uni-t-ut181a: implement device driver for the UNI-T UT181A multimeter

[libsigrok.git] / src / hardware / fx2lafw / protocol.c

diff --git a/src/hardware/fx2lafw/protocol.c b/src/hardware/fx2lafw/protocol.c
index a31231fd41a22813ae3e4f23a69e1c5aa2c71a7d..83315808d0eca129d1e37503d0375ec22de8f250 100644 (file)
--- a/src/hardware/fx2lafw/protocol.c
+++ b/src/hardware/fx2lafw/protocol.c
@@ -112,7 +112,7 @@ static int command_start_acquisition(const struct sr_dev_inst *sdi)
        sr_dbg("GPIF delay = %d, clocksource = %sMHz.", delay,
                (cmd.flags & CMD_START_FLAGS_CLK_48MHZ) ? "48" : "30");
 
-       if (delay <= 0 || delay > MAX_SAMPLE_DELAY) {
+       if (delay < 0 || delay > MAX_SAMPLE_DELAY) {
                sr_err("Unable to sample at %" PRIu64 "Hz.", samplerate);
                return SR_ERR;
        }
@@ -147,7 +147,7 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
        struct dev_context *devc;
        struct drv_context *drvc;
        struct version_info vi;
-       int ret, i, device_count;
+       int ret = SR_ERR, i, device_count;
        uint8_t revid;
        char connection_id[64];
 
@@ -155,10 +155,6 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
        devc = sdi->priv;
        usb = sdi->conn;
 
-       if (sdi->status == SR_ST_ACTIVE)
-               /* Device is already in use. */
-               return SR_ERR;
-
        device_count = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
        if (device_count < 0) {
                sr_err("Failed to get device list: %s.",
@@ -178,7 +174,9 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
                        /*
                         * Check device by its physical USB bus/port address.
                         */
-                       usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
+                       if (usb_get_port_path(devlist[i], connection_id, sizeof(connection_id)) < 0)
+                               continue;
+
                        if (strcmp(sdi->connection_id, connection_id))
                                /* This is not the one. */
                                continue;
@@ -194,6 +192,7 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
                } else {
                        sr_err("Failed to open device: %s.",
                               libusb_error_name(ret));
+                       ret = SR_ERR;
                        break;
                }
 
@@ -202,7 +201,8 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
                                if ((ret = libusb_detach_kernel_driver(usb->devhdl, USB_INTERFACE)) < 0) {
                                        sr_err("Failed to detach kernel driver: %s.",
                                                libusb_error_name(ret));
-                                       return SR_ERR;
+                                       ret = SR_ERR;
+                                       break;
                                }
                        }
                }
@@ -231,7 +231,6 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
                        break;
                }
 
-               sdi->status = SR_ST_ACTIVE;
                sr_info("Opened device on %d.%d (logical) / %s (physical), "
                        "interface %d, firmware %d.%d.",
                        usb->bus, usb->address, connection_id,
@@ -240,14 +239,14 @@ SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
                sr_info("Detected REVID=%d, it's a Cypress CY7C68013%s.",
                        revid, (revid != 1) ? " (FX2)" : "A (FX2LP)");
 
+               ret = SR_OK;
+
                break;
        }
-       libusb_free_device_list(devlist, 1);
 
-       if (sdi->status != SR_ST_ACTIVE)
-               return SR_ERR;
+       libusb_free_device_list(devlist, 1);
 
-       return SR_OK;
+       return ret;
 }
 
 SR_PRIV struct dev_context *fx2lafw_dev_new(void)
@@ -617,7 +616,7 @@ static int start_transfers(const struct sr_dev_inst *sdi)
        if ((trigger = sr_session_trigger_get(sdi->session))) {
                int pre_trigger_samples = 0;
                if (devc->limit_samples > 0)
-                       pre_trigger_samples = devc->capture_ratio * devc->limit_samples/100;
+                       pre_trigger_samples = (devc->capture_ratio * devc->limit_samples) / 100;
                devc->stl = soft_trigger_logic_new(sdi, trigger, pre_trigger_samples);
                if (!devc->stl)
                        return SR_ERR_MALLOC;