libsigrok  0.5.2
sigrok hardware access and backend library
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serial_hid_bu86x.c
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1 /*
2  * This file is part of the libsigrok project.
3  *
4  * Copyright (C) 2019 Gerhard Sittig <gerhard.sittig@gmx.net>
5  *
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.
10  *
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.
15  *
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/>.
18  */
19 
20 /*
21  * This implements serial communication primitives for the Brymen BU-86X
22  * infrared adapter for handheld multimeters. The vendor's protocol spec
23  * http://brymen.com/product-html/images/DownloadList/ProtocolList/BM860-BM860s_List/BM860-BM860s-500000-count-dual-display-DMMs-protocol.pdf
24  * suggests that HID reports get communicated, but only report number 0
25  * is involved, which carries a mere byte stream in 8 byte chunks each.
26  * The frame format and bitrate are fixed, and need not get configured.
27  *
28  * The meter's packet consists of 24 bytes which get received in three
29  * HID reports. Packet reception gets initiated by sending a short HID
30  * report to the meter. It's uncertain which parts of this exchange are
31  * specific to the adapter and to the meter. Using the IR adapter with
32  * other devices, or using the meter with other cables/adapters may need
33  * a little more adjustment with respect to layering.
34  */
35 
36 #include <config.h>
37 #include <glib.h>
38 #include <libsigrok/libsigrok.h>
39 #include "libsigrok-internal.h"
40 #include "serial_hid.h"
41 #include <string.h>
42 
43 /** @cond PRIVATE */
44 #define LOG_PREFIX "serial-bu86x"
45 /** @endcond */
46 
47 #ifdef HAVE_SERIAL_COMM
48 #ifdef HAVE_LIBHIDAPI
49 
50 /**
51  * @file
52  *
53  * Support serial-over-HID, specifically the Brymen BU-86X infrared adapter.
54  */
55 
56 #define BU86X_MAX_BYTES_PER_REQUEST 8
57 
58 static const struct vid_pid_item vid_pid_items_bu86x[] = {
59  { 0x0820, 0x0001, },
60  ALL_ZERO
61 };
62 
63 static int bu86x_read_bytes(struct sr_serial_dev_inst *serial,
64  uint8_t *data, int space, unsigned int timeout)
65 {
66  int rc;
67 
68  if (space > BU86X_MAX_BYTES_PER_REQUEST)
69  space = BU86X_MAX_BYTES_PER_REQUEST;
70  rc = ser_hid_hidapi_get_data(serial, 0, data, space, timeout);
71  if (rc == SR_ERR_TIMEOUT)
72  return 0;
73  if (rc < 0)
74  return rc;
75  if (rc == 0)
76  return 0;
77  return rc;
78 }
79 
80 static int bu86x_write_bytes(struct sr_serial_dev_inst *serial,
81  const uint8_t *data, int size)
82 {
83  return ser_hid_hidapi_set_data(serial, 0, data, size, 0);
84 }
85 
86 static struct ser_hid_chip_functions chip_bu86x = {
87  .chipname = "bu86x",
88  .chipdesc = "Brymen BU-86X",
89  .vid_pid_items = vid_pid_items_bu86x,
90  .max_bytes_per_request = BU86X_MAX_BYTES_PER_REQUEST,
91  /*
92  * The IR adapter's communication parameters are fixed and need
93  * not get configured. Just silently ignore the caller's spec.
94  */
95  .set_params = std_dummy_set_params,
96  .read_bytes = bu86x_read_bytes,
97  .write_bytes = bu86x_write_bytes,
98 };
99 SR_PRIV struct ser_hid_chip_functions *ser_hid_chip_funcs_bu86x = &chip_bu86x;
100 
101 #else
102 
103 SR_PRIV struct ser_hid_chip_functions *ser_hid_chip_funcs_bu86x = NULL;
104 
105 #endif
106 #endif
SR_PRIV int ser_hid_hidapi_set_data(struct sr_serial_dev_inst *serial, uint8_t ep, const uint8_t *data, size_t len, int timeout)
The public libsigrok header file to be used by frontends.
#define SR_PRIV
Definition: libsigrok.h:128
A timeout occurred.
Definition: libsigrok.h:75
SR_PRIV int ser_hid_hidapi_get_data(struct sr_serial_dev_inst *serial, uint8_t ep, uint8_t *data, size_t len, int timeout)