drm/i915: Set invert bit for hpd based on VBT

This patch sets the invert bit for hpd detection for each port
based on VBT configuration. Since each AOB can be designed to
depend on invert bit or not, it is expected if an AOB requires
invert bit, the user will set respective bit in VBT.

v2: Separated VBT parsing from the rest of the logic. (Jani)

v3: Moved setting invert bit logic to bxt_hpd_irq_setup()
    and changed its logic to avoid looping twice. (Ville)

v4: Changed the logic to mask out the bits first and then
    set them to remove need of temporary variable. (Ville)

v5: Moved defines to existing set of defines for the register
    and added required breaks. (Ville)

Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Shubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[Jani: fixed some checkpatch noise, added kernel-doc.]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459420907-11383-2-git-send-email-shubhangi.shrivastava@intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -3408,6 +3408,8 @@ bool intel_bios_is_tv_present(struct drm_i915_private *dev_priv);
 bool intel_bios_is_lvds_present(struct drm_i915_private *dev_priv, u8 *i2c_pin);
 bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
 bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv, enum port *port);
+bool intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
+				     enum port port);
 
 /* intel_opregion.c */
 #ifdef CONFIG_ACPI

drivers/gpu/drm/i915/i915_irq.c

@@ -3500,6 +3500,26 @@ static void bxt_hpd_irq_setup(struct drm_device *dev)
 	hotplug = I915_READ(PCH_PORT_HOTPLUG);
 	hotplug |= PORTC_HOTPLUG_ENABLE | PORTB_HOTPLUG_ENABLE |
 		PORTA_HOTPLUG_ENABLE;
+
+	DRM_DEBUG_KMS("Invert bit setting: hp_ctl:%x hp_port:%x\n",
+		      hotplug, enabled_irqs);
+	hotplug &= ~BXT_DDI_HPD_INVERT_MASK;
+
+	/*
+	 * For BXT invert bit has to be set based on AOB design
+	 * for HPD detection logic, update it based on VBT fields.
+	 */
+
+	if ((enabled_irqs & BXT_DE_PORT_HP_DDIA) &&
+	    intel_bios_is_port_hpd_inverted(dev_priv, PORT_A))
+		hotplug |= BXT_DDIA_HPD_INVERT;
+	if ((enabled_irqs & BXT_DE_PORT_HP_DDIB) &&
+	    intel_bios_is_port_hpd_inverted(dev_priv, PORT_B))
+		hotplug |= BXT_DDIB_HPD_INVERT;
+	if ((enabled_irqs & BXT_DE_PORT_HP_DDIC) &&
+	    intel_bios_is_port_hpd_inverted(dev_priv, PORT_C))
+		hotplug |= BXT_DDIC_HPD_INVERT;
+
 	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
 }
 

drivers/gpu/drm/i915/i915_reg.h

@@ -6196,6 +6196,7 @@ enum skl_disp_power_wells {
 /* digital port hotplug */
 #define PCH_PORT_HOTPLUG		_MMIO(0xc4030)	/* SHOTPLUG_CTL */
 #define  PORTA_HOTPLUG_ENABLE		(1 << 28) /* LPT:LP+ & BXT */
+#define  BXT_DDIA_HPD_INVERT            (1 << 27)
 #define  PORTA_HOTPLUG_STATUS_MASK	(3 << 24) /* SPT+ & BXT */
 #define  PORTA_HOTPLUG_NO_DETECT	(0 << 24) /* SPT+ & BXT */
 #define  PORTA_HOTPLUG_SHORT_DETECT	(1 << 24) /* SPT+ & BXT */
@@ -6211,6 +6212,7 @@ enum skl_disp_power_wells {
 #define  PORTD_HOTPLUG_SHORT_DETECT	(1 << 16)
 #define  PORTD_HOTPLUG_LONG_DETECT	(2 << 16)
 #define  PORTC_HOTPLUG_ENABLE		(1 << 12)
+#define  BXT_DDIC_HPD_INVERT            (1 << 11)
 #define  PORTC_PULSE_DURATION_2ms	(0 << 10) /* pre-LPT */
 #define  PORTC_PULSE_DURATION_4_5ms	(1 << 10) /* pre-LPT */
 #define  PORTC_PULSE_DURATION_6ms	(2 << 10) /* pre-LPT */
@@ -6221,6 +6223,7 @@ enum skl_disp_power_wells {
 #define  PORTC_HOTPLUG_SHORT_DETECT	(1 << 8)
 #define  PORTC_HOTPLUG_LONG_DETECT	(2 << 8)
 #define  PORTB_HOTPLUG_ENABLE		(1 << 4)
+#define  BXT_DDIB_HPD_INVERT            (1 << 3)
 #define  PORTB_PULSE_DURATION_2ms	(0 << 2) /* pre-LPT */
 #define  PORTB_PULSE_DURATION_4_5ms	(1 << 2) /* pre-LPT */
 #define  PORTB_PULSE_DURATION_6ms	(2 << 2) /* pre-LPT */
@@ -6230,6 +6233,9 @@ enum skl_disp_power_wells {
 #define  PORTB_HOTPLUG_NO_DETECT	(0 << 0)
 #define  PORTB_HOTPLUG_SHORT_DETECT	(1 << 0)
 #define  PORTB_HOTPLUG_LONG_DETECT	(2 << 0)
+#define  BXT_DDI_HPD_INVERT_MASK	(BXT_DDIA_HPD_INVERT | \
+					BXT_DDIB_HPD_INVERT | \
+					BXT_DDIC_HPD_INVERT)
 
 #define PCH_PORT_HOTPLUG2		_MMIO(0xc403C)	/* SHOTPLUG_CTL2 SPT+ */
 #define  PORTE_HOTPLUG_ENABLE		(1 << 4)

drivers/gpu/drm/i915/intel_bios.c

@@ -1598,3 +1598,47 @@ bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv,
 
 	return false;
 }
+
+/**
+ * intel_bios_is_port_hpd_inverted - is HPD inverted for %port
+ * @dev_priv:	i915 device instance
+ * @port:	port to check
+ *
+ * Return true if HPD should be inverted for %port.
+ */
+bool
+intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
+				enum port port)
+{
+	int i;
+
+	if (WARN_ON_ONCE(!IS_BROXTON(dev_priv)))
+		return false;
+
+	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
+		if (!dev_priv->vbt.child_dev[i].common.hpd_invert)
+			continue;
+
+		switch (dev_priv->vbt.child_dev[i].common.dvo_port) {
+		case DVO_PORT_DPA:
+		case DVO_PORT_HDMIA:
+			if (port == PORT_A)
+				return true;
+			break;
+		case DVO_PORT_DPB:
+		case DVO_PORT_HDMIB:
+			if (port == PORT_B)
+				return true;
+			break;
+		case DVO_PORT_DPC:
+		case DVO_PORT_HDMIC:
+			if (port == PORT_C)
+				return true;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return false;
+}