X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fusb.c;h=d66f188085c94638efea1283b4dd900d4fb9a130;hb=c2bf5506ee7864975917a7b6e7e93b78226887ce;hp=1b22de41acdb84bca86725da2f7fbdae4dbbe4b7;hpb=041b579d530af4c9bbdb534d0c932c177f1b9014;p=libsigrok.git diff --git a/src/usb.c b/src/usb.c index 1b22de41..d66f1880 100644 --- a/src/usb.c +++ b/src/usb.c @@ -3,10 +3,11 @@ * * Copyright (C) 2012 Uwe Hermann * Copyright (C) 2012 Bert Vermeulen + * Copyright (C) 2015 Daniel Elstner * - * This program is free software; you can redistribute it and/or modify + * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or + * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, @@ -15,8 +16,7 @@ * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * along with this program. If not, see . */ #include @@ -36,6 +36,264 @@ typedef int libusb_os_handle; #endif +/** Custom GLib event source for libusb I/O. + * @internal + */ +struct usb_source { + GSource base; + + int64_t timeout_us; + int64_t due_us; + + /* Needed to keep track of installed sources */ + struct sr_session *session; + + struct libusb_context *usb_ctx; + GPtrArray *pollfds; +}; + +/** USB event source prepare() method. + */ +static gboolean usb_source_prepare(GSource *source, int *timeout) +{ + int64_t now_us, usb_due_us; + struct usb_source *usource; + struct timeval usb_timeout; + int remaining_ms; + int ret; + + usource = (struct usb_source *)source; + + ret = libusb_get_next_timeout(usource->usb_ctx, &usb_timeout); + if (G_UNLIKELY(ret < 0)) { + sr_err("Failed to get libusb timeout: %s", + libusb_error_name(ret)); + } + now_us = g_source_get_time(source); + + if (usource->due_us == 0) { + /* First-time initialization of the expiration time */ + usource->due_us = now_us + usource->timeout_us; + } + if (ret == 1) { + usb_due_us = (int64_t)usb_timeout.tv_sec * G_USEC_PER_SEC + + usb_timeout.tv_usec + now_us; + if (usb_due_us < usource->due_us) + usource->due_us = usb_due_us; + } + if (usource->due_us != INT64_MAX) + remaining_ms = (MAX(0, usource->due_us - now_us) + 999) / 1000; + else + remaining_ms = -1; + + *timeout = remaining_ms; + + return (remaining_ms == 0); +} + +/** USB event source check() method. + */ +static gboolean usb_source_check(GSource *source) +{ + struct usb_source *usource; + GPollFD *pollfd; + unsigned int revents; + unsigned int i; + + usource = (struct usb_source *)source; + revents = 0; + + for (i = 0; i < usource->pollfds->len; i++) { + pollfd = g_ptr_array_index(usource->pollfds, i); + revents |= pollfd->revents; + } + return (revents != 0 || (usource->due_us != INT64_MAX + && usource->due_us <= g_source_get_time(source))); +} + +/** USB event source dispatch() method. + */ +static gboolean usb_source_dispatch(GSource *source, + GSourceFunc callback, void *user_data) +{ + struct usb_source *usource; + GPollFD *pollfd; + unsigned int revents; + unsigned int i; + gboolean keep; + + usource = (struct usb_source *)source; + revents = 0; + /* + * This is somewhat arbitrary, but drivers use revents to distinguish + * actual I/O from timeouts. When we remove the user timeout from the + * driver API, this will no longer be needed. + */ + for (i = 0; i < usource->pollfds->len; i++) { + pollfd = g_ptr_array_index(usource->pollfds, i); + revents |= pollfd->revents; + } + if (revents != 0) + sr_spew("%s: revents 0x%.2X", __func__, revents); + else + sr_spew("%s: timed out", __func__); + + if (!callback) { + sr_err("Callback not set, cannot dispatch event."); + return G_SOURCE_REMOVE; + } + keep = (*(sr_receive_data_callback)callback)(-1, revents, user_data); + + if (G_LIKELY(keep) && G_LIKELY(!g_source_is_destroyed(source))) { + if (usource->timeout_us >= 0) + usource->due_us = g_source_get_time(source) + + usource->timeout_us; + else + usource->due_us = INT64_MAX; + } + return keep; +} + +/** USB event source finalize() method. + */ +static void usb_source_finalize(GSource *source) +{ + struct usb_source *usource; + + usource = (struct usb_source *)source; + + sr_spew("%s", __func__); + + libusb_set_pollfd_notifiers(usource->usb_ctx, NULL, NULL, NULL); + + g_ptr_array_unref(usource->pollfds); + usource->pollfds = NULL; + + sr_session_source_destroyed(usource->session, + usource->usb_ctx, source); +} + +/** Callback invoked when a new libusb FD should be added to the poll set. + */ +static LIBUSB_CALL void usb_pollfd_added(libusb_os_handle fd, + short events, void *user_data) +{ + struct usb_source *usource; + GPollFD *pollfd; + + usource = user_data; + + pollfd = g_slice_new(GPollFD); +#ifdef G_OS_WIN32 + events = G_IO_IN; +#endif + pollfd->fd = (gintptr)fd; + pollfd->events = events; + pollfd->revents = 0; + + g_ptr_array_add(usource->pollfds, pollfd); + g_source_add_poll((GSource *)usource, pollfd); +} + +/** Callback invoked when a libusb FD should be removed from the poll set. + */ +static LIBUSB_CALL void usb_pollfd_removed(libusb_os_handle fd, void *user_data) +{ + struct usb_source *usource; + GPollFD *pollfd; + unsigned int i; + + usource = user_data; + + /* It's likely that the removed poll FD is at the end. + */ + for (i = usource->pollfds->len; G_LIKELY(i > 0); i--) { + pollfd = g_ptr_array_index(usource->pollfds, i - 1); + + if ((libusb_os_handle)pollfd->fd == fd) { + g_source_remove_poll((GSource *)usource, pollfd); + g_ptr_array_remove_index_fast(usource->pollfds, i - 1); + return; + } + } + sr_err("FD to be removed (%" G_GINTPTR_FORMAT + ") not found in event source poll set.", (gintptr)fd); +} + +/** Destroy notify callback for FDs maintained by the USB event source. + */ +static void usb_source_free_pollfd(void *data) +{ + g_slice_free(GPollFD, data); +} + +/** Create an event source for libusb I/O. + * + * TODO: The combination of the USB I/O source with a user timeout is + * conceptually broken. The user timeout supplied here is completely + * unrelated to I/O -- the actual I/O timeout is set when submitting + * a USB transfer. + * The sigrok drivers generally use the timeout to poll device state. + * Usually, this polling can be sensibly done only when there is no + * active USB transfer -- i.e. it's actually mutually exclusive with + * waiting for transfer completion. + * Thus, the user timeout should be removed from the USB event source + * API at some point. Instead, drivers should install separate timer + * event sources for their polling needs. + * + * @param session The session the event source belongs to. + * @param usb_ctx The libusb context for which to handle events. + * @param timeout_ms The timeout interval in ms, or -1 to wait indefinitely. + * @return A new event source object, or NULL on failure. + */ +static GSource *usb_source_new(struct sr_session *session, + struct libusb_context *usb_ctx, int timeout_ms) +{ + static GSourceFuncs usb_source_funcs = { + .prepare = &usb_source_prepare, + .check = &usb_source_check, + .dispatch = &usb_source_dispatch, + .finalize = &usb_source_finalize + }; + GSource *source; + struct usb_source *usource; + const struct libusb_pollfd **upollfds, **upfd; + + upollfds = libusb_get_pollfds(usb_ctx); + if (!upollfds) { + sr_err("Failed to get libusb file descriptors."); + return NULL; + } + source = g_source_new(&usb_source_funcs, sizeof(struct usb_source)); + usource = (struct usb_source *)source; + + g_source_set_name(source, "usb"); + + if (timeout_ms >= 0) { + usource->timeout_us = 1000 * (int64_t)timeout_ms; + usource->due_us = 0; + } else { + usource->timeout_us = -1; + usource->due_us = INT64_MAX; + } + usource->session = session; + usource->usb_ctx = usb_ctx; + usource->pollfds = g_ptr_array_new_full(8, &usb_source_free_pollfd); + + for (upfd = upollfds; *upfd != NULL; upfd++) + usb_pollfd_added((*upfd)->fd, (*upfd)->events, usource); + +#if (LIBUSB_API_VERSION >= 0x01000104) + libusb_free_pollfds(upollfds); +#else + free(upollfds); +#endif + libusb_set_pollfd_notifiers(usb_ctx, + &usb_pollfd_added, &usb_pollfd_removed, usource); + + return source; +} + /** * Find USB devices according to a connection string. * @@ -188,86 +446,27 @@ SR_PRIV void sr_usb_close(struct sr_usb_dev_inst *usb) sr_dbg("Closed USB device %d.%d.", usb->bus, usb->address); } -static LIBUSB_CALL void usb_pollfd_added(libusb_os_handle fd, - short events, void *user_data) -{ - struct sr_session *session; - gintptr tag; - - session = user_data; - tag = (gintptr)session->ctx->libusb_ctx; -#ifdef G_OS_WIN32 - events = G_IO_IN; -#endif - sr_session_source_poll_add(session, tag, (gintptr)fd, events); -} - -static LIBUSB_CALL void usb_pollfd_removed(libusb_os_handle fd, void *user_data) -{ - struct sr_session *session; - gintptr tag; - - session = user_data; - tag = (gintptr)session->ctx->libusb_ctx; - - sr_session_source_poll_remove(session, tag, (gintptr)fd); -} - SR_PRIV int usb_source_add(struct sr_session *session, struct sr_context *ctx, int timeout, sr_receive_data_callback cb, void *cb_data) { - const struct libusb_pollfd **pollfds; - gintptr tag; - int i; + GSource *source; int ret; - int events; - if (ctx->usb_source_present) { - sr_err("A USB event source is already present."); - return SR_ERR; - } - pollfds = libusb_get_pollfds(ctx->libusb_ctx); - if (!pollfds) { - sr_err("Failed to get libusb file descriptors."); + source = usb_source_new(session, ctx->libusb_ctx, timeout); + if (!source) return SR_ERR; - } - tag = (gintptr)ctx->libusb_ctx; - ret = sr_session_source_add_internal(session, - timeout, cb, cb_data, tag); - ctx->usb_source_present = (ret == SR_OK); + g_source_set_callback(source, (GSourceFunc)cb, cb_data, NULL); - for (i = 0; ret == SR_OK && pollfds[i]; ++i) { -#ifdef G_OS_WIN32 - events = G_IO_IN; -#else - events = pollfds[i]->events; -#endif - ret = sr_session_source_poll_add(session, tag, - (gintptr)pollfds[i]->fd, events); - } -#if (LIBUSB_API_VERSION >= 0x01000104) - libusb_free_pollfds(pollfds); -#else - free(pollfds); -#endif - if (ret != SR_OK) - return ret; + ret = sr_session_source_add_internal(session, ctx->libusb_ctx, source); + g_source_unref(source); - libusb_set_pollfd_notifiers(ctx->libusb_ctx, - &usb_pollfd_added, &usb_pollfd_removed, session); - - return SR_OK; + return ret; } SR_PRIV int usb_source_remove(struct sr_session *session, struct sr_context *ctx) { - ctx->usb_source_present = FALSE; - - libusb_set_pollfd_notifiers(ctx->libusb_ctx, NULL, NULL, NULL); - - return sr_session_source_remove_internal(session, - (gintptr)ctx->libusb_ctx); + return sr_session_source_remove_internal(session, ctx->libusb_ctx); } SR_PRIV int usb_get_port_path(libusb_device *dev, char *path, int path_len)