rdtech-um: adjust read/write timeout style for text line length

[libsigrok.git] / src / hardware / rdtech-um / protocol.c

diff --git a/src/hardware/rdtech-um/protocol.c b/src/hardware/rdtech-um/protocol.c
index 78da302b307286eec1f93d5ed345b832a5e74448..763ad95b892dda70bdb83974c792e4f7ad13ea82 100644 (file)
--- a/src/hardware/rdtech-um/protocol.c
+++ b/src/hardware/rdtech-um/protocol.c
@@ -28,12 +28,15 @@
 #include "libsigrok-internal.h"
 #include "protocol.h"
 
-#define SERIAL_WRITE_TIMEOUT_MS 1
+/* Read/write timeouts, poll request intervals. */
+#define PROBE_TO_MS 1000
+#define WRITE_TO_MS 1
+#define POLL_PERIOD_MS 100
 
-#define UM_POLL_LEN 130
-#define UM_POLL_PERIOD_MS 100
-#define UM_TIMEOUT_MS 1000
+/* Expected receive data size for poll responses. */
+#define POLL_RECV_LEN 130
 
+/* Command code to request another poll response. */
 #define UM_CMD_POLL 0xf0
 
 static const struct binary_analog_channel rdtech_default_channels[] = {
@@ -62,7 +65,7 @@ static gboolean csum_ok_fff1(const uint8_t *buf, size_t len)
 {
        uint16_t csum_recv;
 
-       if (len != UM_POLL_LEN)
+       if (len != POLL_RECV_LEN)
                return FALSE;
 
        csum_recv = read_u16be(&buf[len - sizeof(uint16_t)]);
@@ -83,7 +86,7 @@ static gboolean csum_ok_um34c(const uint8_t *buf, size_t len)
        size_t i;
        uint8_t csum_calc, csum_recv;
 
-       if (len != UM_POLL_LEN)
+       if (len != POLL_RECV_LEN)
                return FALSE;
 
        csum_calc = 0;
@@ -118,20 +121,21 @@ static const struct rdtech_um_profile *find_profile(uint16_t id)
 SR_PRIV const struct rdtech_um_profile *rdtech_um_probe(struct sr_serial_dev_inst *serial)
 {
        const struct rdtech_um_profile *p;
-       uint8_t request;
+       uint8_t req;
+       int ret;
        uint8_t buf[RDTECH_UM_BUFSIZE];
        int rcvd;
        uint16_t model_id;
 
-       request = UM_CMD_POLL;
-       if (serial_write_blocking(serial, &request, sizeof(request),
-                       SERIAL_WRITE_TIMEOUT_MS) < 0) {
-               sr_err("Unable to send probe request.");
+       req = UM_CMD_POLL;
+       ret = serial_write_blocking(serial, &req, sizeof(req), WRITE_TO_MS);
+       if (ret < 0) {
+               sr_err("Failed to send probe request.");
                return NULL;
        }
 
-       rcvd = serial_read_blocking(serial, buf, UM_POLL_LEN, UM_TIMEOUT_MS);
-       if (rcvd != UM_POLL_LEN) {
+       rcvd = serial_read_blocking(serial, buf, POLL_RECV_LEN, PROBE_TO_MS);
+       if (rcvd != POLL_RECV_LEN) {
                sr_err("Failed to read probe response.");
                return NULL;
        }
@@ -156,20 +160,21 @@ SR_PRIV int rdtech_um_poll(const struct sr_dev_inst *sdi, gboolean force)
        struct dev_context *devc;
        int64_t now, elapsed;
        struct sr_serial_dev_inst *serial;
-       uint8_t request;
+       uint8_t req;
+       int ret;
 
        /* Check for expired intervals or forced requests. */
        devc = sdi->priv;
        now = g_get_monotonic_time() / 1000;
        elapsed = now - devc->cmd_sent_at;
-       if (!force && elapsed < UM_POLL_PERIOD_MS)
+       if (!force && elapsed < POLL_PERIOD_MS)
                return SR_OK;
 
        /* Send another poll request. Update interval only on success. */
        serial = sdi->conn;
-       request = UM_CMD_POLL;
-       if (serial_write_blocking(serial, &request, sizeof(request),
-                       SERIAL_WRITE_TIMEOUT_MS) < 0) {
+       req = UM_CMD_POLL;
+       ret = serial_write_blocking(serial, &req, sizeof(req), WRITE_TO_MS);
+       if (ret < 0) {
                sr_err("Unable to send poll request.");
                return SR_ERR;
        }
@@ -186,7 +191,7 @@ static void handle_poll_data(const struct sr_dev_inst *sdi)
 
        devc = sdi->priv;
        sr_spew("Received poll packet (len: %zu).", devc->buflen);
-       if (devc->buflen != UM_POLL_LEN) {
+       if (devc->buflen != POLL_RECV_LEN) {
                sr_err("Unexpected poll packet length: %zu", devc->buflen);
                return;
        }
@@ -211,7 +216,7 @@ static void recv_poll_data(struct sr_dev_inst *sdi, struct sr_serial_dev_inst *s
        /* Serial data arrived. */
        devc = sdi->priv;
        p = devc->profile;
-       while (devc->buflen < UM_POLL_LEN) {
+       while (devc->buflen < POLL_RECV_LEN) {
                len = serial_read_nonblocking(serial, devc->buf + devc->buflen, 1);
                if (len < 1)
                        return;
@@ -227,7 +232,7 @@ static void recv_poll_data(struct sr_dev_inst *sdi, struct sr_serial_dev_inst *s
                }
        }
 
-       if (devc->buflen != UM_POLL_LEN)
+       if (devc->buflen != POLL_RECV_LEN)
                sr_warn("Skipping packet, unexpected receive length.");
        else if (!p->csum_ok(devc->buf, devc->buflen))
                sr_warn("Skipping packet, checksum verification failed.");
@@ -246,19 +251,21 @@ SR_PRIV int rdtech_um_receive_data(int fd, int revents, void *cb_data)
 
        if (!(sdi = cb_data))
                return TRUE;
-
        if (!(devc = sdi->priv))
                return TRUE;
 
+       /* Drain and process receive data as it becomes available. */
        serial = sdi->conn;
        if (revents == G_IO_IN)
                recv_poll_data(sdi, serial);
 
+       /* Check configured acquisition limits. */
        if (sr_sw_limits_check(&devc->limits)) {
                sr_dev_acquisition_stop(sdi);
                return TRUE;
        }
 
+       /* Periodically emit measurement requests. */
        (void)rdtech_um_poll(sdi, FALSE);
 
        return TRUE;