+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2020 Andreas Sandberg <andreas@sandberg.pp.se>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <glib.h>
+#include <nettle/aes.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+#include "protocol.h"
+
+#define SERIAL_WRITE_TIMEOUT_MS 1
+
+#define TC_POLL_LEN 192
+#define TC_POLL_PERIOD_MS 100
+#define TC_TIMEOUT_MS 1000
+
+static const char POLL_CMD[] = "getva";
+
+#define MAGIC_PAC1 0x31636170UL
+#define MAGIC_PAC2 0x32636170UL
+#define MAGIC_PAC3 0x33636170UL
+
+/* Length of PAC block excluding CRC */
+#define PAC_DATA_LEN 60
+/* Length of PAC block including CRC */
+#define PAC_LEN 64
+
+/* Offset to PAC block from start of poll data */
+#define OFF_PAC1 (0 * PAC_LEN)
+#define OFF_PAC2 (1 * PAC_LEN)
+#define OFF_PAC3 (2 * PAC_LEN)
+
+#define OFF_MODEL 4
+#define LEN_MODEL 4
+
+#define OFF_FW_VER 8
+#define LEN_FW_VER 4
+
+#define OFF_SERIAL 12
+
+static const uint8_t AES_KEY[] = {
+ 0x58, 0x21, 0xfa, 0x56, 0x01, 0xb2, 0xf0, 0x26,
+ 0x87, 0xff, 0x12, 0x04, 0x62, 0x2a, 0x4f, 0xb0,
+ 0x86, 0xf4, 0x02, 0x60, 0x81, 0x6f, 0x9a, 0x0b,
+ 0xa7, 0xf1, 0x06, 0x61, 0x9a, 0xb8, 0x72, 0x88,
+};
+
+static const struct binary_analog_channel rdtech_tc_channels[] = {
+ { "V", { 0 + 48, BVT_LE_UINT32, 1e-4, }, 4, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
+ { "I", { 0 + 52, BVT_LE_UINT32, 1e-5, }, 5, SR_MQ_CURRENT, SR_UNIT_AMPERE },
+ { "D+", { 64 + 32, BVT_LE_UINT32, 1e-2, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
+ { "D-", { 64 + 36, BVT_LE_UINT32, 1e-2, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
+ { "E0", { 64 + 12, BVT_LE_UINT32, 1e-3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
+ { "E1", { 64 + 20, BVT_LE_UINT32, 1e-3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
+ { NULL, },
+};
+
+static int check_pac_crc(uint8_t *data)
+{
+ uint16_t crc;
+ uint32_t crc_field;
+
+ crc = sr_crc16(SR_CRC16_DEFAULT_INIT, data, PAC_DATA_LEN);
+ crc_field = RL32(data + PAC_DATA_LEN);
+
+ if (crc != crc_field) {
+ sr_spew("CRC error. Calculated: %0x" PRIx16 ", expected: %0x" PRIx32,
+ crc, crc_field);
+ return 0;
+ } else {
+ return 1;
+ }
+}
+
+static int process_poll_pkt(struct dev_context *devc, uint8_t *dst)
+{
+ struct aes256_ctx ctx;
+
+ aes256_set_decrypt_key(&ctx, AES_KEY);
+ aes256_decrypt(&ctx, TC_POLL_LEN, dst, devc->buf);
+
+ if (RL32(dst + OFF_PAC1) != MAGIC_PAC1 ||
+ RL32(dst + OFF_PAC2) != MAGIC_PAC2 ||
+ RL32(dst + OFF_PAC3) != MAGIC_PAC3) {
+ sr_err("Invalid poll packet magic values!");
+ return SR_ERR;
+ }
+
+ if (!check_pac_crc(dst + OFF_PAC1) ||
+ !check_pac_crc(dst + OFF_PAC2) ||
+ !check_pac_crc(dst + OFF_PAC3)) {
+ sr_err("Invalid poll checksum!");
+ return SR_ERR;
+ }
+
+ return SR_OK;
+}
+
+SR_PRIV int rdtech_tc_probe(struct sr_serial_dev_inst *serial, struct dev_context *devc)
+{
+ int len;
+ uint8_t poll_pkt[TC_POLL_LEN];
+
+ if (serial_write_blocking(serial, &POLL_CMD, sizeof(POLL_CMD) - 1,
+ SERIAL_WRITE_TIMEOUT_MS) < 0) {
+ sr_err("Unable to send probe request.");
+ return SR_ERR;
+ }
+
+ len = serial_read_blocking(serial, devc->buf, TC_POLL_LEN, TC_TIMEOUT_MS);
+ if (len != TC_POLL_LEN) {
+ sr_err("Failed to read probe response.");
+ return SR_ERR;
+ }
+
+ if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
+ sr_err("Unrecognized TC device!");
+ return SR_ERR;
+ }
+
+ devc->channels = rdtech_tc_channels;
+ devc->dev_info.model_name = g_strndup((const char *)poll_pkt + OFF_MODEL, LEN_MODEL);
+ devc->dev_info.fw_ver = g_strndup((const char *)poll_pkt + OFF_FW_VER, LEN_FW_VER);
+ devc->dev_info.serial_num = RL32(poll_pkt + OFF_SERIAL);
+
+ return SR_OK;
+}
+
+SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc = sdi->priv;
+ struct sr_serial_dev_inst *serial = sdi->conn;
+
+ if (serial_write_blocking(serial, &POLL_CMD, sizeof(POLL_CMD) - 1,
+ SERIAL_WRITE_TIMEOUT_MS) < 0) {
+ sr_err("Unable to send poll request.");
+ return SR_ERR;
+ }
+
+ devc->cmd_sent_at = g_get_monotonic_time() / 1000;
+
+ return SR_OK;
+}
+
+static void handle_poll_data(const struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc = sdi->priv;
+ uint8_t poll_pkt[TC_POLL_LEN];
+ int i;
+ GSList *ch;
+
+ sr_spew("Received poll packet (len: %d).", devc->buflen);
+ if (devc->buflen != TC_POLL_LEN) {
+ sr_err("Unexpected poll packet length: %i", devc->buflen);
+ return;
+ }
+
+ if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
+ sr_err("Failed to process poll packet.");
+ return;
+ }
+
+ for (ch = sdi->channels, i = 0; ch; ch = g_slist_next(ch), i++) {
+ bv_send_analog_channel(sdi, ch->data,
+ &devc->channels[i], poll_pkt, TC_POLL_LEN);
+ }
+
+ sr_sw_limits_update_samples_read(&devc->limits, 1);
+}
+
+static void recv_poll_data(struct sr_dev_inst *sdi, struct sr_serial_dev_inst *serial)
+{
+ struct dev_context *devc = sdi->priv;
+ int len;
+
+ /* Serial data arrived. */
+ while (devc->buflen < TC_POLL_LEN) {
+ len = serial_read_nonblocking(serial, devc->buf + devc->buflen, 1);
+ if (len < 1)
+ return;
+
+ devc->buflen++;
+ }
+
+ if (devc->buflen == TC_POLL_LEN)
+ handle_poll_data(sdi);
+
+ devc->buflen = 0;
+}
+
+SR_PRIV int rdtech_tc_receive_data(int fd, int revents, void *cb_data)
+{
+ struct sr_dev_inst *sdi;
+ struct dev_context *devc;
+ struct sr_serial_dev_inst *serial;
+ int64_t now, elapsed;
+
+ (void)fd;
+
+ if (!(sdi = cb_data))
+ return TRUE;
+
+ if (!(devc = sdi->priv))
+ return TRUE;
+
+ serial = sdi->conn;
+ if (revents == G_IO_IN)
+ recv_poll_data(sdi, serial);
+
+ if (sr_sw_limits_check(&devc->limits)) {
+ sr_dev_acquisition_stop(sdi);
+ return TRUE;
+ }
+
+ now = g_get_monotonic_time() / 1000;
+ elapsed = now - devc->cmd_sent_at;
+
+ if (elapsed > TC_POLL_PERIOD_MS)
+ rdtech_tc_poll(sdi);
+
+ return TRUE;
+}