+static am7xxx_device *add_new_device(am7xxx_context *ctx)
+{
+ am7xxx_device **devices_list;
+ am7xxx_device *new_device;
+
+ if (ctx == NULL) {
+ fatal("context must not be NULL!\n");
+ return NULL;
+ }
+
+ devices_list = &(ctx->devices_list);
+
+ new_device = malloc(sizeof(*new_device));
+ if (new_device == NULL) {
+ fatal("cannot allocate a new device (%s)\n", strerror(errno));
+ return NULL;
+ }
+ memset(new_device, 0, sizeof(*new_device));
+
+ new_device->ctx = ctx;
+
+ if (*devices_list == NULL) {
+ *devices_list = new_device;
+ } else {
+ am7xxx_device *prev = *devices_list;
+ while (prev->next)
+ prev = prev->next;
+ prev->next = new_device;
+ }
+ return new_device;
+}
+
+static am7xxx_device *find_device(am7xxx_context *ctx,
+ unsigned int device_index)
+{
+ unsigned int i = 0;
+ am7xxx_device *current;
+
+ if (ctx == NULL) {
+ fatal("context must not be NULL!\n");
+ return NULL;
+ }
+
+ current = ctx->devices_list;
+ while (current && i++ < device_index)
+ current = current->next;
+
+ return current;
+}
+
+typedef enum {
+ SCAN_OP_BUILD_DEVLIST,
+ SCAN_OP_OPEN_DEVICE,
+} scan_op;
+
+/**
+ * This is where the central logic of multi-device support is.
+ *
+ * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
+ * 'dev' are ignored; the function returns 0 on success and a negative value
+ * on error.
+ *
+ * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
+ * device with index 'open_device_index' and returns the correspondent
+ * am7xxx_device in the 'dev' parameter; the function returns 0 on success,
+ * 1 if the device was already open and a negative value on error.
+ *
+ * NOTES:
+ * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
+ * the caller might want to call am7xxx_shutdown() in order to remove
+ * devices possibly added before the failure.
+ */
+static int scan_devices(am7xxx_context *ctx, scan_op op,
+ unsigned int open_device_index, am7xxx_device **dev)
+{
+ int num_devices;
+ libusb_device** list;
+ unsigned int current_index;
+ int i;
+ int ret;
+
+ if (ctx == NULL) {
+ fatal("context must not be NULL!\n");
+ return -EINVAL;
+ }
+ if (op == SCAN_OP_BUILD_DEVLIST && ctx->devices_list != NULL) {
+ error(ctx, "device scan done already? Abort!\n");
+ return -EINVAL;
+ }
+
+ num_devices = libusb_get_device_list(ctx->usb_context, &list);
+ if (num_devices < 0) {
+ error(ctx, "USB get device list failed (%s)\n", libusb_error_name(num_devices));
+ ret = -ENODEV;
+ goto out;
+ }
+
+ current_index = 0;
+ for (i = 0; i < num_devices; i++) {
+ struct libusb_device_descriptor desc;
+ unsigned int j;
+
+ ret = libusb_get_device_descriptor(list[i], &desc);
+ if (ret < 0) {
+ debug(ctx, "USB get device descriptor failed (%s)\n", libusb_error_name(ret));
+ continue;
+ }
+
+ for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
+ if (desc.idVendor == supported_devices[j].vendor_id
+ && desc.idProduct == supported_devices[j].product_id) {
+
+ if (op == SCAN_OP_BUILD_DEVLIST) {
+ am7xxx_device *new_device;
+ info(ctx, "am7xxx device found, index: %d, name: %s\n",
+ current_index,
+ supported_devices[j].name);
+ new_device = add_new_device(ctx);
+ if (new_device == NULL) {
+ /* XXX, the caller may want
+ * to call am7xxx_shutdown() if
+ * we fail here, as we may have
+ * added some devices already
+ */
+ debug(ctx, "Cannot create a new device\n");
+ ret = -ENODEV;
+ goto out;
+ }
+ } else if (op == SCAN_OP_OPEN_DEVICE &&
+ current_index == open_device_index) {
+
+ *dev = find_device(ctx, open_device_index);
+ if (*dev == NULL) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /* the usb device has already been opened */
+ if ((*dev)->usb_device) {
+ debug(ctx, "(*dev)->usb_device already set\n");
+ ret = 1;
+ goto out;
+ }
+
+ ret = libusb_open(list[i], &((*dev)->usb_device));
+ if (ret < 0) {
+ debug(ctx, "libusb_open failed (%s)\n", libusb_error_name(ret));
+ goto out;
+ }
+
+ libusb_set_configuration((*dev)->usb_device, 2);
+ libusb_claim_interface((*dev)->usb_device, 0);
+ goto out;
+ }
+ current_index++;
+ }
+ }
+ }
+
+ /* if we made it up to here we didn't find any device to open */
+ if (op == SCAN_OP_OPEN_DEVICE) {
+ error(ctx, "Cannot find any device to open\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /* everything went fine when building the device list */
+ ret = 0;
+out:
+ libusb_free_device_list(list, 1);
+ return ret;
+}
+
+/* Public API */
+
+AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
+{
+ int ret = 0;
+
+ *ctx = malloc(sizeof(**ctx));
+ if (*ctx == NULL) {
+ fatal("cannot allocate the context (%s)\n", strerror(errno));
+ ret = -ENOMEM;
+ goto out;
+ }
+ memset(*ctx, 0, sizeof(**ctx));
+
+ /* Set the highest log level during initialization */
+ (*ctx)->log_level = AM7XXX_LOG_TRACE;
+
+ ret = libusb_init(&((*ctx)->usb_context));
+ if (ret < 0) {
+ fatal("USB initialization failed (%s)\n", libusb_error_name(ret));
+ goto out_free_context;
+ }
+
+ libusb_set_debug((*ctx)->usb_context, 3);
+
+ ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
+ if (ret < 0) {
+ error(*ctx, "scan_devices() failed\n");
+ am7xxx_shutdown(*ctx);
+ goto out;
+ }
+
+ /* Set a quieter log level as default for normal operation */
+ (*ctx)->log_level = AM7XXX_LOG_ERROR;
+ return 0;
+
+out_free_context:
+ free(*ctx);
+ *ctx = NULL;
+out:
+ return ret;
+}
+
+AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
+{
+ am7xxx_device *current;
+
+ if (ctx == NULL) {
+ fatal("context must not be NULL!\n");
+ return;
+ }
+
+ current = ctx->devices_list;
+ while (current) {
+ am7xxx_device *next = current->next;
+ am7xxx_close_device(current);
+ free(current);
+ current = next;
+ }
+
+ libusb_exit(ctx->usb_context);
+ free(ctx);
+ ctx = NULL;
+}
+
+AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
+{
+ ctx->log_level = log_level;
+}
+
+AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
+ unsigned int device_index)
+{
+ int ret;
+
+ if (ctx == NULL) {
+ fatal("context must not be NULL!\n");
+ return -EINVAL;
+ }
+
+ ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
+ if (ret < 0) {
projects / libam7xxx.git / blobdiff