X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Fdemo%2Fdemo.c;h=b317fefed275be6326a426fc22ca169cd83d20ea;hb=c07f60e73dba95479c96650a94db77c3639639ce;hp=923d20a9b60acdd256e3dfba8e2e64faa0b5feed;hpb=4b97c74e0b5c19ad0ee04620b618461248ab69d7;p=libsigrok.git

diff --git a/hardware/demo/demo.c b/hardware/demo/demo.c
index 923d20a9..b317fefe 100644
--- a/hardware/demo/demo.c
+++ b/hardware/demo/demo.c
@@ -1,5 +1,5 @@
 /*
- * This file is part of the sigrok project.
+ * This file is part of the libsigrok project.
  *
  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
  * Copyright (C) 2011 Olivier Fauchon <olivier@aixmarseille.com>
@@ -31,56 +31,68 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
-/* Message logging helpers with driver-specific prefix string. */
-#define DRIVER_LOG_DOMAIN "demo: "
-#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
-#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
+#define LOG_PREFIX "demo"
 
-/* TODO: Number of probes should be configurable. */
-#define NUM_PROBES             8
-
-#define DEMONAME               "Demo device"
+#define DEFAULT_NUM_LOGIC_PROBES     8
+#define DEFAULT_NUM_ANALOG_PROBES    4
 
 /* The size of chunks to send through the session bus. */
-/* TODO: Should be configurable. */
-#define BUFSIZE                4096
+#define LOGIC_BUFSIZE        4096
 
-/* Supported patterns which we can generate */
+/* Patterns we can generate */
 enum {
 	/**
-	 * Pattern which spells "sigrok" using '0's (with '1's as "background")
-	 * when displayed using the 'bits' output format.
+	 * Spells "sigrok" across 8 probes using '0's (with '1's as
+	 * "background") when displayed using the 'bits' output format.
+	 * The pattern is repeasted every 8 probes, shifted to the right
+	 * in time by one bit.
 	 */
 	PATTERN_SIGROK,
 
-	/** Pattern which consists of (pseudo-)random values on all probes. */
+	/** Pseudo-random values on all probes. */
 	PATTERN_RANDOM,
 
 	/**
-	 * Pattern which consists of incrementing numbers.
-	 * TODO: Better description.
+	 * Incrementing number across 8 probes. The pattern is repeasted
+	 * every 8 probes, shifted to the right in time by one bit.
 	 */
 	PATTERN_INC,
 
-	/** Pattern where all probes have a low logic state. */
+	/** All probes have a low logic state. */
 	PATTERN_ALL_LOW,
 
-	/** Pattern where all probes have a high logic state. */
+	/** All probes have a high logic state. */
 	PATTERN_ALL_HIGH,
 };
 
+static const char *pattern_strings[] = {
+	"sigrok",
+	"random",
+	"incremental",
+	"all-low",
+	"all-high",
+};
+
 /* Private, per-device-instance driver context. */
 struct dev_context {
 	int pipe_fds[2];
-	GIOChannel *channels[2];
-	uint8_t sample_generator;
+	GIOChannel *channel;
+	uint64_t cur_samplerate;
+	uint64_t limit_samples;
+	uint64_t limit_msec;
 	uint64_t samples_counter;
-	void *session_dev_id;
 	int64_t starttime;
+	uint64_t step;
+	int32_t num_logic_probes;
+	unsigned int logic_unitsize;
+	uint8_t logic_pattern;
+	unsigned char logic_data[LOGIC_BUFSIZE];
+	int32_t num_analog_probes;
+};
+
+static const int32_t hwopts[] = {
+	SR_CONF_NUM_LOGIC_PROBES,
+	SR_CONF_NUM_ANALOG_PROBES,
 };
 
 static const int hwcaps[] = {
@@ -93,26 +105,10 @@ static const int hwcaps[] = {
 	SR_CONF_CONTINUOUS,
 };
 
-static const struct sr_samplerates samplerates = {
+static const uint64_t samplerates[] = {
 	SR_HZ(1),
 	SR_GHZ(1),
 	SR_HZ(1),
-	NULL,
-};
-
-static const char *pattern_strings[] = {
-	"sigrok",
-	"random",
-	"incremental",
-	"all-low",
-	"all-high",
-	NULL,
-};
-
-/* We name the probes 0-7 on our demo driver. */
-static const char *probe_names[NUM_PROBES + 1] = {
-	"0", "1", "2", "3", "4", "5", "6", "7",
-	NULL,
 };
 
 static uint8_t pattern_sigrok[] = {
@@ -126,65 +122,67 @@ static uint8_t pattern_sigrok[] = {
 	0xbe, 0xbe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 };
 
-/* Private, per-device-instance driver context. */
-/* TODO: struct context as with the other drivers. */
-
-/* List of struct sr_dev_inst, maintained by dev_open()/dev_close(). */
 SR_PRIV struct sr_dev_driver demo_driver_info;
 static struct sr_dev_driver *di = &demo_driver_info;
-static uint64_t cur_samplerate = SR_KHZ(200);
-static uint64_t limit_samples = 0;
-static uint64_t limit_msec = 0;
-static int default_pattern = PATTERN_SIGROK;
 
-static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data);
+static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data);
 
-static int clear_instances(void)
-{
-	/* Nothing needed so far. */
 
-	return SR_OK;
+static int dev_clear(void)
+{
+	return std_dev_clear(di, NULL);
 }
 
-static int hw_init(struct sr_context *sr_ctx)
+static int init(struct sr_context *sr_ctx)
 {
-	struct drv_context *drvc;
-
-	if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
-		sr_err("Driver context malloc failed.");
-		return SR_ERR_MALLOC;
-	}
-
-	drvc->sr_ctx = sr_ctx;
-	di->priv = drvc;
-
-	return SR_OK;
+	return std_init(sr_ctx, di, LOG_PREFIX);
 }
 
-static GSList *hw_scan(GSList *options)
+static GSList *scan(GSList *options)
 {
+	struct drv_context *drvc;
+	struct dev_context *devc;
 	struct sr_dev_inst *sdi;
 	struct sr_probe *probe;
-	struct drv_context *drvc;
-	GSList *devices;
-	int i;
-
-	(void)options;
+	struct sr_config *src;
+	GSList *devices, *l;
+	int num_logic_probes, num_analog_probes, i;
+	char probe_name[16];
 
 	drvc = di->priv;
 
-	devices = NULL;
+	num_logic_probes = DEFAULT_NUM_LOGIC_PROBES;
+	num_analog_probes = DEFAULT_NUM_ANALOG_PROBES;
+	for (l = options; l; l = l->next) {
+		src = l->data;
+		switch (src->key) {
+		case SR_CONF_NUM_LOGIC_PROBES:
+			num_logic_probes = g_variant_get_int32(src->data);
+			break;
+		case SR_CONF_NUM_ANALOG_PROBES:
+			num_analog_probes = g_variant_get_int32(src->data);
+			break;
+		}
+	}
 
-	sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, DEMONAME, NULL, NULL);
+	devices = NULL;
+	sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, "Demo device", NULL, NULL);
 	if (!sdi) {
-		sr_err("%s: sr_dev_inst_new failed", __func__);
-		return 0;
+		sr_err("Device instance creation failed.");
+		return NULL;
 	}
 	sdi->driver = di;
 
-	for (i = 0; probe_names[i]; i++) {
-		if (!(probe = sr_probe_new(i, SR_PROBE_LOGIC, TRUE,
-				probe_names[i])))
+	for (i = 0; i < num_logic_probes; i++) {
+		sprintf(probe_name, "D%d", i);
+		if (!(probe = sr_probe_new(i, SR_PROBE_LOGIC, TRUE, probe_name)))
+			return NULL;
+		sdi->probes = g_slist_append(sdi->probes, probe);
+	}
+
+	for (i = 0; i < num_analog_probes; i++) {
+		sprintf(probe_name, "A%d", i);
+		if (!(probe = sr_probe_new(i, SR_PROBE_ANALOG, TRUE, probe_name)))
 			return NULL;
 		sdi->probes = g_slist_append(sdi->probes, probe);
 	}
@@ -192,231 +190,269 @@ static GSList *hw_scan(GSList *options)
 	devices = g_slist_append(devices, sdi);
 	drvc->instances = g_slist_append(drvc->instances, sdi);
 
+	if (!(devc = g_try_malloc(sizeof(struct dev_context)))) {
+		sr_err("Device context malloc failed.");
+		return NULL;
+	}
+	devc->cur_samplerate = SR_KHZ(200);
+	devc->limit_samples = 0;
+	devc->limit_msec = 0;
+	devc->step = 0;
+	devc->num_logic_probes = num_logic_probes;
+	devc->logic_unitsize = (devc->num_logic_probes + 7) / 8;
+	devc->logic_pattern = PATTERN_SIGROK;
+	devc->num_analog_probes = num_analog_probes;
+
+	sdi->priv = devc;
+
 	return devices;
 }
 
-static GSList *hw_dev_list(void)
+static GSList *dev_list(void)
 {
-	struct drv_context *drvc;
-
-	drvc = di->priv;
-
-	return drvc->instances;
+	return ((struct drv_context *)(di->priv))->instances;
 }
 
-static int hw_dev_open(struct sr_dev_inst *sdi)
+static int dev_open(struct sr_dev_inst *sdi)
 {
-	(void)sdi;
-
-	/* Nothing needed so far. */
+	sdi->status = SR_ST_ACTIVE;
 
 	return SR_OK;
 }
 
-static int hw_dev_close(struct sr_dev_inst *sdi)
+static int dev_close(struct sr_dev_inst *sdi)
 {
-	(void)sdi;
-
-	/* Nothing needed so far. */
+	sdi->status = SR_ST_INACTIVE;
 
 	return SR_OK;
 }
 
-static int hw_cleanup(void)
+static int cleanup(void)
 {
-	/* Nothing needed so far. */
-	return SR_OK;
+	return dev_clear();
 }
 
-static int config_get(int id, const void **data, const struct sr_dev_inst *sdi)
+static int config_get(int id, GVariant **data, const struct sr_dev_inst *sdi,
+		const struct sr_probe_group *probe_group)
 {
-	(void)sdi;
+	struct dev_context *devc;
+
+	(void)probe_group;
 
+	devc = sdi->priv;
 	switch (id) {
 	case SR_CONF_SAMPLERATE:
-		*data = &cur_samplerate;
+		*data = g_variant_new_uint64(devc->cur_samplerate);
+		break;
+	case SR_CONF_LIMIT_SAMPLES:
+		*data = g_variant_new_uint64(devc->limit_samples);
+		break;
+	case SR_CONF_LIMIT_MSEC:
+		*data = g_variant_new_uint64(devc->limit_msec);
+		break;
+	case SR_CONF_PATTERN_MODE:
+		*data = g_variant_new_string(pattern_strings[devc->logic_pattern]);
+		break;
+	case SR_CONF_NUM_LOGIC_PROBES:
+		*data = g_variant_new_int32(devc->num_logic_probes);
+		break;
+	case SR_CONF_NUM_ANALOG_PROBES:
+		*data = g_variant_new_int32(devc->num_analog_probes);
 		break;
 	default:
-		return SR_ERR_ARG;
+		return SR_ERR_NA;
 	}
 
 	return SR_OK;
 }
 
-static int config_set(int id, const void *value, const struct sr_dev_inst *sdi)
+static int config_set(int id, GVariant *data, const struct sr_dev_inst *sdi,
+		const struct sr_probe_group *probe_group)
 {
+	unsigned int i;
 	int ret;
 	const char *stropt;
 
-	(void)sdi;
+	(void)probe_group;
+	struct dev_context *const devc = sdi->priv;
+
+	if (sdi->status != SR_ST_ACTIVE)
+		return SR_ERR_DEV_CLOSED;
 
 	if (id == SR_CONF_SAMPLERATE) {
-		cur_samplerate = *(const uint64_t *)value;
-		sr_dbg("%s: setting samplerate to %" PRIu64, __func__,
-		       cur_samplerate);
+		devc->cur_samplerate = g_variant_get_uint64(data);
+		sr_dbg("Setting samplerate to %" PRIu64, devc->cur_samplerate);
 		ret = SR_OK;
 	} else if (id == SR_CONF_LIMIT_SAMPLES) {
-		limit_msec = 0;
-		limit_samples = *(const uint64_t *)value;
-		sr_dbg("%s: setting limit_samples to %" PRIu64, __func__,
-		       limit_samples);
+		devc->limit_msec = 0;
+		devc->limit_samples = g_variant_get_uint64(data);
+		sr_dbg("Setting limit_samples to %" PRIu64, devc->limit_samples);
 		ret = SR_OK;
 	} else if (id == SR_CONF_LIMIT_MSEC) {
-		limit_msec = *(const uint64_t *)value;
-		limit_samples = 0;
-		sr_dbg("%s: setting limit_msec to %" PRIu64, __func__,
-		       limit_msec);
+		devc->limit_msec = g_variant_get_uint64(data);
+		devc->limit_samples = 0;
+		sr_dbg("Setting limit_msec to %" PRIu64, devc->limit_msec);
 		ret = SR_OK;
 	} else if (id == SR_CONF_PATTERN_MODE) {
-		stropt = value;
-		ret = SR_OK;
-		if (!strcmp(stropt, "sigrok")) {
-			default_pattern = PATTERN_SIGROK;
-		} else if (!strcmp(stropt, "random")) {
-			default_pattern = PATTERN_RANDOM;
-		} else if (!strcmp(stropt, "incremental")) {
-			default_pattern = PATTERN_INC;
-		} else if (!strcmp(stropt, "all-low")) {
-			default_pattern = PATTERN_ALL_LOW;
-		} else if (!strcmp(stropt, "all-high")) {
-			default_pattern = PATTERN_ALL_HIGH;
-		} else {
-			ret = SR_ERR;
+		stropt = g_variant_get_string(data, NULL);
+		ret = SR_ERR;
+		for (i = 0; i < ARRAY_SIZE(pattern_strings); i++) {
+			if (!strcmp(stropt, pattern_strings[i])) {
+				devc->logic_pattern = i;
+				ret = SR_OK;
+				break;
+			}
 		}
-		sr_dbg("%s: setting pattern to %d", __func__, default_pattern);
+		/* Might as well do this now. */
+		if (i == PATTERN_ALL_LOW)
+			memset(devc->logic_data, 0x00, LOGIC_BUFSIZE);
+		else if (i == PATTERN_ALL_HIGH)
+			memset(devc->logic_data, 0xff, LOGIC_BUFSIZE);
+		sr_dbg("Setting pattern to %s", pattern_strings[i]);
 	} else {
-		ret = SR_ERR;
+		ret = SR_ERR_NA;
 	}
 
 	return ret;
 }
 
-static int config_list(int key, const void **data, const struct sr_dev_inst *sdi)
+static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi,
+		const struct sr_probe_group *probe_group)
 {
+	GVariant *gvar;
+	GVariantBuilder gvb;
 
 	(void)sdi;
+	(void)probe_group;
 
 	switch (key) {
+	case SR_CONF_SCAN_OPTIONS:
+		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
+				hwopts, ARRAY_SIZE(hwopts), sizeof(int32_t));
+		break;
 	case SR_CONF_DEVICE_OPTIONS:
-		*data = hwcaps;
+		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
+				hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
 		break;
 	case SR_CONF_SAMPLERATE:
-		*data = &samplerates;
+		g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
+		gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"), samplerates,
+				ARRAY_SIZE(samplerates), sizeof(uint64_t));
+		g_variant_builder_add(&gvb, "{sv}", "samplerate-steps", gvar);
+		*data = g_variant_builder_end(&gvb);
 		break;
 	case SR_CONF_PATTERN_MODE:
-		*data = &pattern_strings;
+		*data = g_variant_new_strv(pattern_strings, ARRAY_SIZE(pattern_strings));
 		break;
 	default:
-		return SR_ERR_ARG;
+		return SR_ERR_NA;
 	}
 
 	return SR_OK;
 }
 
-static void samples_generator(uint8_t *buf, uint64_t size,
-			      struct dev_context *devc)
+static void logic_generator(struct sr_dev_inst *sdi, uint64_t size)
 {
-	static uint64_t p = 0;
-	uint64_t i;
-
-	/* TODO: Needed? */
-	memset(buf, 0, size);
-
-	switch (devc->sample_generator) {
-	case PATTERN_SIGROK: /* sigrok pattern */
-		for (i = 0; i < size; i++) {
-			*(buf + i) = ~(pattern_sigrok[p] >> 1);
-			if (++p == 64)
-				p = 0;
+	struct dev_context *devc;
+	uint64_t i, j;
+	uint8_t pat;
+
+	devc = sdi->priv;
+
+	switch (devc->logic_pattern) {
+	case PATTERN_SIGROK:
+		memset(devc->logic_data, 0x00, size);
+		for (i = 0; i < size; i += devc->logic_unitsize) {
+			for (j = 0; j < devc->logic_unitsize; j++) {
+				pat = pattern_sigrok[(devc->step + j) % sizeof(pattern_sigrok)] >> 1;
+				devc->logic_data[i + j] = ~pat;
+			}
+			devc->step++;
 		}
 		break;
-	case PATTERN_RANDOM: /* Random */
-		for (i = 0; i < size; i++)
-			*(buf + i) = (uint8_t)(rand() & 0xff);
-		break;
-	case PATTERN_INC: /* Simple increment */
+	case PATTERN_RANDOM:
 		for (i = 0; i < size; i++)
-			*(buf + i) = i;
+			devc->logic_data[i] = (uint8_t)(rand() & 0xff);
 		break;
-	case PATTERN_ALL_LOW: /* All probes are low */
-		memset(buf, 0x00, size);
+	case PATTERN_INC:
+		for (i = 0; i < size; i++) {
+			for (j = 0; j < devc->logic_unitsize; j++) {
+				devc->logic_data[i + j] = devc->step;
+			}
+			devc->step++;
+		}
 		break;
-	case PATTERN_ALL_HIGH: /* All probes are high */
-		memset(buf, 0xff, size);
+	case PATTERN_ALL_LOW:
+	case PATTERN_ALL_HIGH:
+		/* These were set when the pattern mode was selected. */
 		break;
 	default:
-		sr_err("Unknown pattern: %d.", devc->sample_generator);
+		sr_err("Unknown pattern: %d.", devc->logic_pattern);
 		break;
 	}
 }
 
 /* Callback handling data */
-static int receive_data(int fd, int revents, void *cb_data)
+static int prepare_data(int fd, int revents, void *cb_data)
 {
-	struct dev_context *devc = cb_data;
+	struct sr_dev_inst *sdi;
+	struct dev_context *devc;
 	struct sr_datafeed_packet packet;
 	struct sr_datafeed_logic logic;
-	uint8_t buf[BUFSIZE];
-	static uint64_t samples_to_send, expected_samplenum, sending_now;
+	uint64_t samples_to_send, expected_samplenum, sending_now;
 	int64_t time, elapsed;
 
 	(void)fd;
 	(void)revents;
 
+	sdi = cb_data;
+	devc = sdi->priv;
+
 	/* How many "virtual" samples should we have collected by now? */
 	time = g_get_monotonic_time();
 	elapsed = time - devc->starttime;
-	expected_samplenum = elapsed * cur_samplerate / 1000000;
+	expected_samplenum = elapsed * devc->cur_samplerate / 1000000;
 	/* Of those, how many do we still have to send? */
 	samples_to_send = expected_samplenum - devc->samples_counter;
 
-	if (limit_samples) {
+	if (devc->limit_samples) {
 		samples_to_send = MIN(samples_to_send,
-				 limit_samples - devc->samples_counter);
+				devc->limit_samples - devc->samples_counter);
 	}
 
 	while (samples_to_send > 0) {
-		sending_now = MIN(samples_to_send, sizeof(buf));
+		sending_now = MIN(samples_to_send, LOGIC_BUFSIZE / devc->logic_unitsize);
 		samples_to_send -= sending_now;
-		samples_generator(buf, sending_now, devc);
 
+		/* Logic */
+		logic_generator(sdi, sending_now * devc->logic_unitsize);
 		packet.type = SR_DF_LOGIC;
 		packet.payload = &logic;
-		logic.length = sending_now;
-		logic.unitsize = 1;
-		logic.data = buf;
-		sr_session_send(devc->session_dev_id, &packet);
+		logic.length = sending_now * devc->logic_unitsize;
+		logic.unitsize = devc->logic_unitsize;
+		logic.data = devc->logic_data;
+		sr_session_send(sdi, &packet);
 		devc->samples_counter += sending_now;
 	}
 
-	if (limit_samples && devc->samples_counter >= limit_samples) {
+	if (devc->limit_samples &&
+		devc->samples_counter >= devc->limit_samples) {
 		sr_info("Requested number of samples reached.");
-		hw_dev_acquisition_stop(NULL, cb_data);
+		dev_acquisition_stop(sdi, cb_data);
 		return TRUE;
 	}
 
 	return TRUE;
 }
 
-static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
-		void *cb_data)
+static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
 {
-	struct sr_datafeed_packet *packet;
-	struct sr_datafeed_header *header;
 	struct dev_context *devc;
 
-	(void)sdi;
-
-	sr_dbg("Starting acquisition.");
-
-	/* TODO: 'devc' is never g_free()'d? */
-	if (!(devc = g_try_malloc(sizeof(struct dev_context)))) {
-		sr_err("%s: devc malloc failed", __func__);
-		return SR_ERR_MALLOC;
-	}
+	if (sdi->status != SR_ST_ACTIVE)
+		return SR_ERR_DEV_CLOSED;
 
-	devc->sample_generator = default_pattern;
-	devc->session_dev_id = cb_data;
+	devc = sdi->priv;
 	devc->samples_counter = 0;
 
 	/*
@@ -427,69 +463,49 @@ static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 	 * up a timeout-based polling mechanism.
 	 */
 	if (pipe(devc->pipe_fds)) {
-		/* TODO: Better error message. */
 		sr_err("%s: pipe() failed", __func__);
 		return SR_ERR;
 	}
 
-	devc->channels[0] = g_io_channel_unix_new(devc->pipe_fds[0]);
-	devc->channels[1] = g_io_channel_unix_new(devc->pipe_fds[1]);
+	devc->channel = g_io_channel_unix_new(devc->pipe_fds[0]);
 
-	g_io_channel_set_flags(devc->channels[0], G_IO_FLAG_NONBLOCK, NULL);
+	g_io_channel_set_flags(devc->channel, G_IO_FLAG_NONBLOCK, NULL);
 
 	/* Set channel encoding to binary (default is UTF-8). */
-	g_io_channel_set_encoding(devc->channels[0], NULL, NULL);
-	g_io_channel_set_encoding(devc->channels[1], NULL, NULL);
+	g_io_channel_set_encoding(devc->channel, NULL, NULL);
 
 	/* Make channels to unbuffered. */
-	g_io_channel_set_buffered(devc->channels[0], FALSE);
-	g_io_channel_set_buffered(devc->channels[1], FALSE);
-
-	sr_session_source_add_channel(devc->channels[0], G_IO_IN | G_IO_ERR,
-		    40, receive_data, devc);
-
-	if (!(packet = g_try_malloc(sizeof(struct sr_datafeed_packet)))) {
-		sr_err("%s: packet malloc failed", __func__);
-		return SR_ERR_MALLOC;
-	}
+	g_io_channel_set_buffered(devc->channel, FALSE);
 
-	if (!(header = g_try_malloc(sizeof(struct sr_datafeed_header)))) {
-		sr_err("%s: header malloc failed", __func__);
-		return SR_ERR_MALLOC;
-	}
+	sr_session_source_add_channel(devc->channel, G_IO_IN | G_IO_ERR,
+			40, prepare_data, (void *)sdi);
 
-	packet->type = SR_DF_HEADER;
-	packet->payload = header;
-	header->feed_version = 1;
-	gettimeofday(&header->starttime, NULL);
-	sr_session_send(devc->session_dev_id, packet);
+	/* Send header packet to the session bus. */
+	std_session_send_df_header(cb_data, LOG_PREFIX);
 
 	/* We use this timestamp to decide how many more samples to send. */
 	devc->starttime = g_get_monotonic_time();
 
-	g_free(header);
-	g_free(packet);
-
 	return SR_OK;
 }
 
-static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
+static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 {
-	struct dev_context *devc;
+	struct dev_context *const devc = sdi->priv;
 	struct sr_datafeed_packet packet;
 
-	(void)sdi;
-
-	devc = cb_data;
+	(void)cb_data;
 
 	sr_dbg("Stopping aquisition.");
 
-	sr_session_source_remove_channel(devc->channels[0]);
-	g_io_channel_shutdown(devc->channels[0], FALSE, NULL);
+	sr_session_source_remove_channel(devc->channel);
+	g_io_channel_shutdown(devc->channel, FALSE, NULL);
+	g_io_channel_unref(devc->channel);
+	devc->channel = NULL;
 
 	/* Send last packet. */
 	packet.type = SR_DF_END;
-	sr_session_send(devc->session_dev_id, &packet);
+	sr_session_send(sdi, &packet);
 
 	return SR_OK;
 }
@@ -498,17 +514,17 @@ SR_PRIV struct sr_dev_driver demo_driver_info = {
 	.name = "demo",
 	.longname = "Demo driver and pattern generator",
 	.api_version = 1,
-	.init = hw_init,
-	.cleanup = hw_cleanup,
-	.scan = hw_scan,
-	.dev_list = hw_dev_list,
-	.dev_clear = clear_instances,
+	.init = init,
+	.cleanup = cleanup,
+	.scan = scan,
+	.dev_list = dev_list,
+	.dev_clear = dev_clear,
 	.config_get = config_get,
 	.config_set = config_set,
 	.config_list = config_list,
-	.dev_open = hw_dev_open,
-	.dev_close = hw_dev_close,
-	.dev_acquisition_start = hw_dev_acquisition_start,
-	.dev_acquisition_stop = hw_dev_acquisition_stop,
+	.dev_open = dev_open,
+	.dev_close = dev_close,
+	.dev_acquisition_start = dev_acquisition_start,
+	.dev_acquisition_stop = dev_acquisition_stop,
 	.priv = NULL,
 };