[Intel-gfx] [PATCH 2/2] drm/i915: Set invert bit for hpd based on VBT

[Shubhangi Shrivastava]

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)

Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
Signed-off-by: Durgadoss R <durgadoss.r at intel.com>
Signed-off-by: Shubhangi Shrivastava <shubhangi.shrivastava at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h   |  1 +
 drivers/gpu/drm/i915/i915_irq.c   | 21 ++++++++++++++++++++
 drivers/gpu/drm/i915/i915_reg.h   |  8 ++++++++
 drivers/gpu/drm/i915/intel_bios.c | 40 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 70 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1557d65..91963d24 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3334,6 +3334,7 @@ extern void intel_i2c_reset(struct drm_device *dev);
 /* intel_bios.c */
 int intel_bios_init(struct drm_i915_private *dev_priv);
 bool intel_bios_is_valid_vbt(const void *buf, size_t size);
+bool intel_bios_is_port_hpd_inverted(struct drm_device *dev, enum port port);
 
 /* intel_opregion.c */
 #ifdef CONFIG_ACPI
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 53e5104..764d8f8 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -36,6 +36,7 @@
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
+#include "intel_bios.h"
 
 /**
  * DOC: interrupt handling
@@ -3503,6 +3504,26 @@ 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, PORT_A))
+		hotplug |= BXT_DDIA_HPD_INVERT;
+	if ((enabled_irqs & BXT_DE_PORT_HP_DDIB) &&
+	     intel_bios_is_port_hpd_inverted(dev, PORT_B))
+		hotplug |= BXT_DDIB_HPD_INVERT;
+	if ((enabled_irqs & BXT_DE_PORT_HP_DDIC) &&
+	     intel_bios_is_port_hpd_inverted(dev, PORT_C))
+		hotplug |= BXT_DDIC_HPD_INVERT;
+
 	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 7dfc400..f80b870 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6213,6 +6213,14 @@ enum skl_disp_power_wells {
 #define  PORTB_HOTPLUG_SHORT_DETECT	(1 << 0)
 #define  PORTB_HOTPLUG_LONG_DETECT	(2 << 0)
 
+/* BXT hotplug control */
+#define BXT_DDIA_HPD_INVERT		(1 << 27)
+#define BXT_DDIC_HPD_INVERT		(1 << 11)
+#define BXT_DDIB_HPD_INVERT		(1 << 3)
+#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)
 #define  PORTE_HOTPLUG_STATUS_MASK	(3 << 0)
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index a26d4b4..d809700 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -105,6 +105,46 @@ find_section(const void *_bdb, int section_id)
 	return NULL;
 }
 
+bool
+intel_bios_is_port_hpd_inverted(struct drm_device *dev, enum port port)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
+
+	if (!IS_BROXTON(dev)) {
+		DRM_ERROR("Bit inversion is not required in this platform\n");
+		return false;
+	}
+
+	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
+
+		if (dev_priv->vbt.child_dev[i].common.hpd_invert == 1) {
+
+			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;
+}
+
 static void
 fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
 			const struct lvds_dvo_timing *dvo_timing)
-- 
2.6.1