#include "libsigrok-internal.h"
#include "protocol.h"
+#define SERIALCOMM "2400/8n1"
+
static const int hwopts[] = {
SR_HWOPT_CONN,
SR_HWOPT_SERIALCOMM,
return SR_OK;
}
+typedef gboolean (*packet_valid_t)(const uint8_t *buf);
+
+/**
+ * Try to find a valid packet in a serial data stream.
+ *
+ * @param serial Previously initialized serial port structure.
+ * @param buf Buffer containing the bytes to write.
+ * @param count Size of the buffer.
+ * @param packet_size Size, in bytes, of a valid packet.
+ * @param is_valid Callback that assesses whether the packet is valid or not.
+ * @param timeout_ms The timeout after which, if no packet is detected, to
+ * abort scanning.
+ * @param baudrate The baudrate of the serial port. This parameter is not
+ * critical, but it helps fine tune the serial port polling
+ * delay.
+ *
+ * @return SR_OK if a valid packet is found within the given timeout,
+ * SR_ERR upon failure.
+ */
+static int serial_stream_detect(struct sr_serial_dev_inst *serial,
+ uint8_t *buf, size_t *buflen,
+ size_t packet_size, packet_valid_t is_valid,
+ uint64_t timeout_ms, int baudrate)
+{
+ uint64_t start, time, byte_delay_us;
+ size_t ibuf, i, maxlen;
+ int len;
+
+ maxlen = *buflen;
+
+ sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
+ "ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
+
+ if (maxlen < (packet_size / 2) ) {
+ sr_err("Buffer size must be at least twice the packet size.");
+ return SR_ERR;
+ }
+
+ timeout_ms *= 1000;
+
+ /* Assume 8n1 transmission. That is 10 bits for every byte. */
+ byte_delay_us = 10 * (1000000 / baudrate);
+ start = g_get_monotonic_time();
+
+ i = ibuf = len = 0;
+ while (ibuf < maxlen) {
+ len = serial_read(serial, &buf[ibuf], 1);
+ if (len > 0) {
+ ibuf += len;
+ } else if (len == 0) {
+ sr_spew("Error: Only read 0 bytes.");
+ } else {
+ /* Error reading byte, but continuing anyway. */
+ }
+ if ((ibuf - i) >= packet_size) {
+ /* We have at least a packet's worth of data. */
+ if (is_valid(&buf[i])) {
+ time = g_get_monotonic_time() - start;
+ time /= 1000;
+ sr_spew("Found valid %d-byte packet after "
+ "%" PRIu64 "ms.", (ibuf - i), time);
+ *buflen = ibuf;
+ return SR_OK;
+ } else {
+ sr_spew("Got %d bytes, but not a valid "
+ "packet.", (ibuf - i));
+ }
+ /* Not a valid packet. Continue searching. */
+ i++;
+ }
+ if (g_get_monotonic_time() - start > timeout_ms) {
+ /* Timeout */
+ sr_dbg("Detection timed out after %dms.", timeout_ms);
+ break;
+ }
+ g_usleep(byte_delay_us);
+ }
+
+ *buflen = ibuf;
+
+ sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
+
+ return SR_ERR;
+}
+
static GSList *lcd14_scan(const char *conn, const char *serialcomm)
{
struct sr_dev_inst *sdi;
struct drv_context *drvc;
struct dev_context *devc;
struct sr_probe *probe;
- struct lcd14_packet *packet;
+ struct sr_serial_dev_inst *serial;
GSList *devices;
- int i, len, fd, retry, good_packets = 0, dropped, ret;
- char buf[128], *b;
+ int dropped, ret;
+ size_t len;
+ uint8_t buf[128];
- if ((fd = serial_open(conn, O_RDONLY | O_NONBLOCK)) == -1) {
- sr_err("Unable to open %s: %s.", conn, strerror(errno));
+ if (!(serial = sr_serial_dev_inst_new(conn, serialcomm)))
return NULL;
- }
- if ((ret = serial_set_paramstr(fd, serialcomm)) != SR_OK) {
- sr_err("Unable to set serial parameters: %d", ret);
+
+ if (serial_open(serial, O_RDONLY | O_NONBLOCK) != SR_OK)
return NULL;
- }
sr_info("Probing port %s readonly.", conn);
drvc = di->priv;
- b = buf;
- retry = 0;
devices = NULL;
- serial_flush(fd);
+ serial_flush(serial);
/*
* There's no way to get an ID from the multimeter. It just sends data
* periodically, so the best we can do is check if the packets match
* the expected format.
*/
- while (!devices && retry < 3) {
- retry++;
-
- /* Let's get a bit of data and see if we can find a packet. */
- len = sizeof(buf);
- serial_readline(fd, &b, &len, 500);
- if ((len == 0) || (len < LCD14_PACKET_SIZE)) {
- /* Not enough data received, is the DMM connected? */
- continue;
- }
- /* Let's treat our buffer like a stream, and find any
- * valid packets */
- for (i = 0; i < len - LCD14_PACKET_SIZE + 1;) {
- packet = (void *)(&buf[i]);
- if (!lcd14_is_packet_valid(packet, NULL)) {
- i++;
- continue;
- }
- good_packets++;
- i += LCD14_PACKET_SIZE;
- }
+ /* Let's get a bit of data and see if we can find a packet. */
+ len = sizeof(buf);
- /*
- * If we dropped more than two packets worth of data,
- * something is wrong.
- */
- dropped = len - (good_packets * LCD14_PACKET_SIZE);
- if (dropped > 2 * LCD14_PACKET_SIZE)
- continue;
-
- /* Let's see if we have anything good. */
- if (good_packets == 0)
- continue;
+ ret = serial_stream_detect(serial, buf, &len, FS9721_PACKET_SIZE,
+ sr_fs9721_packet_valid, 1000, 2400);
+ if (ret != SR_OK)
+ goto scan_cleanup;
- sr_info("Found device on port %s.", conn);
+ /*
+ * If we dropped more than two packets worth of data, something is
+ * wrong. We shouldn't quit however, since the dropped bytes might be
+ * just zeroes at the beginning of the stream. Those can occur as a
+ * combination of the nonstandard cable that ships with this device and
+ * the serial port or USB to serial adapter.
+ */
+ dropped = len - FS9721_PACKET_SIZE;
+ if (dropped > 2 * FS9721_PACKET_SIZE)
+ sr_warn("Had to drop too much data.");
- if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
- "TP4000ZC", "")))
- return NULL;
- if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
- sr_err("Device context malloc failed.");
- return NULL;
- }
+ sr_info("Found device on port %s.", conn);
- devc->serial = sr_serial_dev_inst_new(conn, -1);
- devc->serialcomm = g_strdup(serialcomm);
+ if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
+ "TP4000ZC", "")))
+ goto scan_cleanup;
- sdi->priv = devc;
- sdi->driver = di;
- if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
- return NULL;
- sdi->probes = g_slist_append(sdi->probes, probe);
- drvc->instances = g_slist_append(drvc->instances, sdi);
- devices = g_slist_append(devices, sdi);
- break;
+ if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
+ sr_err("Device context malloc failed.");
+ goto scan_cleanup;
}
- serial_close(fd);
+ devc->serial = serial;
+
+ sdi->priv = devc;
+ sdi->driver = di;
+ if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
+ goto scan_cleanup;
+ sdi->probes = g_slist_append(sdi->probes, probe);
+ drvc->instances = g_slist_append(drvc->instances, sdi);
+ devices = g_slist_append(devices, sdi);
+
+scan_cleanup:
+ serial_close(serial);
+
return devices;
}
/* Use the provided comm specs. */
devices = lcd14_scan(conn, serialcomm);
} else {
- /* Try the default 2400/8n1. */
- devices = lcd14_scan(conn, "2400/8n1");
+ /* Try the default. */
+ devices = lcd14_scan(conn, SERIALCOMM);
}
return devices;
static int hw_dev_open(struct sr_dev_inst *sdi)
{
- int ret;
struct dev_context *devc;
if (!(devc = sdi->priv)) {
return SR_ERR_BUG;
}
- devc->serial->fd = serial_open(devc->serial->port, O_RDONLY);
- if (devc->serial->fd == -1) {
- sr_err("Couldn't open serial port '%s'.", devc->serial->port);
+ if (serial_open(devc->serial, O_RDONLY) != SR_OK)
return SR_ERR;
- }
- ret = serial_set_paramstr(devc->serial->fd, devc->serialcomm);
- if (ret != SR_OK) {
- sr_err("Unable to set serial parameters: %d.", ret);
- return SR_ERR;
- }
sdi->status = SR_ST_ACTIVE;
return SR_OK;
}
if (devc->serial && devc->serial->fd != -1) {
- serial_close(devc->serial->fd);
- devc->serial->fd = -1;
+ serial_close(devc->serial);
sdi->status = SR_ST_INACTIVE;
}
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)
{
struct sr_datafeed_packet packet;
struct dev_context *devc;
projects / libsigrok.git / blobdiff