPLAY_PIPE_C_EVENT_INTERRUPT |
+		I915_DISPLAY_PIPE_C_VBLANK_INTERRUPT;
+	u32 pipestat_enable = PLANE_FLIP_DONE_INT_EN_VLV;
+	unsigned long irqflags;
+	int pipe;
+
+	/*
+	 * Leave vblank interrupts masked initially.  enable/disable will
+	 * toggle them based on usage.
+	 */
+	dev_priv->irq_mask = ~enable_mask |
+		I915_DISPLAY_PIPE_A_VBLANK_INTERRUPT |
+		I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT |
+		I915_DISPLAY_PIPE_C_VBLANK_INTERRUPT;
+
+	for_each_pipe(pipe)
+		I915_WRITE(PIPESTAT(pipe), 0xffff);
+
+	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+	i915_enable_pipestat(dev_priv, 0, PIPE_GMBUS_EVENT_ENABLE);
+	for_each_pipe(pipe)
+		i915_enable_pipestat(dev_priv, pipe, pipestat_enable);
+	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+
+	I915_WRITE(VLV_IIR, 0xffffffff);
+	I915_WRITE(VLV_IMR, dev_priv->irq_mask);
+	I915_WRITE(VLV_IER, enable_mask);
+
+	gen8_gt_irq_postinstall(dev_priv);
+
+	I915_WRITE(GEN8_MASTER_IRQ, MASTER_INTERRUPT_ENABLE);
+	POSTING_READ(GEN8_MASTER_IRQ);
+
+	return 0;
+}
+
 static void gen8_irq_uninstall(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3336,6 +3500,57 @@ static void valleyview_irq_uninstall(struct drm_device *dev)
 	POSTING_READ(VLV_IER);
 }
 
+static void cherryview_irq_uninstall(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int pipe;
+
+	if (!dev_priv)
+		return;
+
+	I915_WRITE(GEN8_MASTER_IRQ, 0);
+	POSTING_READ(GEN8_MASTER_IRQ);
+
+#define GEN8_IRQ_FINI_NDX(type, which)				\
+do {								\
+	I915_WRITE(GEN8_##type##_IMR(which), 0xffffffff);	\
+	I915_WRITE(GEN8_##type##_IER(which), 0);		\
+	I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff);	\
+	POSTING_READ(GEN8_##type##_IIR(which));			\
+	I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff);	\
+} while (0)
+
+#define GEN8_IRQ_FINI(type)				\
+do {							\
+	I915_WRITE(GEN8_##type##_IMR, 0xffffffff);	\
+	I915_WRITE(GEN8_##type##_IER, 0);		\
+	I915_WRITE(GEN8_##type##_IIR, 0xffffffff);	\
+	POSTING_READ(GEN8_##type##_IIR);		\
+	I915_WRITE(GEN8_##type##_IIR, 0xffffffff);	\
+} while (0)
+
+	GEN8_IRQ_FINI_NDX(GT, 0);
+	GEN8_IRQ_FINI_NDX(GT, 1);
+	GEN8_IRQ_FINI_NDX(GT, 2);
+	GEN8_IRQ_FINI_NDX(GT, 3);
+
+	GEN8_IRQ_FINI(PCU);
+
+#undef GEN8_IRQ_FINI
+#undef GEN8_IRQ_FINI_NDX
+
+	I915_WRITE(PORT_HOTPLUG_EN, 0);
+	I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
+
+	for_each_pipe(pipe)
+		I915_WRITE(PIPESTAT(pipe), 0xffff);
+
+	I915_WRITE(VLV_IMR, 0xffffffff);
+	I915_WRITE(VLV_IER, 0x0);
+	I915_WRITE(VLV_IIR, 0xffffffff);
+	POSTING_READ(VLV_IIR);
+}
+
 static void ironlake_irq_uninstall(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -4041,7 +4256,15 @@ void intel_irq_init(struct drm_device *dev)
 		dev->driver->get_scanout_position = i915_get_crtc_scanoutpos;
 	}
 
-	if (IS_VALLEYVIEW(dev)) {
+	if (IS_CHERRYVIEW(dev)) {
+		dev->driver->irq_handler = cherryview_irq_handler;
+		dev->driver->irq_preinstall = cherryview_irq_preinstall;
+		dev->driver->irq_postinstall = cherryview_irq_postinstall;
+		dev->driver->irq_uninstall = cherryview_irq_uninstall;
+		dev->driver->enable_vblank = valleyview_enable_vblank;
+		dev->driver->disable_vblank = valleyview_disable_vblank;
+		dev_priv->display.hpd_irq_setup = i915_hpd_irq_setup;
+	} else if (IS_VALLEYVIEW(dev)) {
 		dev->driver->irq_handler = valleyview_irq_handler;
 		dev->driver->irq_preinstall = valleyview_irq_preinstall;
 		dev->driver->irq_postinstall = valleyview_irq_postinstall;