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Diffstat (limited to 'vendor/github.com/karalabe/hid/libusb/libusb/libusbi.h')
-rw-r--r-- | vendor/github.com/karalabe/hid/libusb/libusb/libusbi.h | 1149 |
1 files changed, 1149 insertions, 0 deletions
diff --git a/vendor/github.com/karalabe/hid/libusb/libusb/libusbi.h b/vendor/github.com/karalabe/hid/libusb/libusb/libusbi.h new file mode 100644 index 000000000..752e39887 --- /dev/null +++ b/vendor/github.com/karalabe/hid/libusb/libusb/libusbi.h @@ -0,0 +1,1149 @@ +/* + * Internal header for libusb + * Copyright © 2007-2009 Daniel Drake <dsd@gentoo.org> + * Copyright © 2001 Johannes Erdfelt <johannes@erdfelt.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef LIBUSBI_H +#define LIBUSBI_H + +#include <config.h> + +#include <stdlib.h> + +#include <stddef.h> +#include <stdint.h> +#include <time.h> +#include <stdarg.h> +#ifdef HAVE_POLL_H +#include <poll.h> +#endif +#ifdef HAVE_MISSING_H +#include <missing.h> +#endif + +#include "libusb.h" +#include "version.h" + +/* Inside the libusb code, mark all public functions as follows: + * return_type API_EXPORTED function_name(params) { ... } + * But if the function returns a pointer, mark it as follows: + * DEFAULT_VISIBILITY return_type * LIBUSB_CALL function_name(params) { ... } + * In the libusb public header, mark all declarations as: + * return_type LIBUSB_CALL function_name(params); + */ +#define API_EXPORTED LIBUSB_CALL DEFAULT_VISIBILITY + +#ifdef __cplusplus +extern "C" { +#endif + +#define DEVICE_DESC_LENGTH 18 + +#define USB_MAXENDPOINTS 32 +#define USB_MAXINTERFACES 32 +#define USB_MAXCONFIG 8 + +/* Backend specific capabilities */ +#define USBI_CAP_HAS_HID_ACCESS 0x00010000 +#define USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER 0x00020000 + +/* Maximum number of bytes in a log line */ +#define USBI_MAX_LOG_LEN 1024 +/* Terminator for log lines */ +#define USBI_LOG_LINE_END "\n" + +/* The following is used to silence warnings for unused variables */ +#define UNUSED(var) do { (void)(var); } while(0) + +#if !defined(ARRAYSIZE) +#define ARRAYSIZE(array) (sizeof(array) / sizeof(array[0])) +#endif + +struct list_head { + struct list_head *prev, *next; +}; + +/* Get an entry from the list + * ptr - the address of this list_head element in "type" + * type - the data type that contains "member" + * member - the list_head element in "type" + */ +#define list_entry(ptr, type, member) \ + ((type *)((uintptr_t)(ptr) - (uintptr_t)offsetof(type, member))) + +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +/* Get each entry from a list + * pos - A structure pointer has a "member" element + * head - list head + * member - the list_head element in "pos" + * type - the type of the first parameter + */ +#define list_for_each_entry(pos, head, member, type) \ + for (pos = list_entry((head)->next, type, member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, type, member)) + +#define list_for_each_entry_safe(pos, n, head, member, type) \ + for (pos = list_entry((head)->next, type, member), \ + n = list_entry(pos->member.next, type, member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, type, member)) + +#define list_empty(entry) ((entry)->next == (entry)) + +static inline void list_init(struct list_head *entry) +{ + entry->prev = entry->next = entry; +} + +static inline void list_add(struct list_head *entry, struct list_head *head) +{ + entry->next = head->next; + entry->prev = head; + + head->next->prev = entry; + head->next = entry; +} + +static inline void list_add_tail(struct list_head *entry, + struct list_head *head) +{ + entry->next = head; + entry->prev = head->prev; + + head->prev->next = entry; + head->prev = entry; +} + +static inline void list_del(struct list_head *entry) +{ + entry->next->prev = entry->prev; + entry->prev->next = entry->next; + entry->next = entry->prev = NULL; +} + +static inline void *usbi_reallocf(void *ptr, size_t size) +{ + void *ret = realloc(ptr, size); + if (!ret) + free(ptr); + return ret; +} + +#define container_of(ptr, type, member) ({ \ + const typeof( ((type *)0)->member ) *mptr = (ptr); \ + (type *)( (char *)mptr - offsetof(type,member) );}) + +#ifndef MIN +#define MIN(a, b) ((a) < (b) ? (a) : (b)) +#endif +#ifndef MAX +#define MAX(a, b) ((a) > (b) ? (a) : (b)) +#endif + +#define TIMESPEC_IS_SET(ts) ((ts)->tv_sec != 0 || (ts)->tv_nsec != 0) + +#if defined(_WIN32) || defined(__CYGWIN__) || defined(_WIN32_WCE) +#define TIMEVAL_TV_SEC_TYPE long +#else +#define TIMEVAL_TV_SEC_TYPE time_t +#endif + +/* Some platforms don't have this define */ +#ifndef TIMESPEC_TO_TIMEVAL +#define TIMESPEC_TO_TIMEVAL(tv, ts) \ + do { \ + (tv)->tv_sec = (TIMEVAL_TV_SEC_TYPE) (ts)->tv_sec; \ + (tv)->tv_usec = (ts)->tv_nsec / 1000; \ + } while (0) +#endif + +void usbi_log(struct libusb_context *ctx, enum libusb_log_level level, + const char *function, const char *format, ...); + +void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level, + const char *function, const char *format, va_list args); + +#if !defined(_MSC_VER) || _MSC_VER >= 1400 + +#ifdef ENABLE_LOGGING +#define _usbi_log(ctx, level, ...) usbi_log(ctx, level, __FUNCTION__, __VA_ARGS__) +#define usbi_dbg(...) _usbi_log(NULL, LIBUSB_LOG_LEVEL_DEBUG, __VA_ARGS__) +#else +#define _usbi_log(ctx, level, ...) do { (void)(ctx); } while(0) +#define usbi_dbg(...) do {} while(0) +#endif + +#define usbi_info(ctx, ...) _usbi_log(ctx, LIBUSB_LOG_LEVEL_INFO, __VA_ARGS__) +#define usbi_warn(ctx, ...) _usbi_log(ctx, LIBUSB_LOG_LEVEL_WARNING, __VA_ARGS__) +#define usbi_err(ctx, ...) _usbi_log(ctx, LIBUSB_LOG_LEVEL_ERROR, __VA_ARGS__) + +#else /* !defined(_MSC_VER) || _MSC_VER >= 1400 */ + +#ifdef ENABLE_LOGGING +#define LOG_BODY(ctxt, level) \ +{ \ + va_list args; \ + va_start(args, format); \ + usbi_log_v(ctxt, level, "", format, args); \ + va_end(args); \ +} +#else +#define LOG_BODY(ctxt, level) \ +{ \ + (void)(ctxt); \ +} +#endif + +static inline void usbi_info(struct libusb_context *ctx, const char *format, ...) + LOG_BODY(ctx, LIBUSB_LOG_LEVEL_INFO) +static inline void usbi_warn(struct libusb_context *ctx, const char *format, ...) + LOG_BODY(ctx, LIBUSB_LOG_LEVEL_WARNING) +static inline void usbi_err(struct libusb_context *ctx, const char *format, ...) + LOG_BODY(ctx, LIBUSB_LOG_LEVEL_ERROR) + +static inline void usbi_dbg(const char *format, ...) + LOG_BODY(NULL, LIBUSB_LOG_LEVEL_DEBUG) + +#endif /* !defined(_MSC_VER) || _MSC_VER >= 1400 */ + +#define USBI_GET_CONTEXT(ctx) \ + do { \ + if (!(ctx)) \ + (ctx) = usbi_default_context; \ + } while(0) + +#define DEVICE_CTX(dev) ((dev)->ctx) +#define HANDLE_CTX(handle) (DEVICE_CTX((handle)->dev)) +#define TRANSFER_CTX(transfer) (HANDLE_CTX((transfer)->dev_handle)) +#define ITRANSFER_CTX(transfer) \ + (TRANSFER_CTX(USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer))) + +#define IS_EPIN(ep) (0 != ((ep) & LIBUSB_ENDPOINT_IN)) +#define IS_EPOUT(ep) (!IS_EPIN(ep)) +#define IS_XFERIN(xfer) (0 != ((xfer)->endpoint & LIBUSB_ENDPOINT_IN)) +#define IS_XFEROUT(xfer) (!IS_XFERIN(xfer)) + +/* Internal abstraction for thread synchronization */ +#if defined(THREADS_POSIX) +#include "os/threads_posix.h" +#elif defined(OS_WINDOWS) || defined(OS_WINCE) +#include "os/threads_windows.h" +#endif + +extern struct libusb_context *usbi_default_context; + +/* Forward declaration for use in context (fully defined inside poll abstraction) */ +struct pollfd; + +struct libusb_context { + int debug; + int debug_fixed; + + /* internal event pipe, used for signalling occurrence of an internal event. */ + int event_pipe[2]; + + struct list_head usb_devs; + usbi_mutex_t usb_devs_lock; + + /* A list of open handles. Backends are free to traverse this if required. + */ + struct list_head open_devs; + usbi_mutex_t open_devs_lock; + + /* A list of registered hotplug callbacks */ + struct list_head hotplug_cbs; + usbi_mutex_t hotplug_cbs_lock; + + /* this is a list of in-flight transfer handles, sorted by timeout + * expiration. URBs to timeout the soonest are placed at the beginning of + * the list, URBs that will time out later are placed after, and urbs with + * infinite timeout are always placed at the very end. */ + struct list_head flying_transfers; + /* Note paths taking both this and usbi_transfer->lock must always + * take this lock first */ + usbi_mutex_t flying_transfers_lock; + + /* user callbacks for pollfd changes */ + libusb_pollfd_added_cb fd_added_cb; + libusb_pollfd_removed_cb fd_removed_cb; + void *fd_cb_user_data; + + /* ensures that only one thread is handling events at any one time */ + usbi_mutex_t events_lock; + + /* used to see if there is an active thread doing event handling */ + int event_handler_active; + + /* A thread-local storage key to track which thread is performing event + * handling */ + usbi_tls_key_t event_handling_key; + + /* used to wait for event completion in threads other than the one that is + * event handling */ + usbi_mutex_t event_waiters_lock; + usbi_cond_t event_waiters_cond; + + /* A lock to protect internal context event data. */ + usbi_mutex_t event_data_lock; + + /* A bitmask of flags that are set to indicate specific events that need to + * be handled. Protected by event_data_lock. */ + unsigned int event_flags; + + /* A counter that is set when we want to interrupt and prevent event handling, + * in order to safely close a device. Protected by event_data_lock. */ + unsigned int device_close; + + /* list and count of poll fds and an array of poll fd structures that is + * (re)allocated as necessary prior to polling. Protected by event_data_lock. */ + struct list_head ipollfds; + struct pollfd *pollfds; + POLL_NFDS_TYPE pollfds_cnt; + + /* A list of pending hotplug messages. Protected by event_data_lock. */ + struct list_head hotplug_msgs; + + /* A list of pending completed transfers. Protected by event_data_lock. */ + struct list_head completed_transfers; + +#ifdef USBI_TIMERFD_AVAILABLE + /* used for timeout handling, if supported by OS. + * this timerfd is maintained to trigger on the next pending timeout */ + int timerfd; +#endif + + struct list_head list; +}; + +enum usbi_event_flags { + /* The list of pollfds has been modified */ + USBI_EVENT_POLLFDS_MODIFIED = 1 << 0, + + /* The user has interrupted the event handler */ + USBI_EVENT_USER_INTERRUPT = 1 << 1, +}; + +/* Macros for managing event handling state */ +#define usbi_handling_events(ctx) \ + (usbi_tls_key_get((ctx)->event_handling_key) != NULL) + +#define usbi_start_event_handling(ctx) \ + usbi_tls_key_set((ctx)->event_handling_key, ctx) + +#define usbi_end_event_handling(ctx) \ + usbi_tls_key_set((ctx)->event_handling_key, NULL) + +/* Update the following macro if new event sources are added */ +#define usbi_pending_events(ctx) \ + ((ctx)->event_flags || (ctx)->device_close \ + || !list_empty(&(ctx)->hotplug_msgs) || !list_empty(&(ctx)->completed_transfers)) + +#ifdef USBI_TIMERFD_AVAILABLE +#define usbi_using_timerfd(ctx) ((ctx)->timerfd >= 0) +#else +#define usbi_using_timerfd(ctx) (0) +#endif + +struct libusb_device { + /* lock protects refcnt, everything else is finalized at initialization + * time */ + usbi_mutex_t lock; + int refcnt; + + struct libusb_context *ctx; + + uint8_t bus_number; + uint8_t port_number; + struct libusb_device* parent_dev; + uint8_t device_address; + uint8_t num_configurations; + enum libusb_speed speed; + + struct list_head list; + unsigned long session_data; + + struct libusb_device_descriptor device_descriptor; + int attached; + + unsigned char os_priv +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) + [] /* valid C99 code */ +#else + [0] /* non-standard, but usually working code */ +#endif +#if defined(OS_SUNOS) + __attribute__ ((aligned (8))); +#else + ; +#endif +}; + +struct libusb_device_handle { + /* lock protects claimed_interfaces */ + usbi_mutex_t lock; + unsigned long claimed_interfaces; + + struct list_head list; + struct libusb_device *dev; + int auto_detach_kernel_driver; + unsigned char os_priv +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) + [] /* valid C99 code */ +#else + [0] /* non-standard, but usually working code */ +#endif +#if defined(OS_SUNOS) + __attribute__ ((aligned (8))); +#else + ; +#endif +}; + +enum { + USBI_CLOCK_MONOTONIC, + USBI_CLOCK_REALTIME +}; + +/* in-memory transfer layout: + * + * 1. struct usbi_transfer + * 2. struct libusb_transfer (which includes iso packets) [variable size] + * 3. os private data [variable size] + * + * from a libusb_transfer, you can get the usbi_transfer by rewinding the + * appropriate number of bytes. + * the usbi_transfer includes the number of allocated packets, so you can + * determine the size of the transfer and hence the start and length of the + * OS-private data. + */ + +struct usbi_transfer { + int num_iso_packets; + struct list_head list; + struct list_head completed_list; + struct timeval timeout; + int transferred; + uint32_t stream_id; + uint8_t state_flags; /* Protected by usbi_transfer->lock */ + uint8_t timeout_flags; /* Protected by the flying_stransfers_lock */ + + /* this lock is held during libusb_submit_transfer() and + * libusb_cancel_transfer() (allowing the OS backend to prevent duplicate + * cancellation, submission-during-cancellation, etc). the OS backend + * should also take this lock in the handle_events path, to prevent the user + * cancelling the transfer from another thread while you are processing + * its completion (presumably there would be races within your OS backend + * if this were possible). + * Note paths taking both this and the flying_transfers_lock must + * always take the flying_transfers_lock first */ + usbi_mutex_t lock; +}; + +enum usbi_transfer_state_flags { + /* Transfer successfully submitted by backend */ + USBI_TRANSFER_IN_FLIGHT = 1 << 0, + + /* Cancellation was requested via libusb_cancel_transfer() */ + USBI_TRANSFER_CANCELLING = 1 << 1, + + /* Operation on the transfer failed because the device disappeared */ + USBI_TRANSFER_DEVICE_DISAPPEARED = 1 << 2, +}; + +enum usbi_transfer_timeout_flags { + /* Set by backend submit_transfer() if the OS handles timeout */ + USBI_TRANSFER_OS_HANDLES_TIMEOUT = 1 << 0, + + /* The transfer timeout has been handled */ + USBI_TRANSFER_TIMEOUT_HANDLED = 1 << 1, + + /* The transfer timeout was successfully processed */ + USBI_TRANSFER_TIMED_OUT = 1 << 2, +}; + +#define USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer) \ + ((struct libusb_transfer *)(((unsigned char *)(transfer)) \ + + sizeof(struct usbi_transfer))) +#define LIBUSB_TRANSFER_TO_USBI_TRANSFER(transfer) \ + ((struct usbi_transfer *)(((unsigned char *)(transfer)) \ + - sizeof(struct usbi_transfer))) + +static inline void *usbi_transfer_get_os_priv(struct usbi_transfer *transfer) +{ + return ((unsigned char *)transfer) + sizeof(struct usbi_transfer) + + sizeof(struct libusb_transfer) + + (transfer->num_iso_packets + * sizeof(struct libusb_iso_packet_descriptor)); +} + +/* bus structures */ + +/* All standard descriptors have these 2 fields in common */ +struct usb_descriptor_header { + uint8_t bLength; + uint8_t bDescriptorType; +}; + +/* shared data and functions */ + +int usbi_io_init(struct libusb_context *ctx); +void usbi_io_exit(struct libusb_context *ctx); + +struct libusb_device *usbi_alloc_device(struct libusb_context *ctx, + unsigned long session_id); +struct libusb_device *usbi_get_device_by_session_id(struct libusb_context *ctx, + unsigned long session_id); +int usbi_sanitize_device(struct libusb_device *dev); +void usbi_handle_disconnect(struct libusb_device_handle *dev_handle); + +int usbi_handle_transfer_completion(struct usbi_transfer *itransfer, + enum libusb_transfer_status status); +int usbi_handle_transfer_cancellation(struct usbi_transfer *transfer); +void usbi_signal_transfer_completion(struct usbi_transfer *transfer); + +int usbi_parse_descriptor(const unsigned char *source, const char *descriptor, + void *dest, int host_endian); +int usbi_device_cache_descriptor(libusb_device *dev); +int usbi_get_config_index_by_value(struct libusb_device *dev, + uint8_t bConfigurationValue, int *idx); + +void usbi_connect_device (struct libusb_device *dev); +void usbi_disconnect_device (struct libusb_device *dev); + +int usbi_signal_event(struct libusb_context *ctx); +int usbi_clear_event(struct libusb_context *ctx); + +/* Internal abstraction for poll (needs struct usbi_transfer on Windows) */ +#if defined(OS_LINUX) || defined(OS_DARWIN) || defined(OS_OPENBSD) || defined(OS_NETBSD) ||\ + defined(OS_HAIKU) || defined(OS_SUNOS) +#include <unistd.h> +#include "os/poll_posix.h" +#elif defined(OS_WINDOWS) || defined(OS_WINCE) +#include "os/poll_windows.h" +#endif + +#if defined(_MSC_VER) && (_MSC_VER < 1900) +#define snprintf usbi_snprintf +#define vsnprintf usbi_vsnprintf +int usbi_snprintf(char *dst, size_t size, const char *format, ...); +int usbi_vsnprintf(char *dst, size_t size, const char *format, va_list ap); +#define LIBUSB_PRINTF_WIN32 +#endif + +struct usbi_pollfd { + /* must come first */ + struct libusb_pollfd pollfd; + + struct list_head list; +}; + +int usbi_add_pollfd(struct libusb_context *ctx, int fd, short events); +void usbi_remove_pollfd(struct libusb_context *ctx, int fd); + +/* device discovery */ + +/* we traverse usbfs without knowing how many devices we are going to find. + * so we create this discovered_devs model which is similar to a linked-list + * which grows when required. it can be freed once discovery has completed, + * eliminating the need for a list node in the libusb_device structure + * itself. */ +struct discovered_devs { + size_t len; + size_t capacity; + struct libusb_device *devices +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) + [] /* valid C99 code */ +#else + [0] /* non-standard, but usually working code */ +#endif + ; +}; + +struct discovered_devs *discovered_devs_append( + struct discovered_devs *discdevs, struct libusb_device *dev); + +/* OS abstraction */ + +/* This is the interface that OS backends need to implement. + * All fields are mandatory, except ones explicitly noted as optional. */ +struct usbi_os_backend { + /* A human-readable name for your backend, e.g. "Linux usbfs" */ + const char *name; + + /* Binary mask for backend specific capabilities */ + uint32_t caps; + + /* Perform initialization of your backend. You might use this function + * to determine specific capabilities of the system, allocate required + * data structures for later, etc. + * + * This function is called when a libusb user initializes the library + * prior to use. + * + * Return 0 on success, or a LIBUSB_ERROR code on failure. + */ + int (*init)(struct libusb_context *ctx); + + /* Deinitialization. Optional. This function should destroy anything + * that was set up by init. + * + * This function is called when the user deinitializes the library. + */ + void (*exit)(void); + + /* Enumerate all the USB devices on the system, returning them in a list + * of discovered devices. + * + * Your implementation should enumerate all devices on the system, + * regardless of whether they have been seen before or not. + * + * When you have found a device, compute a session ID for it. The session + * ID should uniquely represent that particular device for that particular + * connection session since boot (i.e. if you disconnect and reconnect a + * device immediately after, it should be assigned a different session ID). + * If your OS cannot provide a unique session ID as described above, + * presenting a session ID of (bus_number << 8 | device_address) should + * be sufficient. Bus numbers and device addresses wrap and get reused, + * but that is an unlikely case. + * + * After computing a session ID for a device, call + * usbi_get_device_by_session_id(). This function checks if libusb already + * knows about the device, and if so, it provides you with a reference + * to a libusb_device structure for it. + * + * If usbi_get_device_by_session_id() returns NULL, it is time to allocate + * a new device structure for the device. Call usbi_alloc_device() to + * obtain a new libusb_device structure with reference count 1. Populate + * the bus_number and device_address attributes of the new device, and + * perform any other internal backend initialization you need to do. At + * this point, you should be ready to provide device descriptors and so + * on through the get_*_descriptor functions. Finally, call + * usbi_sanitize_device() to perform some final sanity checks on the + * device. Assuming all of the above succeeded, we can now continue. + * If any of the above failed, remember to unreference the device that + * was returned by usbi_alloc_device(). + * + * At this stage we have a populated libusb_device structure (either one + * that was found earlier, or one that we have just allocated and + * populated). This can now be added to the discovered devices list + * using discovered_devs_append(). Note that discovered_devs_append() + * may reallocate the list, returning a new location for it, and also + * note that reallocation can fail. Your backend should handle these + * error conditions appropriately. + * + * This function should not generate any bus I/O and should not block. + * If I/O is required (e.g. reading the active configuration value), it is + * OK to ignore these suggestions :) + * + * This function is executed when the user wishes to retrieve a list + * of USB devices connected to the system. + * + * If the backend has hotplug support, this function is not used! + * + * Return 0 on success, or a LIBUSB_ERROR code on failure. + */ + int (*get_device_list)(struct libusb_context *ctx, + struct discovered_devs **discdevs); + + /* Apps which were written before hotplug support, may listen for + * hotplug events on their own and call libusb_get_device_list on + * device addition. In this case libusb_get_device_list will likely + * return a list without the new device in there, as the hotplug + * event thread will still be busy enumerating the device, which may + * take a while, or may not even have seen the event yet. + * + * To avoid this libusb_get_device_list will call this optional + * function for backends with hotplug support before copying + * ctx->usb_devs to the user. In this function the backend should + * ensure any pending hotplug events are fully processed before + * returning. + * + * Optional, should be implemented by backends with hotplug support. + */ + void (*hotplug_poll)(void); + + /* Open a device for I/O and other USB operations. The device handle + * is preallocated for you, you can retrieve the device in question + * through handle->dev. + * + * Your backend should allocate any internal resources required for I/O + * and other operations so that those operations can happen (hopefully) + * without hiccup. This is also a good place to inform libusb that it + * should monitor certain file descriptors related to this device - + * see the usbi_add_pollfd() function. + * + * This function should not generate any bus I/O and should not block. + * + * This function is called when the user attempts to obtain a device + * handle for a device. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_ACCESS if the user has insufficient permissions + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since + * discovery + * - another LIBUSB_ERROR code on other failure + * + * Do not worry about freeing the handle on failed open, the upper layers + * do this for you. + */ + int (*open)(struct libusb_device_handle *dev_handle); + + /* Close a device such that the handle cannot be used again. Your backend + * should destroy any resources that were allocated in the open path. + * This may also be a good place to call usbi_remove_pollfd() to inform + * libusb of any file descriptors associated with this device that should + * no longer be monitored. + * + * This function is called when the user closes a device handle. + */ + void (*close)(struct libusb_device_handle *dev_handle); + + /* Retrieve the device descriptor from a device. + * + * The descriptor should be retrieved from memory, NOT via bus I/O to the + * device. This means that you may have to cache it in a private structure + * during get_device_list enumeration. Alternatively, you may be able + * to retrieve it from a kernel interface (some Linux setups can do this) + * still without generating bus I/O. + * + * This function is expected to write DEVICE_DESC_LENGTH (18) bytes into + * buffer, which is guaranteed to be big enough. + * + * This function is called when sanity-checking a device before adding + * it to the list of discovered devices, and also when the user requests + * to read the device descriptor. + * + * This function is expected to return the descriptor in bus-endian format + * (LE). If it returns the multi-byte values in host-endian format, + * set the host_endian output parameter to "1". + * + * Return 0 on success or a LIBUSB_ERROR code on failure. + */ + int (*get_device_descriptor)(struct libusb_device *device, + unsigned char *buffer, int *host_endian); + + /* Get the ACTIVE configuration descriptor for a device. + * + * The descriptor should be retrieved from memory, NOT via bus I/O to the + * device. This means that you may have to cache it in a private structure + * during get_device_list enumeration. You may also have to keep track + * of which configuration is active when the user changes it. + * + * This function is expected to write len bytes of data into buffer, which + * is guaranteed to be big enough. If you can only do a partial write, + * return an error code. + * + * This function is expected to return the descriptor in bus-endian format + * (LE). If it returns the multi-byte values in host-endian format, + * set the host_endian output parameter to "1". + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if the device is in unconfigured state + * - another LIBUSB_ERROR code on other failure + */ + int (*get_active_config_descriptor)(struct libusb_device *device, + unsigned char *buffer, size_t len, int *host_endian); + + /* Get a specific configuration descriptor for a device. + * + * The descriptor should be retrieved from memory, NOT via bus I/O to the + * device. This means that you may have to cache it in a private structure + * during get_device_list enumeration. + * + * The requested descriptor is expressed as a zero-based index (i.e. 0 + * indicates that we are requesting the first descriptor). The index does + * not (necessarily) equal the bConfigurationValue of the configuration + * being requested. + * + * This function is expected to write len bytes of data into buffer, which + * is guaranteed to be big enough. If you can only do a partial write, + * return an error code. + * + * This function is expected to return the descriptor in bus-endian format + * (LE). If it returns the multi-byte values in host-endian format, + * set the host_endian output parameter to "1". + * + * Return the length read on success or a LIBUSB_ERROR code on failure. + */ + int (*get_config_descriptor)(struct libusb_device *device, + uint8_t config_index, unsigned char *buffer, size_t len, + int *host_endian); + + /* Like get_config_descriptor but then by bConfigurationValue instead + * of by index. + * + * Optional, if not present the core will call get_config_descriptor + * for all configs until it finds the desired bConfigurationValue. + * + * Returns a pointer to the raw-descriptor in *buffer, this memory + * is valid as long as device is valid. + * + * Returns the length of the returned raw-descriptor on success, + * or a LIBUSB_ERROR code on failure. + */ + int (*get_config_descriptor_by_value)(struct libusb_device *device, + uint8_t bConfigurationValue, unsigned char **buffer, + int *host_endian); + + /* Get the bConfigurationValue for the active configuration for a device. + * Optional. This should only be implemented if you can retrieve it from + * cache (don't generate I/O). + * + * If you cannot retrieve this from cache, either do not implement this + * function, or return LIBUSB_ERROR_NOT_SUPPORTED. This will cause + * libusb to retrieve the information through a standard control transfer. + * + * This function must be non-blocking. + * Return: + * - 0 on success + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - LIBUSB_ERROR_NOT_SUPPORTED if the value cannot be retrieved without + * blocking + * - another LIBUSB_ERROR code on other failure. + */ + int (*get_configuration)(struct libusb_device_handle *dev_handle, int *config); + + /* Set the active configuration for a device. + * + * A configuration value of -1 should put the device in unconfigured state. + * + * This function can block. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if the configuration does not exist + * - LIBUSB_ERROR_BUSY if interfaces are currently claimed (and hence + * configuration cannot be changed) + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure. + */ + int (*set_configuration)(struct libusb_device_handle *dev_handle, int config); + + /* Claim an interface. When claimed, the application can then perform + * I/O to an interface's endpoints. + * + * This function should not generate any bus I/O and should not block. + * Interface claiming is a logical operation that simply ensures that + * no other drivers/applications are using the interface, and after + * claiming, no other drivers/applications can use the interface because + * we now "own" it. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if the interface does not exist + * - LIBUSB_ERROR_BUSY if the interface is in use by another driver/app + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*claim_interface)(struct libusb_device_handle *dev_handle, int interface_number); + + /* Release a previously claimed interface. + * + * This function should also generate a SET_INTERFACE control request, + * resetting the alternate setting of that interface to 0. It's OK for + * this function to block as a result. + * + * You will only ever be asked to release an interface which was + * successfully claimed earlier. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*release_interface)(struct libusb_device_handle *dev_handle, int interface_number); + + /* Set the alternate setting for an interface. + * + * You will only ever be asked to set the alternate setting for an + * interface which was successfully claimed earlier. + * + * It's OK for this function to block. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if the alternate setting does not exist + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*set_interface_altsetting)(struct libusb_device_handle *dev_handle, + int interface_number, int altsetting); + + /* Clear a halt/stall condition on an endpoint. + * + * It's OK for this function to block. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*clear_halt)(struct libusb_device_handle *dev_handle, + unsigned char endpoint); + + /* Perform a USB port reset to reinitialize a device. + * + * If possible, the device handle should still be usable after the reset + * completes, assuming that the device descriptors did not change during + * reset and all previous interface state can be restored. + * + * If something changes, or you cannot easily locate/verify the resetted + * device, return LIBUSB_ERROR_NOT_FOUND. This prompts the application + * to close the old handle and re-enumerate the device. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if re-enumeration is required, or if the device + * has been disconnected since it was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*reset_device)(struct libusb_device_handle *dev_handle); + + /* Alloc num_streams usb3 bulk streams on the passed in endpoints */ + int (*alloc_streams)(struct libusb_device_handle *dev_handle, + uint32_t num_streams, unsigned char *endpoints, int num_endpoints); + + /* Free usb3 bulk streams allocated with alloc_streams */ + int (*free_streams)(struct libusb_device_handle *dev_handle, + unsigned char *endpoints, int num_endpoints); + + /* Allocate persistent DMA memory for the given device, suitable for + * zerocopy. May return NULL on failure. Optional to implement. + */ + unsigned char *(*dev_mem_alloc)(struct libusb_device_handle *handle, + size_t len); + + /* Free memory allocated by dev_mem_alloc. */ + int (*dev_mem_free)(struct libusb_device_handle *handle, + unsigned char *buffer, size_t len); + + /* Determine if a kernel driver is active on an interface. Optional. + * + * The presence of a kernel driver on an interface indicates that any + * calls to claim_interface would fail with the LIBUSB_ERROR_BUSY code. + * + * Return: + * - 0 if no driver is active + * - 1 if a driver is active + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*kernel_driver_active)(struct libusb_device_handle *dev_handle, + int interface_number); + + /* Detach a kernel driver from an interface. Optional. + * + * After detaching a kernel driver, the interface should be available + * for claim. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active + * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - another LIBUSB_ERROR code on other failure + */ + int (*detach_kernel_driver)(struct libusb_device_handle *dev_handle, + int interface_number); + + /* Attach a kernel driver to an interface. Optional. + * + * Reattach a kernel driver to the device. + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active + * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it + * was opened + * - LIBUSB_ERROR_BUSY if a program or driver has claimed the interface, + * preventing reattachment + * - another LIBUSB_ERROR code on other failure + */ + int (*attach_kernel_driver)(struct libusb_device_handle *dev_handle, + int interface_number); + + /* Destroy a device. Optional. + * + * This function is called when the last reference to a device is + * destroyed. It should free any resources allocated in the get_device_list + * path. + */ + void (*destroy_device)(struct libusb_device *dev); + + /* Submit a transfer. Your implementation should take the transfer, + * morph it into whatever form your platform requires, and submit it + * asynchronously. + * + * This function must not block. + * + * This function gets called with the flying_transfers_lock locked! + * + * Return: + * - 0 on success + * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * - another LIBUSB_ERROR code on other failure + */ + int (*submit_transfer)(struct usbi_transfer *itransfer); + + /* Cancel a previously submitted transfer. + * + * This function must not block. The transfer cancellation must complete + * later, resulting in a call to usbi_handle_transfer_cancellation() + * from the context of handle_events. + */ + int (*cancel_transfer)(struct usbi_transfer *itransfer); + + /* Clear a transfer as if it has completed or cancelled, but do not + * report any completion/cancellation to the library. You should free + * all private data from the transfer as if you were just about to report + * completion or cancellation. + * + * This function might seem a bit out of place. It is used when libusb + * detects a disconnected device - it calls this function for all pending + * transfers before reporting completion (with the disconnect code) to + * the user. Maybe we can improve upon this internal interface in future. + */ + void (*clear_transfer_priv)(struct usbi_transfer *itransfer); + + /* Handle any pending events on file descriptors. Optional. + * + * Provide this function when file descriptors directly indicate device + * or transfer activity. If your backend does not have such file descriptors, + * implement the handle_transfer_completion function below. + * + * This involves monitoring any active transfers and processing their + * completion or cancellation. + * + * The function is passed an array of pollfd structures (size nfds) + * as a result of the poll() system call. The num_ready parameter + * indicates the number of file descriptors that have reported events + * (i.e. the poll() return value). This should be enough information + * for you to determine which actions need to be taken on the currently + * active transfers. + * + * For any cancelled transfers, call usbi_handle_transfer_cancellation(). + * For completed transfers, call usbi_handle_transfer_completion(). + * For control/bulk/interrupt transfers, populate the "transferred" + * element of the appropriate usbi_transfer structure before calling the + * above functions. For isochronous transfers, populate the status and + * transferred fields of the iso packet descriptors of the transfer. + * + * This function should also be able to detect disconnection of the + * device, reporting that situation with usbi_handle_disconnect(). + * + * When processing an event related to a transfer, you probably want to + * take usbi_transfer.lock to prevent races. See the documentation for + * the usbi_transfer structure. + * + * Return 0 on success, or a LIBUSB_ERROR code on failure. + */ + int (*handle_events)(struct libusb_context *ctx, + struct pollfd *fds, POLL_NFDS_TYPE nfds, int num_ready); + + /* Handle transfer completion. Optional. + * + * Provide this function when there are no file descriptors available + * that directly indicate device or transfer activity. If your backend does + * have such file descriptors, implement the handle_events function above. + * + * Your backend must tell the library when a transfer has completed by + * calling usbi_signal_transfer_completion(). You should store any private + * information about the transfer and its completion status in the transfer's + * private backend data. + * + * During event handling, this function will be called on each transfer for + * which usbi_signal_transfer_completion() was called. + * + * For any cancelled transfers, call usbi_handle_transfer_cancellation(). + * For completed transfers, call usbi_handle_transfer_completion(). + * For control/bulk/interrupt transfers, populate the "transferred" + * element of the appropriate usbi_transfer structure before calling the + * above functions. For isochronous transfers, populate the status and + * transferred fields of the iso packet descriptors of the transfer. + * + * Return 0 on success, or a LIBUSB_ERROR code on failure. + */ + int (*handle_transfer_completion)(struct usbi_transfer *itransfer); + + /* Get time from specified clock. At least two clocks must be implemented + by the backend: USBI_CLOCK_REALTIME, and USBI_CLOCK_MONOTONIC. + + Description of clocks: + USBI_CLOCK_REALTIME : clock returns time since system epoch. + USBI_CLOCK_MONOTONIC: clock returns time since unspecified start + time (usually boot). + */ + int (*clock_gettime)(int clkid, struct timespec *tp); + +#ifdef USBI_TIMERFD_AVAILABLE + /* clock ID of the clock that should be used for timerfd */ + clockid_t (*get_timerfd_clockid)(void); +#endif + + /* Number of bytes to reserve for per-device private backend data. + * This private data area is accessible through the "os_priv" field of + * struct libusb_device. */ + size_t device_priv_size; + + /* Number of bytes to reserve for per-handle private backend data. + * This private data area is accessible through the "os_priv" field of + * struct libusb_device. */ + size_t device_handle_priv_size; + + /* Number of bytes to reserve for per-transfer private backend data. + * This private data area is accessible by calling + * usbi_transfer_get_os_priv() on the appropriate usbi_transfer instance. + */ + size_t transfer_priv_size; +}; + +extern const struct usbi_os_backend * const usbi_backend; + +extern const struct usbi_os_backend linux_usbfs_backend; +extern const struct usbi_os_backend darwin_backend; +extern const struct usbi_os_backend openbsd_backend; +extern const struct usbi_os_backend netbsd_backend; +extern const struct usbi_os_backend windows_backend; +extern const struct usbi_os_backend usbdk_backend; +extern const struct usbi_os_backend wince_backend; +extern const struct usbi_os_backend haiku_usb_raw_backend; +extern const struct usbi_os_backend sunos_backend; + +extern struct list_head active_contexts_list; +extern usbi_mutex_static_t active_contexts_lock; + +#ifdef __cplusplus +} +#endif + +#endif |