2 * This file is part of the libsigrok project.
4 * Copyright (C) 2018-2019 Gerhard Sittig <gerhard.sittig@gmx.net>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include <libsigrok/libsigrok.h>
23 #include "libsigrok-internal.h"
27 #define LOG_PREFIX "serial-bt"
29 #ifdef HAVE_SERIAL_COMM
32 #define SER_BT_CONN_PREFIX "bt"
33 #define SER_BT_CHUNK_SIZE 1200
35 #define SER_BT_PARAM_PREFIX_CHANNEL "channel="
36 #define SER_BT_PARAM_PREFIX_HDL_RX "handle_rx="
37 #define SER_BT_PARAM_PREFIX_HDL_TX "handle_tx="
38 #define SER_BT_PARAM_PREFIX_HDL_CCCD "handle_cccd="
39 #define SER_BT_PARAM_PREFIX_VAL_CCCD "value_cccd="
44 * Serial port handling, wraps the external BT/BLE dependencies.
48 * @defgroup grp_serial_bt Serial port handling, BT/BLE group
50 * Make serial-over-BT communication appear like a regular serial port.
55 /* {{{ support for serial-over-BT channels */
57 static const struct scan_supported_item {
59 enum ser_bt_conn_t type;
60 } scan_supported_items[] = {
61 /* Guess connection types from device names (useful for scans). */
62 { "121GW", SER_BT_CONN_BLE122, },
63 { "Adafruit Bluefruit LE 8134", SER_BT_CONN_NRF51, },
64 { "HC-05", SER_BT_CONN_RFCOMM, },
65 { NULL, SER_BT_CONN_UNKNOWN, },
68 static const char *ser_bt_conn_names[SER_BT_CONN_MAX] = {
69 [SER_BT_CONN_UNKNOWN] = "<type>",
70 [SER_BT_CONN_RFCOMM] = "rfcomm",
71 [SER_BT_CONN_BLE122] = "ble122",
72 [SER_BT_CONN_NRF51] = "nrf51",
73 [SER_BT_CONN_CC254x] = "cc254x",
76 static enum ser_bt_conn_t lookup_conn_name(const char *name)
82 return SER_BT_CONN_UNKNOWN;
83 idx = ARRAY_SIZE(ser_bt_conn_names);
85 item = ser_bt_conn_names[idx];
86 if (strcmp(item, name) == 0)
90 return SER_BT_CONN_UNKNOWN;
93 static const char *conn_name_text(enum ser_bt_conn_t type)
95 if (type >= ARRAY_SIZE(ser_bt_conn_names))
96 type = SER_BT_CONN_UNKNOWN;
98 return ser_bt_conn_names[type];
102 * Parse conn= specs for serial over Bluetooth communication.
104 * @param[in] serial The serial port that is about to get opened.
105 * @param[in] spec The caller provided conn= specification.
106 * @param[out] conn_type The type of BT comm (BT RFCOMM, BLE notify).
107 * @param[out] remote_addr The remote device address.
108 * @param[out] rfcomm_channel The RFCOMM channel (if applicable).
109 * @param[out] read_hdl The BLE notify read handle (if applicable).
110 * @param[out] write_hdl The BLE notify write handle (if applicable).
111 * @param[out] cccd_hdl The BLE notify CCCD handle (if applicable).
112 * @param[out] cccd_val The BLE notify CCCD value (if applicable).
114 * @return 0 upon success, non-zero upon failure.
116 * Summary of parsing rules as they are implemented:
117 * - Implementor's note: Automatic scan for available devices is not
118 * yet implemented. So strictly speaking some parts of the input
119 * spec are optional, but fallbacks may not take effect ATM.
120 * - Insist on the "bt" prefix. Accept "bt" alone without any other
122 * - The first field that follows is the connection type. Supported
123 * types are 'rfcomm', 'ble122', 'cc254x', and potentially others
124 * in a future implementation.
125 * - The next field is the remote device's address, either separated
126 * by colons or dashes or spaces, or not separated at all.
127 * - Other parameters (RFCOMM channel, notify handles and write values)
128 * get derived from the connection type. A future implementation may
129 * accept more fields, but the syntax is yet to get developed.
131 * Supported formats resulting from these rules:
135 * bt/rfcomm/11-22-33-44-55-66
136 * bt/ble122/88:6b:12:34:56:78
137 * bt/cc254x/0123456789ab
139 * It's assumed that users easily can create those conn= specs from
140 * available information, or that scan routines will create such specs
141 * that copy'n'paste results (or GUI choices from previous scan results)
142 * can get processed here.
144 static int ser_bt_parse_conn_spec(
145 struct sr_serial_dev_inst *serial, const char *spec,
146 enum ser_bt_conn_t *conn_type, const char **remote_addr,
147 size_t *rfcomm_channel,
148 uint16_t *read_hdl, uint16_t *write_hdl,
149 uint16_t *cccd_hdl, uint16_t *cccd_val)
151 char **fields, *field;
152 enum ser_bt_conn_t type;
155 size_t fields_count, field_idx;
157 unsigned long parm_val;
160 *conn_type = SER_BT_CONN_UNKNOWN;
174 if (!serial || !spec || !spec[0])
177 /* Evaluate the mandatory first three fields. */
178 fields = g_strsplit_set(spec, "/", 0);
181 if (g_strv_length(fields) < 3) {
186 if (strcmp(field, SER_BT_CONN_PREFIX) != 0) {
191 type = lookup_conn_name(field);
199 if (!field || !*field) {
203 addr = g_strdup(field);
207 /* Derive default parameters that match the connection type. */
208 /* TODO Lookup defaults from a table? */
210 case SER_BT_CONN_RFCOMM:
214 case SER_BT_CONN_BLE122:
224 case SER_BT_CONN_NRF51:
226 * Are these values appropriate? Check the learn article at
227 * https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-friend?view=all
237 /* TODO 'random' type, sec-level=high */
239 case SER_BT_CONN_CC254x:
240 /* TODO Are these values appropriate? Just guessing here. */
255 * Preset a successful return value for the conn= parse call.
256 * Scan optional additional fields which specify more params.
257 * Update the defaults which were setup above. Pessimize the
258 * routine's return value in error paths.
261 fields_count = g_strv_length(fields);
262 for (field_idx = 3; field_idx < fields_count; field_idx++) {
263 field = fields[field_idx];
264 if (!field || !*field)
266 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_CHANNEL)) {
267 field += strlen(SER_BT_PARAM_PREFIX_CHANNEL);
269 ret = sr_atoul_base(field, &parm_val, &endp, 0);
270 if (ret != SR_OK || !endp || *endp != '\0') {
271 ret_parse = SR_ERR_ARG;
275 *rfcomm_channel = parm_val;
278 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_RX)) {
279 field += strlen(SER_BT_PARAM_PREFIX_HDL_RX);
281 ret = sr_atoul_base(field, &parm_val, &endp, 0);
282 if (ret != SR_OK || !endp || *endp != '\0') {
283 ret_parse = SR_ERR_ARG;
287 *read_hdl = parm_val;
290 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_TX)) {
291 field += strlen(SER_BT_PARAM_PREFIX_HDL_TX);
293 ret = sr_atoul_base(field, &parm_val, &endp, 0);
294 if (ret != SR_OK || !endp || *endp != '\0') {
295 ret_parse = SR_ERR_ARG;
299 *write_hdl = parm_val;
302 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_CCCD)) {
303 field += strlen(SER_BT_PARAM_PREFIX_HDL_CCCD);
305 ret = sr_atoul_base(field, &parm_val, &endp, 0);
306 if (ret != SR_OK || !endp || *endp != '\0') {
307 ret_parse = SR_ERR_ARG;
311 *cccd_hdl = parm_val;
314 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_VAL_CCCD)) {
315 field += strlen(SER_BT_PARAM_PREFIX_VAL_CCCD);
317 ret = sr_atoul_base(field, &parm_val, &endp, 0);
318 if (ret != SR_OK || !endp || *endp != '\0') {
319 ret_parse = SR_ERR_ARG;
323 *cccd_val = parm_val;
333 static void ser_bt_mask_databits(struct sr_serial_dev_inst *serial,
334 uint8_t *data, size_t len)
340 if ((serial->comm_params.data_bits % 8) == 0)
343 mask32 = (1UL << serial->comm_params.data_bits) - 1;
344 mask = mask32 & 0xff;
345 for (idx = 0; idx < len; idx++)
349 static int ser_bt_data_cb(void *cb_data, uint8_t *data, size_t dlen)
351 struct sr_serial_dev_inst *serial;
357 ser_bt_mask_databits(serial, data, dlen);
358 sr_ser_queue_rx_data(serial, data, dlen);
364 /* {{{ wrap serial-over-BT operations in a common serial.c API */
366 /* See if a serial port's name refers to a BT type. */
367 SR_PRIV int ser_name_is_bt(struct sr_serial_dev_inst *serial)
374 if (!serial->port || !*serial->port)
377 /* Accept either "bt" alone, or "bt/" as a prefix. */
378 if (!g_str_has_prefix(serial->port, SER_BT_CONN_PREFIX))
380 off = strlen(SER_BT_CONN_PREFIX);
381 sep = serial->port[off];
382 if (sep != '\0' && sep != '/')
388 /* The open() wrapper for BT ports. */
389 static int ser_bt_open(struct sr_serial_dev_inst *serial, int flags)
391 enum ser_bt_conn_t conn_type;
392 const char *remote_addr;
393 size_t rfcomm_channel;
394 uint16_t read_hdl, write_hdl, cccd_hdl, cccd_val;
396 struct sr_bt_desc *desc;
400 /* Derive BT specific parameters from the port spec. */
401 rc = ser_bt_parse_conn_spec(serial, serial->port,
402 &conn_type, &remote_addr,
404 &read_hdl, &write_hdl,
405 &cccd_hdl, &cccd_val);
409 if (!conn_type || !remote_addr || !remote_addr[0]) {
410 /* TODO Auto-search for available connections? */
414 /* Create the connection. Only store params after successful use. */
415 desc = sr_bt_desc_new();
418 serial->bt_desc = desc;
419 rc = sr_bt_config_addr_remote(desc, remote_addr);
422 serial->bt_addr_remote = g_strdup(remote_addr);
424 case SER_BT_CONN_RFCOMM:
425 rc = sr_bt_config_rfcomm(desc, rfcomm_channel);
428 serial->bt_rfcomm_channel = rfcomm_channel;
430 case SER_BT_CONN_BLE122:
431 case SER_BT_CONN_NRF51:
432 case SER_BT_CONN_CC254x:
433 rc = sr_bt_config_notify(desc,
434 read_hdl, write_hdl, cccd_hdl, cccd_val);
437 serial->bt_notify_handle_read = read_hdl;
438 serial->bt_notify_handle_write = write_hdl;
439 serial->bt_notify_handle_cccd = cccd_hdl;
440 serial->bt_notify_value_cccd = cccd_val;
443 /* Unsupported type, or incomplete implementation. */
446 serial->bt_conn_type = conn_type;
448 /* Make sure the receive buffer can accept input data. */
449 if (!serial->rcv_buffer)
450 serial->rcv_buffer = g_string_sized_new(SER_BT_CHUNK_SIZE);
451 rc = sr_bt_config_cb_data(desc, ser_bt_data_cb, serial);
455 /* Open the connection. */
457 case SER_BT_CONN_RFCOMM:
458 rc = sr_bt_connect_rfcomm(desc);
462 case SER_BT_CONN_BLE122:
463 case SER_BT_CONN_NRF51:
464 case SER_BT_CONN_CC254x:
465 rc = sr_bt_connect_ble(desc);
468 rc = sr_bt_start_notify(desc);
479 static int ser_bt_close(struct sr_serial_dev_inst *serial)
484 if (!serial->bt_desc)
487 sr_bt_disconnect(serial->bt_desc);
488 sr_bt_desc_free(serial->bt_desc);
489 serial->bt_desc = NULL;
491 g_free(serial->bt_addr_local);
492 serial->bt_addr_local = NULL;
493 g_free(serial->bt_addr_remote);
494 serial->bt_addr_remote = NULL;
495 g_slist_free_full(serial->bt_source_args, g_free);
496 serial->bt_source_args = NULL;
501 /* Flush, discards pending RX data, empties buffers. */
502 static int ser_bt_flush(struct sr_serial_dev_inst *serial)
510 /* Drain, waits for completion of pending TX data. */
511 static int ser_bt_drain(struct sr_serial_dev_inst *serial)
514 /* EMPTY */ /* TODO? */
519 static int ser_bt_write(struct sr_serial_dev_inst *serial,
520 const void *buf, size_t count,
521 int nonblocking, unsigned int timeout_ms)
526 * TODO Support chunked transmission when callers' requests
527 * exceed the BT channel's capacity? See ser_hid_write().
530 switch (serial->bt_conn_type) {
531 case SER_BT_CONN_RFCOMM:
534 wrlen = sr_bt_write(serial->bt_desc, buf, count);
538 case SER_BT_CONN_BLE122:
539 case SER_BT_CONN_NRF51:
540 case SER_BT_CONN_CC254x:
542 * Assume that when applications call the serial layer's
543 * write routine, then the BLE chip/module does support
544 * a TX handle. Just call the serial-BT library's write
549 wrlen = sr_bt_write(serial->bt_desc, buf, count);
559 static int ser_bt_read(struct sr_serial_dev_inst *serial,
560 void *buf, size_t count,
561 int nonblocking, unsigned int timeout_ms)
563 gint64 deadline_us, now_us;
564 uint8_t buffer[SER_BT_CHUNK_SIZE];
570 * Immediately satisfy the caller's request from the RX buffer
571 * if the requested amount of data is available already.
573 if (sr_ser_has_queued_data(serial) >= count)
574 return sr_ser_unqueue_rx_data(serial, buf, count);
577 * When a timeout was specified, then determine the deadline
578 * where to stop reception.
582 now_us = g_get_monotonic_time();
583 deadline_us = now_us + timeout_ms * 1000;
587 * Keep receiving from the port until the caller's requested
588 * amount of data has become available, or the timeout has
589 * expired. In the absence of a timeout, stop reading when an
590 * attempt no longer yields receive data.
593 /* Run another attempt to receive data. */
594 switch (serial->bt_conn_type) {
595 case SER_BT_CONN_RFCOMM:
596 rdlen = sr_bt_read(serial->bt_desc, buffer, sizeof(buffer));
599 rc = ser_bt_data_cb(serial, buffer, rdlen);
603 case SER_BT_CONN_BLE122:
604 case SER_BT_CONN_NRF51:
605 case SER_BT_CONN_CC254x:
606 dlen = sr_ser_has_queued_data(serial);
607 rc = sr_bt_check_notify(serial->bt_desc);
610 else if (sr_ser_has_queued_data(serial) != dlen)
621 * Stop upon receive errors, or timeout expiration. Only
622 * stop upon empty reception in the absence of a timeout.
626 if (nonblocking && !rdlen)
629 now_us = g_get_monotonic_time();
630 if (now_us > deadline_us)
634 /* Also stop when sufficient data has become available. */
635 if (sr_ser_has_queued_data(serial) >= count)
640 * Satisfy the caller's demand for receive data from previously
641 * queued incoming data.
643 dlen = sr_ser_has_queued_data(serial);
649 return sr_ser_unqueue_rx_data(serial, buf, dlen);
652 struct bt_source_args_t {
653 /* The application callback. */
654 sr_receive_data_callback cb;
656 /* The serial device, to store RX data. */
657 struct sr_serial_dev_inst *serial;
661 * Gets periodically invoked by the glib main loop. "Drives" (checks)
662 * progress of BT communication, and invokes the application's callback
663 * which processes RX data (when some has become available), as well as
664 * handles application level timeouts.
666 static int bt_source_cb(int fd, int revents, void *cb_data)
668 struct bt_source_args_t *args;
669 struct sr_serial_dev_inst *serial;
670 uint8_t rx_buf[SER_BT_CHUNK_SIZE];
678 serial = args->serial;
681 if (!serial->bt_conn_type)
685 * Drain receive data which the channel might have pending.
686 * This is "a copy" of the "background part" of ser_bt_read(),
687 * without the timeout support code, and not knowing how much
688 * data the application is expecting.
691 switch (serial->bt_conn_type) {
692 case SER_BT_CONN_RFCOMM:
693 rdlen = sr_bt_read(serial->bt_desc, rx_buf, sizeof(rx_buf));
696 rc = ser_bt_data_cb(serial, rx_buf, rdlen);
700 case SER_BT_CONN_BLE122:
701 case SER_BT_CONN_NRF51:
702 case SER_BT_CONN_CC254x:
703 dlen = sr_ser_has_queued_data(serial);
704 rc = sr_bt_check_notify(serial->bt_desc);
707 else if (sr_ser_has_queued_data(serial) != dlen)
719 * When RX data became available (now or earlier), pass this
720 * condition to the application callback. Always periodically
721 * run the application callback, since it handles timeouts and
722 * might carry out other tasks as well like signalling progress.
724 if (sr_ser_has_queued_data(args->serial))
726 rc = args->cb(fd, revents, args->cb_data);
731 /* TODO Can we use the Bluetooth socket's file descriptor? Probably not portably. */
732 #define WITH_MAXIMUM_TIMEOUT_VALUE 0
733 static int ser_bt_setup_source_add(struct sr_session *session,
734 struct sr_serial_dev_inst *serial,
735 int events, int timeout,
736 sr_receive_data_callback cb, void *cb_data)
738 struct bt_source_args_t *args;
743 /* Optionally enforce a minimum poll period. */
744 if (WITH_MAXIMUM_TIMEOUT_VALUE && timeout > WITH_MAXIMUM_TIMEOUT_VALUE)
745 timeout = WITH_MAXIMUM_TIMEOUT_VALUE;
747 /* Allocate status container for background data reception. */
748 args = g_malloc0(sizeof(*args));
750 args->cb_data = cb_data;
751 args->serial = serial;
754 * Have a periodic timer installed. Register the allocated block
755 * with the serial device, since the GSource's finalizer won't
756 * free the memory, and we haven't bothered to create a custom
757 * BT specific GSource.
759 rc = sr_session_source_add(session, -1, events, timeout, bt_source_cb, args);
764 serial->bt_source_args = g_slist_append(serial->bt_source_args, args);
769 static int ser_bt_setup_source_remove(struct sr_session *session,
770 struct sr_serial_dev_inst *serial)
774 (void)sr_session_source_remove(session, -1);
775 /* Release callback args here already? */
780 static enum ser_bt_conn_t scan_is_supported(const char *name)
783 const struct scan_supported_item *item;
785 for (idx = 0; idx < ARRAY_SIZE(scan_supported_items); idx++) {
786 item = &scan_supported_items[idx];
789 if (strcmp(name, item->name) != 0)
794 return SER_BT_CONN_UNKNOWN;
797 struct bt_scan_args_t {
799 sr_ser_list_append_t append;
804 static void scan_cb(void *cb_args, const char *addr, const char *name)
806 struct bt_scan_args_t *scan_args;
809 enum ser_bt_conn_t type;
810 char *port_name, *port_desc;
816 sr_info("BT scan, found: %s - %s\n", addr, name);
818 /* Check whether the device was seen before. */
819 for (l = scan_args->addr_list; l; l = l->next) {
820 if (strcmp(addr, l->data) == 0)
824 /* Substitute colons in the address by dashes. */
827 snprintf(addr_text, sizeof(addr_text), "%s", addr);
828 g_strcanon(addr_text, "0123456789abcdefABCDEF", '-');
830 /* Create a port name, and a description. */
831 type = scan_is_supported(name);
832 port_name = g_strdup_printf("%s/%s/%s",
833 SER_BT_CONN_PREFIX, conn_name_text(type), addr_text);
834 port_desc = g_strdup_printf("%s (%s)", name, scan_args->bt_type);
836 scan_args->port_list = scan_args->append(scan_args->port_list, port_name, port_desc);
840 /* Keep track of the handled address. */
841 addr_copy = g_strdup(addr);
842 scan_args->addr_list = g_slist_append(scan_args->addr_list, addr_copy);
845 static GSList *ser_bt_list(GSList *list, sr_ser_list_append_t append)
847 static const int scan_duration = 2;
849 struct bt_scan_args_t scan_args;
850 struct sr_bt_desc *desc;
853 * Implementor's note: This "list" routine is best-effort. We
854 * assume that registering callbacks always succeeds. Silently
855 * ignore failure to scan for devices. Just return those which
859 desc = sr_bt_desc_new();
863 memset(&scan_args, 0, sizeof(scan_args));
864 scan_args.port_list = list;
865 scan_args.append = append;
867 scan_args.addr_list = NULL;
868 scan_args.bt_type = "BT";
869 (void)sr_bt_config_cb_scan(desc, scan_cb, &scan_args);
870 (void)sr_bt_scan_bt(desc, scan_duration);
871 g_slist_free_full(scan_args.addr_list, g_free);
873 scan_args.addr_list = NULL;
874 scan_args.bt_type = "BLE";
875 (void)sr_bt_config_cb_scan(desc, scan_cb, &scan_args);
876 (void)sr_bt_scan_le(desc, scan_duration);
877 g_slist_free_full(scan_args.addr_list, g_free);
879 sr_bt_desc_free(desc);
881 return scan_args.port_list;
884 static struct ser_lib_functions serlib_bt = {
886 .close = ser_bt_close,
887 .flush = ser_bt_flush,
888 .drain = ser_bt_drain,
889 .write = ser_bt_write,
892 * Bluetooth communication has no concept of bitrate, so ignore
893 * these arguments silently. Neither need we pass the frame format
894 * down to internal BT comm routines, nor need we keep the values
895 * here, since the caller will cache/register them already.
897 .set_params = std_dummy_set_params,
898 .set_handshake = std_dummy_set_handshake,
899 .setup_source_add = ser_bt_setup_source_add,
900 .setup_source_remove = ser_bt_setup_source_remove,
902 .get_frame_format = NULL,
904 SR_PRIV struct ser_lib_functions *ser_lib_funcs_bt = &serlib_bt;
909 SR_PRIV int ser_name_is_bt(struct sr_serial_dev_inst *serial)
916 SR_PRIV struct ser_lib_functions *ser_lib_funcs_bt = NULL;