[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 PROBE_TO_MS	1000
#define WRITE_TO_MS	1
#define POLL_PERIOD_MS	100

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 rdtech_tc_channel_desc rdtech_tc_channels[] = {
	{ "V",  {   0 + 48, BVT_LE_UINT32, 1, }, { 100, 1e6, }, 4, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	{ "I",  {   0 + 52, BVT_LE_UINT32, 1, }, {  10, 1e6, }, 5, SR_MQ_CURRENT, SR_UNIT_AMPERE },
	{ "D+", {  64 + 32, BVT_LE_UINT32, 1, }, {  10, 1e3, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	{ "D-", {  64 + 36, BVT_LE_UINT32, 1, }, {  10, 1e3, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	{ "E0", {  64 + 12, BVT_LE_UINT32, 1, }, {   1, 1e3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
	{ "E1", {  64 + 20, BVT_LE_UINT32, 1, }, {   1, 1e3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
};

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];

	len = serial_write_blocking(serial,
		poll_cmd, strlen(poll_cmd), WRITE_TO_MS);
	if (len < 0) {
		sr_err("Failed to send probe request.");
		return SR_ERR;
	}

	len = serial_read_blocking(serial, devc->buf, TC_POLL_LEN, PROBE_TO_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->channel_count = ARRAY_SIZE(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;
	int len;

	/*
	 * Don't send the request while receive data is being accumulated.
	 */
	devc = sdi->priv;
	if (!force && devc->buflen)
		return SR_OK;

	/*
	 * Send the request when the transmit interval was reached. Or
	 * when the caller forced the transmission.
	 */
	now = g_get_monotonic_time() / 1000;
	elapsed = now - devc->cmd_sent_at;
	if (!force && elapsed < POLL_PERIOD_MS)
		return SR_OK;

	/*
	 * Transmit another measurement request. Only advance the
	 * interval after successful transmission.
	 */
	serial = sdi->conn;
	len = serial_write_blocking(serial,
		poll_cmd, strlen(poll_cmd), WRITE_TO_MS);
	if (len < 0) {
		sr_err("Unable to send poll request.");
		return SR_ERR;
	}
	devc->cmd_sent_at = now;

	return SR_OK;
}

static int handle_poll_data(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	uint8_t poll_pkt[TC_POLL_LEN];
	size_t ch_idx;
	const struct rdtech_tc_channel_desc *pch;
	int ret;
	float v;

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

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

	ret = SR_OK;
	std_session_send_df_frame_begin(sdi);
	for (ch_idx = 0; ch_idx < devc->channel_count; ch_idx++) {
		pch = &devc->channels[ch_idx];
		ret = bv_get_value(&v, &pch->spec, poll_pkt, TC_POLL_LEN);
		if (ret != SR_OK)
			break;
		ret = feed_queue_analog_submit(devc->feeds[ch_idx], v, 1);
		if (ret != SR_OK)
			break;
	}
	std_session_send_df_frame_end(sdi);

	sr_sw_limits_update_frames_read(&devc->limits, 1);
	if (sr_sw_limits_check(&devc->limits))
		sr_dev_acquisition_stop(sdi);

	return ret;
}

static int recv_poll_data(struct sr_dev_inst *sdi, struct sr_serial_dev_inst *serial)
{
	struct dev_context *devc;
	size_t space;
	int len;
	int ret;

	/* Receive data became available. Drain the transport layer. */
	devc = sdi->priv;
	while (devc->buflen < TC_POLL_LEN) {
		space = sizeof(devc->buf) - devc->buflen;
		len = serial_read_nonblocking(serial,
			&devc->buf[devc->buflen], space);
		if (len < 0)
			return SR_ERR_IO;
		if (len == 0)
			return SR_OK;
		devc->buflen += len;
	}

	/*
	 * TODO Want to (re-)synchronize to the packet stream? The
	 * 'pac1' string literal would be a perfect match for that.
	 */

	/* Process packets when their reception has completed. */
	while (devc->buflen >= TC_POLL_LEN) {
		ret = handle_poll_data(sdi);
		if (ret != SR_OK)
			return ret;
		devc->buflen -= TC_POLL_LEN;
		if (devc->buflen)
			memmove(&devc->buf[0], &devc->buf[TC_POLL_LEN], devc->buflen);
	}

	return SR_OK;
}

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;
	int ret;

	(void)fd;

	if (!(sdi = cb_data))
		return TRUE;
	if (!(devc = sdi->priv))
		return TRUE;

	/* Handle availability of receive data. */
	serial = sdi->conn;
	if (revents == G_IO_IN) {
		ret = recv_poll_data(sdi, serial);
		if (ret != SR_OK)
			sr_dev_acquisition_stop(sdi);
	}

	/* Check configured acquisition limits. */
	if (sr_sw_limits_check(&devc->limits)) {
		sr_dev_acquisition_stop(sdi);
		return TRUE;
	}

	/* Periodically retransmit measurement requests. */
	(void)rdtech_tc_poll(sdi, FALSE);

	return TRUE;
}
Commit	Line	Data
cae33a58 AS	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>
ea5fc667	21
cae33a58	22	#include <glib.h>
cae33a58	23	#include <libsigrok/libsigrok.h>
ea5fc667 GS	24	#include <math.h>
	25	#include <nettle/aes.h>
	26	#include <stdlib.h>
	27	#include <string.h>
	28
cae33a58 AS	29	#include "libsigrok-internal.h"
	30	#include "protocol.h"
	31
861fa81f GS	32	#define PROBE_TO_MS 1000
	33	#define WRITE_TO_MS 1
	34	#define POLL_PERIOD_MS 100
cae33a58	35
f7c74c7f	36	static const char *poll_cmd = "getva";
cae33a58	37
a780870c GS	38	/*
	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.
	44	*/
	45
	46	#define MAGIC_PAC1 0x70616331 /* 'pac1' */
	47	#define MAGIC_PAC2 0x70616332 /* 'pac2' */
	48	#define MAGIC_PAC3 0x70616333 /* 'pac3' */
cae33a58	49
cae33a58	50	#define PAC_LEN 64
a780870c	51	#define PAC_CRC_POS (PAC_LEN - sizeof(uint32_t))
cae33a58 AS	52
	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)
a780870c	57	#define TC_POLL_LEN (3 * PAC_LEN)
cae33a58 AS	58
	59	#define OFF_MODEL 4
	60	#define LEN_MODEL 4
	61
	62	#define OFF_FW_VER 8
	63	#define LEN_FW_VER 4
	64
	65	#define OFF_SERIAL 12
	66
	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,
	72	};
	73
b3df7668 GS	74	static const struct rdtech_tc_channel_desc rdtech_tc_channels[] = {
	75	{ "V", { 0 + 48, BVT_LE_UINT32, 1, }, { 100, 1e6, }, 4, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	76	{ "I", { 0 + 52, BVT_LE_UINT32, 1, }, { 10, 1e6, }, 5, SR_MQ_CURRENT, SR_UNIT_AMPERE },
	77	{ "D+", { 64 + 32, BVT_LE_UINT32, 1, }, { 10, 1e3, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	78	{ "D-", { 64 + 36, BVT_LE_UINT32, 1, }, { 10, 1e3, }, 2, SR_MQ_VOLTAGE, SR_UNIT_VOLT },
	79	{ "E0", { 64 + 12, BVT_LE_UINT32, 1, }, { 1, 1e3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
	80	{ "E1", { 64 + 20, BVT_LE_UINT32, 1, }, { 1, 1e3, }, 3, SR_MQ_ENERGY, SR_UNIT_WATT_HOUR },
cae33a58 AS	81	};
cae33a58 AS	82
a780870c	83	static gboolean check_pac_crc(uint8_t *data)
cae33a58 AS	84	{
	85	uint16_t crc;
	86	uint32_t crc_field;
	87
a780870c GS	88	crc = sr_crc16(SR_CRC16_DEFAULT_INIT, data, PAC_CRC_POS);
a780870c GS	89	crc_field = read_u32le(&data[PAC_CRC_POS]);
cae33a58 AS	90	if (crc != crc_field) {
	91	sr_spew("CRC error. Calculated: %0x" PRIx16 ", expected: %0x" PRIx32,
	92	crc, crc_field);
a780870c	93	return FALSE;
cae33a58	94	}
a780870c GS	95
a780870c GS	96	return TRUE;
cae33a58 AS	97	}
cae33a58 AS	98
5955b58c	99	static int process_poll_pkt(struct dev_context devc, uint8_t dst)
cae33a58 AS	100	{
cae33a58 AS	101	struct aes256_ctx ctx;
a780870c	102	gboolean ok;
cae33a58 AS	103
	104	aes256_set_decrypt_key(&ctx, AES_KEY);
	105	aes256_decrypt(&ctx, TC_POLL_LEN, dst, devc->buf);
	106
a780870c GS	107	ok = TRUE;
	108	ok &= read_u32be(&dst[OFF_PAC1]) == MAGIC_PAC1;
	109	ok &= read_u32be(&dst[OFF_PAC2]) == MAGIC_PAC2;
	110	ok &= read_u32be(&dst[OFF_PAC3]) == MAGIC_PAC3;
	111	if (!ok) {
	112	sr_err("Invalid poll response packet (magic values).");
	113	return SR_ERR_DATA;
cae33a58 AS	114	}
cae33a58 AS	115
a780870c GS	116	ok &= check_pac_crc(&dst[OFF_PAC1]);
	117	ok &= check_pac_crc(&dst[OFF_PAC2]);
	118	ok &= check_pac_crc(&dst[OFF_PAC3]);
	119	if (!ok) {
	120	sr_err("Invalid poll response packet (checksum).");
	121	return SR_ERR_DATA;
cae33a58 AS	122	}
	123
	124	return SR_OK;
	125	}
	126
5955b58c	127	SR_PRIV int rdtech_tc_probe(struct sr_serial_dev_inst serial, struct dev_context devc)
cae33a58 AS	128	{
	129	int len;
	130	uint8_t poll_pkt[TC_POLL_LEN];
	131
861fa81f GS	132	len = serial_write_blocking(serial,
	133	poll_cmd, strlen(poll_cmd), WRITE_TO_MS);
	134	if (len < 0) {
a780870c	135	sr_err("Failed to send probe request.");
cae33a58 AS	136	return SR_ERR;
	137	}
	138
861fa81f	139	len = serial_read_blocking(serial, devc->buf, TC_POLL_LEN, PROBE_TO_MS);
cae33a58 AS	140	if (len != TC_POLL_LEN) {
	141	sr_err("Failed to read probe response.");
	142	return SR_ERR;
	143	}
	144
	145	if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
	146	sr_err("Unrecognized TC device!");
	147	return SR_ERR;
	148	}
	149
	150	devc->channels = rdtech_tc_channels;
b3df7668	151	devc->channel_count = ARRAY_SIZE(rdtech_tc_channels);
a780870c GS	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]);
cae33a58 AS	155
	156	return SR_OK;
	157	}
	158
a82490b6	159	SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi, gboolean force)
cae33a58	160	{
c1f9428a	161	struct dev_context *devc;
a82490b6	162	int64_t now, elapsed;
c1f9428a	163	struct sr_serial_dev_inst *serial;
861fa81f	164	int len;
cae33a58	165
8817bd6f GS	166	/*
	167	* Don't send the request while receive data is being accumulated.
	168	*/
a82490b6	169	devc = sdi->priv;
8817bd6f GS	170	if (!force && devc->buflen)
	171	return SR_OK;
	172
	173	/*
	174	* Send the request when the transmit interval was reached. Or
	175	* when the caller forced the transmission.
	176	*/
a82490b6 GS	177	now = g_get_monotonic_time() / 1000;
a82490b6 GS	178	elapsed = now - devc->cmd_sent_at;
861fa81f	179	if (!force && elapsed < POLL_PERIOD_MS)
a82490b6 GS	180	return SR_OK;
a82490b6 GS	181
8817bd6f GS	182	/*
	183	* Transmit another measurement request. Only advance the
	184	* interval after successful transmission.
	185	*/
c1f9428a	186	serial = sdi->conn;
861fa81f GS	187	len = serial_write_blocking(serial,
	188	poll_cmd, strlen(poll_cmd), WRITE_TO_MS);
	189	if (len < 0) {
cae33a58 AS	190	sr_err("Unable to send poll request.");
	191	return SR_ERR;
	192	}
a82490b6	193	devc->cmd_sent_at = now;
cae33a58 AS	194
	195	return SR_OK;
	196	}
	197
269f1e0e	198	static int handle_poll_data(struct sr_dev_inst *sdi)
cae33a58	199	{
c1f9428a	200	struct dev_context *devc;
cae33a58	201	uint8_t poll_pkt[TC_POLL_LEN];
b3df7668 GS	202	size_t ch_idx;
b3df7668 GS	203	const struct rdtech_tc_channel_desc *pch;
269f1e0e	204	int ret;
b3df7668	205	float v;
cae33a58	206
c1f9428a	207	devc = sdi->priv;
63f46e3e	208	sr_spew("Received poll packet (len: %zu).", devc->buflen);
8817bd6f GS	209	if (devc->buflen < TC_POLL_LEN) {
8817bd6f GS	210	sr_err("Insufficient poll packet length: %zu", devc->buflen);
269f1e0e	211	return SR_ERR_DATA;
cae33a58 AS	212	}
	213
	214	if (process_poll_pkt(devc, poll_pkt) != SR_OK) {
	215	sr_err("Failed to process poll packet.");
269f1e0e	216	return SR_ERR_DATA;
cae33a58 AS	217	}
cae33a58 AS	218
15ceaf9d GS	219	ret = SR_OK;
15ceaf9d GS	220	std_session_send_df_frame_begin(sdi);
b3df7668 GS	221	for (ch_idx = 0; ch_idx < devc->channel_count; ch_idx++) {
	222	pch = &devc->channels[ch_idx];
	223	ret = bv_get_value(&v, &pch->spec, poll_pkt, TC_POLL_LEN);
	224	if (ret != SR_OK)
15ceaf9d	225	break;
b3df7668	226	ret = feed_queue_analog_submit(devc->feeds[ch_idx], v, 1);
269f1e0e	227	if (ret != SR_OK)
15ceaf9d	228	break;
5955b58c	229	}
15ceaf9d	230	std_session_send_df_frame_end(sdi);
cae33a58	231
15ceaf9d	232	sr_sw_limits_update_frames_read(&devc->limits, 1);
269f1e0e GS	233	if (sr_sw_limits_check(&devc->limits))
	234	sr_dev_acquisition_stop(sdi);
	235
15ceaf9d	236	return ret;
cae33a58 AS	237	}
cae33a58 AS	238
269f1e0e	239	static int recv_poll_data(struct sr_dev_inst sdi, struct sr_serial_dev_inst serial)
cae33a58	240	{
c1f9428a	241	struct dev_context *devc;
8817bd6f	242	size_t space;
cae33a58	243	int len;
269f1e0e	244	int ret;
cae33a58	245
8817bd6f	246	/* Receive data became available. Drain the transport layer. */
c1f9428a	247	devc = sdi->priv;
cae33a58	248	while (devc->buflen < TC_POLL_LEN) {
8817bd6f GS	249	space = sizeof(devc->buf) - devc->buflen;
	250	len = serial_read_nonblocking(serial,
	251	&devc->buf[devc->buflen], space);
269f1e0e GS	252	if (len < 0)
	253	return SR_ERR_IO;
	254	if (len == 0)
	255	return SR_OK;
	256	devc->buflen += len;
cae33a58 AS	257	}
cae33a58 AS	258
8817bd6f GS	259	/*
	260	* TODO Want to (re-)synchronize to the packet stream? The
	261	* 'pac1' string literal would be a perfect match for that.
	262	*/
	263
	264	/* Process packets when their reception has completed. */
	265	while (devc->buflen >= TC_POLL_LEN) {
269f1e0e GS	266	ret = handle_poll_data(sdi);
	267	if (ret != SR_OK)
	268	return ret;
8817bd6f GS	269	devc->buflen -= TC_POLL_LEN;
	270	if (devc->buflen)
	271	memmove(&devc->buf[0], &devc->buf[TC_POLL_LEN], devc->buflen);
269f1e0e	272	}
269f1e0e GS	273
269f1e0e GS	274	return SR_OK;
cae33a58 AS	275	}
	276
	277	SR_PRIV int rdtech_tc_receive_data(int fd, int revents, void *cb_data)
	278	{
	279	struct sr_dev_inst *sdi;
	280	struct dev_context *devc;
	281	struct sr_serial_dev_inst *serial;
269f1e0e	282	int ret;
cae33a58 AS	283
	284	(void)fd;
	285
	286	if (!(sdi = cb_data))
	287	return TRUE;
cae33a58 AS	288	if (!(devc = sdi->priv))
	289	return TRUE;
	290
269f1e0e	291	/* Handle availability of receive data. */
cae33a58	292	serial = sdi->conn;
269f1e0e GS	293	if (revents == G_IO_IN) {
	294	ret = recv_poll_data(sdi, serial);
	295	if (ret != SR_OK)
	296	sr_dev_acquisition_stop(sdi);
	297	}
cae33a58	298
269f1e0e	299	/* Check configured acquisition limits. */
cae33a58 AS	300	if (sr_sw_limits_check(&devc->limits)) {
	301	sr_dev_acquisition_stop(sdi);
	302	return TRUE;
	303	}
	304
269f1e0e GS	305	/* Periodically retransmit measurement requests. */
269f1e0e GS	306	(void)rdtech_tc_poll(sdi, FALSE);
cae33a58 AS	307
	308	return TRUE;
	309	}