usb: add support for listing devices

When working with multiple devices and the --serial argument, the serial
numbers must be known.

Add a new command "qdl list" to list the connected devices in EDL mode
and their serial number.

Signed-off-by: lucarin91 <lucarin@protonmail.com>
[bjorn: Replaced --list with list, changed output to only print serial, some stylistic changes]
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>

Author: lucarin91

qdl.c

@@ -417,6 +417,7 @@ static void print_usage(FILE *out)
 
 	fprintf(out, "Usage: %s [options] <prog.mbn> (<program-xml> | <patch-xml> | <read-xml>)...\n", __progname);
 	fprintf(out, "       %s [options] <prog.mbn> ((read | write) <address> <binary>)...\n", __progname);
+	fprintf(out, "       %s list\n", __progname);
 	fprintf(out, " -d, --debug\t\t\tPrint detailed debug info\n");
 	fprintf(out, " -v, --version\t\t\tPrint the current version and exit\n");
 	fprintf(out, " -n, --dry-run\t\t\tDry run execution, no device reading or flashing\n");
@@ -440,6 +441,29 @@ static void print_usage(FILE *out)
 	fprintf(out, "Example: %s prog_firehose_ddr.elf rawprogram*.xml patch*.xml\n", __progname);
 }
 
+static int qdl_list(FILE *out)
+{
+	struct qdl_device_desc *devices;
+	unsigned int count;
+	unsigned int i;
+
+	devices = usb_list(&count);
+	if (!devices)
+		return 1;
+
+	if (count == 0) {
+		fprintf(out, "No devices found\n");
+	} else {
+		for (i = 0; i < count; i++)
+			fprintf(out, "%04x:%04x\t%s\n",
+				devices[i].vid, devices[i].pid, devices[i].serial);
+	}
+
+	free(devices);
+
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	enum qdl_storage_type storage_type = QDL_STORAGE_UFS;
@@ -478,6 +502,9 @@ int main(int argc, char **argv)
 		{0, 0, 0, 0}
 	};
 
+	if (argc == 2 && !strcmp(argv[1], "list"))
+		return qdl_list(stdout);
+
 	while ((opt = getopt_long(argc, argv, "dvi:lu:S:D:s:fcnt:T:h", options, NULL)) != -1) {
 		switch (opt) {
 		case 'd':

qdl.h

@@ -89,6 +89,14 @@ int qdl_vip_transfer_enable(struct qdl_device *qdl, const char *vip_table_path);
 struct qdl_device *usb_init(void);
 struct qdl_device *sim_init(void);
 
+struct qdl_device_desc {
+	int vid;
+	int pid;
+	char serial[16];
+};
+
+struct qdl_device_desc *usb_list(unsigned int *devices_found);
+
 int firehose_run(struct qdl_device *qdl);
 int firehose_provision(struct qdl_device *qdl);
 int firehose_read_buf(struct qdl_device *qdl, struct read_op *read_op, void *out_buf, size_t out_size);

usb.c

@@ -223,6 +223,89 @@ static int usb_open(struct qdl_device *qdl, const char *serial)
 	return -1;
 }
 
+struct qdl_device_desc *usb_list(unsigned int *devices_found)
+{
+	struct libusb_device_descriptor desc;
+	struct libusb_device_handle *handle;
+	struct qdl_device_desc *result;
+	struct libusb_device **devices;
+	struct libusb_device *dev;
+	unsigned long serial_len;
+	unsigned char buf[128];
+	ssize_t device_count;
+	unsigned int count = 0;
+	char *serial;
+	int ret;
+	int i;
+
+	ret = libusb_init(NULL);
+	if (ret < 0)
+		err(1, "failed to initialize libusb");
+
+	device_count = libusb_get_device_list(NULL, &devices);
+	if (device_count < 0)
+		err(1, "failed to list USB devices");
+	if (device_count == 0)
+		return NULL;
+
+	result = calloc(device_count, sizeof(struct qdl_device));
+	if (!result)
+		err(1, "failed to allocate devices array\n");
+
+	for (i = 0; i < device_count; i++) {
+		dev = devices[i];
+
+		ret = libusb_get_device_descriptor(dev, &desc);
+		if (ret < 0) {
+			warnx("failed to get USB device descriptor");
+			continue;
+		}
+
+		if (desc.idVendor != 0x05c6)
+			continue;
+		if (desc.idProduct != 0x9008 && desc.idProduct != 0x900e && desc.idProduct != 0x901d)
+			continue;
+
+		ret = libusb_open(dev, &handle);
+		if (ret < 0) {
+			warnx("unable to open USB device");
+			continue;
+		}
+
+		ret = libusb_get_string_descriptor_ascii(handle, desc.iProduct, buf, sizeof(buf) - 1);
+		if (ret < 0) {
+			warnx("failed to read iProduct descriptor: %s", libusb_strerror(ret));
+			continue;
+		}
+		buf[ret] = '\0';
+
+		serial = strstr((char *)buf, "_SN:");
+		if (!serial) {
+			ux_err("ignoring device with no serial number\n");
+			continue;
+		}
+
+		serial += strlen("_SN:");
+		serial_len = strcspn(serial, " _");
+		if (serial_len + 1 > sizeof(result[count].serial)) {
+			ux_err("ignoring device with unexpectedly long serial number\n");
+			continue;
+		}
+
+		memcpy(result[count].serial, serial, serial_len);
+		result[count].serial[serial_len] = '\0';
+
+		result[count].vid = desc.idVendor;
+		result[count].pid = desc.idProduct;
+		count++;
+	}
+
+	libusb_free_device_list(devices, 1);
+	*devices_found = count;
+
+	return result;
+}
+
 static void usb_close(struct qdl_device *qdl)
 {
 	struct qdl_device_usb *qdl_usb = container_of(qdl, struct qdl_device_usb, base);