2 * This file is part of the libsigrok project.
4 * Copyright (C) 2020 Andreas Sandberg <andreas@sandberg.pp.se>
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/>.
23 #include <libsigrok/libsigrok.h>
25 #include <nettle/aes.h>
29 #include "libsigrok-internal.h"
32 #define PROBE_TO_MS 1000
34 #define POLL_PERIOD_MS 100
36 static const char *poll_cmd = "getva";
39 * Response data (raw sample data) consists of three adjacent chunks
40 * of 64 bytes each. These chunks start with their magic string, and
41 * end in a 32bit checksum field. Measurement values are scattered
42 * across these 192 bytes total size. All multi-byte integer values
43 * are represented in little endian format. Typical size is 32 bits.
46 #define MAGIC_PAC1 0x70616331 /* 'pac1' */
47 #define MAGIC_PAC2 0x70616332 /* 'pac2' */
48 #define MAGIC_PAC3 0x70616333 /* 'pac3' */
51 #define PAC_CRC_POS (PAC_LEN - sizeof(uint32_t))
53 /* Offset to PAC block from start of poll data */
54 #define OFF_PAC1 (0 * PAC_LEN)
55 #define OFF_PAC2 (1 * PAC_LEN)
56 #define OFF_PAC3 (2 * PAC_LEN)
57 #define TC_POLL_LEN (3 * PAC_LEN)
67 static const uint8_t AES_KEY[] = {
68 0x58, 0x21, 0xfa, 0x56, 0x01, 0xb2, 0xf0, 0x26,
69 0x87, 0xff, 0x12, 0x04, 0x62, 0x2a, 0x4f, 0xb0,
70 0x86, 0xf4, 0x02, 0x60, 0x81, 0x6f, 0x9a, 0x0b,
71 0xa7, 0xf1, 0x06, 0x61, 0x9a, 0xb8, 0x72, 0x88,
74 static const struct binary_analog_channel rdtech_tc_channels[] = {
75 { "V", { 0 + 48, BVT_LE_UINT32, 1e-4, }, 4, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
76 { "I", { 0 + 52, BVT_LE_UINT32, 1e-5, }, 5, SR_MQ_CURRENT, SR_UNIT_AMPERE },
77 { "D+", { 64 + 32, BVT_LE_UINT32, 1e-2, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
78 { "D-", { 64 + 36, BVT_LE_UINT32, 1e-2, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
79 { "E0", { 64 + 12, BVT_LE_UINT32, 1e-3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
80 { "E1", { 64 + 20, BVT_LE_UINT32, 1e-3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
84 static gboolean check_pac_crc(uint8_t *data)
89 crc = sr_crc16(SR_CRC16_DEFAULT_INIT, data, PAC_CRC_POS);
90 crc_field = read_u32le(&data[PAC_CRC_POS]);
91 if (crc != crc_field) {
92 sr_spew("CRC error. Calculated: %0x" PRIx16 ", expected: %0x" PRIx32,
100 static int process_poll_pkt(struct dev_context *devc, uint8_t *dst)
102 struct aes256_ctx ctx;
105 aes256_set_decrypt_key(&ctx, AES_KEY);
106 aes256_decrypt(&ctx, TC_POLL_LEN, dst, devc->buf);
109 ok &= read_u32be(&dst[OFF_PAC1]) == MAGIC_PAC1;
110 ok &= read_u32be(&dst[OFF_PAC2]) == MAGIC_PAC2;
111 ok &= read_u32be(&dst[OFF_PAC3]) == MAGIC_PAC3;
113 sr_err("Invalid poll response packet (magic values).");
117 ok &= check_pac_crc(&dst[OFF_PAC1]);
118 ok &= check_pac_crc(&dst[OFF_PAC2]);
119 ok &= check_pac_crc(&dst[OFF_PAC3]);
121 sr_err("Invalid poll response packet (checksum).");
128 SR_PRIV int rdtech_tc_probe(struct sr_serial_dev_inst *serial, struct dev_context *devc)
131 uint8_t poll_pkt[TC_POLL_LEN];
133 len = serial_write_blocking(serial,
134 poll_cmd, strlen(poll_cmd), WRITE_TO_MS);
136 sr_err("Failed to send probe request.");
140 len = serial_read_blocking(serial, devc->buf, TC_POLL_LEN, PROBE_TO_MS);
141 if (len != TC_POLL_LEN) {
142 sr_err("Failed to read probe response.");
146 if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
147 sr_err("Unrecognized TC device!");
151 devc->channels = rdtech_tc_channels;
152 devc->dev_info.model_name = g_strndup((const char *)&poll_pkt[OFF_MODEL], LEN_MODEL);
153 devc->dev_info.fw_ver = g_strndup((const char *)&poll_pkt[OFF_FW_VER], LEN_FW_VER);
154 devc->dev_info.serial_num = read_u32le(&poll_pkt[OFF_SERIAL]);
159 SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi, gboolean force)
161 struct dev_context *devc;
162 int64_t now, elapsed;
163 struct sr_serial_dev_inst *serial;
167 * Don't send the request while receive data is being accumulated.
170 if (!force && devc->buflen)
174 * Send the request when the transmit interval was reached. Or
175 * when the caller forced the transmission.
177 now = g_get_monotonic_time() / 1000;
178 elapsed = now - devc->cmd_sent_at;
179 if (!force && elapsed < POLL_PERIOD_MS)
183 * Transmit another measurement request. Only advance the
184 * interval after successful transmission.
187 len = serial_write_blocking(serial,
188 poll_cmd, strlen(poll_cmd), WRITE_TO_MS);
190 sr_err("Unable to send poll request.");
193 devc->cmd_sent_at = now;
198 static int handle_poll_data(struct sr_dev_inst *sdi)
200 struct dev_context *devc;
201 uint8_t poll_pkt[TC_POLL_LEN];
207 sr_spew("Received poll packet (len: %zu).", devc->buflen);
208 if (devc->buflen < TC_POLL_LEN) {
209 sr_err("Insufficient poll packet length: %zu", devc->buflen);
213 if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
214 sr_err("Failed to process poll packet.");
219 for (ch = sdi->channels; ch; ch = g_slist_next(ch)) {
220 ret = bv_send_analog_channel(sdi, ch->data,
221 &devc->channels[i], poll_pkt, TC_POLL_LEN);
227 sr_sw_limits_update_samples_read(&devc->limits, 1);
228 if (sr_sw_limits_check(&devc->limits))
229 sr_dev_acquisition_stop(sdi);
234 static int recv_poll_data(struct sr_dev_inst *sdi, struct sr_serial_dev_inst *serial)
236 struct dev_context *devc;
241 /* Receive data became available. Drain the transport layer. */
243 while (devc->buflen < TC_POLL_LEN) {
244 space = sizeof(devc->buf) - devc->buflen;
245 len = serial_read_nonblocking(serial,
246 &devc->buf[devc->buflen], space);
255 * TODO Want to (re-)synchronize to the packet stream? The
256 * 'pac1' string literal would be a perfect match for that.
259 /* Process packets when their reception has completed. */
260 while (devc->buflen >= TC_POLL_LEN) {
261 ret = handle_poll_data(sdi);
264 devc->buflen -= TC_POLL_LEN;
266 memmove(&devc->buf[0], &devc->buf[TC_POLL_LEN], devc->buflen);
272 SR_PRIV int rdtech_tc_receive_data(int fd, int revents, void *cb_data)
274 struct sr_dev_inst *sdi;
275 struct dev_context *devc;
276 struct sr_serial_dev_inst *serial;
281 if (!(sdi = cb_data))
283 if (!(devc = sdi->priv))
286 /* Handle availability of receive data. */
288 if (revents == G_IO_IN) {
289 ret = recv_poll_data(sdi, serial);
291 sr_dev_acquisition_stop(sdi);
294 /* Check configured acquisition limits. */
295 if (sr_sw_limits_check(&devc->limits)) {
296 sr_dev_acquisition_stop(sdi);
300 /* Periodically retransmit measurement requests. */
301 (void)rdtech_tc_poll(sdi, FALSE);