[libsigrok.git] / src / hardware / baylibre-acme / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2015 Bartosz Golaszewski <bgolaszewski@baylibre.com>
 *
 * 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 <string.h>
#include <stdlib.h> /* strtol() */
#include <errno.h>
#include <fcntl.h> /* open(), etc... */
#include <glib/gstdio.h>
#include "protocol.h"

struct channel_group_priv {
	int hwmon_num;
	int probe_type;
};

struct channel_priv {
	int ch_type;
	struct channel_group_priv *probe;
};

static const uint8_t enrg_i2c_addrs[] = {
	0x40, 0x41, 0x44, 0x45, 0x42, 0x43, 0x46, 0x47,
};

static const uint8_t temp_i2c_addrs[] = {
	0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
};

#define MOHM_TO_UOHM(x) ((x) * 1000)
#define UOHM_TO_MOHM(x) ((x) / 1000)

SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
{
	return enrg_i2c_addrs[index];
}

SR_PRIV uint8_t bl_acme_get_temp_addr(int index)
{
	return temp_i2c_addrs[index];
}

SR_PRIV gboolean bl_acme_is_sane(void)
{
	gboolean status;

	/*
	 * We expect sysfs to be present and mounted at /sys, ina226 and
	 * tmp435 sensors detected by the system and their appropriate
	 * drivers loaded and functional.
	 */
	status = g_file_test("/sys", G_FILE_TEST_IS_DIR);
	if (!status) {
		sr_err("/sys/ directory not found - sysfs not mounted?");
		return FALSE;
	}

	return TRUE;
}

static void probe_name_path(unsigned int addr, GString *path)
{
	g_string_printf(path,
			"/sys/class/i2c-adapter/i2c-1/1-00%02x/name", addr);
}

/*
 * For given address fill buf with the path to appropriate hwmon entry.
 */
static void probe_hwmon_path(unsigned int addr, GString *path)
{
	g_string_printf(path,
			"/sys/class/i2c-adapter/i2c-1/1-00%02x/hwmon", addr);
}

SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
				      int prb_num, const char *prb_name)
{
	gboolean ret = FALSE, status;
	char *buf = NULL;
	GString *path = g_string_sized_new(64);
	GError *err = NULL;
	gsize size;

	probe_name_path(addr, path);
	status = g_file_get_contents(path->str, &buf, &size, &err);
	if (!status) {
		sr_dbg("Name for probe %d can't be read: %s",
		       prb_num, err->message);
		g_string_free(path, TRUE);
		return ret;

	}

	if (strncmp(buf, prb_name, strlen(prb_name)) == 0) {
		/*
		 * Correct driver registered on this address - but is
		 * there an actual probe connected?
		 */
		probe_hwmon_path(addr, path);
		status = g_file_test(path->str, G_FILE_TEST_IS_DIR);
		if (status) {
			/* We have found an ACME probe. */
			ret = TRUE;
		}
	}

	g_free(buf);
	g_string_free(path, TRUE);

	return ret;
}

static int get_hwmon_index(unsigned int addr)
{
	int status, hwmon;
	GString *path = g_string_sized_new(64);
	GError *err = NULL;
	GDir *dir;

	probe_hwmon_path(addr, path);
	dir = g_dir_open(path->str, 0, &err);
	if (dir == NULL) {
		sr_err("Error opening %s: %s", path->str, err->message);
		g_string_free(path, TRUE);
		return -1;
	}

	g_string_free(path, TRUE);

	/*
	 * The directory should contain a single file named hwmonX where X
	 * is the hwmon index.
	 */
	status = sscanf(g_dir_read_name(dir), "hwmon%d", &hwmon);
	g_dir_close(dir);
	if (status != 1) {
		sr_err("Unable to determine the hwmon entry");
		return -1;
	}

	return hwmon;
}

static void append_channel(struct sr_dev_inst *sdi,
			   struct sr_channel_group *cg,
			   int index, int type)
{
	struct channel_priv *cp;
	struct dev_context *devc;
	struct sr_channel *ch;
	char *name;

	devc = sdi->priv;

	switch (type) {
	case ENRG_PWR:
		name = g_strdup_printf("P%d_ENRG_PWR", index);
		break;
	case ENRG_CURR:
		name = g_strdup_printf("P%d_ENRG_CURR", index);
		break;
	case ENRG_VOL:
		name = g_strdup_printf("P%d_ENRG_VOL", index);
		break;
	case TEMP_IN:
		name = g_strdup_printf("P%d_TEMP_IN", index);
		break;
	case TEMP_OUT:
		name = g_strdup_printf("P%d_TEMP_OUT", index);
		break;
	default:
		sr_err("Bug in the code: invalid channel type!");
		return;
	}

	cp = g_malloc0(sizeof(struct channel_priv));
	cp->ch_type = type;
	cp->probe = cg->priv;

	ch = sr_channel_new(devc->num_channels++,
			    SR_CHANNEL_ANALOG, TRUE, name);
	g_free(name);

	ch->priv = cp;
	cg->channels = g_slist_append(cg->channels, ch);
	sdi->channels = g_slist_append(sdi->channels, ch);
}

SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
					unsigned int addr, int prb_num)
{
	struct sr_channel_group *cg;
	struct channel_group_priv *cgp;
	int hwmon;

	/* Obtain the hwmon index. */
	hwmon = get_hwmon_index(addr);
	if (hwmon < 0)
		return FALSE;

	cg = g_malloc0(sizeof(struct sr_channel_group));
	cgp = g_malloc0(sizeof(struct channel_group_priv));
	cgp->hwmon_num = hwmon;
	cgp->probe_type = type;
	cg->name = g_strdup_printf("Probe_%d", prb_num);
	cg->priv = cgp;

	if (type == PROBE_ENRG) {
		append_channel(sdi, cg, prb_num, ENRG_PWR);
		append_channel(sdi, cg, prb_num, ENRG_CURR);
		append_channel(sdi, cg, prb_num, ENRG_VOL);
	} else if (type == PROBE_TEMP) {
		append_channel(sdi, cg, prb_num, TEMP_IN);
		append_channel(sdi, cg, prb_num, TEMP_OUT);
	} else {
		sr_err("Bug in the code: invalid probe type!");
	}

	sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);

	return TRUE;
}

/*
 * Sets path to the hwmon attribute if this channel group
 * supports shunt resistance setting. The caller has to supply
 * a valid GString.
 */
static int get_shunt_path(const struct sr_channel_group *cg, GString *path)
{
	struct channel_group_priv *cgp;
	int ret = SR_OK, status;

	cgp = cg->priv;

	if (cgp->probe_type != PROBE_ENRG) {
		sr_err("Probe doesn't support shunt resistance setting");
		return SR_ERR_ARG;
	}

	g_string_append_printf(path,
			       "/sys/class/hwmon/hwmon%d/shunt_resistor",
			       cgp->hwmon_num);

	/*
	 * The shunt_resistor sysfs attribute is available
	 * in the Linux kernel since version 3.20. We have
	 * to notify the user if this attribute is not
	 * present.
	 */
	status = g_file_test(path->str, G_FILE_TEST_EXISTS);
	if (!status) {
		sr_err("shunt_resistance attribute not present please update "
		       "your kernel to version >=3.20");
		return SR_ERR_NA;
	}

	return ret;
}

SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
			      uint64_t *shunt)
{
	GString *path = g_string_sized_new(64);
	gchar *contents;
	int status, ret = SR_OK;
	GError *err = NULL;

	status = get_shunt_path(cg, path);
	if (status != SR_OK) {
		ret = status;
		goto out;
	}

	status = g_file_get_contents(path->str, &contents, NULL, &err);
	if (!status) {
		sr_err("Error reading shunt resistance: %s", err->message);
		ret = SR_ERR_IO;
		goto out;
	}

	*shunt = UOHM_TO_MOHM(strtol(contents, NULL, 10));

out:
	g_string_free(path, TRUE);
	return ret;
}

SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg,
			      uint64_t shunt)
{
	GString *path = g_string_sized_new(64);;
	int status, ret = SR_OK;
	FILE *fd;

	status = get_shunt_path(cg, path);
	if (status != SR_OK) {
		ret = status;
		goto out;
	}

	/*
	 * Can't use g_file_set_contents() here, as it calls open() with
	 * O_EXEC flag in a sysfs directory thus failing with EACCES.
	 */
	fd = g_fopen(path->str, "w");
	if (!fd) {
		sr_err("Error opening %s: %s", path->str, strerror(errno));
		g_string_free(path, TRUE);
		return SR_ERR_IO;
	}

	g_string_free(path, TRUE);
	g_fprintf(fd, "%llu\n", MOHM_TO_UOHM(shunt));
	/*
	 * XXX There's no g_fclose() in GLib. This seems to work,
	 * but is it safe?
	 */
	fclose(fd);

out:
	g_string_free(path, TRUE);
	return ret;
}

static int channel_to_mq(struct sr_channel *ch)
{
	struct channel_priv *chp;

	chp = ch->priv;

	switch (chp->ch_type) {
	case ENRG_PWR:
		return SR_MQ_POWER;
	case ENRG_CURR:
		return SR_MQ_CURRENT;
	case ENRG_VOL:
		return SR_MQ_VOLTAGE;
	case TEMP_IN:
	case TEMP_OUT:
		return SR_MQ_TEMPERATURE;
	default:
		return -1;
	}
}

static int channel_to_unit(struct sr_channel *ch)
{
	struct channel_priv *chp;

	chp = ch->priv;

	switch (chp->ch_type) {
	case ENRG_PWR:
		return SR_UNIT_WATT;
	case ENRG_CURR:
		return SR_UNIT_AMPERE;
	case ENRG_VOL:
		return SR_UNIT_VOLT;
	case TEMP_IN:
	case TEMP_OUT:
		return SR_UNIT_CELSIUS;
	default:
		return -1;
	}
}

/* We need to scale measurements down from the units used by the drivers. */
static float adjust_data(int val, int type)
{
	switch (type) {
	case ENRG_PWR:
		return ((float)val) / 1000000.0;
	case ENRG_CURR:
	case ENRG_VOL:
	case TEMP_IN:
	case TEMP_OUT:
		return ((float)val) / 1000.0;
	default:
		return 0.0;
	}
}

static float read_sample(struct sr_channel *ch)
{
	struct channel_priv *chp;
	char path[64], *file, buf[16];
	ssize_t len;
	int fd;

	chp = ch->priv;

	switch (chp->ch_type) {
	case ENRG_PWR:	file = "power1_input";	break;
	case ENRG_CURR:	file = "curr1_input";	break;
	case ENRG_VOL:	file = "in1_input";	break;
	case TEMP_IN:	file = "temp1_input";	break;
	case TEMP_OUT:	file = "temp2_input";	break;
	default:
		sr_err("Bug in the code: invalid channel type!");
		return -1.0;
	}

	snprintf(path, sizeof(path),
		 "/sys/class/hwmon/hwmon%d/%s",
		 chp->probe->hwmon_num, file);
	fd = open(path, O_RDONLY);
	if (fd < 0) {
		sr_err("Error opening %s: %s", path, strerror(errno));
		ch->enabled = FALSE;
		return -1.0;
	}

	len = read(fd, buf, sizeof(buf));
	close(fd);
	if (len < 0) {
		sr_err("error reading from %s: %s", path, strerror(errno));
		ch->enabled = FALSE;
		return -1.0;
	}

	return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
}

SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
{
	uint32_t cur_time, elapsed_time, diff_time;
	int64_t time_to_sleep;
	struct sr_datafeed_packet packet, framep;
	struct sr_datafeed_analog analog;
	struct sr_dev_inst *sdi;
	struct sr_channel *ch;
	struct dev_context *devc;
	GSList *chl, chonly;
	float valf;

	(void)fd;
	(void)revents;

	sdi = cb_data;
	if (!sdi)
		return TRUE;

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

	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;
	memset(&analog, 0, sizeof(analog));
	analog.data = &valf;

	/*
	 * Reading from sysfs takes some time - try to
	 * keep up with samplerate.
	 */
	if (devc->samples_read) {
		cur_time = g_get_monotonic_time();
		diff_time = cur_time - devc->last_sample_fin;
		time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time;
		if (time_to_sleep > 0)
			g_usleep(time_to_sleep);
	}

	framep.type = SR_DF_FRAME_BEGIN;
	sr_session_send(cb_data, &framep);

	/*
	 * Due to different units used in each channel we're sending
	 * samples one-by-one.
	 */
	for (chl = sdi->channels; chl; chl = chl->next) {
		ch = chl->data;
		if (!ch->enabled)
			continue;
		chonly.next = NULL;
		chonly.data = ch;
		analog.channels = &chonly;
		analog.num_samples = 1;
		analog.mq = channel_to_mq(chl->data);
		analog.unit = channel_to_unit(ch);

		valf = read_sample(ch);

		sr_session_send(cb_data, &packet);
	}

	framep.type = SR_DF_FRAME_END;
	sr_session_send(cb_data, &framep);

	devc->samples_read++;
	if (devc->limit_samples > 0 &&
	    devc->samples_read >= devc->limit_samples) {
		sr_info("Requested number of samples reached.");
		sdi->driver->dev_acquisition_stop(sdi, cb_data);
		devc->last_sample_fin = g_get_monotonic_time();
		return TRUE;
	} else if (devc->limit_msec > 0) {
		cur_time = g_get_monotonic_time();
		elapsed_time = cur_time - devc->start_time;

		if (elapsed_time >= devc->limit_msec) {
			sr_info("Sampling time limit reached.");
			sdi->driver->dev_acquisition_stop(sdi, cb_data);
			devc->last_sample_fin = g_get_monotonic_time();
			return TRUE;
		}
	}

	devc->last_sample_fin = g_get_monotonic_time();
	return TRUE;
}
Commit	Line	Data
dfaee1de BG	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2015 Bartosz Golaszewski <bgolaszewski@baylibre.com>
	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
6b80b80d BG	20	#include <string.h>
	21	#include <stdlib.h> /* strtol() */
	22	#include <errno.h>
	23	#include <fcntl.h> /* open(), etc... */
61f2b7f7	24	#include <glib/gstdio.h>
dfaee1de BG	25	#include "protocol.h"
dfaee1de BG	26
6b80b80d BG	27	struct channel_group_priv {
6b80b80d BG	28	int hwmon_num;
61f2b7f7	29	int probe_type;
6b80b80d BG	30	};
	31
	32	struct channel_priv {
	33	int ch_type;
	34	struct channel_group_priv *probe;
	35	};
	36
	37	static const uint8_t enrg_i2c_addrs[] = {
	38	0x40, 0x41, 0x44, 0x45, 0x42, 0x43, 0x46, 0x47,
	39	};
	40
	41	static const uint8_t temp_i2c_addrs[] = {
	42	0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
	43	};
	44
61f2b7f7 BG	45	#define MOHM_TO_UOHM(x) ((x) * 1000)
	46	#define UOHM_TO_MOHM(x) ((x) / 1000)
	47
6b80b80d BG	48	SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
	49	{
	50	return enrg_i2c_addrs[index];
	51	}
	52
	53	SR_PRIV uint8_t bl_acme_get_temp_addr(int index)
	54	{
	55	return temp_i2c_addrs[index];
	56	}
	57
	58	SR_PRIV gboolean bl_acme_is_sane(void)
	59	{
	60	gboolean status;
	61
	62	/*
	63	* We expect sysfs to be present and mounted at /sys, ina226 and
	64	* tmp435 sensors detected by the system and their appropriate
	65	* drivers loaded and functional.
	66	*/
	67	status = g_file_test("/sys", G_FILE_TEST_IS_DIR);
	68	if (!status) {
	69	sr_err("/sys/ directory not found - sysfs not mounted?");
	70	return FALSE;
	71	}
	72
	73	return TRUE;
	74	}
	75
	76	static void probe_name_path(unsigned int addr, GString *path)
	77	{
	78	g_string_printf(path,
	79	"/sys/class/i2c-adapter/i2c-1/1-00%02x/name", addr);
	80	}
	81
	82	/*
	83	* For given address fill buf with the path to appropriate hwmon entry.
	84	*/
	85	static void probe_hwmon_path(unsigned int addr, GString *path)
	86	{
	87	g_string_printf(path,
	88	"/sys/class/i2c-adapter/i2c-1/1-00%02x/hwmon", addr);
	89	}
	90
	91	SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
	92	int prb_num, const char *prb_name)
	93	{
	94	gboolean ret = FALSE, status;
	95	char *buf = NULL;
	96	GString *path = g_string_sized_new(64);
	97	GError *err = NULL;
	98	gsize size;
	99
	100	probe_name_path(addr, path);
	101	status = g_file_get_contents(path->str, &buf, &size, &err);
	102	if (!status) {
	103	sr_dbg("Name for probe %d can't be read: %s",
	104	prb_num, err->message);
	105	g_string_free(path, TRUE);
	106	return ret;
	107
	108	}
	109
	110	if (strncmp(buf, prb_name, strlen(prb_name)) == 0) {
	111	/*
112	* Correct driver registered on this address - but is
113	* there an actual probe connected?
114	*/
115	probe_hwmon_path(addr, path);
116	status = g_file_test(path->str, G_FILE_TEST_IS_DIR);
117	if (status) {
118	/* We have found an ACME probe. */
119	ret = TRUE;
120	}
121	}
122
123	g_free(buf);
124	g_string_free(path, TRUE);
125
126	return ret;
127	}
128
129	static int get_hwmon_index(unsigned int addr)
130	{
131	int status, hwmon;
132	GString *path = g_string_sized_new(64);
133	GError *err = NULL;
134	GDir *dir;
135
136	probe_hwmon_path(addr, path);
137	dir = g_dir_open(path->str, 0, &err);
138	if (dir == NULL) {
139	sr_err("Error opening %s: %s", path->str, err->message);
140	g_string_free(path, TRUE);
141	return -1;
142	}
143
144	g_string_free(path, TRUE);
145
146	/*
147	* The directory should contain a single file named hwmonX where X
148	* is the hwmon index.
149	*/
150	status = sscanf(g_dir_read_name(dir), "hwmon%d", &hwmon);
151	g_dir_close(dir);
152	if (status != 1) {
153	sr_err("Unable to determine the hwmon entry");
154	return -1;
155	}
156
157	return hwmon;
158	}
159
160	static void append_channel(struct sr_dev_inst *sdi,
161	struct sr_channel_group *cg,
162	int index, int type)
163	{
164	struct channel_priv *cp;
165	struct dev_context *devc;
166	struct sr_channel *ch;
167	char *name;
168
169	devc = sdi->priv;
170
171	switch (type) {
172	case ENRG_PWR:
173	name = g_strdup_printf("P%d_ENRG_PWR", index);
174	break;
175	case ENRG_CURR:
176	name = g_strdup_printf("P%d_ENRG_CURR", index);
177	break;
178	case ENRG_VOL:
179	name = g_strdup_printf("P%d_ENRG_VOL", index);
180	break;
181	case TEMP_IN:
182	name = g_strdup_printf("P%d_TEMP_IN", index);
183	break;
184	case TEMP_OUT:
185	name = g_strdup_printf("P%d_TEMP_OUT", index);
186	break;
187	default:
188	sr_err("Bug in the code: invalid channel type!");
189	return;
190	}
191
192	cp = g_malloc0(sizeof(struct channel_priv));
193	cp->ch_type = type;
194	cp->probe = cg->priv;
195
196	ch = sr_channel_new(devc->num_channels++,
197	SR_CHANNEL_ANALOG, TRUE, name);
198	g_free(name);
199
200	ch->priv = cp;
201	cg->channels = g_slist_append(cg->channels, ch);
202	sdi->channels = g_slist_append(sdi->channels, ch);
203	}
204
205	SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
206	unsigned int addr, int prb_num)
207	{
208	struct sr_channel_group *cg;
209	struct channel_group_priv *cgp;
210	int hwmon;
211
212	/* Obtain the hwmon index. */
213	hwmon = get_hwmon_index(addr);
214	if (hwmon < 0)
215	return FALSE;
216
217	cg = g_malloc0(sizeof(struct sr_channel_group));
218	cgp = g_malloc0(sizeof(struct channel_group_priv));
219	cgp->hwmon_num = hwmon;
61f2b7f7	220	cgp->probe_type = type;
6b80b80d BG	221	cg->name = g_strdup_printf("Probe_%d", prb_num);
	222	cg->priv = cgp;
	223
	224	if (type == PROBE_ENRG) {
	225	append_channel(sdi, cg, prb_num, ENRG_PWR);
	226	append_channel(sdi, cg, prb_num, ENRG_CURR);
	227	append_channel(sdi, cg, prb_num, ENRG_VOL);
	228	} else if (type == PROBE_TEMP) {
	229	append_channel(sdi, cg, prb_num, TEMP_IN);
	230	append_channel(sdi, cg, prb_num, TEMP_OUT);
	231	} else {
	232	sr_err("Bug in the code: invalid probe type!");
	233	}
	234
	235	sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
	236
	237	return TRUE;
	238	}
	239
61f2b7f7 BG	240	/*
	241	* Sets path to the hwmon attribute if this channel group
	242	* supports shunt resistance setting. The caller has to supply
	243	* a valid GString.
	244	*/
	245	static int get_shunt_path(const struct sr_channel_group cg, GString path)
	246	{
	247	struct channel_group_priv *cgp;
	248	int ret = SR_OK, status;
	249
	250	cgp = cg->priv;
	251
	252	if (cgp->probe_type != PROBE_ENRG) {
	253	sr_err("Probe doesn't support shunt resistance setting");
	254	return SR_ERR_ARG;
	255	}
	256
	257	g_string_append_printf(path,
	258	"/sys/class/hwmon/hwmon%d/shunt_resistor",
	259	cgp->hwmon_num);
	260
	261	/*
	262	* The shunt_resistor sysfs attribute is available
	263	* in the Linux kernel since version 3.20. We have
	264	* to notify the user if this attribute is not
	265	* present.
	266	*/
	267	status = g_file_test(path->str, G_FILE_TEST_EXISTS);
	268	if (!status) {
	269	sr_err("shunt_resistance attribute not present please update "
	270	"your kernel to version >=3.20");
	271	return SR_ERR_NA;
	272	}
	273
	274	return ret;
	275	}
	276
	277	SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
	278	uint64_t *shunt)
	279	{
	280	GString *path = g_string_sized_new(64);
	281	gchar *contents;
	282	int status, ret = SR_OK;
	283	GError *err = NULL;
	284
	285	status = get_shunt_path(cg, path);
	286	if (status != SR_OK) {
	287	ret = status;
	288	goto out;
	289	}
	290
	291	status = g_file_get_contents(path->str, &contents, NULL, &err);
	292	if (!status) {
	293	sr_err("Error reading shunt resistance: %s", err->message);
	294	ret = SR_ERR_IO;
	295	goto out;
	296	}
	297
	298	*shunt = UOHM_TO_MOHM(strtol(contents, NULL, 10));
	299
	300	out:
	301	g_string_free(path, TRUE);
	302	return ret;
	303	}
304
305	SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg,
306	uint64_t shunt)
307	{
308	GString *path = g_string_sized_new(64);;
309	int status, ret = SR_OK;
310	FILE *fd;
311
312	status = get_shunt_path(cg, path);
313	if (status != SR_OK) {
314	ret = status;
315	goto out;
316	}
317
318	/*
319	* Can't use g_file_set_contents() here, as it calls open() with
320	* O_EXEC flag in a sysfs directory thus failing with EACCES.
321	*/
322	fd = g_fopen(path->str, "w");
323	if (!fd) {
324	sr_err("Error opening %s: %s", path->str, strerror(errno));
325	g_string_free(path, TRUE);
326	return SR_ERR_IO;
327	}
328
329	g_string_free(path, TRUE);
330	g_fprintf(fd, "%llu\n", MOHM_TO_UOHM(shunt));
331	/*
332	* XXX There's no g_fclose() in GLib. This seems to work,
333	* but is it safe?
334	*/
335	fclose(fd);
336
337	out:
338	g_string_free(path, TRUE);
339	return ret;
340	}
341
6b80b80d	342	static int channel_to_mq(struct sr_channel *ch)
dfaee1de	343	{
6b80b80d BG	344	struct channel_priv *chp;
	345
	346	chp = ch->priv;
	347
	348	switch (chp->ch_type) {
	349	case ENRG_PWR:
	350	return SR_MQ_POWER;
	351	case ENRG_CURR:
	352	return SR_MQ_CURRENT;
	353	case ENRG_VOL:
	354	return SR_MQ_VOLTAGE;
	355	case TEMP_IN:
	356	case TEMP_OUT:
	357	return SR_MQ_TEMPERATURE;
	358	default:
	359	return -1;
	360	}
	361	}
	362
	363	static int channel_to_unit(struct sr_channel *ch)
	364	{
	365	struct channel_priv *chp;
	366
	367	chp = ch->priv;
	368
	369	switch (chp->ch_type) {
	370	case ENRG_PWR:
	371	return SR_UNIT_WATT;
	372	case ENRG_CURR:
	373	return SR_UNIT_AMPERE;
	374	case ENRG_VOL:
	375	return SR_UNIT_VOLT;
	376	case TEMP_IN:
	377	case TEMP_OUT:
	378	return SR_UNIT_CELSIUS;
	379	default:
	380	return -1;
	381	}
	382	}
	383
	384	/* We need to scale measurements down from the units used by the drivers. */
	385	static float adjust_data(int val, int type)
	386	{
	387	switch (type) {
	388	case ENRG_PWR:
	389	return ((float)val) / 1000000.0;
	390	case ENRG_CURR:
	391	case ENRG_VOL:
	392	case TEMP_IN:
	393	case TEMP_OUT:
	394	return ((float)val) / 1000.0;
	395	default:
	396	return 0.0;
	397	}
	398	}
	399
	400	static float read_sample(struct sr_channel *ch)
	401	{
	402	struct channel_priv *chp;
	403	char path[64], *file, buf[16];
	404	ssize_t len;
	405	int fd;
	406
	407	chp = ch->priv;
408
409	switch (chp->ch_type) {
410	case ENRG_PWR: file = "power1_input"; break;
411	case ENRG_CURR: file = "curr1_input"; break;
412	case ENRG_VOL: file = "in1_input"; break;
413	case TEMP_IN: file = "temp1_input"; break;
414	case TEMP_OUT: file = "temp2_input"; break;
415	default:
416	sr_err("Bug in the code: invalid channel type!");
417	return -1.0;
418	}
419
420	snprintf(path, sizeof(path),
421	"/sys/class/hwmon/hwmon%d/%s",
422	chp->probe->hwmon_num, file);
423	fd = open(path, O_RDONLY);
424	if (fd < 0) {
425	sr_err("Error opening %s: %s", path, strerror(errno));
426	ch->enabled = FALSE;
427	return -1.0;
428	}
429
430	len = read(fd, buf, sizeof(buf));
431	close(fd);
432	if (len < 0) {
433	sr_err("error reading from %s: %s", path, strerror(errno));
434	ch->enabled = FALSE;
435	return -1.0;
436	}
437
438	return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
439	}
440
441	SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
442	{
443	uint32_t cur_time, elapsed_time, diff_time;
444	int64_t time_to_sleep;
445	struct sr_datafeed_packet packet, framep;
446	struct sr_datafeed_analog analog;
447	struct sr_dev_inst *sdi;
448	struct sr_channel *ch;
dfaee1de	449	struct dev_context *devc;
6b80b80d BG	450	GSList *chl, chonly;
6b80b80d BG	451	float valf;
dfaee1de BG	452
dfaee1de BG	453	(void)fd;
6b80b80d BG	454	(void)revents;
	455
	456	sdi = cb_data;
	457	if (!sdi)
	458	return TRUE;
dfaee1de	459
6b80b80d BG	460	devc = sdi->priv;
6b80b80d BG	461	if (!devc)
dfaee1de BG	462	return TRUE;
dfaee1de BG	463
6b80b80d BG	464	packet.type = SR_DF_ANALOG;
	465	packet.payload = &analog;
	466	memset(&analog, 0, sizeof(analog));
	467	analog.data = &valf;
	468
	469	/*
	470	* Reading from sysfs takes some time - try to
	471	* keep up with samplerate.
	472	*/
	473	if (devc->samples_read) {
	474	cur_time = g_get_monotonic_time();
	475	diff_time = cur_time - devc->last_sample_fin;
	476	time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time;
	477	if (time_to_sleep > 0)
	478	g_usleep(time_to_sleep);
	479	}
	480
	481	framep.type = SR_DF_FRAME_BEGIN;
	482	sr_session_send(cb_data, &framep);
	483
	484	/*
	485	* Due to different units used in each channel we're sending
	486	* samples one-by-one.
	487	*/
	488	for (chl = sdi->channels; chl; chl = chl->next) {
	489	ch = chl->data;
	490	if (!ch->enabled)
	491	continue;
	492	chonly.next = NULL;
	493	chonly.data = ch;
	494	analog.channels = &chonly;
	495	analog.num_samples = 1;
	496	analog.mq = channel_to_mq(chl->data);
	497	analog.unit = channel_to_unit(ch);
	498
	499	valf = read_sample(ch);
	500
	501	sr_session_send(cb_data, &packet);
	502	}
	503
	504	framep.type = SR_DF_FRAME_END;
	505	sr_session_send(cb_data, &framep);
	506
	507	devc->samples_read++;
	508	if (devc->limit_samples > 0 &&
	509	devc->samples_read >= devc->limit_samples) {
	510	sr_info("Requested number of samples reached.");
	511	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	512	devc->last_sample_fin = g_get_monotonic_time();
dfaee1de	513	return TRUE;
6b80b80d BG	514	} else if (devc->limit_msec > 0) {
	515	cur_time = g_get_monotonic_time();
	516	elapsed_time = cur_time - devc->start_time;
dfaee1de	517
6b80b80d BG	518	if (elapsed_time >= devc->limit_msec) {
	519	sr_info("Sampling time limit reached.");
	520	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	521	devc->last_sample_fin = g_get_monotonic_time();
	522	return TRUE;
	523	}
dfaee1de BG	524	}
dfaee1de BG	525
6b80b80d	526	devc->last_sample_fin = g_get_monotonic_time();
dfaee1de BG	527	return TRUE;
dfaee1de BG	528	}