From: Aurelien Jacobs <redacted>
Date: Wed, 19 Feb 2014 14:09:03 +0000 (+0100)
Subject: brymen-bm86x: actual driver implementation
X-Git-Tag: libsigrok-0.3.0~133
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=ecaa89af0e01f9c3f585e82eb849bf616bff22cf;p=libsigrok.git

brymen-bm86x: actual driver implementation
---

diff --git a/README.devices b/README.devices
index 136db62c..30f8e474 100644
--- a/README.devices
+++ b/README.devices
@@ -52,6 +52,7 @@ The following drivers/devices do not need any firmware upload:
  - agilent-dmm
  - alsa
  - appa-55ii
+ - brymen-bm86x
  - brymen-dmm
  - cem-dt-885x
  - center-3xx (including all subdrivers)
@@ -117,6 +118,7 @@ The following drivers/devices do not require a serial port specification:
 
  - alsa
  - asix-sigma
+ - brymen-bm86x
  - chronovu-la8
  - demo
  - fx2lafw
diff --git a/hardware/brymen-bm86x/api.c b/hardware/brymen-bm86x/api.c
index feb877d1..9ab60dff 100644
--- a/hardware/brymen-bm86x/api.c
+++ b/hardware/brymen-bm86x/api.c
@@ -19,6 +19,19 @@
 
 #include "protocol.h"
 
+#define BRYMEN_BC86X "0820.0001"
+
+static const int32_t hwopts[] = {
+	SR_CONF_CONN,
+};
+
+static const int32_t hwcaps[] = {
+	SR_CONF_MULTIMETER,
+	SR_CONF_LIMIT_SAMPLES,
+	SR_CONF_LIMIT_MSEC,
+	SR_CONF_CONTINUOUS,
+};
+
 SR_PRIV struct sr_dev_driver brymen_bm86x_driver_info;
 static struct sr_dev_driver *di = &brymen_bm86x_driver_info;
 
@@ -29,17 +42,63 @@ static int init(struct sr_context *sr_ctx)
 
 static GSList *scan(GSList *options)
 {
+	GSList *usb_devices, *devices, *l;
 	struct drv_context *drvc;
-	GSList *devices;
-
-	(void)options;
+	struct dev_context *devc;
+	struct sr_dev_inst *sdi;
+	struct sr_usb_dev_inst *usb;
+	struct sr_config *src;
+	struct sr_probe *probe;
+	const char *conn;
 
-	devices = NULL;
 	drvc = di->priv;
 	drvc->instances = NULL;
 
-	/* TODO: scan for devices, either based on a SR_CONF_CONN option
-	 * or on a USB scan. */
+	conn = BRYMEN_BC86X;
+	for (l = options; l; l = l->next) {
+		src = l->data;
+		switch (src->key) {
+		case SR_CONF_CONN:
+			conn = g_variant_get_string(src->data, NULL);
+			break;
+		}
+	}
+
+	devices = NULL;
+	if (!(usb_devices = sr_usb_find(drvc->sr_ctx->libusb_ctx, conn))) {
+		g_slist_free_full(usb_devices, g_free);
+		return NULL;
+	}
+
+	for (l = usb_devices; l; l = l->next) {
+		usb = l->data;
+
+		if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE,
+		                            "Brymen", "BM869", NULL))) {
+			sr_err("sr_dev_inst_new returned NULL.");
+			return NULL;
+		}
+
+		if (!(devc = g_try_malloc0(sizeof(*devc)))) {
+			sr_err("Device context malloc failed.");
+			return NULL;
+		}
+
+		sdi->priv = devc;
+		sdi->driver = di;
+		if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
+			return NULL;
+		sdi->probes = g_slist_append(sdi->probes, probe);
+		if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P2")))
+			return NULL;
+		sdi->probes = g_slist_append(sdi->probes, probe);
+
+		sdi->inst_type = SR_INST_USB;
+		sdi->conn = usb;
+
+		drvc->instances = g_slist_append(drvc->instances, sdi);
+		devices = g_slist_append(devices, sdi);
+	}
 
 	return devices;
 }
@@ -56,117 +115,184 @@ static int dev_clear(void)
 
 static int dev_open(struct sr_dev_inst *sdi)
 {
-	(void)sdi;
+	struct drv_context *drvc = di->priv;
+	struct sr_usb_dev_inst *usb;
+	struct dev_context *devc;
+	int ret;
 
-	/* TODO: get handle from sdi->conn and open it. */
+	usb = sdi->conn;
+	devc = sdi->priv;
+
+	if ((ret = sr_usb_open(drvc->sr_ctx->libusb_ctx, usb)) == SR_OK)
+		sdi->status = SR_ST_ACTIVE;
+
+	/* Detach kernel drivers which grabbed this device (if any). */
+	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
+		ret = libusb_detach_kernel_driver(usb->devhdl, 0);
+		if (ret < 0) {
+			sr_err("Failed to detach kernel driver: %s.",
+			       libusb_error_name(ret));
+			return SR_ERR;
+		}
+		devc->detached_kernel_driver = 1;
+		sr_dbg("Successfully detached kernel driver.");
+	} else {
+		sr_dbg("No need to detach a kernel driver.");
+	}
 
-	sdi->status = SR_ST_ACTIVE;
+	/* Claim interface 0. */
+	if ((ret = libusb_claim_interface(usb->devhdl, 0)) < 0) {
+		sr_err("Failed to claim interface 0: %s.",
+		       libusb_error_name(ret));
+		return SR_ERR;
+	}
+	sr_dbg("Successfully claimed interface 0.");
 
-	return SR_OK;
+	return ret;
 }
 
 static int dev_close(struct sr_dev_inst *sdi)
 {
-	(void)sdi;
+	struct sr_usb_dev_inst *usb;
+	struct dev_context *devc;
+	int ret;
+
+	usb = sdi->conn;
+	devc = sdi->priv;
+
+	if ((ret = libusb_release_interface(usb->devhdl, 0)))
+		sr_err("Failed to release interface 0: %s.\n", libusb_error_name(ret));
+	else
+		sr_dbg("Successfully released interface 0.\n");
+
+	if (!ret && devc->detached_kernel_driver) {
+		if ((ret = libusb_attach_kernel_driver(usb->devhdl, 0))) {
+			sr_err("Failed to attach kernel driver: %s.\n",
+			       libusb_error_name(ret));
+		} else {
+			devc->detached_kernel_driver = 0;
+			sr_dbg("Successfully attached kernel driver.\n");
+		}
+	}
 
-	/* TODO: get handle from sdi->conn and close it. */
+	libusb_close(usb->devhdl);
 
 	sdi->status = SR_ST_INACTIVE;
 
-	return SR_OK;
+	return ret;
 }
 
 static int cleanup(void)
 {
-	dev_clear();
-
-	/* TODO: free other driver resources, if any. */
-
-	return SR_OK;
+	return dev_clear();
 }
 
 static int config_get(int key, GVariant **data, const struct sr_dev_inst *sdi,
 		const struct sr_probe_group *probe_group)
 {
-	int ret;
+	struct dev_context *devc = sdi->priv;
 
-	(void)sdi;
-	(void)data;
 	(void)probe_group;
 
-	ret = SR_OK;
 	switch (key) {
-	/* TODO */
+	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;
 	default:
 		return SR_ERR_NA;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
 static int config_set(int key, GVariant *data, const struct sr_dev_inst *sdi,
 		const struct sr_probe_group *probe_group)
 {
-	int ret;
+	struct dev_context *devc;
 
-	(void)data;
 	(void)probe_group;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
-	ret = SR_OK;
+	if (!(devc = sdi->priv)) {
+		sr_err("sdi->priv was NULL.");
+		return SR_ERR_BUG;
+	}
+
 	switch (key) {
-	/* TODO */
+	case SR_CONF_LIMIT_SAMPLES:
+		devc->limit_samples = g_variant_get_uint64(data);
+		sr_dbg("Setting sample limit to %" PRIu64 ".", devc->limit_samples);
+		break;
+	case SR_CONF_LIMIT_MSEC:
+		devc->limit_msec = g_variant_get_uint64(data);
+		sr_dbg("Setting time limit to %" PRIu64 "ms.", devc->limit_msec);
+		break;
 	default:
-		ret = SR_ERR_NA;
+		return SR_ERR_NA;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
 static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi,
 		const struct sr_probe_group *probe_group)
 {
-	int ret;
-
 	(void)sdi;
-	(void)data;
 	(void)probe_group;
 
-	ret = SR_OK;
 	switch (key) {
-	/* TODO */
+	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 = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
+				hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
+		break;
 	default:
 		return SR_ERR_NA;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
 static int dev_acquisition_start(const struct sr_dev_inst *sdi,
 				    void *cb_data)
 {
-	(void)sdi;
-	(void)cb_data;
+	struct dev_context *devc;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
-	/* TODO: configure hardware, reset acquisition state, set up
-	 * callbacks and send header packet. */
+	devc = sdi->priv;
+	devc->session_cb_data = cb_data;
+	devc->start_time = g_get_monotonic_time();
+
+	/* Send header packet to the session bus. */
+	std_session_send_df_header(cb_data, LOG_PREFIX);
+
+	sr_source_add(0, 0, 10, brymen_bm86x_receive_data, (void *)sdi);
 
 	return SR_OK;
 }
 
 static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 {
-	(void)cb_data;
+	struct sr_datafeed_packet packet;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
-	/* TODO: stop acquisition. */
+	/* Send end packet to the session bus. */
+	packet.type = SR_DF_END;
+	sr_session_send(cb_data, &packet);
+
+	sr_source_remove(0);
 
 	return SR_OK;
 }
diff --git a/hardware/brymen-bm86x/protocol.c b/hardware/brymen-bm86x/protocol.c
index 7c0a9a1f..85329ac4 100644
--- a/hardware/brymen-bm86x/protocol.c
+++ b/hardware/brymen-bm86x/protocol.c
@@ -17,14 +17,297 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <string.h>
+#include <math.h>
 #include "protocol.h"
 
+#define USB_TIMEOUT 500
+
+static char char_map[128] = {
+	[0x20] = '-',
+	[0x5F] = '0',
+	[0x50] = '1',
+	[0x6D] = '2',
+	[0x7C] = '3',
+	[0x72] = '4',
+	[0x3E] = '5',
+	[0x3F] = '6',
+	[0x54] = '7',
+	[0x7F] = '8',
+	[0x7E] = '9',
+	[0x0F] = 'C',
+	[0x27] = 'F',
+	[0x0B] = 'L',
+	[0x79] = 'd',
+	[0x10] = 'i',
+	[0x39] = 'o',
+};
+
+static int brymen_bm86x_parse_digits(const unsigned char *buf, int length,
+                                     char *str, float *floatval,
+                                     char *temp_unit, int flag)
+{
+	char c, *p = str;
+	int i, ret;
+
+	if (buf[0] & flag)
+		*p++ = '-';
+	for (i = 0; i < length; i++) {
+		if (i && i < 5 && buf[i+1] & 0x01)
+			*p++ = '.';
+		c = char_map[buf[i+1] >> 1];
+		if (i == 5 && (c == 'C' || c == 'F'))
+			*temp_unit = c;
+		else if (c)
+			*p++ = c;
+	}
+	*p = 0;
+
+	if ((ret = sr_atof_ascii(str, floatval))) {
+		sr_dbg("invalid float string: '%s'", str);
+		return ret;
+	}
+
+	return SR_OK;
+}
+
+static void brymen_bm86x_parse(unsigned char *buf, float *floatval,
+                               struct sr_datafeed_analog *analog)
+{
+	char str[16], temp_unit;
+	int ret1, ret2, over_limit;
+
+	ret1 = brymen_bm86x_parse_digits(buf+2, 6, str, &floatval[0],
+	                                 &temp_unit, 0x80);
+	over_limit = strstr(str, "0L") || strstr(str, "0.L");
+	ret2 = brymen_bm86x_parse_digits(buf+9, 4, str, &floatval[1],
+	                                 &temp_unit, 0x10);
+
+	/* main display */
+	if (ret1 == SR_OK || over_limit) {
+		/* SI unit */
+		if (buf[8] & 0x01) {
+			analog[0].mq = SR_MQ_VOLTAGE;
+			analog[0].unit = SR_UNIT_VOLT;
+			if (!strcmp(str, "diod"))
+				analog[0].mqflags |= SR_MQFLAG_DIODE;
+		} else if (buf[14] & 0x80) {
+			analog[0].mq = SR_MQ_CURRENT;
+			analog[0].unit = SR_UNIT_AMPERE;
+		} else if (buf[14] & 0x20) {
+			analog[0].mq = SR_MQ_CAPACITANCE;
+			analog[0].unit = SR_UNIT_FARAD;
+		} else if (buf[14] & 0x10) {
+			analog[0].mq = SR_MQ_CONDUCTANCE;
+			analog[0].unit = SR_UNIT_SIEMENS;
+		} else if (buf[15] & 0x01) {
+			analog[0].mq = SR_MQ_FREQUENCY;
+			analog[0].unit = SR_UNIT_HERTZ;
+		} else if (buf[10] & 0x01) {
+			analog[0].mq = SR_MQ_CONTINUITY;
+			analog[0].unit = SR_UNIT_OHM;
+		} else if (buf[15] & 0x10) {
+			analog[0].mq = SR_MQ_RESISTANCE;
+			analog[0].unit = SR_UNIT_OHM;
+		} else if (buf[15] & 0x02) {
+			analog[0].mq = SR_MQ_POWER;
+			analog[0].unit = SR_UNIT_DECIBEL_MW;
+		} else if (buf[15] & 0x80) {
+			analog[0].mq = SR_MQ_DUTY_CYCLE;
+			analog[0].unit = SR_UNIT_PERCENTAGE;
+		} else if (buf[ 2] & 0x0A) {
+			analog[0].mq = SR_MQ_TEMPERATURE;
+			if (temp_unit == 'F')
+				analog[0].unit = SR_UNIT_FAHRENHEIT;
+			else
+				analog[0].unit = SR_UNIT_CELSIUS;
+		}
+
+		/* when MIN MAX and AVG are displayed at the same time, remove them */
+		if ((buf[1] & 0xE0) == 0xE0)
+			buf[1] &= ~0xE0;
+
+		/* AC/DC/Auto flags */
+		if (buf[1] & 0x10)  analog[0].mqflags |= SR_MQFLAG_DC;
+		if (buf[2] & 0x01)  analog[0].mqflags |= SR_MQFLAG_AC;
+		if (buf[1] & 0x01)  analog[0].mqflags |= SR_MQFLAG_AUTORANGE;
+		if (buf[1] & 0x08)  analog[0].mqflags |= SR_MQFLAG_HOLD;
+		if (buf[1] & 0x20)  analog[0].mqflags |= SR_MQFLAG_MAX;
+		if (buf[1] & 0x40)  analog[0].mqflags |= SR_MQFLAG_MIN;
+		if (buf[1] & 0x80)  analog[0].mqflags |= SR_MQFLAG_AVG;
+		if (buf[3] & 0x01)  analog[0].mqflags |= SR_MQFLAG_RELATIVE;
+
+		/* when dBm is displayed, remove the m suffix so that it is
+		   not considered as the 10e-3 SI prefix */
+		if (buf[15] & 0x02)
+			buf[15] &= ~0x04;
+
+		/* SI prefix */
+		if (buf[14] & 0x40)  floatval[0] *= 1e-9;  /* n */
+		if (buf[15] & 0x08)  floatval[0] *= 1e-6;  /* µ */
+		if (buf[15] & 0x04)  floatval[0] *= 1e-3;  /* m */
+		if (buf[15] & 0x40)  floatval[0] *= 1e3;   /* k */
+		if (buf[15] & 0x20)  floatval[0] *= 1e6;   /* M */
+
+		if (over_limit)      floatval[0] = INFINITY;
+	}
+
+	/* secondary display */
+	if (ret2 == SR_OK) {
+		/* SI unit */
+		if (buf[14] & 0x08) {
+			analog[1].mq = SR_MQ_VOLTAGE;
+			analog[1].unit = SR_UNIT_VOLT;
+		} else if (buf[9] & 0x04) {
+			analog[1].mq = SR_MQ_CURRENT;
+			analog[1].unit = SR_UNIT_AMPERE;
+		} else if (buf[14] & 0x04) {
+			analog[1].mq = SR_MQ_FREQUENCY;
+			analog[1].unit = SR_UNIT_HERTZ;
+		} else if (buf[9] & 0x40) {
+			analog[1].mq = SR_MQ_TEMPERATURE;
+			if (temp_unit == 'F')
+				analog[1].unit = SR_UNIT_FAHRENHEIT;
+			else
+				analog[1].unit = SR_UNIT_CELSIUS;
+		}
+
+		/* AC flag */
+		if (buf[9] & 0x20)  analog[1].mqflags |= SR_MQFLAG_AC;
+
+		/* SI prefix */
+		if (buf[ 9] & 0x01)  floatval[1] *= 1e-6;  /* µ */
+		if (buf[ 9] & 0x02)  floatval[1] *= 1e-3;  /* m */
+		if (buf[14] & 0x02)  floatval[1] *= 1e3;   /* k */
+		if (buf[14] & 0x01)  floatval[1] *= 1e6;   /* M */
+	}
+
+	if (buf[9] & 0x80)
+		sr_spew("Battery is low.");
+}
+
+static void brymen_bm86x_handle_packet(const struct sr_dev_inst *sdi,
+                                       unsigned char *buf)
+{
+	struct dev_context *devc;
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_analog analog[2];
+	float floatval[2];
+
+	devc = sdi->priv;
+
+	analog[0].mq = -1;
+	analog[0].mqflags = 0;
+
+	analog[1].mq = -1;
+	analog[1].mqflags = 0;
+
+	brymen_bm86x_parse(buf, floatval, analog);
+
+	if (analog[0].mq != -1) {
+		/* Got a measurement. */
+		analog[0].num_samples = 1;
+		analog[0].data = &floatval[0];
+		analog[0].probes = g_slist_append(NULL, sdi->probes->data);
+		packet.type = SR_DF_ANALOG;
+		packet.payload = &analog[0];
+		sr_session_send(devc->session_cb_data, &packet);
+		g_slist_free(analog[0].probes);
+	}
+
+	if (analog[1].mq != -1) {
+		/* Got a measurement. */
+		analog[1].num_samples = 1;
+		analog[1].data = &floatval[1];
+		analog[1].probes = g_slist_append(NULL, sdi->probes->next->data);
+		packet.type = SR_DF_ANALOG;
+		packet.payload = &analog[1];
+		sr_session_send(devc->session_cb_data, &packet);
+		g_slist_free(analog[1].probes);
+	}
+
+	if (analog[0].mq != -1 || analog[1].mq != -1)
+		devc->num_samples++;
+}
+
+static int brymen_bm86x_send_command(const struct sr_dev_inst *sdi)
+{
+	struct sr_usb_dev_inst *usb;
+	unsigned char buf[] = { 0x00, 0x86, 0x66 };
+	int ret;
+
+	usb = sdi->conn;
+
+	sr_dbg("Sending HID set report.");
+	ret = libusb_control_transfer(usb->devhdl,
+	                              LIBUSB_REQUEST_TYPE_CLASS  |
+	                              LIBUSB_RECIPIENT_INTERFACE |
+	                              LIBUSB_ENDPOINT_OUT,
+	                              9,     /* bRequest: HID set_report */
+	                              0x300, /* wValue: HID feature, report num 0 */
+	                              0,     /* wIndex: interface 0 */
+	                              buf, sizeof(buf), USB_TIMEOUT);
+
+	if (ret < 0) {
+		sr_err("HID feature report error: %s.", libusb_error_name(ret));
+		return SR_ERR;
+	}
+
+	if (ret != sizeof(buf)) {
+		sr_err("Short packet: sent %d/%ld bytes.", ret, sizeof(buf));
+		return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
+static int brymen_bm86x_read_interrupt(const struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	struct sr_usb_dev_inst *usb;
+	unsigned char buf[24];
+	int ret, transferred;
+
+	devc = sdi->priv;
+	usb = sdi->conn;
+
+	sr_dbg("Reading HID interrupt report.");
+	/* Get data from EP1 using an interrupt transfer. */
+	ret = libusb_interrupt_transfer(usb->devhdl,
+	                                LIBUSB_ENDPOINT_IN | 1, /* EP1, IN */
+	                                buf, sizeof(buf),
+	                                &transferred, USB_TIMEOUT);
+
+	if (ret == LIBUSB_ERROR_TIMEOUT) {
+		if (++devc->interrupt_pending > 3)
+			devc->interrupt_pending = 0;
+		return SR_OK;
+	}
+
+	if (ret < 0) {
+		sr_err("USB receive error: %s.", libusb_error_name(ret));
+		return SR_ERR;
+	}
+
+	if (transferred != sizeof(buf)) {
+		sr_err("Short packet: received %d/%d bytes.", transferred, sizeof(buf));
+		return SR_ERR;
+	}
+
+	devc->interrupt_pending = 0;
+	brymen_bm86x_handle_packet(sdi, buf);
+
+	return SR_OK;
+}
+
 SR_PRIV int brymen_bm86x_receive_data(int fd, int revents, void *cb_data)
 {
-	const struct sr_dev_inst *sdi;
+	struct sr_dev_inst *sdi;
 	struct dev_context *devc;
+	int64_t time;
 
 	(void)fd;
+	(void)revents;
 
 	if (!(sdi = cb_data))
 		return TRUE;
@@ -32,8 +315,28 @@ SR_PRIV int brymen_bm86x_receive_data(int fd, int revents, void *cb_data)
 	if (!(devc = sdi->priv))
 		return TRUE;
 
-	if (revents == G_IO_IN) {
-		/* TODO */
+	if (!devc->interrupt_pending) {
+		if (brymen_bm86x_send_command(sdi))
+			return FALSE;
+		devc->interrupt_pending = 1;
+	}
+
+	if (brymen_bm86x_read_interrupt(sdi))
+		return FALSE;
+
+	if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
+		sr_info("Requested number of samples reached, stopping.");
+		sdi->driver->dev_acquisition_stop(sdi, cb_data);
+		return TRUE;
+	}
+
+	if (devc->limit_msec) {
+		time = (g_get_monotonic_time() - devc->start_time) / 1000;
+		if (time > (int64_t)devc->limit_msec) {
+			sr_info("Requested time limit reached, stopping.");
+			sdi->driver->dev_acquisition_stop(sdi, cb_data);
+			return TRUE;
+		}
 	}
 
 	return TRUE;
diff --git a/hardware/brymen-bm86x/protocol.h b/hardware/brymen-bm86x/protocol.h
index db6f7d9b..5590d4e3 100644
--- a/hardware/brymen-bm86x/protocol.h
+++ b/hardware/brymen-bm86x/protocol.h
@@ -30,14 +30,18 @@
 
 /** Private, per-device-instance driver context. */
 struct dev_context {
-	/* Model-specific information */
-
 	/* Acquisition settings */
+	uint64_t limit_samples;    /**< The sampling limit (in number of samples).*/
+	uint64_t limit_msec;       /**< The time limit (in milliseconds). */
+	void *session_cb_data;     /**< Opaque pointer passed in by the frontend. */
 
 	/* Operational state */
+	int detached_kernel_driver;/**< Whether kernel driver was detached or not */
+	uint64_t num_samples;      /**< The number of already received samples. */
+	int64_t start_time;        /**< The time at which sampling started. */
 
 	/* Temporary state across callbacks */
-
+	int interrupt_pending;
 };
 
 SR_PRIV int brymen_bm86x_receive_data(int fd, int revents, void *cb_data);