struct _am7xxx_device {
libusb_device_handle *usb_device;
uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
+ am7xxx_device *next;
+};
+
+struct _am7xxx_context {
+ libusb_context *usb_context;
+ am7xxx_device *devices_list;
};
typedef enum {
return ret;
}
-am7xxx_device *am7xxx_init(void)
+static am7xxx_device *add_new_device(am7xxx_device **devices_list)
{
- unsigned int i;
+ am7xxx_device *new_device;
- am7xxx_device *dev = malloc(sizeof(*dev));
- if (dev == NULL) {
+ new_device = malloc(sizeof(*new_device));
+ if (new_device == NULL) {
perror("malloc");
+ return NULL;
+ }
+ memset(new_device, 0, sizeof(*new_device));
+
+ 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_device *devices_list,
+ unsigned int device_index)
+{
+ unsigned int i = 0;
+ am7xxx_device *current = 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) {
+ fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+ return -EINVAL;
+ }
+ if (op == SCAN_OP_BUILD_DEVLIST && ctx->devices_list != NULL) {
+ fprintf(stderr, "%s: device scan done already? Abort!\n", __func__);
+ return -EINVAL;
+ }
+
+ num_devices = libusb_get_device_list(ctx->usb_context, &list);
+ if (num_devices < 0) {
+ ret = -ENODEV;
goto out;
}
- memset(dev, 0, sizeof(*dev));
-
- libusb_init(NULL);
- libusb_set_debug(NULL, 3);
-
- for (i = 0; i < ARRAY_SIZE(supported_devices); i++) {
- dev->usb_device = libusb_open_device_with_vid_pid(NULL,
- supported_devices[i].vendor_id,
- supported_devices[i].product_id);
- if (dev->usb_device) {
- printf("%s: device found: %s\n", __func__, supported_devices[i].name);
- break;
+
+ 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)
+ 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;
+ /* debug */
+ printf("am7xxx device found, index: %d, name: %s\n",
+ current_index,
+ supported_devices[j].name);
+ new_device = add_new_device(&(ctx->devices_list));
+ 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
+ */
+ ret = -ENODEV;
+ goto out;
+ }
+ } else if (op == SCAN_OP_OPEN_DEVICE &&
+ current_index == open_device_index) {
+
+ *dev = find_device(ctx->devices_list, open_device_index);
+ if (*dev == NULL) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /* the usb device has already been opened */
+ if ((*dev)->usb_device) {
+ ret = 1;
+ goto out;
+ }
+
+ ret = libusb_open(list[i], &((*dev)->usb_device));
+ if (ret < 0)
+ goto out;
+
+ libusb_set_configuration((*dev)->usb_device, 1);
+ libusb_claim_interface((*dev)->usb_device, 0);
+ goto out;
+ }
+ current_index++;
+ }
}
}
- if (dev->usb_device == NULL) {
- errno = ENODEV;
- perror("libusb_open_device_with_vid_pid");
- goto out_libusb_exit;
+
+ /* if we made it up to here we didn't find any device to open */
+ if (op == SCAN_OP_OPEN_DEVICE) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+out:
+ libusb_free_device_list(list, 1);
+ return ret;
+}
+
+int am7xxx_init(am7xxx_context **ctx)
+{
+ int ret = 0;
+
+ *ctx = malloc(sizeof(**ctx));
+ if (*ctx == NULL) {
+ perror("malloc");
+ ret = -ENOMEM;
+ goto out;
}
+ memset(*ctx, 0, sizeof(**ctx));
- libusb_set_configuration(dev->usb_device, 1);
- libusb_claim_interface(dev->usb_device, 0);
+ ret = libusb_init(&((*ctx)->usb_context));
+ if (ret < 0)
+ goto out_free_context;
+
+ libusb_set_debug((*ctx)->usb_context, 3);
+
+ ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
+ if (ret < 0) {
+ fprintf(stderr, "%s: scan_devices failed\n", __func__);
+ am7xxx_shutdown(*ctx);
+ goto out;
+ }
- return dev;
+ return 0;
-out_libusb_exit:
- libusb_exit(NULL);
- free(dev);
+out_free_context:
+ free(*ctx);
+ *ctx = NULL;
out:
- return NULL;
+ return ret;
+}
+
+void am7xxx_shutdown(am7xxx_context *ctx)
+{
+ am7xxx_device *current;
+
+ if (ctx == NULL) {
+ fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+ 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;
+}
+
+int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
+ unsigned int device_index)
+{
+ int ret;
+
+ if (ctx == NULL) {
+ fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+ return -EINVAL;
+ }
+
+ ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
+ if (ret < 0) {
+ errno = ENODEV;
+ } else if (ret > 0) {
+ /* warning */
+ fprintf(stderr, "%s: device %d already open\n", __func__, device_index);
+ errno = EBUSY;
+ ret = -EBUSY;
+ }
+
+ return ret;
}
-void am7xxx_shutdown(am7xxx_device *dev)
+int am7xxx_close_device(am7xxx_device *dev)
{
- if (dev) {
+ if (dev == NULL) {
+ fprintf(stderr, "%s: dev must not be NULL!\n", __func__);
+ return -EINVAL;
+ }
+ if (dev->usb_device) {
+ libusb_release_interface(dev->usb_device, 0);
libusb_close(dev->usb_device);
- libusb_exit(NULL);
- free(dev);
- dev = NULL;
+ dev->usb_device = NULL;
}
+ return 0;
}
int am7xxx_get_device_info(am7xxx_device *dev,
projects / libam7xxx.git / blobdiff