X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=hardware%2Fcommon%2Fscpi_usbtmc.c;h=1ffc34ae9392c8826161e21e669eaef232daafeb;hb=50e6311a1b76ead9e082d99bdea91c1cba08fd4e;hp=3c98c06bc8c87bfa2eeb38cf962f821c271cd675;hpb=d87c1766f2968d121cea9d913b06dc3493adfd9e;p=libsigrok.git

diff --git a/hardware/common/scpi_usbtmc.c b/hardware/common/scpi_usbtmc.c
index 3c98c06b..1ffc34ae 100644
--- a/hardware/common/scpi_usbtmc.c
+++ b/hardware/common/scpi_usbtmc.c
@@ -37,11 +37,35 @@ struct usbtmc_scpi {
 	int response_bytes_read;
 };
 
-static int scpi_usbtmc_dev_inst_new(void *priv, const char *resource,
-		char **params, const char *serialcomm)
+static GSList *scpi_usbtmc_scan(struct drv_context *drvc)
+{
+	GSList *resources = NULL;
+	GDir *dir;
+	const char *dev_name;
+	char *resource;
+
+	(void)drvc;
+
+	if (!(dir = g_dir_open("/sys/class/usbmisc/", 0, NULL)))
+		if (!(dir = g_dir_open("/sys/class/usb/", 0, NULL)))
+			return NULL;
+	while ((dev_name = g_dir_read_name(dir))) {
+		if (strncmp(dev_name, "usbtmc", 6))
+			continue;
+		resource = g_strconcat("/dev/", dev_name, NULL);
+		resources = g_slist_append(resources, resource);
+	}
+	g_dir_close(dir);
+
+	return resources;
+}
+
+static int scpi_usbtmc_dev_inst_new(void *priv, struct drv_context *drvc,
+		const char *resource, char **params, const char *serialcomm)
 {
 	struct usbtmc_scpi *uscpi = priv;
 
+	(void)drvc;
 	(void)params;
 	(void)serialcomm;
 
@@ -119,6 +143,8 @@ static int scpi_usbtmc_read_begin(void *priv)
 	uscpi->response_length = len;
 	uscpi->response_bytes_read = 0;
 
+	sr_spew("Read %d bytes from device into buffer", len);
+
 	return SR_OK;
 }
 
@@ -127,13 +153,18 @@ static int scpi_usbtmc_read_data(void *priv, char *buf, int maxlen)
 	struct usbtmc_scpi *uscpi = priv;
 	int read_length;
 
-	if (uscpi->response_length == MAX_READ_LENGTH
-	    && uscpi->response_bytes_read == uscpi->response_length)
-		if (scpi_usbtmc_read_begin(uscpi) != SR_OK)
-			return SR_ERR;
+	sr_spew("%d bytes requested", maxlen);
 
-	if (uscpi->response_bytes_read >= uscpi->response_length)
-		return SR_ERR;
+	if (uscpi->response_bytes_read == uscpi->response_length) {
+		sr_spew("Buffer is empty.");
+		if (uscpi->response_length == MAX_READ_LENGTH) {
+			sr_spew("Previous read was of maximum length, reading again.");
+			if (scpi_usbtmc_read_begin(uscpi) != SR_OK)
+				return SR_ERR;
+		} else {
+			return SR_ERR;
+		}
+	}
 
 	read_length = uscpi->response_length - uscpi->response_bytes_read;
 
@@ -144,6 +175,9 @@ static int scpi_usbtmc_read_data(void *priv, char *buf, int maxlen)
 
 	uscpi->response_bytes_read += read_length;
 
+	sr_spew("Returned %d bytes from buffer, %d/%d bytes of buffer now read",
+			read_length, uscpi->response_bytes_read, uscpi->response_length);
+
 	return read_length;
 }
 
@@ -179,6 +213,7 @@ SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_dev = {
 	.name          = "USBTMC",
 	.prefix        = "/dev/usbtmc",
 	.priv_size     = sizeof(struct usbtmc_scpi),
+	.scan          = scpi_usbtmc_scan,
 	.dev_inst_new  = scpi_usbtmc_dev_inst_new,
 	.open          = scpi_usbtmc_open,
 	.source_add    = scpi_usbtmc_source_add,