drm: Add support for device_id based detection.

DP quirk list just compare sink or branch device's OUI so far.
That means particular vendor's products will be applied specific
change. This change would confirm device_id the same or not.
Then driver can implement some changes for branch/sink device
that really need additional WA.

v2: use sizeof instead of hard coded '6'
v3: add lost commit messages back for version 2
v4: send patch to both intel-gfx and dri-devel

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Clint Taylor <clinton.a.taylor@intel.com>
Tested-by: NClint Taylor <clinton.a.taylor@intel.com>
Signed-off-by: NLee, Shawn C <shawn.c.lee@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1536733371-25004-2-git-send-email-shawn.c.lee@intel.com

drivers/gpu/drm/drm_dp_helper.c

@@ -1257,15 +1257,20 @@ EXPORT_SYMBOL(drm_dp_stop_crc);
 
 struct dpcd_quirk {
 	u8 oui[3];
+	u8 device_id[6];
 	bool is_branch;
 	u32 quirks;
 };
 
 #define OUI(first, second, third) { (first), (second), (third) }
+#define DEVICE_ID(first, second, third, fourth, fifth, sixth) \
+	{ (first), (second), (third), (fourth), (fifth), (sixth) }
+
+#define DEVICE_ID_ANY	DEVICE_ID(0, 0, 0, 0, 0, 0)
 
 static const struct dpcd_quirk dpcd_quirk_list[] = {
 	/* Analogix 7737 needs reduced M and N at HBR2 link rates */
-	{ OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) },
+	{ OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) },
 };
 
 #undef OUI
@@ -1284,6 +1289,7 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
 	const struct dpcd_quirk *quirk;
 	u32 quirks = 0;
 	int i;
+	u8 any_device[] = DEVICE_ID_ANY;
 
 	for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) {
 		quirk = &dpcd_quirk_list[i];
@@ -1294,12 +1300,19 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
 		if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0)
 			continue;
 
+		if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 &&
+		    memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0)
+			continue;
+
 		quirks |= quirk->quirks;
 	}
 
 	return quirks;
 }
 
+#undef DEVICE_ID_ANY
+#undef DEVICE_ID
+
 /**
  * drm_dp_read_desc - read sink/branch descriptor from DPCD
  * @aux: DisplayPort AUX channel