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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, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <config.h>
21#include <string.h>
22#include <glib.h>
23#include <libsigrok/libsigrok.h>
24#include "libsigrok-internal.h"
25#include "protocol.h"
26
27/*
28 * Driver for various UNI-T multimeters (and rebranded ones).
29 *
30 * Most UNI-T DMMs can be used with two (three) different PC interface cables:
31 * - The UT-D04 USB/HID cable, old version with Hoitek HE2325U chip.
32 * - The UT-D04 USB/HID cable, new version with WCH CH9325 chip.
33 * - The UT-D02 RS232 cable.
34 *
35 * This driver is meant to support all USB/HID cables, and various DMMs that
36 * can be attached to a PC via these cables. Currently only the UT-D04 cable
37 * (new version) is supported/tested.
38 * The UT-D02 RS232 cable is handled by the 'serial-dmm' driver.
39 *
40 * The data for one DMM packet (e.g. 14 bytes if the respective DMM uses a
41 * Fortune Semiconductor FS9922-DMM4 chip) is spread across multiple
42 * 8-byte chunks.
43 *
44 * An 8-byte chunk looks like this:
45 * - Byte 0: 0xfz, where z is the number of actual data bytes in this chunk.
46 * - Bytes 1-7: z data bytes, the rest of the bytes should be ignored.
47 *
48 * Example:
49 * f0 00 00 00 00 00 00 00 (no data bytes)
50 * f2 55 77 00 00 00 00 00 (2 data bytes, 0x55 and 0x77)
51 * f1 d1 00 00 00 00 00 00 (1 data byte, 0xd1)
52 */
53
54static void decode_packet(struct sr_dev_inst *sdi, const uint8_t *buf)
55{
56 struct dev_context *devc;
57 struct dmm_info *dmm;
58 struct sr_datafeed_packet packet;
59 struct sr_datafeed_analog analog;
60 struct sr_analog_encoding encoding;
61 struct sr_analog_meaning meaning;
62 struct sr_analog_spec spec;
63 float floatval;
64 void *info;
65 int ret;
66
67 devc = sdi->priv;
68 dmm = (struct dmm_info *)sdi->driver;
69 /* Note: digits/spec_digits will be overridden by the DMM parsers. */
70 sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
71 info = g_malloc(dmm->info_size);
72
73 /* Parse the protocol packet. */
74 ret = dmm->packet_parse(buf, &floatval, &analog, info);
75 if (ret != SR_OK) {
76 sr_dbg("Invalid DMM packet, ignoring.");
77 g_free(info);
78 return;
79 }
80
81 /* If this DMM needs additional handling, call the resp. function. */
82 if (dmm->dmm_details)
83 dmm->dmm_details(&analog, info);
84
85 g_free(info);
86
87 /* Send a sample packet with one analog value. */
88 analog.meaning->channels = sdi->channels;
89 analog.num_samples = 1;
90 analog.data = &floatval;
91 packet.type = SR_DF_ANALOG;
92 packet.payload = &analog;
93 sr_session_send(sdi, &packet);
94
95 sr_sw_limits_update_samples_read(&devc->limits, 1);
96}
97
98static int hid_chip_init(struct sr_dev_inst *sdi, uint16_t baudrate)
99{
100 int ret;
101 uint8_t buf[5];
102 struct sr_usb_dev_inst *usb;
103
104 usb = sdi->conn;
105
106 /* Detach kernel drivers which grabbed this device (if any). */
107 if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
108 ret = libusb_detach_kernel_driver(usb->devhdl, 0);
109 if (ret < 0) {
110 sr_err("Failed to detach kernel driver: %s.",
111 libusb_error_name(ret));
112 return SR_ERR;
113 }
114 sr_dbg("Successfully detached kernel driver.");
115 } else {
116 sr_dbg("No need to detach a kernel driver.");
117 }
118
119 /* Claim interface 0. */
120 if ((ret = libusb_claim_interface(usb->devhdl, 0)) < 0) {
121 sr_err("Failed to claim interface 0: %s.",
122 libusb_error_name(ret));
123 return SR_ERR;
124 }
125 sr_dbg("Successfully claimed interface 0.");
126
127 /* Set data for the HID feature report (e.g. baudrate). */
128 buf[0] = baudrate & 0xff; /* Baudrate, LSB */
129 buf[1] = (baudrate >> 8) & 0xff; /* Baudrate, MSB */
130 buf[2] = 0x00; /* Unknown/unused (?) */
131 buf[3] = 0x00; /* Unknown/unused (?) */
132 buf[4] = 0x03; /* Unknown, always 0x03. */
133
134 /* Send HID feature report to setup the baudrate/chip. */
135 sr_dbg("Sending initial HID feature report.");
136 sr_spew("HID init = 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x (%d baud)",
137 buf[0], buf[1], buf[2], buf[3], buf[4], baudrate);
138 ret = libusb_control_transfer(
139 usb->devhdl, /* libusb device handle */
140 LIBUSB_REQUEST_TYPE_CLASS |
141 LIBUSB_RECIPIENT_INTERFACE |
142 LIBUSB_ENDPOINT_OUT,
143 9, /* bRequest: HID set_report */
144 0x300, /* wValue: HID feature, report number 0 */
145 0, /* wIndex: interface 0 */
146 (unsigned char *)&buf, /* payload buffer */
147 5, /* wLength: 5 bytes payload */
148 1000 /* timeout (ms) */);
149
150 if (ret < 0) {
151 sr_err("HID feature report error: %s.", libusb_error_name(ret));
152 return SR_ERR;
153 }
154
155 if (ret != 5) {
156 /* TODO: Handle better by also sending the remaining bytes. */
157 sr_err("Short packet: sent %d/5 bytes.", ret);
158 return SR_ERR;
159 }
160
161 sr_dbg("Successfully sent initial HID feature report.");
162
163 return SR_OK;
164}
165
166static void log_8byte_chunk(const uint8_t *buf)
167{
168 sr_spew("8-byte chunk: %02x %02x %02x %02x %02x %02x %02x %02x "
169 "(%d data bytes)", buf[0], buf[1], buf[2], buf[3],
170 buf[4], buf[5], buf[6], buf[7], (buf[0] & 0x0f));
171}
172
173static void log_dmm_packet(const uint8_t *buf)
174{
175 sr_dbg("DMM packet: %02x %02x %02x %02x %02x %02x %02x"
176 " %02x %02x %02x %02x %02x %02x %02x",
177 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
178 buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13]);
179}
180
181static int get_and_handle_data(struct sr_dev_inst *sdi)
182{
183 struct dev_context *devc;
184 struct dmm_info *dmm;
185 uint8_t buf[CHUNK_SIZE], *pbuf;
186 int i, ret, len, num_databytes_in_chunk;
187 struct sr_usb_dev_inst *usb;
188
189 devc = sdi->priv;
190 dmm = (struct dmm_info *)sdi->driver;
191 usb = sdi->conn;
192 pbuf = devc->protocol_buf;
193
194 /* On the first run, we need to init the HID chip. */
195 if (devc->first_run) {
196 if ((ret = hid_chip_init(sdi, dmm->baudrate)) != SR_OK) {
197 sr_err("HID chip init failed: %d.", ret);
198 return SR_ERR;
199 }
200 memset(pbuf, 0x00, DMM_BUFSIZE);
201 devc->first_run = FALSE;
202 }
203
204 memset(&buf, 0x00, CHUNK_SIZE);
205
206 /* Get data from EP2 using an interrupt transfer. */
207 ret = libusb_interrupt_transfer(
208 usb->devhdl, /* libusb device handle */
209 LIBUSB_ENDPOINT_IN | 2, /* EP2, IN */
210 (unsigned char *)&buf, /* receive buffer */
211 CHUNK_SIZE, /* wLength */
212 &len, /* actually received byte count */
213 1000 /* timeout (ms) */);
214
215 if (ret < 0) {
216 sr_err("USB receive error: %s.", libusb_error_name(ret));
217 return SR_ERR;
218 }
219
220 if (len != CHUNK_SIZE) {
221 sr_err("Short packet: received %d/%d bytes.", len, CHUNK_SIZE);
222 /* TODO: Print the bytes? */
223 return SR_ERR;
224 }
225
226 log_8byte_chunk((const uint8_t *)&buf);
227
228 /* If there are no data bytes just return (without error). */
229 if (buf[0] == 0xf0)
230 return SR_OK;
231
232 devc->bufoffset = 0;
233
234 /*
235 * Append the 1-7 data bytes of this chunk to pbuf.
236 *
237 * Special case:
238 * DMMs with Cyrustek ES51922 chip and UT71x DMMs need serial settings
239 * of 7o1. The WCH CH9325 UART to USB/HID chip used in (some
240 * versions of) the UNI-T UT-D04 cable however, will also send
241 * the parity bit to the host in the 8-byte data chunks. This bit
242 * is encoded in bit 7 of each of the 1-7 data bytes and must thus
243 * be removed in order for the actual protocol parser to work properly.
244 */
245 num_databytes_in_chunk = buf[0] & 0x0f;
246 for (i = 0; i < num_databytes_in_chunk; i++, devc->buflen++) {
247 pbuf[devc->buflen] = buf[1 + i];
248 if ((dmm->packet_parse == sr_es519xx_19200_14b_parse) ||
249 (dmm->packet_parse == sr_es519xx_19200_11b_parse) ||
250 (dmm->packet_parse == sr_es519xx_2400_11b_parse) ||
251 (dmm->packet_parse == sr_ut71x_parse)) {
252 /* Mask off the parity bit. */
253 pbuf[devc->buflen] &= ~(1 << 7);
254 }
255 }
256
257 /* Now look for packets in that data. */
258 while ((devc->buflen - devc->bufoffset) >= dmm->packet_size) {
259 if (dmm->packet_valid(pbuf + devc->bufoffset)) {
260 log_dmm_packet(pbuf + devc->bufoffset);
261 decode_packet(sdi, pbuf + devc->bufoffset);
262 devc->bufoffset += dmm->packet_size;
263 } else {
264 devc->bufoffset++;
265 }
266 }
267
268 /* Move remaining bytes to beginning of buffer. */
269 for (i = 0; i < devc->buflen - devc->bufoffset; i++)
270 pbuf[i] = pbuf[devc->bufoffset + i];
271 devc->buflen -= devc->bufoffset;
272
273 return SR_OK;
274}
275
276SR_PRIV int uni_t_dmm_receive_data(int fd, int revents, void *cb_data)
277{
278 int ret;
279 struct sr_dev_inst *sdi;
280 struct dev_context *devc;
281
282 (void)fd;
283 (void)revents;
284
285 sdi = cb_data;
286 devc = sdi->priv;
287
288 if ((ret = get_and_handle_data(sdi)) != SR_OK)
289 return FALSE;
290
291 /* Abort acquisition if we acquired enough samples. */
292 if (sr_sw_limits_check(&devc->limits))
293 sr_dev_acquisition_stop(sdi);
294
295 return TRUE;
296}