drm/i915: Introduce spt_irq_handler()

Starting from SPT the only interrupts living in the south are GMBUS and
HPD. What's worse some of the SPT specific new bits conflict with some
other bits on earlier PCH generations. So better not use the
cpt_irq_handler() for SPT+ anymore.

Also kill the hand rolled port E handling with something more
standardish. This also avoids accidentally confusing port B and port E
long pulses since the bits occupy the same positions, just in different
registers.

Also add a comment noting that the short pulse duration bits are
reserved on LPT+. The 2ms value we program is 0, so no issue wrt. the
MBZ in the spec.

v2: Call intel_hpd_irq_handler() only once (Paulo)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -1262,6 +1262,16 @@ static bool bxt_port_hotplug_long_detect(enum port port, u32 val)
 	}
 }
 
+static bool spt_port_hotplug2_long_detect(enum port port, u32 val)
+{
+	switch (port) {
+	case PORT_E:
+		return val & PORTE_HOTPLUG_LONG_DETECT;
+	default:
+		return false;
+	}
+}
+
 static bool pch_port_hotplug_long_detect(enum port port, u32 val)
 {
 	switch (port) {
@@ -1271,8 +1281,6 @@ static bool pch_port_hotplug_long_detect(enum port port, u32 val)
 		return val & PORTC_HOTPLUG_LONG_DETECT;
 	case PORT_D:
 		return val & PORTD_HOTPLUG_LONG_DETECT;
-	case PORT_E:
-		return val & PORTE_HOTPLUG_LONG_DETECT;
 	default:
 		return false;
 	}
@@ -1776,12 +1784,7 @@ static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int pipe;
-	u32 hotplug_trigger;
-
-	if (HAS_PCH_SPT(dev))
-		hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_SPT;
-	else
-		hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_CPT;
+	u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_CPT;
 
 	if (hotplug_trigger) {
 		u32 dig_hotplug_reg, pin_mask = 0, long_mask = 0;
@@ -1789,18 +1792,6 @@ static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
 		dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
 		I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg);
 
-		if (HAS_PCH_SPT(dev)) {
-			intel_get_hpd_pins(&pin_mask, &long_mask,
-					   hotplug_trigger,
-					   dig_hotplug_reg, hpd_spt,
-					   pch_port_hotplug_long_detect);
-
-			/* detect PORTE HP event */
-			dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG2);
-			if (pch_port_hotplug_long_detect(PORT_E,
-							 dig_hotplug_reg))
-				long_mask |= 1 << HPD_PORT_E;
-		} else
 		intel_get_hpd_pins(&pin_mask, &long_mask,
 				   hotplug_trigger,
 				   dig_hotplug_reg, hpd_cpt,
@@ -1838,6 +1829,43 @@ static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
 		cpt_serr_int_handler(dev);
 }
 
+static void spt_irq_handler(struct drm_device *dev, u32 pch_iir)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_SPT &
+		~SDE_PORTE_HOTPLUG_SPT;
+	u32 hotplug2_trigger = pch_iir & SDE_PORTE_HOTPLUG_SPT;
+	u32 pin_mask = 0, long_mask = 0;
+
+	if (hotplug_trigger) {
+		u32 dig_hotplug_reg;
+
+		dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
+		I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg);
+
+		intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
+				   dig_hotplug_reg, hpd_spt,
+				   pch_port_hotplug_long_detect);
+	}
+
+	if (hotplug2_trigger) {
+		u32 dig_hotplug_reg;
+
+		dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG2);
+		I915_WRITE(PCH_PORT_HOTPLUG2, dig_hotplug_reg);
+
+		intel_get_hpd_pins(&pin_mask, &long_mask, hotplug2_trigger,
+				   dig_hotplug_reg, hpd_spt,
+				   spt_port_hotplug2_long_detect);
+	}
+
+	if (pin_mask)
+		intel_hpd_irq_handler(dev, pin_mask, long_mask);
+
+	if (pch_iir & SDE_GMBUS_CPT)
+		gmbus_irq_handler(dev);
+}
+
 static void ilk_display_irq_handler(struct drm_device *dev, u32 de_iir)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -2156,6 +2184,10 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
 		if (pch_iir) {
 			I915_WRITE(SDEIIR, pch_iir);
 			ret = IRQ_HANDLED;
+
+			if (HAS_PCH_SPT(dev_priv))
+				spt_irq_handler(dev, pch_iir);
+			else
 				cpt_irq_handler(dev, pch_iir);
 		} else
 			DRM_ERROR("The master control interrupt lied (SDE)!\n");
@@ -3038,9 +3070,6 @@ static void ibx_hpd_irq_setup(struct drm_device *dev)
 	if (HAS_PCH_IBX(dev)) {
 		hotplug_irqs = SDE_HOTPLUG_MASK;
 		enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_ibx);
-	} else if (HAS_PCH_SPT(dev)) {
-		hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
-		enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_spt);
 	} else {
 		hotplug_irqs = SDE_HOTPLUG_MASK_CPT;
 		enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_cpt);
@@ -3050,9 +3079,8 @@ static void ibx_hpd_irq_setup(struct drm_device *dev)
 
 	/*
 	 * Enable digital hotplug on the PCH, and configure the DP short pulse
-	 * duration to 2ms (which is the minimum in the Display Port spec)
-	 *
-	 * This register is the same on all known PCH chips.
+	 * duration to 2ms (which is the minimum in the Display Port spec).
+	 * The pulse duration bits are reserved on LPT+.
 	 */
 	hotplug = I915_READ(PCH_PORT_HOTPLUG);
 	hotplug &= ~(PORTD_PULSE_DURATION_MASK|PORTC_PULSE_DURATION_MASK|PORTB_PULSE_DURATION_MASK);
@@ -3060,13 +3088,27 @@ static void ibx_hpd_irq_setup(struct drm_device *dev)
 	hotplug |= PORTC_HOTPLUG_ENABLE | PORTC_PULSE_DURATION_2ms;
 	hotplug |= PORTB_HOTPLUG_ENABLE | PORTB_PULSE_DURATION_2ms;
 	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
+}
+
+static void spt_hpd_irq_setup(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 hotplug_irqs, hotplug, enabled_irqs;
+
+	hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
+	enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_spt);
+
+	ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
+
+	/* Enable digital hotplug on the PCH */
+	hotplug = I915_READ(PCH_PORT_HOTPLUG);
+	hotplug |= PORTD_HOTPLUG_ENABLE | PORTC_HOTPLUG_ENABLE |
+		PORTB_HOTPLUG_ENABLE;
+	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
 
-	/* enable SPT PORTE hot plug */
-	if (HAS_PCH_SPT(dev)) {
 	hotplug = I915_READ(PCH_PORT_HOTPLUG2);
 	hotplug |= PORTE_HOTPLUG_ENABLE;
 	I915_WRITE(PCH_PORT_HOTPLUG2, hotplug);
-	}
 }
 
 static void bxt_hpd_irq_setup(struct drm_device *dev)
@@ -4171,10 +4213,12 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
 		dev->driver->irq_uninstall = gen8_irq_uninstall;
 		dev->driver->enable_vblank = gen8_enable_vblank;
 		dev->driver->disable_vblank = gen8_disable_vblank;
-		if (HAS_PCH_SPLIT(dev))
-			dev_priv->display.hpd_irq_setup = ibx_hpd_irq_setup;
-		else
+		if (IS_BROXTON(dev))
 			dev_priv->display.hpd_irq_setup = bxt_hpd_irq_setup;
+		else if (HAS_PCH_SPT(dev))
+			dev_priv->display.hpd_irq_setup = spt_hpd_irq_setup;
+		else
+			dev_priv->display.hpd_irq_setup = ibx_hpd_irq_setup;
 	} else if (HAS_PCH_SPLIT(dev)) {
 		dev->driver->irq_handler = ironlake_irq_handler;
 		dev->driver->irq_preinstall = ironlake_irq_reset;