usbdev: Extract libusb1 device discovery into a separate file

Currently there is a TODO-like comment in the dediprog driver: "Might be
useful for other USB devices as well". Act on this comment by collecting
all the device discovery code for libusb1 devices into a separate file.

Change-Id: Idfcc79371241c2c1dea97faf5e532aa971546a79
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-on: https://review.coreboot.org/27443
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 130 insertions, 0 deletions

diff --git a/usbdev.c b/usbdev.c
new file mode 100644
index 000000000..5c34ba127
--- /dev/null
+++ b/usbdev.c
@@ -0,0 +1,130 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2016 secunet Security Networks AG
+ * Copyright (C) 2018 Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <string.h>
+#include <libusb.h>
+#include "programmer.h"
+
+struct libusb_device_handle *usb_dev_get_by_vid_pid_serial(
+		struct libusb_context *usb_ctx, uint16_t vid, uint16_t pid, const char *serialno)
+{
+	struct libusb_device **list;
+	ssize_t count = libusb_get_device_list(usb_ctx, &list);
+	if (count < 0) {
+		msg_perr("Getting the USB device list failed (%s)!\n", libusb_error_name(count));
+		return NULL;
+	}
+
+	ssize_t i = 0;
+	for (i = 0; i < count; i++) {
+		struct libusb_device *dev = list[i];
+		struct libusb_device_descriptor desc;
+		struct libusb_device_handle *handle;
+
+		int res = libusb_get_device_descriptor(dev, &desc);
+		if (res != 0) {
+			msg_perr("Reading the USB device descriptor failed (%s)!\n", libusb_error_name(res));
+			continue;
+		}
+
+		if ((desc.idVendor != vid) && (desc.idProduct != pid))
+			continue;
+
+		msg_pdbg("Found USB device %04"PRIx16":%04"PRIx16" at address %d-%d.\n",
+			 desc.idVendor, desc.idProduct,
+			 libusb_get_bus_number(dev), libusb_get_device_address(dev));
+
+		res = libusb_open(dev, &handle);
+		if (res != 0) {
+			msg_perr("Opening the USB device failed (%s)!\n", libusb_error_name(res));
+			continue;
+		}
+
+		if (serialno) {
+			unsigned char myserial[64];
+			res = libusb_get_string_descriptor_ascii(handle, desc.iSerialNumber, myserial,
+					sizeof(myserial));
+			if (res < 0) {
+				msg_perr("Reading the USB serialno failed (%s)!\n", libusb_error_name(res));
+				libusb_close(handle);
+				continue;
+			}
+			msg_pdbg("Serial number is %s\n", myserial);
+
+			/* Reject any serial number that does not commence with serialno */
+			if (0 != strncmp(serialno, (char *)myserial, strlen(serialno))) {
+				libusb_close(handle);
+				continue;
+			}
+		}
+
+		libusb_free_device_list(list, 1);
+		return handle;
+	}
+
+	libusb_free_device_list(list, 1);
+	return NULL;
+}
+
+/*
+ * This function allows different devices to be targeted based on enumeration order. Different
+ * hotplug sequencing (or simply a reboot) may change the enumeration order. This function should
+ * only be used if a programmers does not provide an alternative way to identify itself uniquely
+ * (such as a unique serial number).
+ */
+struct libusb_device_handle *usb_dev_get_by_vid_pid_number(
+		struct libusb_context *usb_ctx, uint16_t vid, uint16_t pid, unsigned int num)
+{
+	struct libusb_device **list;
+	ssize_t count = libusb_get_device_list(usb_ctx, &list);
+	if (count < 0) {
+		msg_perr("Getting the USB device list failed (%s)!\n", libusb_error_name(count));
+		return NULL;
+	}
+
+	struct libusb_device_handle *handle = NULL;
+	ssize_t i = 0;
+	for (i = 0; i < count; i++) {
+		struct libusb_device *dev = list[i];
+		struct libusb_device_descriptor desc;
+		int err = libusb_get_device_descriptor(dev, &desc);
+		if (err != 0) {
+			msg_perr("Reading the USB device descriptor failed (%s)!\n", libusb_error_name(err));
+			libusb_free_device_list(list, 1);
+			return NULL;
+		}
+		if ((desc.idVendor == vid) && (desc.idProduct == pid)) {
+			msg_pdbg("Found USB device %04"PRIx16":%04"PRIx16" at address %d-%d.\n",
+				 desc.idVendor, desc.idProduct,
+				 libusb_get_bus_number(dev), libusb_get_device_address(dev));
+			if (num == 0) {
+				err = libusb_open(dev, &handle);
+				if (err != 0) {
+					msg_perr("Opening the USB device failed (%s)!\n",
+						 libusb_error_name(err));
+					libusb_free_device_list(list, 1);
+					return NULL;
+				}
+				break;
+			}
+			num--;
+		}
+	}
+	libusb_free_device_list(list, 1);
+
+	return handle;
+}