[libsigrok.git] / src / hardware / rdtech-tc / protocol.c

/*
 * 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 <glib.h>
#include <libsigrok/libsigrok.h>
#include <math.h>
#include <nettle/aes.h>
#include <stdlib.h>
#include <string.h>

#include "libsigrok-internal.h"
#include "protocol.h"

#define SERIAL_WRITE_TIMEOUT_MS 1

#define TC_POLL_PERIOD_MS 100
#define TC_TIMEOUT_MS 1000

static const char *poll_cmd = "getva";

/*
 * Response data (raw sample data) consists of three adjacent chunks
 * of 64 bytes each. These chunks start with their magic string, and
 * end in a 32bit checksum field. Measurement values are scattered
 * across these 192 bytes total size. All multi-byte integer values
 * are represented in little endian format. Typical size is 32 bits.
 */

#define MAGIC_PAC1	0x70616331	/* 'pac1' */
#define MAGIC_PAC2	0x70616332	/* 'pac2' */
#define MAGIC_PAC3	0x70616333	/* 'pac3' */

#define PAC_LEN 64
#define PAC_CRC_POS (PAC_LEN - sizeof(uint32_t))

/* 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 TC_POLL_LEN (3 * 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 },
	ALL_ZERO,
};

static gboolean check_pac_crc(uint8_t *data)
{
	uint16_t crc;
	uint32_t crc_field;

	crc = sr_crc16(SR_CRC16_DEFAULT_INIT, data, PAC_CRC_POS);
	crc_field = read_u32le(&data[PAC_CRC_POS]);
	if (crc != crc_field) {
		sr_spew("CRC error. Calculated: %0x" PRIx16 ", expected: %0x" PRIx32,
			crc, crc_field);
		return FALSE;
	}

	return TRUE;
}

static int process_poll_pkt(struct dev_context *devc, uint8_t *dst)
{
	struct aes256_ctx ctx;
	gboolean ok;

	aes256_set_decrypt_key(&ctx, AES_KEY);
	aes256_decrypt(&ctx, TC_POLL_LEN, dst, devc->buf);

	ok = TRUE;
	ok &= read_u32be(&dst[OFF_PAC1]) == MAGIC_PAC1;
	ok &= read_u32be(&dst[OFF_PAC2]) == MAGIC_PAC2;
	ok &= read_u32be(&dst[OFF_PAC3]) == MAGIC_PAC3;
	if (!ok) {
		sr_err("Invalid poll response packet (magic values).");
		return SR_ERR_DATA;
	}

	ok &= check_pac_crc(&dst[OFF_PAC1]);
	ok &= check_pac_crc(&dst[OFF_PAC2]);
	ok &= check_pac_crc(&dst[OFF_PAC3]);
	if (!ok) {
		sr_err("Invalid poll response packet (checksum).");
		return SR_ERR_DATA;
	}

	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, strlen(poll_cmd),
			SERIAL_WRITE_TIMEOUT_MS) < 0) {
		sr_err("Failed 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 = read_u32le(&poll_pkt[OFF_SERIAL]);

	return SR_OK;
}

SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi, gboolean force)
{
	struct dev_context *devc;
	int64_t now, elapsed;
	struct sr_serial_dev_inst *serial;

	devc = sdi->priv;
	now = g_get_monotonic_time() / 1000;
	elapsed = now - devc->cmd_sent_at;
	if (!force && elapsed < TC_POLL_PERIOD_MS)
		return SR_OK;

	serial = sdi->conn;
	if (serial_write_blocking(serial, poll_cmd, strlen(poll_cmd),
			SERIAL_WRITE_TIMEOUT_MS) < 0) {
		sr_err("Unable to send poll request.");
		return SR_ERR;
	}
	devc->cmd_sent_at = now;

	return SR_OK;
}

static void handle_poll_data(const struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	uint8_t poll_pkt[TC_POLL_LEN];
	size_t i;
	GSList *ch;

	devc = sdi->priv;
	sr_spew("Received poll packet (len: %zu).", devc->buflen);
	if (devc->buflen != TC_POLL_LEN) {
		sr_err("Unexpected poll packet length: %zu", devc->buflen);
		return;
	}

	if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
		sr_err("Failed to process poll packet.");
		return;
	}

	i = 0;
	for (ch = sdi->channels; ch; ch = g_slist_next(ch)) {
		bv_send_analog_channel(sdi, ch->data,
			&devc->channels[i], poll_pkt, TC_POLL_LEN);
		i++;
	}

	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;
	int len;

	/* Serial data arrived. */
	devc = sdi->priv;
	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;

	(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;
	}

	rdtech_tc_poll(sdi, FALSE);

	return TRUE;
}
Commit	Line	Data
	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2020 Andreas Sandberg <andreas@sandberg.pp.se>
	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	#include <config.h>
	21
	22	#include <glib.h>
	23	#include <libsigrok/libsigrok.h>
	24	#include <math.h>
	25	#include <nettle/aes.h>
	26	#include <stdlib.h>
	27	#include <string.h>
	28
	29	#include "libsigrok-internal.h"
	30	#include "protocol.h"
	31
	32	#define SERIAL_WRITE_TIMEOUT_MS 1
	33
	34	#define TC_POLL_PERIOD_MS 100
	35	#define TC_TIMEOUT_MS 1000
	36
	37	static const char *poll_cmd = "getva";
	38
	39	/*
	40	* Response data (raw sample data) consists of three adjacent chunks
	41	* of 64 bytes each. These chunks start with their magic string, and
	42	* end in a 32bit checksum field. Measurement values are scattered
	43	* across these 192 bytes total size. All multi-byte integer values
	44	* are represented in little endian format. Typical size is 32 bits.
	45	*/
	46
	47	#define MAGIC_PAC1 0x70616331 /* 'pac1' */
	48	#define MAGIC_PAC2 0x70616332 /* 'pac2' */
	49	#define MAGIC_PAC3 0x70616333 /* 'pac3' */
	50
	51	#define PAC_LEN 64
	52	#define PAC_CRC_POS (PAC_LEN - sizeof(uint32_t))
	53
	54	/* Offset to PAC block from start of poll data */
	55	#define OFF_PAC1 (0 * PAC_LEN)
	56	#define OFF_PAC2 (1 * PAC_LEN)
	57	#define OFF_PAC3 (2 * PAC_LEN)
	58	#define TC_POLL_LEN (3 * PAC_LEN)
	59
	60	#define OFF_MODEL 4
	61	#define LEN_MODEL 4
	62
	63	#define OFF_FW_VER 8
	64	#define LEN_FW_VER 4
	65
	66	#define OFF_SERIAL 12
	67
	68	static const uint8_t AES_KEY[] = {
	69	0x58, 0x21, 0xfa, 0x56, 0x01, 0xb2, 0xf0, 0x26,
	70	0x87, 0xff, 0x12, 0x04, 0x62, 0x2a, 0x4f, 0xb0,
	71	0x86, 0xf4, 0x02, 0x60, 0x81, 0x6f, 0x9a, 0x0b,
	72	0xa7, 0xf1, 0x06, 0x61, 0x9a, 0xb8, 0x72, 0x88,
	73	};
	74
	75	static const struct binary_analog_channel rdtech_tc_channels[] = {
	76	{ "V", { 0 + 48, BVT_LE_UINT32, 1e-4, }, 4, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	77	{ "I", { 0 + 52, BVT_LE_UINT32, 1e-5, }, 5, SR_MQ_CURRENT, SR_UNIT_AMPERE },
	78	{ "D+", { 64 + 32, BVT_LE_UINT32, 1e-2, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	79	{ "D-", { 64 + 36, BVT_LE_UINT32, 1e-2, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	80	{ "E0", { 64 + 12, BVT_LE_UINT32, 1e-3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
	81	{ "E1", { 64 + 20, BVT_LE_UINT32, 1e-3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
	82	ALL_ZERO,
	83	};
	84
	85	static gboolean check_pac_crc(uint8_t *data)
	86	{
	87	uint16_t crc;
	88	uint32_t crc_field;
	89
	90	crc = sr_crc16(SR_CRC16_DEFAULT_INIT, data, PAC_CRC_POS);
	91	crc_field = read_u32le(&data[PAC_CRC_POS]);
	92	if (crc != crc_field) {
	93	sr_spew("CRC error. Calculated: %0x" PRIx16 ", expected: %0x" PRIx32,
	94	crc, crc_field);
	95	return FALSE;
	96	}
	97
	98	return TRUE;
	99	}
	100
	101	static int process_poll_pkt(struct dev_context devc, uint8_t dst)
	102	{
	103	struct aes256_ctx ctx;
	104	gboolean ok;
	105
	106	aes256_set_decrypt_key(&ctx, AES_KEY);
	107	aes256_decrypt(&ctx, TC_POLL_LEN, dst, devc->buf);
	108
	109	ok = TRUE;
	110	ok &= read_u32be(&dst[OFF_PAC1]) == MAGIC_PAC1;
	111	ok &= read_u32be(&dst[OFF_PAC2]) == MAGIC_PAC2;
	112	ok &= read_u32be(&dst[OFF_PAC3]) == MAGIC_PAC3;
	113	if (!ok) {
	114	sr_err("Invalid poll response packet (magic values).");
	115	return SR_ERR_DATA;
	116	}
	117
	118	ok &= check_pac_crc(&dst[OFF_PAC1]);
	119	ok &= check_pac_crc(&dst[OFF_PAC2]);
	120	ok &= check_pac_crc(&dst[OFF_PAC3]);
	121	if (!ok) {
	122	sr_err("Invalid poll response packet (checksum).");
	123	return SR_ERR_DATA;
	124	}
	125
	126	return SR_OK;
	127	}
	128
	129	SR_PRIV int rdtech_tc_probe(struct sr_serial_dev_inst serial, struct dev_context devc)
	130	{
	131	int len;
	132	uint8_t poll_pkt[TC_POLL_LEN];
	133
	134	if (serial_write_blocking(serial, poll_cmd, strlen(poll_cmd),
	135	SERIAL_WRITE_TIMEOUT_MS) < 0) {
	136	sr_err("Failed to send probe request.");
	137	return SR_ERR;
	138	}
	139
	140	len = serial_read_blocking(serial, devc->buf, TC_POLL_LEN, TC_TIMEOUT_MS);
	141	if (len != TC_POLL_LEN) {
	142	sr_err("Failed to read probe response.");
	143	return SR_ERR;
	144	}
	145
	146	if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
	147	sr_err("Unrecognized TC device!");
	148	return SR_ERR;
	149	}
	150
	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]);
	155
	156	return SR_OK;
	157	}
	158
	159	SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi, gboolean force)
	160	{
	161	struct dev_context *devc;
	162	int64_t now, elapsed;
	163	struct sr_serial_dev_inst *serial;
	164
	165	devc = sdi->priv;
	166	now = g_get_monotonic_time() / 1000;
	167	elapsed = now - devc->cmd_sent_at;
	168	if (!force && elapsed < TC_POLL_PERIOD_MS)
	169	return SR_OK;
	170
	171	serial = sdi->conn;
	172	if (serial_write_blocking(serial, poll_cmd, strlen(poll_cmd),
	173	SERIAL_WRITE_TIMEOUT_MS) < 0) {
	174	sr_err("Unable to send poll request.");
	175	return SR_ERR;
	176	}
	177	devc->cmd_sent_at = now;
	178
	179	return SR_OK;
	180	}
	181
	182	static void handle_poll_data(const struct sr_dev_inst *sdi)
	183	{
	184	struct dev_context *devc;
	185	uint8_t poll_pkt[TC_POLL_LEN];
	186	size_t i;
	187	GSList *ch;
	188
	189	devc = sdi->priv;
	190	sr_spew("Received poll packet (len: %zu).", devc->buflen);
	191	if (devc->buflen != TC_POLL_LEN) {
	192	sr_err("Unexpected poll packet length: %zu", devc->buflen);
	193	return;
	194	}
	195
	196	if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
	197	sr_err("Failed to process poll packet.");
	198	return;
	199	}
	200
	201	i = 0;
	202	for (ch = sdi->channels; ch; ch = g_slist_next(ch)) {
	203	bv_send_analog_channel(sdi, ch->data,
	204	&devc->channels[i], poll_pkt, TC_POLL_LEN);
	205	i++;
	206	}
	207
	208	sr_sw_limits_update_samples_read(&devc->limits, 1);
	209	}
	210
	211	static void recv_poll_data(struct sr_dev_inst sdi, struct sr_serial_dev_inst serial)
	212	{
	213	struct dev_context *devc;
	214	int len;
	215
	216	/* Serial data arrived. */
	217	devc = sdi->priv;
	218	while (devc->buflen < TC_POLL_LEN) {
	219	len = serial_read_nonblocking(serial, devc->buf + devc->buflen, 1);
	220	if (len < 1)
	221	return;
	222
	223	devc->buflen++;
	224	}
	225
	226	if (devc->buflen == TC_POLL_LEN)
	227	handle_poll_data(sdi);
	228
	229	devc->buflen = 0;
	230	}
	231
	232	SR_PRIV int rdtech_tc_receive_data(int fd, int revents, void *cb_data)
	233	{
	234	struct sr_dev_inst *sdi;
	235	struct dev_context *devc;
	236	struct sr_serial_dev_inst *serial;
	237
	238	(void)fd;
	239
	240	if (!(sdi = cb_data))
	241	return TRUE;
	242	if (!(devc = sdi->priv))
	243	return TRUE;
	244
	245	serial = sdi->conn;
	246	if (revents == G_IO_IN)
	247	recv_poll_data(sdi, serial);
	248
	249	if (sr_sw_limits_check(&devc->limits)) {
	250	sr_dev_acquisition_stop(sdi);
	251	return TRUE;
	252	}
	253
	254	rdtech_tc_poll(sdi, FALSE);
	255
	256	return TRUE;
	257	}