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authorHarald Welte <laforge@osmocom.org>2020-01-12 23:45:42 +0100
committerHarald Welte <laforge@osmocom.org>2020-03-16 12:02:04 +0100
commit0609b8cc8206e94ddd316d4c570abf19f08a8d63 (patch)
tree121227ed02fee3370557667ae41bf92d252dfbe8
parent3c44a646bd036785fd54dd3ae9fb06d9d6d3d107 (diff)
usb: Add osmo_libusb_find_open_claim() all-in-one API
This function offers the highest level of API among all libosmousb helper functions. It is intended as a one-stop shop for everything related to grabbing an interface. Change-Id: I748ded6cc7b73a73625588bd7a34a017a905b6bf
-rw-r--r--include/osmocom/usb/libusb.h30
-rw-r--r--src/usb/osmo_libusb.c96
2 files changed, 126 insertions, 0 deletions
diff --git a/include/osmocom/usb/libusb.h b/include/osmocom/usb/libusb.h
index 2220e03d..9ad3f71a 100644
--- a/include/osmocom/usb/libusb.h
+++ b/include/osmocom/usb/libusb.h
@@ -55,6 +55,31 @@ struct usb_interface_match {
uint8_t string_idx;
};
+/*! Description of the USB device+interface we're looking for */
+struct osmo_usb_matchspec {
+ /*! specify the USB device */
+ struct {
+ int vendor_id; /*!< typically -1 for compile time defaults */
+ int product_id; /*!< typically -1 for compile time defaults */
+ char *path; /*!< used for disambiguation when multiple matches; can be NULL */
+ } dev;
+
+ /*! specify the USB configuration */
+ int config_id; /*!< typically -1 unless user selects specific configuration */
+
+ /*! specify the USB interface */
+ struct {
+ /* typically those three are set to application defaults */
+ int class; /*!< -1 or a user-specified class */
+ int subclass; /*!< -1 or a user-specified subclass */
+ int proto; /*!< -1 or a user-specified protocol */
+
+ /* typically those two are -1; but user can override them */
+ int num;
+ int altsetting;
+ } intf;
+};
+
char *osmo_libusb_dev_get_path_buf(char *buf, size_t bufsize, libusb_device *dev);
char *osmo_libusb_dev_get_path_c(void *ctx, libusb_device *dev);
@@ -81,6 +106,11 @@ int osmo_libusb_find_matching_interfaces(libusb_context *luctx, const struct dev
libusb_device_handle *osmo_libusb_open_claim_interface(void *ctx, libusb_context *luctx,
const struct usb_interface_match *ifm);
+void osmo_libusb_match_init(struct osmo_usb_matchspec *cfg, int if_class, int if_subclass, int if_proto);
+
+libusb_device_handle *osmo_libusb_find_open_claim(const struct osmo_usb_matchspec *cfg,
+ const struct dev_id *default_dev_ids);
+
int osmo_libusb_get_ep_addrs(libusb_device_handle *devh, unsigned int if_num,
uint8_t *out, uint8_t *in, uint8_t *irq);
diff --git a/src/usb/osmo_libusb.c b/src/usb/osmo_libusb.c
index 3c8a22a8..bb862067 100644
--- a/src/usb/osmo_libusb.c
+++ b/src/usb/osmo_libusb.c
@@ -590,6 +590,102 @@ libusb_device_handle *osmo_libusb_open_claim_interface(void *ctx, libusb_context
return usb_devh;
}
+void osmo_libusb_match_init(struct osmo_usb_matchspec *cfg, int if_class, int if_subclass, int if_proto)
+{
+ cfg->dev.vendor_id = -1;
+ cfg->dev.product_id = -1;
+ cfg->dev.path = NULL;
+
+ cfg->config_id = -1;
+
+ cfg->intf.class = if_class;
+ cfg->intf.subclass = if_subclass;
+ cfg->intf.proto = if_proto;
+
+ cfg->intf.num = cfg->intf.altsetting = -1;
+}
+
+
+/*! high-level all-in-one function for USB device, config + interface matching + opening.
+ * This function offers the highest level of API among all libosmousb helper functions. It
+ * is intended as a one-stop shop for everything related to grabbing an interface.
+ *
+ * 1) looks for a device matching either the VID/PID from 'cfg' or 'default_dev_ids',
+ * if more than one is found, the user is expected to fill in cfg->dev.path to disambiguate.
+ * 2) find any interfaces on the device that match the specification in 'cfg'. The match
+ * could be done based on any of (class, subclass, proto, interface number). If there
+ * are multiple matches, the caller must disambiguate by specifying the interface number.
+ * 3) open the USB device; set the configuration (if needed); claim the interface and set
+ * the altsetting
+ *
+ * \param[in] cfg user-supplied match configuration (from command line or config file)
+ * \param[in] default_dev_ids Default list of supported VendorId/ProductIds
+ * \returns libusb_device_handle on success, NULL on error
+ */
+libusb_device_handle *osmo_libusb_find_open_claim(const struct osmo_usb_matchspec *cfg,
+ const struct dev_id *default_dev_ids)
+{
+ struct usb_interface_match if_matches[16];
+ struct usb_interface_match *ifm = NULL;
+ libusb_device_handle *usb_devh = NULL;
+ struct dev_id user_dev_ids[2] = {
+ { cfg->dev.vendor_id, cfg->dev.product_id },
+ { 0, 0 }
+ };
+ const struct dev_id *dev_ids = default_dev_ids;
+ libusb_device *dev;
+ int rc, i;
+
+ /* Stage 1: Find a device matching either the user-specified VID/PID or
+ * the list of IDs in default_dev_ids plus optionally the user-specified path */
+ if (cfg->dev.vendor_id != -1 || cfg->dev.product_id != -1)
+ dev_ids = user_dev_ids;
+ dev = osmo_libusb_find_matching_dev_path(NULL, dev_ids, cfg->dev.path);
+ if (!dev)
+ goto close_exit;
+
+ /* Stage 2: Find any interfaces matching the class/subclass/proto as specified */
+ rc = osmo_libusb_dev_find_matching_interfaces(dev, cfg->intf.class, cfg->intf.subclass,
+ cfg->intf.proto, if_matches, sizeof(if_matches));
+ if (rc < 1) {
+ LOGP(DLUSB, LOGL_NOTICE, "can't find matching USB interface at device\n");
+ goto close_exit;
+ } else if (rc == 1) {
+ ifm = if_matches;
+ } else if (rc > 1) {
+ if (cfg->intf.num == -1) {
+ LOGP(DLUSB, LOGL_ERROR, "Found %d matching USB interfaces, you "
+ "have to specify the interface number\n", rc);
+ goto close_exit;
+ }
+ for (i = 0; i < rc; i++) {
+ if (if_matches[i].interface == cfg->intf.num) {
+ ifm = &if_matches[i];
+ break;
+ }
+ /* FIXME: match altsetting */
+ }
+ }
+ if (!ifm) {
+ LOGP(DLUSB, LOGL_NOTICE, "Couldn't find matching interface\n");
+ goto close_exit;
+ }
+
+ /* Stage 3: Open device; set config (if required); claim interface; set altsetting */
+ usb_devh = osmo_libusb_open_claim_interface(NULL, NULL, ifm);
+ if (!usb_devh) {
+ LOGP(DLUSB, LOGL_ERROR, "can't open USB device (permissions issue?)\n");
+ goto close_exit;
+ }
+ return usb_devh;
+close_exit:
+ /* release if_matches */
+ if (usb_devh)
+ libusb_close(usb_devh);
+
+ return NULL;
+}
+
/*! obtain the endpoint addresses for a given USB interface.
* \param[in] devh USB device handle on which to operate
* \param[in] if_num USB Interface number on which to operate