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

[Jani Nikula]

From: Shashank Sharma <shashank.sharma at intel.com>

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.

While we do not enable any lspcon handling yet, debug log about ports
with lspcon.

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

V3: Addressed review comments from Rodrigo
- Create a HAS_LSPCON() macro for better use case handling.
- Do not dump warnings for non-gen-9 platforms, it will be noise.

V4: Rebase
V5: Rebase

v6 by Jani: rebase, debug log

Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>

---

Shashank, your series [1] didn't apply on nightly, so you'll need to
rebase and post again anyway. However, please let's merge this patch
from your series first, and we can even backport this so that we have
debug logging about LSPCON devices.

BR,
Jani.
---
 drivers/gpu/drm/i915/i915_drv.h   |  4 ++++
 drivers/gpu/drm/i915/intel_bios.c | 49 +++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_ddi.c  |  4 ++++
 3 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index fe875b27a6bf..7c706a1ab7fe 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2814,6 +2814,8 @@ struct drm_i915_cmd_table {
 
 #define HAS_DP_MST(dev)	(INTEL_INFO(dev)->has_dp_mst)
 
+#define HAS_LSPCON(dev_priv)	(IS_GEN9(dev_priv))
+
 #define HAS_DDI(dev_priv)	((dev_priv)->info.has_ddi)
 #define HAS_FPGA_DBG_UNCLAIMED(dev)	(INTEL_INFO(dev)->has_fpga_dbg)
 #define HAS_PSR(dev)		(INTEL_INFO(dev)->has_psr)
@@ -3631,6 +3633,8 @@ 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 83667e8cdd6b..6f49b2364b70 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -1763,3 +1763,52 @@ 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 (!HAS_LSPCON(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;
+}
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index a76afd7a6616..adf731ac189b 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2470,6 +2470,10 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
 	init_hdmi = (dev_priv->vbt.ddi_port_info[port].supports_dvi ||
 		     dev_priv->vbt.ddi_port_info[port].supports_hdmi);
 	init_dp = dev_priv->vbt.ddi_port_info[port].supports_dp;
+
+	if (intel_bios_is_lspcon_present(dev_priv, port))
+		DRM_DEBUG_KMS("VBT says port %c has LSPCON\n", port_name(port));
+
 	if (!init_dp && !init_hdmi) {
 		DRM_DEBUG_KMS("VBT says port %c is not DVI/HDMI/DP compatible, respect it\n",
 			      port_name(port));
-- 
2.1.4