From: Bert Vermeulen <redacted>
Date: Tue, 6 Nov 2012 14:14:34 +0000 (+0100)
Subject: victor-dmm: add basic USB driver skeleton
X-Git-Tag: dsupstream~584
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=7a36037546aaf11b91ff5d63fbd571e15407e357;p=libsigrok.git

victor-dmm: add basic USB driver skeleton
---

diff --git a/hardware/victor-dmm/api.c b/hardware/victor-dmm/api.c
index b24b77e9..9ee2b286 100644
--- a/hardware/victor-dmm/api.c
+++ b/hardware/victor-dmm/api.c
@@ -21,9 +21,33 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 #include "protocol.h"
+#include <libusb.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define VICTOR_VID 0x1244
+#define VICTOR_PID 0xd237
+#define VICTOR_VENDOR "Victor"
+#define VICTOR_INTERFACE 0
+#define VICTOR_ENDPOINT LIBUSB_ENDPOINT_IN | 1
 
 SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
 static struct sr_dev_driver *di = &victor_dmm_driver_info;
+static int hw_dev_close(struct sr_dev_inst *sdi);
+static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data);
+
+static const int hwcaps[] = {
+	SR_HWCAP_MULTIMETER,
+	SR_HWCAP_LIMIT_MSEC,
+	SR_HWCAP_LIMIT_SAMPLES,
+	SR_HWCAP_CONTINUOUS,
+	0
+};
+
+static const char *probe_names[] = {
+	"P1",
+};
+
 
 /* Properly close and free all devices. */
 static int clear_instances(void)
@@ -33,15 +57,17 @@ static int clear_instances(void)
 	struct dev_context *devc;
 	GSList *l;
 
-	drvc = di->priv;
+	if (!(drvc = di->priv))
+		/* Can get called on an unused driver, doesn't matter. */
+		return SR_OK;
+
 	for (l = drvc->instances; l; l = l->next) {
 		if (!(sdi = l->data))
 			continue;
 		if (!(devc = sdi->priv))
 			continue;
-
-		/* TODO */
-
+		hw_dev_close(sdi);
+		sr_usb_dev_inst_free(devc->usb);
 		sr_dev_inst_free(sdi);
 	}
 
@@ -59,9 +85,6 @@ static int hw_init(void)
 		sr_err("Driver context malloc failed.");
 		return SR_ERR_MALLOC;
 	}
-
-	/* TODO */
-
 	di->priv = drvc;
 
 	return SR_OK;
@@ -70,15 +93,58 @@ static int hw_init(void)
 static GSList *hw_scan(GSList *options)
 {
 	struct drv_context *drvc;
+	struct dev_context *devc;
+	struct sr_dev_inst *sdi;
+	struct sr_probe *probe;
+	struct libusb_device_descriptor des;
+	libusb_device **devlist;
 	GSList *devices;
+	int ret, devcnt, i;
 
 	(void)options;
 
+	if (!(drvc = di->priv)) {
+		sr_err("Driver was not initialized.");
+		return NULL;
+	}
+
+	/* USB scan is always authoritative. */
+	clear_instances();
+
 	devices = NULL;
-	drvc = di->priv;
-	drvc->instances = NULL;
+	libusb_get_device_list(NULL, &devlist);
+	for (i = 0; devlist[i]; i++) {
+		if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
+			sr_warn("Failed to get device descriptor: %s",
+					libusb_error_name(ret));
+			continue;
+		}
 
-	/* TODO */
+		if (des.idVendor != VICTOR_VID || des.idProduct != VICTOR_PID)
+			continue;
+
+		devcnt = g_slist_length(drvc->instances);
+		if (!(sdi = sr_dev_inst_new(devcnt, SR_ST_INACTIVE, VICTOR_VENDOR,
+				NULL, NULL)))
+			return NULL;
+		sdi->driver = di;
+
+		if (!(devc = g_try_malloc0(sizeof(struct dev_context))))
+			return NULL;
+		sdi->priv = devc;
+
+		if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
+			return NULL;
+		sdi->probes = g_slist_append(NULL, probe);
+
+		if (!(devc->usb = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
+				libusb_get_device_address(devlist[i]), NULL)))
+			return NULL;
+
+		drvc->instances = g_slist_append(drvc->instances, sdi);
+		devices = g_slist_append(devices, sdi);
+	}
+	libusb_free_device_list(devlist, 1);
 
 	return devices;
 }
@@ -87,30 +153,95 @@ static GSList *hw_dev_list(void)
 {
 	struct drv_context *drvc;
 
-	drvc = di->priv;
+	if (!(drvc = di->priv)) {
+		sr_err("Driver was not initialized.");
+		return NULL;
+	}
 
 	return drvc->instances;
 }
 
 static int hw_dev_open(struct sr_dev_inst *sdi)
 {
-	/* TODO */
+	struct dev_context *devc;
+	libusb_device **devlist;
+	int ret, i;
+
+	if (!di->priv) {
+		sr_err("Driver was not initialized.");
+		return SR_ERR;
+	}
+
+	devc = sdi->priv;
+	libusb_get_device_list(NULL, &devlist);
+	for (i = 0; devlist[i]; i++) {
+		if (libusb_get_bus_number(devlist[i]) != devc->usb->bus
+				|| libusb_get_device_address(devlist[i]) != devc->usb->address)
+			continue;
+		if ((ret = libusb_open(devlist[i], &devc->usb->devhdl))) {
+			sr_err("Failed to open device: %s", libusb_error_name(ret));
+			return SR_ERR;
+		}
+		break;
+	}
+	libusb_free_device_list(devlist, 1);
+	if (!devlist[i]) {
+		sr_err("Device not found.");
+		return SR_ERR;
+	}
+
+	/* The device reports as HID class, so the kernel would have
+	 * claimed it. */
+	if (libusb_kernel_driver_active(devc->usb->devhdl, 0) == 1) {
+		if (libusb_detach_kernel_driver(devc->usb->devhdl, 0) < 0) {
+			sr_err("Failed to detach kernel driver.");
+			return SR_ERR;
+		}
+	}
+
+	if ((ret = libusb_claim_interface(devc->usb->devhdl,
+			VICTOR_INTERFACE))) {
+		sr_err("Failed to claim interface: %s", libusb_error_name(ret));
+		return SR_ERR;
+	}
+	sdi->status = SR_ST_ACTIVE;
 
 	return SR_OK;
 }
 
 static int hw_dev_close(struct sr_dev_inst *sdi)
 {
-	/* TODO */
+	struct dev_context *devc;
+
+	if (!di->priv) {
+		sr_err("Driver was not initialized.");
+		return SR_ERR;
+	}
+
+	devc = sdi->priv;
+	if (!devc->usb->devhdl)
+		/*  Nothing to do. */
+		return SR_OK;
+
+	libusb_release_interface(devc->usb->devhdl, VICTOR_INTERFACE);
+	libusb_close(devc->usb->devhdl);
+	devc->usb->devhdl = NULL;
+	sdi->status = SR_ST_INACTIVE;
 
 	return SR_OK;
 }
 
 static int hw_cleanup(void)
 {
-	clear_instances();
+	struct drv_context *drvc;
+
+	if (!(drvc = di->priv))
+		/* Can get called on an unused driver, doesn't matter. */
+		return SR_OK;
 
-	/* TODO */
+	clear_instances();
+	g_free(drvc);
+	di->priv = NULL;
 
 	return SR_OK;
 }
@@ -118,11 +249,21 @@ static int hw_cleanup(void)
 static int hw_info_get(int info_id, const void **data,
 		       const struct sr_dev_inst *sdi)
 {
+
+	(void)sdi;
+
 	switch (info_id) {
-	/* TODO */
-	default:
-		sr_err("Unknown info_id: %d.", info_id);
-		return SR_ERR_ARG;
+		case SR_DI_HWCAPS:
+			*data = hwcaps;
+			break;
+		case SR_DI_NUM_PROBES:
+			*data = GINT_TO_POINTER(1);
+			break;
+		case SR_DI_PROBE_NAMES:
+			*data = probe_names;
+			break;
+		default:
+			return SR_ERR_ARG;
 	}
 
 	return SR_OK;
@@ -131,16 +272,35 @@ static int hw_info_get(int info_id, const void **data,
 static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 			     const void *value)
 {
+	struct dev_context *devc;
+	gint64 now;
 	int ret;
 
+	if (!di->priv) {
+		sr_err("Driver was not initialized.");
+		return SR_ERR;
+	}
+
 	if (sdi->status != SR_ST_ACTIVE) {
 		sr_err("Device inactive, can't set config options.");
 		return SR_ERR;
 	}
 
+	devc = sdi->priv;
 	ret = SR_OK;
 	switch (hwcap) {
-	/* TODO */
+		case SR_HWCAP_LIMIT_MSEC:
+			devc->limit_msec = *(const int64_t *)value;
+			now = g_get_monotonic_time() / 1000;
+			devc->end_time = now + devc->limit_msec;
+			sr_dbg("setting time limit to %" PRIu64 "ms.",
+					devc->limit_msec);
+			break;
+		case SR_HWCAP_LIMIT_SAMPLES:
+			devc->limit_samples = *(const uint64_t *)value;
+			sr_dbg("setting sample limit to %" PRIu64 ".",
+					devc->limit_samples);
+			break;
 	default:
 		sr_err("Unknown hardware capability: %d.", hwcap);
 		ret = SR_ERR_ARG;
@@ -149,32 +309,172 @@ static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 	return ret;
 }
 
+static void receive_transfer(struct libusb_transfer *transfer)
+{
+	struct dev_context *devc;
+	struct sr_dev_inst *sdi;
+	int ret;
+
+	sdi = transfer->user_data;
+	devc = sdi->priv;
+	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
+		/* USB device was unplugged. */
+		hw_dev_acquisition_stop(sdi, sdi);
+	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
+		sr_dbg("got %d-byte packet", transfer->actual_length);
+		if (transfer->actual_length == 14) {
+			devc->num_samples++;
+			/* TODO */
+
+			if (devc->limit_samples) {
+				if (devc->num_samples >= devc->limit_samples)
+					hw_dev_acquisition_stop(sdi, sdi);
+			}
+		}
+	}
+	/* Anything else is either an error or a timeout, which is fine:
+	 * we were just going to send another transfer request anyway. */
+
+	if (sdi->status == SR_ST_ACTIVE) {
+		/* Send the same request again. */
+		if ((ret = libusb_submit_transfer(transfer) != 0)) {
+			sr_err("unable to resubmit transfer: %s", libusb_error_name(ret));
+			libusb_free_transfer(transfer);
+			g_free(transfer->buffer);
+			hw_dev_acquisition_stop(sdi, sdi);
+		}
+	} else {
+		/* This was the last transfer we're going to receive, so
+		 * clean up now. */
+		libusb_free_transfer(transfer);
+		g_free(transfer->buffer);
+	}
+
+}
+
+static int handle_events(int fd, int revents, void *cb_data)
+{
+	struct dev_context *devc;
+	struct sr_datafeed_packet packet;
+	struct sr_dev_inst *sdi;
+	struct timeval tv;
+	gint64 now;
+	int i;
+
+	(void)fd;
+	(void)revents;
+
+	sdi = cb_data;
+	devc = sdi->priv;
+
+	if (devc->limit_msec) {
+		now = g_get_monotonic_time() / 1000;
+		if (now > devc->end_time)
+			hw_dev_acquisition_stop(sdi, sdi);
+	}
+
+	if (sdi->status == SR_ST_STOPPING) {
+		for (i = 0; devc->usbfd[i] != -1; i++)
+			sr_source_remove(devc->usbfd[i]);
+
+		hw_dev_close(sdi);
+
+		packet.type = SR_DF_END;
+		sr_session_send(cb_data, &packet);
+	}
+
+	memset(&tv, 0, sizeof(struct timeval));
+	libusb_handle_events_timeout_completed(NULL, &tv, NULL);
+
+	return TRUE;
+}
+
 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 				    void *cb_data)
 {
-	/* TODO */
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_header header;
+	struct sr_datafeed_meta_analog meta;
+	struct dev_context *devc;
+	const struct libusb_pollfd **pfd;
+	struct libusb_transfer *transfer;
+	int ret, i;
+	unsigned char *buf;
+
+	if (!di->priv) {
+		sr_err("Driver was not initialized.");
+		return SR_ERR;
+	}
+
+	sr_dbg("Starting acquisition.");
+
+	devc = sdi->priv;
+	devc->cb_data = cb_data;
+
+	/* Send header packet to the session bus. */
+	sr_dbg("Sending SR_DF_HEADER.");
+	packet.type = SR_DF_HEADER;
+	packet.payload = (uint8_t *)&header;
+	header.feed_version = 1;
+	sr_session_send(devc->cb_data, &packet);
+
+	/* Send metadata about the SR_DF_ANALOG packets to come. */
+	packet.type = SR_DF_META_ANALOG;
+	packet.payload = &meta;
+	meta.num_probes = 1;
+	sr_session_send(devc->cb_data, &packet);
+
+	pfd = libusb_get_pollfds(NULL);
+	for (i = 0; pfd[i]; i++) {
+		/* Handle USB events every 100ms, for decent latency. */
+		sr_source_add(pfd[i]->fd, pfd[i]->events, 100,
+				handle_events, (void *)sdi);
+		/* We'll need to remove this fd later. */
+		devc->usbfd[i] = pfd[i]->fd;
+	}
+	devc->usbfd[i] = -1;
+
+	buf = g_try_malloc(14);
+	transfer = libusb_alloc_transfer(0);
+	/* Each transfer request gets 100ms to arrive before it's restarted.
+	 * The device only sends 1 transfer/second no matter how many
+	 * times you ask, but we want to keep step with the USB events
+	 * handling above. */
+	libusb_fill_interrupt_transfer(transfer, devc->usb->devhdl,
+			VICTOR_ENDPOINT, buf, 14, receive_transfer, cb_data, 100);
+	if ((ret = libusb_submit_transfer(transfer) != 0)) {
+		sr_err("unable to submit transfer: %s", libusb_error_name(ret));
+		libusb_free_transfer(transfer);
+		g_free(buf);
+		return SR_ERR;
+	}
 
 	return SR_OK;
 }
 
-static int hw_dev_acquisition_stop(const struct sr_dev_inst *sdi,
-				   void *cb_data)
+static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 {
+
 	(void)cb_data;
 
+	if (!di->priv) {
+		sr_err("Driver was not initialized.");
+		return SR_ERR;
+	}
+
 	if (sdi->status != SR_ST_ACTIVE) {
-		sr_err("Device inactive, can't stop acquisition.");
+		sr_err("Device not active, can't stop acquisition.");
 		return SR_ERR;
 	}
 
-	/* TODO */
+	sdi->status = SR_ST_STOPPING;
 
 	return SR_OK;
 }
 
 SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
 	.name = "victor-dmm",
-	.longname = "victor-dmm",
+	.longname = "Victor DMMs",
 	.api_version = 1,
 	.init = hw_init,
 	.cleanup = hw_cleanup,
diff --git a/hardware/victor-dmm/protocol.h b/hardware/victor-dmm/protocol.h
index beea3e82..cab77774 100644
--- a/hardware/victor-dmm/protocol.h
+++ b/hardware/victor-dmm/protocol.h
@@ -46,6 +46,11 @@ struct dev_context {
 
 	/** The current number of already received samples. */
 	uint64_t num_samples;
+	gint64 end_time;
+
+	struct sr_usb_dev_inst *usb;
+	/* Only requires 3 really. */
+	int usbfd[10];
 };
 
 SR_PRIV int victor_dmm_receive_data(int fd, int revents, void *cb_data);