[Intel-gfx] [PATCH v2 3/4] drm/i915: Parse VBT data for lspcon

[Shashank Sharma]

Many GEN9 boards come with on-board lspcon cards.
Fot these boards, VBT configuration should properly point out
if a particular port contains lspcon device, so that driver can
initialize it properly.

This patch adds a utility function, which checks the VBT flag
for lspcon bit, and tells us if a port is configured to have a
lspcon device or not.

V2: Fixed review comments from Ville
- Do not forget PORT_D while checking lspcon for GEN9

Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h   |  3 +++
 drivers/gpu/drm/i915/intel_bios.c | 49 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 25ebe46..3719b81 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3671,6 +3671,9 @@ bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum por
 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);
+bool intel_bios_is_lspcon_present(struct drm_i915_private *dev_priv,
+				enum port port);
+
 
 /* intel_opregion.c */
 #ifdef CONFIG_ACPI
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index da5ed4a..2b00c89 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -1759,3 +1759,52 @@ intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
 
 	return false;
 }
+
+/**
+ * intel_bios_is_lspcon_present - if LSPCON is attached on %port
+ * @dev_priv:	i915 device instance
+ * @port:	port to check
+ *
+ * Return true if LSPCON is present on this port
+ */
+bool
+intel_bios_is_lspcon_present(struct drm_i915_private *dev_priv,
+				enum port port)
+{
+	int i;
+
+	if (WARN_ON_ONCE(!IS_GEN9(dev_priv)))
+		return false;
+
+	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
+		if (!dev_priv->vbt.child_dev[i].common.lspcon)
+			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;
+		case DVO_PORT_DPD:
+		case DVO_PORT_HDMID:
+			if (port == PORT_D)
+				return true;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return false;
+}
-- 
1.9.1