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From:   Ricardo Ribalda <ribalda@chromium.org>
Date:   Thu, 03 Nov 2022 14:40:43 +0100
Subject: [PATCH v2 2/8] media: uvc: Allow quirking by entity guid
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Message-Id: <20220920-resend-hwtimestamp-v2-2-d8d0616bb612@chromium.org>
References: <20220920-resend-hwtimestamp-v2-0-d8d0616bb612@chromium.org>
In-Reply-To: <20220920-resend-hwtimestamp-v2-0-d8d0616bb612@chromium.org>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     HungNien Chen <hn.chen@sunplusit.com>,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        Ricardo Ribalda <ribalda@chromium.org>
Precedence: bulk

When an IP is shared by multiple devices its erratas will be shared by
all of them. Instead of creating a long list of device quirks, or
waiting for the users to report errors in their hardware lets add a
routine to add quirks based on the entity guid.

Tested-by: HungNien Chen <hn.chen@sunplusit.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 9c05776f11d1..c63ecfd4617d 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1493,6 +1493,28 @@ static int uvc_parse_control(struct uvc_device *dev)
 	return 0;
 }
 
+static const struct uvc_entity_quirk {
+	u8 guid[16];
+	u32 quirks;
+} uvc_entity_quirk[] = {
+};
+
+static void uvc_entity_quirks(struct uvc_device *dev)
+{
+	struct uvc_entity *entity;
+	int i;
+
+	list_for_each_entry(entity, &dev->entities, list) {
+		for (i = 0; i < ARRAY_SIZE(uvc_entity_quirk); i++) {
+			if (memcmp(entity->guid, uvc_entity_quirk[i].guid,
+				   sizeof(entity->guid)) == 0) {
+				dev->quirks |= uvc_entity_quirk[i].quirks;
+				break;
+			}
+		}
+	}
+}
+
 /* -----------------------------------------------------------------------------
  * Privacy GPIO
  */
@@ -2452,6 +2474,9 @@ static int uvc_probe(struct usb_interface *intf,
 		goto error;
 	}
 
+	/* Apply entity based quirks */
+	uvc_entity_quirks(dev);
+
 	dev_info(&dev->udev->dev, "Found UVC %u.%02x device %s (%04x:%04x)\n",
 		 dev->uvc_version >> 8, dev->uvc_version & 0xff,
 		 udev->product ? udev->product : "<unnamed>",

-- 
b4 0.11.0-dev-d93f8