[PATCH 17/20] drm/i915: check LSPCON vendor OUI

[Shashank Sharma]

Intel LSPCON chip is provided by 2 vendors:
- Megachips America (MCA)
- Parade technologies (Parade tech)

Its important to know the vendor of this chip, as the address to
write AVI infoframes is different for those two.

This patch reads the vendor OUI signature, and marks into LSPCON
encoder structure for future usages.

Cc: Imre Deak <imre.deak at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/i915/intel_drv.h    |  6 ++++++
 drivers/gpu/drm/i915/intel_lspcon.c | 24 ++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 68b4fba..ed04de9 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1063,9 +1063,15 @@ struct intel_dp {
 	struct intel_dp_compliance compliance;
 };
 
+enum lspcon_vendor {
+	LSPCON_VENDOR_MCA,
+	LSPCON_VENDOR_PARADE
+};
+
 struct intel_lspcon {
 	bool active;
 	enum drm_lspcon_mode mode;
+	enum lspcon_vendor vendor;
 };
 
 struct intel_digital_port {
diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
index 5abef482..a350d79 100644
--- a/drivers/gpu/drm/i915/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -27,6 +27,10 @@
 #include <drm/drm_dp_dual_mode_helper.h>
 #include "intel_drv.h"
 
+/* LSPCON OUI Vendor ID(signatures) */
+#define LSPCON_VENDOR_PARADE_OUI 0x001CF8
+#define LSPCON_VENDOR_MCA_OUI 0x0060AD
+
 static struct intel_dp *lspcon_to_intel_dp(struct intel_lspcon *lspcon)
 {
 	struct intel_digital_port *dig_port =
@@ -136,6 +140,7 @@ static bool lspcon_probe(struct intel_lspcon *lspcon)
 	enum drm_dp_dual_mode_type adaptor_type;
 	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
 	enum drm_lspcon_mode expected_mode;
+	uint32_t vendor_oui;
 
 	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
 			DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
@@ -151,6 +156,25 @@ static bool lspcon_probe(struct intel_lspcon *lspcon)
 	/* Yay ... got a LSPCON device */
 	DRM_DEBUG_KMS("LSPCON detected\n");
 	lspcon->mode = lspcon_wait_mode(lspcon, expected_mode);
+
+	/* Check if this is a Parade LSPCON or MCA LSPCON */
+	vendor_oui = drm_lspcon_get_vendor_oui(adapter);
+	switch (vendor_oui) {
+	case LSPCON_VENDOR_MCA_OUI:
+		lspcon->vendor = LSPCON_VENDOR_MCA;
+		DRM_DEBUG_KMS("Vendor: Mega Chips\n");
+		break;
+
+	case LSPCON_VENDOR_PARADE_OUI:
+		lspcon->vendor = LSPCON_VENDOR_PARADE;
+		DRM_DEBUG_KMS("Vendor: Parade Tech\n");
+		break;
+
+	default:
+		DRM_ERROR("Can't read OUI /Invalid OUI\n");
+		return false;
+	}
+
 	lspcon->active = true;
 	return true;
 }
-- 
2.7.4