From 3edd70c1f1cf1238f30e4d63866c9462be92441f Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Sun, 12 Jan 2020 23:45:42 +0100 Subject: 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 --- include/osmocom/usb/libusb.h | 30 ++++++++++++++ src/usb/osmo_libusb.c | 96 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 126 insertions(+) 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 -- cgit v1.2.3