#include <math.h>
#include "protocol.h"
+#define SEP "\r\n"
+#define BLANK ':'
+#define NEG ';'
+
+/*
+ * Get a temperature value from a four-character buffer. The value is
+ * encoded in ASCII and the unit is deci-degrees (tenths of degrees).
+ */
static float parse_temperature(unsigned char *buf)
{
float temp;
negative = FALSE;
temp = 0.0;
for (i = 0; i < 4; i++) {
- if (buf[i] == 0x3a)
+ if (buf[i] == BLANK)
continue;
- if (buf[i] == 0x3b) {
+ if (buf[i] == NEG) {
if (negative) {
sr_dbg("Double negative sign!");
return NAN;
- } else {
- negative = TRUE;
- continue;
}
+ negative = TRUE;
+ continue;
}
- if (buf[i] < 0x30 || buf[i] > 0x39) {
+ if (buf[i] < '0' || buf[i] > '9') {
sr_dbg("Invalid digit '%.2x'!", buf[i]);
return NAN;
}
temp *= 10;
- temp += (buf[i] - 0x30);
+ temp += buf[i] - '0';
}
temp /= 10;
if (negative)
return temp;
}
-static void process_packet(struct sr_dev_inst *sdi)
+static void process_packet(struct sr_dev_inst *sdi, uint8_t *pkt, size_t len)
{
struct dev_context *devc;
struct sr_datafeed_packet packet;
struct sr_analog_spec spec;
GString *spew;
float temp;
- int i;
gboolean is_valid;
- devc = sdi->priv;
- sr_dbg("Received full 19-byte packet.");
if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
- spew = g_string_sized_new(60);
- for (i = 0; i < devc->packet_len; i++)
- g_string_append_printf(spew, "%.2x ", devc->packet[i]);
- sr_spew("%s", spew->str);
- g_string_free(spew, TRUE);
+ spew = sr_hexdump_new(pkt, len);
+ sr_spew("Got a packet, len %zu, bytes%s", len, spew->str);
+ sr_hexdump_free(spew);
}
+ if (len != PACKET_SIZE)
+ return;
+ if (pkt[17] != SEP[0] || pkt[18] != SEP[1])
+ return;
+ if (pkt[8] != '0' || pkt[16] != '1')
+ return;
+ sr_dbg("Processing 19-byte packet.");
is_valid = TRUE;
- if (devc->packet[1] == 0x3b && devc->packet[2] == 0x3b
- && devc->packet[3] == 0x3b && devc->packet[4] == 0x3b)
+ if (pkt[1] == NEG && pkt[2] == NEG && pkt[3] == NEG && pkt[4] == NEG)
/* No measurement: missing channel, empty storage location, ... */
is_valid = FALSE;
- temp = parse_temperature(devc->packet + 1);
+ temp = parse_temperature(&pkt[1]);
if (isnan(temp))
is_valid = FALSE;
if (is_valid) {
+ memset(&packet, 0, sizeof(packet));
sr_analog_init(&analog, &encoding, &meaning, &spec, 1);
analog.meaning->mq = SR_MQ_TEMPERATURE;
analog.meaning->mqflags = 0;
- switch (devc->packet[5] - 0x30) {
+ switch (pkt[5] - '0') {
case 1:
analog.meaning->unit = SR_UNIT_CELSIUS;
break;
break;
default:
/* We can still pass on the measurement, whatever it is. */
- sr_dbg("Unknown unit 0x%.2x.", devc->packet[5]);
+ sr_dbg("Unknown unit 0x%.2x.", pkt[5]);
}
- switch (devc->packet[13] - 0x30) {
+ switch (pkt[13] - '0') {
case 0:
/* Channel T1. */
analog.meaning->channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
analog.meaning->mqflags |= SR_MQFLAG_RELATIVE;
break;
default:
- sr_err("Unknown channel 0x%.2x.", devc->packet[13]);
+ sr_err("Unknown channel 0x%.2x.", pkt[13]);
is_valid = FALSE;
}
if (is_valid) {
}
}
- /* We count packets even if the temperature was invalid. This way
- * a sample limit on "Memory" data source still works: unused
- * memory slots come through as "----" measurements. */
- devc->num_samples++;
- if (devc->limit_samples && devc->num_samples >= devc->limit_samples)
+ /*
+ * We count packets even if the measurement was invalid. This way
+ * a sample limit on "Memory" data source still works: Unused
+ * memory slots come through as "----" measurements.
+ */
+ devc = sdi->priv;
+ sr_sw_limits_update_samples_read(&devc->limits, 1);
+ if (sr_sw_limits_check(&devc->limits))
sr_dev_acquisition_stop(sdi);
}
-SR_PRIV void LIBUSB_CALL uni_t_ut32x_receive_transfer(struct libusb_transfer *transfer)
+static int process_buffer(struct sr_dev_inst *sdi)
{
struct dev_context *devc;
- struct sr_dev_inst *sdi;
- int hid_payload_len, ret;
+ uint8_t *pkt;
+ size_t remain, idx;
- sdi = transfer->user_data;
+ /*
+ * Specifically do not insist on finding the packet boundary at
+ * the end of the most recently received data chunk. Serial
+ * ports might involve hardware buffers (FIFO). We want to sync
+ * as fast as possible.
+ *
+ * Handle the synchronized situation first. Process complete
+ * packets that reside at the start of the buffer. Then fallback
+ * to incomplete or unaligned packets if the receive buffer
+ * still contains data bytes. (Depending on the bitrate and the
+ * poll interval, we may always end up in the manual search. But
+ * considering the update rate - two or three packets per second
+ * - this is not an issue.)
+ */
devc = sdi->priv;
- if (transfer->actual_length == 8) {
- /* CH9325 encodes length in low nibble of first byte, with
- * bytes 1-7 being the (padded) payload. */
- hid_payload_len = transfer->buffer[0] & 0x0f;
- memcpy(devc->packet + devc->packet_len, transfer->buffer + 1,
- hid_payload_len);
- devc->packet_len += hid_payload_len;
- if (devc->packet_len >= 2
- && devc->packet[devc->packet_len - 2] == 0x0d
- && devc->packet[devc->packet_len - 1] == 0x0a) {
- /* Got end of packet, but do we have a complete packet? */
- if (devc->packet_len == 19)
- process_packet(sdi);
- /* Either way, done with it. */
- devc->packet_len = 0;
- } else if (devc->packet_len > 19) {
- /* Guard against garbage from the device overrunning
- * our packet buffer. */
- sr_dbg("Buffer overrun!");
- devc->packet_len = 0;
- }
+ pkt = &devc->packet[0];
+ while (devc->packet_len >= PACKET_SIZE &&
+ pkt[PACKET_SIZE - 2] == SEP[0] &&
+ pkt[PACKET_SIZE - 1] == SEP[1]) {
+ process_packet(sdi, &pkt[0], PACKET_SIZE);
+ remain = devc->packet_len - PACKET_SIZE;
+ if (remain)
+ memmove(&pkt[0], &pkt[PACKET_SIZE], remain);
+ devc->packet_len -= PACKET_SIZE;
}
- /* Get the next transfer (unless we're shutting down). */
- if (sdi->status != SR_ST_STOPPING) {
- if ((ret = libusb_submit_transfer(devc->xfer)) != 0) {
- sr_dbg("Failed to resubmit transfer: %s", libusb_error_name(ret));
- sdi->status = SR_ST_STOPPING;
- libusb_free_transfer(devc->xfer);
- }
- } else
- libusb_free_transfer(devc->xfer);
+ /*
+ * The 'for' loop and the increment upon re-iteration after
+ * setting the loop var to zero is not an issue. The marker has
+ * two bytes, so effectively starting the search at offset 1 is
+ * fine for the specific packet layout.
+ */
+ for (idx = 0; idx < devc->packet_len; idx++) {
+ if (idx < 1)
+ continue;
+ if (pkt[idx - 1] != SEP[0] || pkt[idx] != SEP[1])
+ continue;
+ /* Found a packet that spans up to and including 'idx'. */
+ idx++;
+ process_packet(sdi, &pkt[0], idx);
+ remain = devc->packet_len - idx;
+ if (remain)
+ memmove(&pkt[0], &pkt[idx], remain);
+ devc->packet_len -= idx;
+ idx = 0;
+ }
+ return 0;
}
-SR_PRIV int uni_t_ut32x_handle_events(int fd, int revents, void *cb_data)
+/* Gets invoked when RX data is available. */
+static int ut32x_receive_data(struct sr_dev_inst *sdi)
{
- struct drv_context *drvc;
struct dev_context *devc;
- struct sr_dev_driver *di;
+ struct sr_serial_dev_inst *serial;
+ size_t len;
+
+ devc = sdi->priv;
+ serial = sdi->conn;
+
+ /*
+ * Discard receive data when the buffer is exhausted. This shall
+ * allow to (re-)synchronize to the data stream when we find it
+ * in an arbitrary state. Drain more data from the serial port,
+ * and check the receive buffer for packets.
+ */
+ if (devc->packet_len == sizeof(devc->packet)) {
+ process_packet(sdi, &devc->packet[0], devc->packet_len);
+ devc->packet_len = 0;
+ }
+ len = sizeof(devc->packet) - devc->packet_len;
+ len = serial_read_nonblocking(serial,
+ &devc->packet[devc->packet_len], len);
+ if (!len)
+ return 0;
+
+ devc->packet_len += len;
+ process_buffer(sdi);
+
+ return 0;
+}
+
+/* Gets periodically invoked by the glib main loop. */
+SR_PRIV int ut32x_handle_events(int fd, int revents, void *cb_data)
+{
struct sr_dev_inst *sdi;
- struct sr_usb_dev_inst *usb;
- struct timeval tv;
- int len, ret;
- unsigned char cmd[2];
+ struct sr_serial_dev_inst *serial;
+ uint8_t cmd;
(void)fd;
- (void)revents;
- if (!(sdi = cb_data))
+ sdi = cb_data;
+ if (!sdi)
return TRUE;
-
- di = sdi->driver;
- drvc = di->context;
-
- if (!(devc = sdi->priv))
+ serial = sdi->conn;
+ if (!serial)
return TRUE;
- memset(&tv, 0, sizeof(struct timeval));
- libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
- NULL);
+ if (revents & G_IO_IN)
+ ut32x_receive_data(sdi);
if (sdi->status == SR_ST_STOPPING) {
- usb_source_remove(sdi->session, drvc->sr_ctx);
+ serial_source_remove(sdi->session, serial);
std_session_send_df_end(sdi);
-
- /* Tell the device to stop sending USB packets. */
- usb = sdi->conn;
- cmd[0] = 0x01;
- cmd[1] = CMD_STOP;
- ret = libusb_bulk_transfer(usb->devhdl, EP_OUT, cmd, 2, &len, 5);
- if (ret != 0 || len != 2) {
- /* Warning only, doesn't matter. */
- sr_dbg("Failed to send stop command: %s", libusb_error_name(ret));
- }
-
sdi->status = SR_ST_ACTIVE;
- return TRUE;
+
+ /* Tell the device to stop sending data. */
+ cmd = CMD_STOP;
+ serial_write_blocking(serial, &cmd, sizeof(cmd), 0);
}
return TRUE;
projects / libsigrok.git / blobdiff