serial-dmm: Implement request timeout mechanism.

[libsigrok.git] / hardware / serial-dmm / protocol.c

diff --git a/hardware/serial-dmm/protocol.c b/hardware/serial-dmm/protocol.c
index 36e69444d8f7a815ccdc9483ce856ec1442e3ae3..0b2472fbb70401096073d0b24399fc07e0b633d7 100644 (file)
--- a/hardware/serial-dmm/protocol.c
+++ b/hardware/serial-dmm/protocol.c
@@ -68,6 +68,37 @@ static void handle_packet(const uint8_t *buf, struct sr_dev_inst *sdi,
        }
 }
 
+/** Request packet, if required. */
+SR_PRIV int req_packet(struct sr_dev_inst *sdi, int dmm)
+{
+       struct dev_context *devc;
+       struct sr_serial_dev_inst *serial;
+       int ret;
+
+       if (!dmms[dmm].packet_request)
+               return SR_OK;
+
+       devc = sdi->priv;
+       serial = sdi->conn;
+
+       if (devc->req_next_at && (devc->req_next_at > g_get_monotonic_time())) {
+               sr_spew("Not requesting new packet yet, %" PRIi64 " ms left.",
+                       ((devc->req_next_at - g_get_monotonic_time()) / 1000));
+               return SR_OK;
+       }
+
+       ret = dmms[dmm].packet_request(serial);
+       if (ret < 0) {
+               sr_err("Failed to request packet: %d.", ret);
+               return ret;
+       }
+
+       if (dmms[dmm].req_timeout_ms)
+               devc->req_next_at = g_get_monotonic_time() + (dmms[dmm].req_timeout_ms * 1000);
+
+       return SR_OK;
+}
+
 static void handle_new_data(struct sr_dev_inst *sdi, int dmm, void *info)
 {
        struct dev_context *devc;
@@ -93,6 +124,14 @@ static void handle_new_data(struct sr_dev_inst *sdi, int dmm, void *info)
                if (dmms[dmm].packet_valid(devc->buf + offset)) {
                        handle_packet(devc->buf + offset, sdi, dmm, info);
                        offset += dmms[dmm].packet_size;
+
+                       /* Request next packet, if required. */
+                       if (!dmms[dmm].packet_request)
+                               break;
+                       if (dmms[dmm].req_timeout_ms || dmms[dmm].req_delay_ms)
+                               devc->req_next_at = g_get_monotonic_time() +
+                                       dmms[dmm].req_delay_ms * 1000;
+                       req_packet(sdi, dmm);
                } else {
                        offset++;
                }
@@ -108,9 +147,7 @@ static int receive_data(int fd, int revents, int dmm, void *info, void *cb_data)
 {
        struct sr_dev_inst *sdi;
        struct dev_context *devc;
-       struct sr_serial_dev_inst *serial;
        int64_t time;
-       int ret;
 
        (void)fd;
 
@@ -120,20 +157,13 @@ static int receive_data(int fd, int revents, int dmm, void *info, void *cb_data)
        if (!(devc = sdi->priv))
                return TRUE;
 
-       serial = sdi->conn;
-
        if (revents == G_IO_IN) {
                /* Serial data arrived. */
                handle_new_data(sdi, dmm, info);
        } else {
-               /* Timeout, send another packet request (if DMM needs it). */
-               if (dmms[dmm].packet_request) {
-                       ret = dmms[dmm].packet_request(serial);
-                       if (ret < 0) {
-                               sr_err("Failed to request packet: %d.", ret);
-                               return FALSE;
-                       }
-               }
+               /* Timeout; send another packet request if DMM needs it. */
+               if (dmms[dmm].packet_request && (req_packet(sdi, dmm) < 0))
+                       return FALSE;
        }
 
        if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {