]> sigrok.org Git - libsigrok.git/blame_incremental - src/hardware/uni-t-dmm/protocol.c
Document if or why sometimes digits/spec_digits is 0.
[libsigrok.git] / src / hardware / uni-t-dmm / protocol.c
... / ...
CommitLineData
1/*
2 * This file is part of the libsigrok project.
3 *
4 * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
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 2 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, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include <config.h>
22#include <string.h>
23#include <glib.h>
24#include <libsigrok/libsigrok.h>
25#include "libsigrok-internal.h"
26#include "protocol.h"
27
28/*
29 * Driver for various UNI-T multimeters (and rebranded ones).
30 *
31 * Most UNI-T DMMs can be used with two (three) different PC interface cables:
32 * - The UT-D04 USB/HID cable, old version with Hoitek HE2325U chip.
33 * - The UT-D04 USB/HID cable, new version with WCH CH9325 chip.
34 * - The UT-D02 RS232 cable.
35 *
36 * This driver is meant to support all USB/HID cables, and various DMMs that
37 * can be attached to a PC via these cables. Currently only the UT-D04 cable
38 * (new version) is supported/tested.
39 * The UT-D02 RS232 cable is handled by the 'serial-dmm' driver.
40 *
41 * The data for one DMM packet (e.g. 14 bytes if the respective DMM uses a
42 * Fortune Semiconductor FS9922-DMM4 chip) is spread across multiple
43 * 8-byte chunks.
44 *
45 * An 8-byte chunk looks like this:
46 * - Byte 0: 0xfz, where z is the number of actual data bytes in this chunk.
47 * - Bytes 1-7: z data bytes, the rest of the bytes should be ignored.
48 *
49 * Example:
50 * f0 00 00 00 00 00 00 00 (no data bytes)
51 * f2 55 77 00 00 00 00 00 (2 data bytes, 0x55 and 0x77)
52 * f1 d1 00 00 00 00 00 00 (1 data byte, 0xd1)
53 */
54
55static void decode_packet(struct sr_dev_inst *sdi, const uint8_t *buf)
56{
57 struct dev_context *devc;
58 struct dmm_info *dmm;
59 struct sr_datafeed_packet packet;
60 struct sr_datafeed_analog analog;
61 struct sr_analog_encoding encoding;
62 struct sr_analog_meaning meaning;
63 struct sr_analog_spec spec;
64 float floatval;
65 void *info;
66 int ret;
67
68 devc = sdi->priv;
69 dmm = (struct dmm_info *)sdi->driver;
70 /* Note: digits/spec_digits will be overridden by the DMM parsers. */
71 sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
72 info = g_malloc(dmm->info_size);
73
74 /* Parse the protocol packet. */
75 ret = dmm->packet_parse(buf, &floatval, &analog, info);
76 if (ret != SR_OK) {
77 sr_dbg("Invalid DMM packet, ignoring.");
78 g_free(info);
79 return;
80 }
81
82 /* If this DMM needs additional handling, call the resp. function. */
83 if (dmm->dmm_details)
84 dmm->dmm_details(&analog, info);
85
86 g_free(info);
87
88 /* Send a sample packet with one analog value. */
89 analog.meaning->channels = sdi->channels;
90 analog.num_samples = 1;
91 analog.data = &floatval;
92 packet.type = SR_DF_ANALOG;
93 packet.payload = &analog;
94 sr_session_send(sdi, &packet);
95
96 sr_sw_limits_update_samples_read(&devc->limits, 1);
97}
98
99static int hid_chip_init(struct sr_dev_inst *sdi, uint16_t baudrate)
100{
101 int ret;
102 uint8_t buf[5];
103 struct sr_usb_dev_inst *usb;
104
105 usb = sdi->conn;
106
107 /* Detach kernel drivers which grabbed this device (if any). */
108 if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
109 ret = libusb_detach_kernel_driver(usb->devhdl, 0);
110 if (ret < 0) {
111 sr_err("Failed to detach kernel driver: %s.",
112 libusb_error_name(ret));
113 return SR_ERR;
114 }
115 sr_dbg("Successfully detached kernel driver.");
116 } else {
117 sr_dbg("No need to detach a kernel driver.");
118 }
119
120 /* Claim interface 0. */
121 if ((ret = libusb_claim_interface(usb->devhdl, 0)) < 0) {
122 sr_err("Failed to claim interface 0: %s.",
123 libusb_error_name(ret));
124 return SR_ERR;
125 }
126 sr_dbg("Successfully claimed interface 0.");
127
128 /* Set data for the HID feature report (e.g. baudrate). */
129 buf[0] = baudrate & 0xff; /* Baudrate, LSB */
130 buf[1] = (baudrate >> 8) & 0xff; /* Baudrate, MSB */
131 buf[2] = 0x00; /* Unknown/unused (?) */
132 buf[3] = 0x00; /* Unknown/unused (?) */
133 buf[4] = 0x03; /* Unknown, always 0x03. */
134
135 /* Send HID feature report to setup the baudrate/chip. */
136 sr_dbg("Sending initial HID feature report.");
137 sr_spew("HID init = 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x (%d baud)",
138 buf[0], buf[1], buf[2], buf[3], buf[4], baudrate);
139 ret = libusb_control_transfer(
140 usb->devhdl, /* libusb device handle */
141 LIBUSB_REQUEST_TYPE_CLASS |
142 LIBUSB_RECIPIENT_INTERFACE |
143 LIBUSB_ENDPOINT_OUT,
144 9, /* bRequest: HID set_report */
145 0x300, /* wValue: HID feature, report number 0 */
146 0, /* wIndex: interface 0 */
147 (unsigned char *)&buf, /* payload buffer */
148 5, /* wLength: 5 bytes payload */
149 1000 /* timeout (ms) */);
150
151 if (ret < 0) {
152 sr_err("HID feature report error: %s.", libusb_error_name(ret));
153 return SR_ERR;
154 }
155
156 if (ret != 5) {
157 /* TODO: Handle better by also sending the remaining bytes. */
158 sr_err("Short packet: sent %d/5 bytes.", ret);
159 return SR_ERR;
160 }
161
162 sr_dbg("Successfully sent initial HID feature report.");
163
164 return SR_OK;
165}
166
167static void log_8byte_chunk(const uint8_t *buf)
168{
169 sr_spew("8-byte chunk: %02x %02x %02x %02x %02x %02x %02x %02x "
170 "(%d data bytes)", buf[0], buf[1], buf[2], buf[3],
171 buf[4], buf[5], buf[6], buf[7], (buf[0] & 0x0f));
172}
173
174static void log_dmm_packet(const uint8_t *buf)
175{
176 sr_dbg("DMM packet: %02x %02x %02x %02x %02x %02x %02x"
177 " %02x %02x %02x %02x %02x %02x %02x",
178 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
179 buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13]);
180}
181
182static int get_and_handle_data(struct sr_dev_inst *sdi)
183{
184 struct dev_context *devc;
185 struct dmm_info *dmm;
186 uint8_t buf[CHUNK_SIZE], *pbuf;
187 int i, ret, len, num_databytes_in_chunk;
188 struct sr_usb_dev_inst *usb;
189
190 devc = sdi->priv;
191 dmm = (struct dmm_info *)sdi->driver;
192 usb = sdi->conn;
193 pbuf = devc->protocol_buf;
194
195 /* On the first run, we need to init the HID chip. */
196 if (devc->first_run) {
197 if ((ret = hid_chip_init(sdi, dmm->baudrate)) != SR_OK) {
198 sr_err("HID chip init failed: %d.", ret);
199 return SR_ERR;
200 }
201 memset(pbuf, 0x00, DMM_BUFSIZE);
202 devc->first_run = FALSE;
203 }
204
205 memset(&buf, 0x00, CHUNK_SIZE);
206
207 /* Get data from EP2 using an interrupt transfer. */
208 ret = libusb_interrupt_transfer(
209 usb->devhdl, /* libusb device handle */
210 LIBUSB_ENDPOINT_IN | 2, /* EP2, IN */
211 (unsigned char *)&buf, /* receive buffer */
212 CHUNK_SIZE, /* wLength */
213 &len, /* actually received byte count */
214 1000 /* timeout (ms) */);
215
216 if (ret < 0) {
217 sr_err("USB receive error: %s.", libusb_error_name(ret));
218 return SR_ERR;
219 }
220
221 if (len != CHUNK_SIZE) {
222 sr_err("Short packet: received %d/%d bytes.", len, CHUNK_SIZE);
223 /* TODO: Print the bytes? */
224 return SR_ERR;
225 }
226
227 log_8byte_chunk((const uint8_t *)&buf);
228
229 /* If there are no data bytes just return (without error). */
230 if (buf[0] == 0xf0)
231 return SR_OK;
232
233 devc->bufoffset = 0;
234
235 /*
236 * Append the 1-7 data bytes of this chunk to pbuf.
237 *
238 * Special case:
239 * DMMs with Cyrustek ES51922 chip and UT71x DMMs need serial settings
240 * of 7o1. The WCH CH9325 UART to USB/HID chip used in (some
241 * versions of) the UNI-T UT-D04 cable however, will also send
242 * the parity bit to the host in the 8-byte data chunks. This bit
243 * is encoded in bit 7 of each of the 1-7 data bytes and must thus
244 * be removed in order for the actual protocol parser to work properly.
245 */
246 num_databytes_in_chunk = buf[0] & 0x0f;
247 for (i = 0; i < num_databytes_in_chunk; i++, devc->buflen++) {
248 pbuf[devc->buflen] = buf[1 + i];
249 if ((dmm->packet_parse == sr_es519xx_19200_14b_parse) ||
250 (dmm->packet_parse == sr_ut71x_parse)) {
251 /* Mask off the parity bit. */
252 pbuf[devc->buflen] &= ~(1 << 7);
253 }
254 }
255
256 /* Now look for packets in that data. */
257 while ((devc->buflen - devc->bufoffset) >= dmm->packet_size) {
258 if (dmm->packet_valid(pbuf + devc->bufoffset)) {
259 log_dmm_packet(pbuf + devc->bufoffset);
260 decode_packet(sdi, pbuf + devc->bufoffset);
261 devc->bufoffset += dmm->packet_size;
262 } else {
263 devc->bufoffset++;
264 }
265 }
266
267 /* Move remaining bytes to beginning of buffer. */
268 for (i = 0; i < devc->buflen - devc->bufoffset; i++)
269 pbuf[i] = pbuf[devc->bufoffset + i];
270 devc->buflen -= devc->bufoffset;
271
272 return SR_OK;
273}
274
275SR_PRIV int uni_t_dmm_receive_data(int fd, int revents, void *cb_data)
276{
277 int ret;
278 struct sr_dev_inst *sdi;
279 struct dev_context *devc;
280
281 (void)fd;
282 (void)revents;
283
284 sdi = cb_data;
285 devc = sdi->priv;
286
287 if ((ret = get_and_handle_data(sdi)) != SR_OK)
288 return FALSE;
289
290 /* Abort acquisition if we acquired enough samples. */
291 if (sr_sw_limits_check(&devc->limits))
292 sdi->driver->dev_acquisition_stop(sdi);
293
294 return TRUE;
295}