#include <fcntl.h>
#include <errno.h>
-/* Message logging helpers with subsystem-specific prefix string. */
-#define LOG_PREFIX "scpi_usbtmc: "
-#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
-#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
-#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
-#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
-#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
-
-SR_PRIV int scpi_usbtmc_open(void *priv)
+#define LOG_PREFIX "scpi_usbtmc"
+
+#define MAX_READ_LENGTH 2048
+
+struct usbtmc_scpi {
+ struct sr_usbtmc_dev_inst *usbtmc;
+ char response_buffer[MAX_READ_LENGTH];
+ int response_length;
+ int response_bytes_read;
+};
+
+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 sr_usbtmc_dev_inst *usbtmc = priv;
+ struct usbtmc_scpi *uscpi = priv;
+
+ (void)drvc;
+ (void)params;
+ (void)serialcomm;
+
+ if (!(uscpi->usbtmc = sr_usbtmc_dev_inst_new(resource)))
+ return SR_ERR;
+
+ return SR_OK;
+}
+
+static int scpi_usbtmc_open(void *priv)
+{
+ struct usbtmc_scpi *uscpi = priv;
+ struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
if ((usbtmc->fd = open(usbtmc->device, O_RDWR)) < 0)
return SR_ERR;
return SR_OK;
}
-SR_PRIV int scpi_usbtmc_source_add(void *priv, int events, int timeout,
- sr_receive_data_callback_t cb, void *cb_data)
+static int scpi_usbtmc_source_add(void *priv, int events, int timeout,
+ sr_receive_data_callback cb, void *cb_data)
{
- struct sr_usbtmc_dev_inst *usbtmc = priv;
+ struct usbtmc_scpi *uscpi = priv;
+ struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
return sr_source_add(usbtmc->fd, events, timeout, cb, cb_data);
}
-SR_PRIV int scpi_usbtmc_source_remove(void *priv)
+static int scpi_usbtmc_source_remove(void *priv)
{
- struct sr_usbtmc_dev_inst *usbtmc = priv;
+ struct usbtmc_scpi *uscpi = priv;
+ struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
return sr_source_remove(usbtmc->fd);
}
-SR_PRIV int scpi_usbtmc_send(void *priv, const char *command)
+static int scpi_usbtmc_send(void *priv, const char *command)
{
- struct sr_usbtmc_dev_inst *usbtmc = priv;
+ struct usbtmc_scpi *uscpi = priv;
+ struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
int len, out;
len = strlen(command);
return SR_OK;
}
-SR_PRIV int scpi_usbtmc_receive(void *priv, char **scpi_response)
+static int scpi_usbtmc_read_begin(void *priv)
{
- struct sr_usbtmc_dev_inst *usbtmc = priv;
- GString *response;
- char buf[256];
+ struct usbtmc_scpi *uscpi = priv;
+ struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
int len;
- response = g_string_sized_new(1024);
-
- len = read(usbtmc->fd, buf, sizeof(buf));
+ len = read(usbtmc->fd, uscpi->response_buffer, MAX_READ_LENGTH);
if (len < 0) {
sr_err("Read error: %s", strerror(errno));
- g_string_free(response, TRUE);
return SR_ERR;
}
- response = g_string_append_len(response, buf, len);
+ uscpi->response_length = len;
+ uscpi->response_bytes_read = 0;
- *scpi_response = response->str;
+ sr_spew("Read %d bytes from device into buffer", len);
- sr_dbg("SCPI response received (length %d): '%.50s'",
- response->len, response->str);
+ return SR_OK;
+}
- g_string_free(response, FALSE);
+static int scpi_usbtmc_read_data(void *priv, char *buf, int maxlen)
+{
+ struct usbtmc_scpi *uscpi = priv;
+ int read_length;
+
+ sr_spew("%d bytes requested", maxlen);
+
+ 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;
+ }
+ }
- return SR_OK;
+ read_length = uscpi->response_length - uscpi->response_bytes_read;
+
+ if (read_length > maxlen)
+ read_length = maxlen;
+
+ memcpy(buf, uscpi->response_buffer + uscpi->response_bytes_read, read_length);
+
+ 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;
}
-SR_PRIV int scpi_usbtmc_close(void *priv)
+static int scpi_usbtmc_read_complete(void *priv)
{
- struct sr_usbtmc_dev_inst *usbtmc = priv;
+ struct usbtmc_scpi *uscpi = priv;
- if (close(usbtmc->fd) < 0)
- return SR_ERR;
+ if (uscpi->response_length == MAX_READ_LENGTH
+ && uscpi->response_bytes_read == uscpi->response_length)
+ scpi_usbtmc_read_begin(uscpi);
- return SR_OK;
+ return (uscpi->response_bytes_read >= uscpi->response_length);
}
-SR_PRIV struct sr_scpi_dev_inst *scpi_usbtmc_dev_inst_new(const char *device)
+static int scpi_usbtmc_close(void *priv)
{
- struct sr_scpi_dev_inst *scpi;
- struct sr_usbtmc_dev_inst *usbtmc;
+ struct usbtmc_scpi *uscpi = priv;
- scpi = g_try_malloc(sizeof(struct sr_scpi_dev_inst));
+ if (close(uscpi->usbtmc->fd) < 0)
+ return SR_ERR;
- if (!(usbtmc = sr_usbtmc_dev_inst_new(device)))
- {
- g_free(scpi);
- return NULL;
- }
+ return SR_OK;
+}
- scpi->open = scpi_usbtmc_open;
- scpi->source_add = scpi_usbtmc_source_add;
- scpi->source_remove = scpi_usbtmc_source_remove;
- scpi->send = scpi_usbtmc_send;
- scpi->receive = scpi_usbtmc_receive;
- scpi->close = scpi_usbtmc_close;
- scpi->free = sr_usbtmc_dev_inst_free;
- scpi->priv = usbtmc;
+static void scpi_usbtmc_free(void *priv)
+{
+ struct usbtmc_scpi *uscpi = priv;
- return scpi;
+ sr_usbtmc_dev_inst_free(uscpi->usbtmc);
}
+
+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,
+ .source_remove = scpi_usbtmc_source_remove,
+ .send = scpi_usbtmc_send,
+ .read_begin = scpi_usbtmc_read_begin,
+ .read_data = scpi_usbtmc_read_data,
+ .read_complete = scpi_usbtmc_read_complete,
+ .close = scpi_usbtmc_close,
+ .free = scpi_usbtmc_free,
+};
projects / libsigrok.git / blobdiff