Input: usbtouchscreen - refactor endpoint lookup

Use the common USB helpers for looking up bulk and interrupt endpoints
(and determining endpoint numbers) instead of open coding.

Note that the NEXIO data interface has two bulk endpoints (see commit
5197424 ("Input: usbtouchscreen - add NEXIO (or iNexio) support")
for the descriptors).

The lookup in probe handles both bulk-in and interrupt-in endpoints and
was added to handle NEXIO devices. Replace the open coded lookup with a
lookup for the common interrupt endpoint and an explicit fallback
accepting a bulk endpoint.

This iterates over the (two) endpoints twice for NEXIO devices but makes
it more clear what is going on.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260401082212.2180434-1-johan@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: jhovold

drivers/input/touchscreen/usbtouchscreen.c

@@ -969,24 +969,21 @@ static int nexio_init(struct usbtouch_usb *usbtouch)
 {
 	struct usb_device *dev = interface_to_usbdev(usbtouch->interface);
 	struct usb_host_interface *interface = usbtouch->interface->cur_altsetting;
+	struct usb_endpoint_descriptor *ep_in, *ep_out;
 	struct nexio_priv *priv = usbtouch->priv;
-	int ret = -ENOMEM;
 	int actual_len, i;
 	char *firmware_ver = NULL, *device_name = NULL;
-	int input_ep = 0, output_ep = 0;
+	int input_ep, output_ep;
+	int ret;
 
 	/* find first input and output endpoint */
-	for (i = 0; i < interface->desc.bNumEndpoints; i++) {
-		if (!input_ep &&
-		    usb_endpoint_dir_in(&interface->endpoint[i].desc))
-			input_ep = interface->endpoint[i].desc.bEndpointAddress;
-		if (!output_ep &&
-		    usb_endpoint_dir_out(&interface->endpoint[i].desc))
-			output_ep = interface->endpoint[i].desc.bEndpointAddress;
-	}
-	if (!input_ep || !output_ep)
+	ret = usb_find_common_endpoints(interface, &ep_in, &ep_out, NULL, NULL);
+	if (ret)
 		return -ENXIO;
 
+	input_ep = usb_endpoint_num(ep_in);
+	output_ep = usb_endpoint_num(ep_out);
+
 	u8 *buf __free(kfree) = kmalloc(NEXIO_BUFSIZE, GFP_NOIO);
 	if (!buf)
 		return -ENOMEM;
@@ -1427,18 +1424,6 @@ static void usbtouch_free_buffers(struct usb_device *udev,
 	kfree(usbtouch->buffer);
 }
 
-static struct usb_endpoint_descriptor *
-usbtouch_get_input_endpoint(struct usb_host_interface *interface)
-{
-	int i;
-
-	for (i = 0; i < interface->desc.bNumEndpoints; i++)
-		if (usb_endpoint_dir_in(&interface->endpoint[i].desc))
-			return &interface->endpoint[i].desc;
-
-	return NULL;
-}
-
 static int usbtouch_probe(struct usb_interface *intf,
 			  const struct usb_device_id *id)
 {
@@ -1447,17 +1432,21 @@ static int usbtouch_probe(struct usb_interface *intf,
 	struct usb_endpoint_descriptor *endpoint;
 	struct usb_device *udev = interface_to_usbdev(intf);
 	const struct usbtouch_device_info *type;
-	int err = -ENOMEM;
+	int err;
 
 	/* some devices are ignored */
 	type = (const struct usbtouch_device_info *)id->driver_info;
 	if (!type)
 		return -ENODEV;
 
-	endpoint = usbtouch_get_input_endpoint(intf->cur_altsetting);
-	if (!endpoint)
-		return -ENXIO;
+	err = usb_find_int_in_endpoint(intf->cur_altsetting, &endpoint);
+	if (err) {
+		err = usb_find_bulk_in_endpoint(intf->cur_altsetting, &endpoint);
+		if (err)
+			return -ENXIO;
+	}
 
+	err = -ENOMEM;
 	usbtouch = kzalloc_obj(*usbtouch);
 	input_dev = input_allocate_device();
 	if (!usbtouch || !input_dev)