sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
- /* Default to the libserialport transport layer. */
- serial->lib_funcs = ser_lib_funcs_libsp;
+ /*
+ * Determine which serial transport library to use. Derive the
+ * variant from the serial port's name. Default to libserialport
+ * for backwards compatibility.
+ */
+ if (ser_name_is_hid(serial))
+ serial->lib_funcs = ser_lib_funcs_hid;
+ else
+ serial->lib_funcs = ser_lib_funcs_libsp;
if (!serial->lib_funcs)
return SR_ERR_NA;
+ /*
+ * Note that use of the 'rcv_buffer' is optional, and the buffer's
+ * size heavily depends on the specific transport. That's why the
+ * buffer's content gets accessed and the buffer is released here in
+ * common code, but the buffer gets allocated in libraries' open()
+ * routines.
+ */
+
/*
* Run the transport's open routine. Setup the bitrate and the
* UART frame format.
*/
SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
{
+ int rc;
+
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
if (!serial->lib_funcs || !serial->lib_funcs->close)
return SR_ERR_NA;
- return serial->lib_funcs->close(serial);
+ rc = serial->lib_funcs->close(serial);
+ if (rc == SR_OK && serial->rcv_buffer) {
+ g_string_free(serial->rcv_buffer, TRUE);
+ serial->rcv_buffer = NULL;
+ }
+
+ return rc;
}
/**
sr_spew("Flushing serial port %s.", serial->port);
+ sr_ser_discard_queued_data(serial);
+
if (!serial->lib_funcs || !serial->lib_funcs->flush)
return SR_ERR_NA;
return serial->lib_funcs->drain(serial);
}
+/*
+ * Provide an internal RX data buffer for the serial port. This is not
+ * supposed to be used directly by applications. Instead optional and
+ * alternative transports for serial communication can use this buffer
+ * if their progress is driven from background activity, and is not
+ * (directly) driven by external API calls.
+ *
+ * BEWARE! This implementation assumes that data which gets communicated
+ * via UART can get stored in a GString (which is a char array). Since
+ * the API hides this detail, we can address this issue later when needed.
+ * Callers use the API which communicates bytes.
+ */
+
+/**
+ * Discard previously queued RX data. Internal to the serial subsystem,
+ * coordination between common and transport specific support code.
+ *
+ * @param[in] serial Previously opened serial port instance.
+ *
+ * @internal
+ */
+SR_PRIV void sr_ser_discard_queued_data(struct sr_serial_dev_inst *serial)
+{
+ if (!serial)
+ return;
+ if (!serial->rcv_buffer)
+ return;
+
+ g_string_truncate(serial->rcv_buffer, 0);
+}
+
+/**
+ * Get amount of queued RX data. Internal to the serial subsystem,
+ * coordination between common and transport specific support code.
+ *
+ * @param[in] serial Previously opened serial port instance.
+ *
+ * @internal
+ */
+SR_PRIV size_t sr_ser_has_queued_data(struct sr_serial_dev_inst *serial)
+{
+ if (!serial)
+ return 0;
+ if (!serial->rcv_buffer)
+ return 0;
+
+ return serial->rcv_buffer->len;
+}
+
+/**
+ * Queue received data. Internal to the serial subsystem, coordination
+ * between common and transport specific support code.
+ *
+ * @param[in] serial Previously opened serial port instance.
+ * @param[in] data Pointer to data bytes to queue.
+ * @param[in] len Number of data bytes to queue.
+ *
+ * @internal
+ */
+SR_PRIV void sr_ser_queue_rx_data(struct sr_serial_dev_inst *serial,
+ const uint8_t *data, size_t len)
+{
+ if (!serial)
+ return;
+ if (!data || !len)
+ return;
+
+ if (serial->rcv_buffer)
+ g_string_append_len(serial->rcv_buffer, (const gchar *)data, len);
+}
+
+/**
+ * Retrieve previously queued RX data. Internal to the serial subsystem,
+ * coordination between common and transport specific support code.
+ *
+ * @param[in] serial Previously opened serial port instance.
+ * @param[out] data Pointer to store retrieved data bytes into.
+ * @param[in] len Number of data bytes to retrieve.
+ *
+ * @internal
+ */
+SR_PRIV size_t sr_ser_unqueue_rx_data(struct sr_serial_dev_inst *serial,
+ uint8_t *data, size_t len)
+{
+ size_t qlen;
+ GString *buf;
+
+ if (!serial)
+ return 0;
+ if (!data || !len)
+ return 0;
+
+ qlen = sr_ser_has_queued_data(serial);
+ if (!qlen)
+ return 0;
+
+ buf = serial->rcv_buffer;
+ if (len > buf->len)
+ len = buf->len;
+ if (len) {
+ memcpy(data, buf->str, len);
+ g_string_erase(buf, 0, len);
+ }
+
+ return len;
+}
+
/**
* Check for available receive data.
*
*/
SR_PRIV size_t serial_has_receive_data(struct sr_serial_dev_inst *serial)
{
- size_t lib_count;
+ size_t lib_count, buf_count;
if (!serial)
return 0;
if (serial->lib_funcs && serial->lib_funcs->get_rx_avail)
lib_count = serial->lib_funcs->get_rx_avail(serial);
- return lib_count;
+ buf_count = sr_ser_has_queued_data(serial);
+
+ return lib_count + buf_count;
}
static int _serial_write(struct sr_serial_dev_inst *serial,
list_func = ser_lib_funcs_libsp->list;
tty_devs = list_func(tty_devs, append_port_list);
}
+ if (ser_lib_funcs_hid && ser_lib_funcs_hid->list) {
+ list_func = ser_lib_funcs_hid->list;
+ tty_devs = list_func(tty_devs, append_port_list);
+ }
return tty_devs;
}
tty_devs = find_func(tty_devs, append_port_find,
vendor_id, product_id);
}
+ if (ser_lib_funcs_hid && ser_lib_funcs_hid->find_usb) {
+ find_func = ser_lib_funcs_hid->find_usb;
+ tty_devs = find_func(tty_devs, append_port_find,
+ vendor_id, product_id);
+ }
return tty_devs;
}
projects / libsigrok.git / blobdiff