[libsigrok.git] / src / hardware / devantech-eth008 / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2023 Gerhard Sittig <gerhard.sittig@gmx.net>
 *
 * 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/>.
 */

/*
 * Communicate to the Devantech ETH008 relay card via TCP and Ethernet.
 *
 * See http://www.robot-electronics.co.uk/files/eth008b.pdf for device
 * capabilities and a protocol discussion.
 * See https://github.com/devantech/devantech_eth_python for Python
 * source code which is maintained by the vendor.
 *
 * The device provides several means of communication: HTTP requests
 * (as well as an interactive web form). Raw TCP communication with
 * binary requests and responses. Text requests and responses over
 * TCP sockets. Some of these depend on the firmware version. Version
 * checks before command transmission is essentially non-existent in
 * this sigrok driver implementation. Binary transmission is preferred
 * because it is assumed that this existed in all firmware versions.
 * The firmware interestingly accepts concurrent network connections
 * (up to five of them, all share the same password). Which means that
 * the peripheral's state can change even while we control it.
 *
 * It's assumed that WLAN models differ from Ethernet devices in terms
 * of their hardware, but TCP communication should not bother about the
 * underlying physics, and WLAN cards can re-use model IDs and firmware
 * implementations. Given sigrok's abstraction of the serial transport
 * those cards could also be attached by means of COM ports.
 *
 * TCP communication seems to rely on network fragmentation and assumes
 * that software stacks provide all of a request in a single receive
 * call on the firmware side. Which works for local communication, but
 * could become an issue when long distances and tunnels are involved.
 * This sigrok driver also assumes complete reception within a single
 * receive call. The short length of binary transmission helps here
 * (the largest payloads has a length of three bytes).
 *
 * The lack of length specs as well as termination in the protocol
 * (both binary as well as text variants over TCP sockets) results in
 * the inability to synchronize to the firmware when connecting and
 * after hiccups in an established connection. The fixed length of
 * requests and responses for binary payloads helps a little bit,
 * assuming that TCP connect is used to recover. The overhead of
 * HTTP requests and responses is considered undesirable for this
 * sigrok driver implementation. [This also means that a transport
 * which lacks the concept of network frames cannot send passwords.]
 * The binary transport appears to lack HELLO or NOP requests that
 * could be used to synchronize. Firmware just would not respond to
 * unsupported commands. Maybe a repeated sequence of identity reads
 * combined with a read timeout could help synchronize, but only if
 * the response is known because the model was identified before.
 *
 * The sigrok driver source code was phrased with the addition of more
 * models in mind. Only few code paths require adjustment when similar
 * variants of requests or responses are involved in the communication
 * to relay cards that support between two and twenty channels. Chances
 * are good, existing firmware is compatible across firmware versions,
 * and even across hardware revisions (model upgrades). Firmware just
 * happens to not respond to unknown requests.
 *
 * TODO
 * - Add support for other models. Currently exclusively supports the
 *   ETH008-B model which was used during implementation of the driver.
 * - Add support for password protection?
 *   - See command 0x79 to "login" (beware of the differing return value
 *     compared to other commands), command 0x7a to check if passwords
 *     are involved and whether the login needs refreshing, command 0x7b
 *     for immediate "logout" in contrast to expiration.
 *   - Alternatively consider switching to the "text protocol" in that
 *     use case, which can send an optional password in every request
 *     that controls relays (command 0x3a).
 *   - How to specify the password in applications and how to pass them
 *     to this driver is yet another issue that needs consideration.
 */

#include "config.h"

#include <string.h>

#include "protocol.h"

#define READ_TIMEOUT_MS	20

enum cmd_code {
	CMD_GET_MODULE_INFO = 0x10,
	CMD_DIGITAL_ACTIVE = 0x20,
	CMD_DIGITAL_INACTIVE = 0x21,
	CMD_DIGITAL_SET_OUTPUTS = 0x23,
	CMD_DIGITAL_GET_OUTPUTS = 0x24,
	CMD_ASCII_TEXT_COMMAND = 0x3a,
	CMD_GET_SERIAL_NUMBER = 0x77,
	CMD_GET_SUPPLY_VOLTS = 0x78,
	CMD_PASSWORD_ENTRY = 0x79,
	CMD_GET_UNLOCK_TIME = 0x7a,
	CMD_IMMEDIATE_LOGOUT = 0x7b,
};

/*
 * Transmit a request to the relay card. Checks that all bytes get sent,
 * short writes are considered fatal.
 */
static int send_request(struct sr_serial_dev_inst *ser,
	const uint8_t *data, size_t dlen)
{
	int ret;
	size_t written;

	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
		GString *txt = sr_hexdump_new(data, dlen);
		sr_spew("TX --> %s.", txt->str);
		sr_hexdump_free(txt);
	}
	ret = serial_write_blocking(ser, data, dlen, 0);
	if (ret < 0)
		return ret;
	written = (size_t)ret;
	if (written != dlen)
		return SR_ERR_DATA;
	return SR_OK;
}

/*
 * Receive a response from the relay card. Assumes fixed size payload,
 * considers short reads fatal.
 */
static int recv_response(struct sr_serial_dev_inst *ser,
	uint8_t *data, size_t dlen)
{
	int ret;
	size_t got;

	ret = serial_read_blocking(ser, data, dlen, READ_TIMEOUT_MS);
	if (ret < 0)
		return ret;
	got = (size_t)ret;
	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
		GString *txt = sr_hexdump_new(data, got);
		sr_spew("<-- RX %s.", txt->str);
		sr_hexdump_free(txt);
	}
	if (got != dlen)
		return SR_ERR_DATA;
	return SR_OK;
}

/* Send a request then receive a response. Convenience routine. */
static int send_then_recv(struct sr_serial_dev_inst *serial,
	const uint8_t *tx_data, size_t tx_length,
	uint8_t *rx_data, size_t rx_length)
{
	int ret;

	if (tx_data && tx_length) {
		ret = send_request(serial, tx_data, tx_length);
		if (ret != SR_OK)
			return ret;
	}

	if (rx_data && rx_length) {
		ret = recv_response(serial, rx_data, rx_length);
		if (ret != SR_OK)
			return ret;
	}

	return SR_OK;
}

/* Identify the relay card, gather version information details. */
SR_PRIV int devantech_eth008_get_model(struct sr_serial_dev_inst *serial,
	uint8_t *model_code, uint8_t *hw_version, uint8_t *fw_version)
{
	uint8_t req[1], *wrptr;
	uint8_t rsp[3], v8;
	const uint8_t *rdptr;
	int ret;

	if (model_code)
		*model_code = 0;
	if (hw_version)
		*hw_version = 0;
	if (fw_version)
		*fw_version = 0;

	wrptr = req;
	write_u8_inc(&wrptr, CMD_GET_MODULE_INFO);
	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
	if (ret != SR_OK)
		return ret;
	rdptr = rsp;

	v8 = read_u8_inc(&rdptr);
	if (model_code)
		*model_code = v8;
	v8 = read_u8_inc(&rdptr);
	if (hw_version)
		*hw_version = v8;
	v8 = read_u8_inc(&rdptr);
	if (fw_version)
		*fw_version = v8;

	return SR_OK;
}

/* Get the relay card's serial number (its MAC address). */
SR_PRIV int devantech_eth008_get_serno(struct sr_serial_dev_inst *serial,
	char *text_buffer, size_t text_length)
{
	uint8_t req[1], *wrptr;
	uint8_t rsp[6], b;
	const uint8_t *rdptr, *endptr;
	size_t written;
	int ret;

	if (text_buffer && !text_length)
		return SR_ERR_ARG;
	if (text_buffer)
		memset(text_buffer, 0, text_length);

	wrptr = req;
	write_u8_inc(&wrptr, CMD_GET_SERIAL_NUMBER);
	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
	if (ret != SR_OK)
		return ret;
	rdptr = rsp;

	endptr = rsp + sizeof(rsp);
	while (rdptr < endptr && text_buffer && text_length >= 3) {
		b = read_u8_inc(&rdptr);
		written = snprintf(text_buffer, text_length, "%02x", b);
		text_buffer += written;
		text_length -= written;
	}

	return SR_OK;
}

/* Update an internal cache from the relay card's current state. */
SR_PRIV int devantech_eth008_cache_state(const struct sr_dev_inst *sdi)
{
	struct sr_serial_dev_inst *serial;
	struct dev_context *devc;
	size_t rx_size;
	uint8_t req[1], *wrptr;
	uint8_t rsp[1];
	const uint8_t *rdptr;
	uint32_t have;
	int ret;

	serial = sdi->conn;
	if (!serial)
		return SR_ERR_ARG;
	devc = sdi->priv;
	if (!devc)
		return SR_ERR_ARG;

	rx_size = devc->model->width_do;
	if (rx_size > sizeof(rsp))
		return SR_ERR_NA;

	wrptr = req;
	write_u8_inc(&wrptr, CMD_DIGITAL_GET_OUTPUTS);
	ret = send_then_recv(serial, req, wrptr - req, rsp, rx_size);
	if (ret != SR_OK)
		return ret;
	rdptr = rsp;

	switch (rx_size) {
	case 1:
		have = read_u8_inc(&rdptr);
		break;
	default:
		return SR_ERR_NA;
	}
	have &= devc->mask_do;
	devc->curr_do = have;

	return SR_OK;
}

/* Query the state of an individual relay channel. */
SR_PRIV int devantech_eth008_query_do(const struct sr_dev_inst *sdi,
	const struct sr_channel_group *cg, gboolean *on)
{
	struct dev_context *devc;
	struct channel_group_context *cgc;
	uint32_t have;
	int ret;

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

	/* Unconditionally update the internal cache. */
	ret = devantech_eth008_cache_state(sdi);
	if (ret != SR_OK)
		return ret;

	/*
	 * Only reject unexpected requeusts after the update. Get the
	 * individual channel's state from the cache of all channels.
	 */
	if (!cg)
		return SR_ERR_ARG;
	cgc = cg->priv;
	if (!cgc)
		return SR_ERR_BUG;
	if (cgc->index >= devc->model->ch_count_do)
		return SR_ERR_ARG;
	have = devc->curr_do;
	have >>= cgc->index;
	have &= 1 << 0;
	if (on)
		*on = have ? TRUE : FALSE;

	return SR_OK;
}

/*
 * Manipulate the state of an individual relay channel (when cg is given).
 * Or set/clear all channels at the same time (when cg is NULL).
 */
SR_PRIV int devantech_eth008_setup_do(const struct sr_dev_inst *sdi,
	const struct sr_channel_group *cg, gboolean on)
{
	struct sr_serial_dev_inst *serial;
	struct dev_context *devc;
	size_t width_do;
	struct channel_group_context *cgc;
	size_t number;
	uint32_t reg;
	uint8_t req[3], *wrptr, cmd;
	uint8_t rsp[1], v8;
	const uint8_t *rdptr;
	int ret;

	serial = sdi->conn;
	if (!serial)
		return SR_ERR_ARG;
	devc = sdi->priv;
	if (!devc)
		return SR_ERR_ARG;
	cgc = cg ? cg->priv : NULL;
	if (cgc && cgc->index >= devc->model->ch_count_do)
		return SR_ERR_ARG;

	width_do = devc->model->width_do;
	if (1 + width_do > sizeof(req))
		return SR_ERR_NA;

	wrptr = req;
	if (cgc) {
		/* Manipulate an individual channel. */
		cmd = on ? CMD_DIGITAL_ACTIVE : CMD_DIGITAL_INACTIVE;
		number = cgc->number;
		write_u8_inc(&wrptr, cmd);
		write_u8_inc(&wrptr, number & 0xff);
		write_u8_inc(&wrptr, 0); /* Just set/clear, no pulse. */
	} else {
		/* Manipulate all channels at the same time. */
		reg = on ? devc->mask_do : 0;
		write_u8_inc(&wrptr, CMD_DIGITAL_SET_OUTPUTS);
		switch (width_do) {
		case 1:
			write_u8_inc(&wrptr, reg & 0xff);
			break;
		default:
			return SR_ERR_NA;
		}
	}
	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
	if (ret != SR_OK)
		return ret;
	rdptr = rsp;

	v8 = read_u8_inc(&rdptr);
	if (v8 != 0)
		return SR_ERR_DATA;

	return SR_OK;
}

SR_PRIV int devantech_eth008_query_supply(const struct sr_dev_inst *sdi,
	const struct sr_channel_group *cg, uint16_t *millivolts)
{
	struct sr_serial_dev_inst *serial;
	uint8_t req[1], *wrptr;
	uint8_t rsp[1];
	const uint8_t *rdptr;
	uint16_t have;
	int ret;

	(void)cg;

	serial = sdi->conn;
	if (!serial)
		return SR_ERR_ARG;

	wrptr = req;
	write_u8_inc(&wrptr, CMD_GET_SUPPLY_VOLTS);
	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
	if (ret != SR_OK)
		return ret;
	rdptr = rsp;

	/* Gets a byte for voltage in units of 0.1V. Scale up to mV. */
	have = read_u8_inc(&rdptr);
	have *= 100;
	if (millivolts)
		*millivolts = have;

	return SR_OK;
}
Commit	Line	Data
c12ca361 GS	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2023 Gerhard Sittig <gerhard.sittig@gmx.net>
	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
8712c783 GS	20	/*
	21	* Communicate to the Devantech ETH008 relay card via TCP and Ethernet.
	22	*
	23	* See http://www.robot-electronics.co.uk/files/eth008b.pdf for device
	24	* capabilities and a protocol discussion.
	25	* See https://github.com/devantech/devantech_eth_python for Python
	26	* source code which is maintained by the vendor.
	27	*
	28	* The device provides several means of communication: HTTP requests
	29	* (as well as an interactive web form). Raw TCP communication with
	30	* binary requests and responses. Text requests and responses over
	31	* TCP sockets. Some of these depend on the firmware version. Version
	32	* checks before command transmission is essentially non-existent in
	33	* this sigrok driver implementation. Binary transmission is preferred
	34	* because it is assumed that this existed in all firmware versions.
	35	* The firmware interestingly accepts concurrent network connections
	36	* (up to five of them, all share the same password). Which means that
	37	* the peripheral's state can change even while we control it.
	38	*
	39	* It's assumed that WLAN models differ from Ethernet devices in terms
	40	* of their hardware, but TCP communication should not bother about the
	41	* underlying physics, and WLAN cards can re-use model IDs and firmware
	42	* implementations. Given sigrok's abstraction of the serial transport
	43	* those cards could also be attached by means of COM ports.
	44	*
	45	* TCP communication seems to rely on network fragmentation and assumes
	46	* that software stacks provide all of a request in a single receive
	47	* call on the firmware side. Which works for local communication, but
	48	* could become an issue when long distances and tunnels are involved.
	49	* This sigrok driver also assumes complete reception within a single
	50	* receive call. The short length of binary transmission helps here
	51	* (the largest payloads has a length of three bytes).
	52	*
	53	* The lack of length specs as well as termination in the protocol
	54	* (both binary as well as text variants over TCP sockets) results in
	55	* the inability to synchronize to the firmware when connecting and
	56	* after hiccups in an established connection. The fixed length of
	57	* requests and responses for binary payloads helps a little bit,
	58	* assuming that TCP connect is used to recover. The overhead of
	59	* HTTP requests and responses is considered undesirable for this
	60	* sigrok driver implementation. [This also means that a transport
	61	* which lacks the concept of network frames cannot send passwords.]
	62	* The binary transport appears to lack HELLO or NOP requests that
	63	* could be used to synchronize. Firmware just would not respond to
	64	* unsupported commands. Maybe a repeated sequence of identity reads
	65	* combined with a read timeout could help synchronize, but only if
	66	* the response is known because the model was identified before.
	67	*
	68	* The sigrok driver source code was phrased with the addition of more
	69	* models in mind. Only few code paths require adjustment when similar
	70	* variants of requests or responses are involved in the communication
	71	* to relay cards that support between two and twenty channels. Chances
	72	* are good, existing firmware is compatible across firmware versions,
	73	* and even across hardware revisions (model upgrades). Firmware just
	74	* happens to not respond to unknown requests.
	75	*
	76	* TODO
	77	* - Add support for other models. Currently exclusively supports the
	78	* ETH008-B model which was used during implementation of the driver.
	79	* - Add support for password protection?
	80	* - See command 0x79 to "login" (beware of the differing return value
	81	* compared to other commands), command 0x7a to check if passwords
	82	* are involved and whether the login needs refreshing, command 0x7b
	83	* for immediate "logout" in contrast to expiration.
84	* - Alternatively consider switching to the "text protocol" in that
85	* use case, which can send an optional password in every request
86	* that controls relays (command 0x3a).
87	* - How to specify the password in applications and how to pass them
88	* to this driver is yet another issue that needs consideration.
89	*/
90
91	#include "config.h"
92
93	#include <string.h>
94
c12ca361 GS	95	#include "protocol.h"
c12ca361 GS	96
8712c783 GS	97	#define READ_TIMEOUT_MS 20
	98
	99	enum cmd_code {
	100	CMD_GET_MODULE_INFO = 0x10,
	101	CMD_DIGITAL_ACTIVE = 0x20,
	102	CMD_DIGITAL_INACTIVE = 0x21,
	103	CMD_DIGITAL_SET_OUTPUTS = 0x23,
	104	CMD_DIGITAL_GET_OUTPUTS = 0x24,
	105	CMD_ASCII_TEXT_COMMAND = 0x3a,
	106	CMD_GET_SERIAL_NUMBER = 0x77,
	107	CMD_GET_SUPPLY_VOLTS = 0x78,
	108	CMD_PASSWORD_ENTRY = 0x79,
	109	CMD_GET_UNLOCK_TIME = 0x7a,
	110	CMD_IMMEDIATE_LOGOUT = 0x7b,
	111	};
	112
	113	/*
	114	* Transmit a request to the relay card. Checks that all bytes get sent,
	115	* short writes are considered fatal.
	116	*/
	117	static int send_request(struct sr_serial_dev_inst *ser,
	118	const uint8_t *data, size_t dlen)
	119	{
	120	int ret;
	121	size_t written;
	122
	123	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
	124	GString *txt = sr_hexdump_new(data, dlen);
	125	sr_spew("TX --> %s.", txt->str);
	126	sr_hexdump_free(txt);
	127	}
	128	ret = serial_write_blocking(ser, data, dlen, 0);
	129	if (ret < 0)
	130	return ret;
	131	written = (size_t)ret;
	132	if (written != dlen)
	133	return SR_ERR_DATA;
	134	return SR_OK;
	135	}
	136
	137	/*
	138	* Receive a response from the relay card. Assumes fixed size payload,
	139	* considers short reads fatal.
	140	*/
	141	static int recv_response(struct sr_serial_dev_inst *ser,
	142	uint8_t *data, size_t dlen)
	143	{
	144	int ret;
	145	size_t got;
	146
	147	ret = serial_read_blocking(ser, data, dlen, READ_TIMEOUT_MS);
	148	if (ret < 0)
	149	return ret;
	150	got = (size_t)ret;
	151	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
	152	GString *txt = sr_hexdump_new(data, got);
	153	sr_spew("<-- RX %s.", txt->str);
	154	sr_hexdump_free(txt);
	155	}
	156	if (got != dlen)
	157	return SR_ERR_DATA;
	158	return SR_OK;
	159	}
	160
161	/* Send a request then receive a response. Convenience routine. */
162	static int send_then_recv(struct sr_serial_dev_inst *serial,
163	const uint8_t *tx_data, size_t tx_length,
164	uint8_t *rx_data, size_t rx_length)
165	{
166	int ret;
167
168	if (tx_data && tx_length) {
169	ret = send_request(serial, tx_data, tx_length);
170	if (ret != SR_OK)
171	return ret;
172	}
173
174	if (rx_data && rx_length) {
175	ret = recv_response(serial, rx_data, rx_length);
176	if (ret != SR_OK)
177	return ret;
178	}
179
180	return SR_OK;
181	}
182
183	/* Identify the relay card, gather version information details. */
184	SR_PRIV int devantech_eth008_get_model(struct sr_serial_dev_inst *serial,
185	uint8_t model_code, uint8_t hw_version, uint8_t *fw_version)
c12ca361	186	{
8712c783 GS	187	uint8_t req[1], *wrptr;
	188	uint8_t rsp[3], v8;
	189	const uint8_t *rdptr;
	190	int ret;
	191
	192	if (model_code)
	193	*model_code = 0;
	194	if (hw_version)
	195	*hw_version = 0;
	196	if (fw_version)
	197	*fw_version = 0;
	198
	199	wrptr = req;
	200	write_u8_inc(&wrptr, CMD_GET_MODULE_INFO);
	201	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
	202	if (ret != SR_OK)
	203	return ret;
	204	rdptr = rsp;
	205
	206	v8 = read_u8_inc(&rdptr);
	207	if (model_code)
	208	*model_code = v8;
	209	v8 = read_u8_inc(&rdptr);
	210	if (hw_version)
	211	*hw_version = v8;
	212	v8 = read_u8_inc(&rdptr);
	213	if (fw_version)
	214	*fw_version = v8;
	215
	216	return SR_OK;
	217	}
	218
	219	/* Get the relay card's serial number (its MAC address). */
	220	SR_PRIV int devantech_eth008_get_serno(struct sr_serial_dev_inst *serial,
	221	char *text_buffer, size_t text_length)
	222	{
	223	uint8_t req[1], *wrptr;
	224	uint8_t rsp[6], b;
	225	const uint8_t rdptr, endptr;
	226	size_t written;
	227	int ret;
	228
	229	if (text_buffer && !text_length)
	230	return SR_ERR_ARG;
	231	if (text_buffer)
	232	memset(text_buffer, 0, text_length);
	233
	234	wrptr = req;
	235	write_u8_inc(&wrptr, CMD_GET_SERIAL_NUMBER);
	236	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
	237	if (ret != SR_OK)
	238	return ret;
	239	rdptr = rsp;
	240
	241	endptr = rsp + sizeof(rsp);
	242	while (rdptr < endptr && text_buffer && text_length >= 3) {
	243	b = read_u8_inc(&rdptr);
	244	written = snprintf(text_buffer, text_length, "%02x", b);
	245	text_buffer += written;
	246	text_length -= written;
	247	}
	248
	249	return SR_OK;
	250	}
251
252	/* Update an internal cache from the relay card's current state. */
253	SR_PRIV int devantech_eth008_cache_state(const struct sr_dev_inst *sdi)
254	{
255	struct sr_serial_dev_inst *serial;
c12ca361	256	struct dev_context *devc;
8712c783 GS	257	size_t rx_size;
	258	uint8_t req[1], *wrptr;
	259	uint8_t rsp[1];
	260	const uint8_t *rdptr;
	261	uint32_t have;
	262	int ret;
c12ca361	263
8712c783 GS	264	serial = sdi->conn;
	265	if (!serial)
	266	return SR_ERR_ARG;
	267	devc = sdi->priv;
	268	if (!devc)
	269	return SR_ERR_ARG;
c12ca361	270
8712c783 GS	271	rx_size = devc->model->width_do;
	272	if (rx_size > sizeof(rsp))
	273	return SR_ERR_NA;
c12ca361	274
8712c783 GS	275	wrptr = req;
	276	write_u8_inc(&wrptr, CMD_DIGITAL_GET_OUTPUTS);
	277	ret = send_then_recv(serial, req, wrptr - req, rsp, rx_size);
	278	if (ret != SR_OK)
	279	return ret;
	280	rdptr = rsp;
c12ca361	281
8712c783 GS	282	switch (rx_size) {
	283	case 1:
	284	have = read_u8_inc(&rdptr);
	285	break;
	286	default:
	287	return SR_ERR_NA;
c12ca361	288	}
8712c783 GS	289	have &= devc->mask_do;
	290	devc->curr_do = have;
	291
	292	return SR_OK;
	293	}
	294
	295	/* Query the state of an individual relay channel. */
	296	SR_PRIV int devantech_eth008_query_do(const struct sr_dev_inst *sdi,
	297	const struct sr_channel_group cg, gboolean on)
	298	{
	299	struct dev_context *devc;
	300	struct channel_group_context *cgc;
	301	uint32_t have;
	302	int ret;
	303
	304	devc = sdi->priv;
	305	if (!devc)
	306	return SR_ERR_ARG;
	307
	308	/* Unconditionally update the internal cache. */
	309	ret = devantech_eth008_cache_state(sdi);
	310	if (ret != SR_OK)
	311	return ret;
	312
	313	/*
	314	* Only reject unexpected requeusts after the update. Get the
	315	* individual channel's state from the cache of all channels.
	316	*/
	317	if (!cg)
	318	return SR_ERR_ARG;
	319	cgc = cg->priv;
	320	if (!cgc)
	321	return SR_ERR_BUG;
	322	if (cgc->index >= devc->model->ch_count_do)
	323	return SR_ERR_ARG;
	324	have = devc->curr_do;
	325	have >>= cgc->index;
	326	have &= 1 << 0;
	327	if (on)
	328	*on = have ? TRUE : FALSE;
	329
	330	return SR_OK;
	331	}
	332
	333	/*
	334	* Manipulate the state of an individual relay channel (when cg is given).
	335	* Or set/clear all channels at the same time (when cg is NULL).
	336	*/
	337	SR_PRIV int devantech_eth008_setup_do(const struct sr_dev_inst *sdi,
	338	const struct sr_channel_group *cg, gboolean on)
	339	{
	340	struct sr_serial_dev_inst *serial;
	341	struct dev_context *devc;
	342	size_t width_do;
	343	struct channel_group_context *cgc;
	344	size_t number;
	345	uint32_t reg;
	346	uint8_t req[3], *wrptr, cmd;
	347	uint8_t rsp[1], v8;
	348	const uint8_t *rdptr;
	349	int ret;
	350
	351	serial = sdi->conn;
	352	if (!serial)
353	return SR_ERR_ARG;
354	devc = sdi->priv;
355	if (!devc)
356	return SR_ERR_ARG;
357	cgc = cg ? cg->priv : NULL;
358	if (cgc && cgc->index >= devc->model->ch_count_do)
359	return SR_ERR_ARG;
360
361	width_do = devc->model->width_do;
362	if (1 + width_do > sizeof(req))
363	return SR_ERR_NA;
364
365	wrptr = req;
366	if (cgc) {
367	/* Manipulate an individual channel. */
368	cmd = on ? CMD_DIGITAL_ACTIVE : CMD_DIGITAL_INACTIVE;
369	number = cgc->number;
370	write_u8_inc(&wrptr, cmd);
371	write_u8_inc(&wrptr, number & 0xff);
372	write_u8_inc(&wrptr, 0); /* Just set/clear, no pulse. */
373	} else {
374	/* Manipulate all channels at the same time. */
375	reg = on ? devc->mask_do : 0;
376	write_u8_inc(&wrptr, CMD_DIGITAL_SET_OUTPUTS);
377	switch (width_do) {
378	case 1:
379	write_u8_inc(&wrptr, reg & 0xff);
380	break;
381	default:
382	return SR_ERR_NA;
383	}
384	}
385	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
386	if (ret != SR_OK)
387	return ret;
388	rdptr = rsp;
389
390	v8 = read_u8_inc(&rdptr);
391	if (v8 != 0)
392	return SR_ERR_DATA;
393
394	return SR_OK;
395	}
396
397	SR_PRIV int devantech_eth008_query_supply(const struct sr_dev_inst *sdi,
398	const struct sr_channel_group cg, uint16_t millivolts)
399	{
400	struct sr_serial_dev_inst *serial;
401	uint8_t req[1], *wrptr;
402	uint8_t rsp[1];
403	const uint8_t *rdptr;
404	uint16_t have;
405	int ret;
406
407	(void)cg;
408
409	serial = sdi->conn;
410	if (!serial)
411	return SR_ERR_ARG;
412
413	wrptr = req;
414	write_u8_inc(&wrptr, CMD_GET_SUPPLY_VOLTS);
415	ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
416	if (ret != SR_OK)
417	return ret;
418	rdptr = rsp;
419
420	/* Gets a byte for voltage in units of 0.1V. Scale up to mV. */
421	have = read_u8_inc(&rdptr);
422	have *= 100;
423	if (millivolts)
424	*millivolts = have;
c12ca361	425
8712c783	426	return SR_OK;
c12ca361	427	}