atten-pps3xxx: Initial driver skeleton.

[libsigrok.git] / hardware / common / usb.c

diff --git a/hardware/common/usb.c b/hardware/common/usb.c
index 64f887de91458c7a0ac75ff6c89168dba5170ff8..6e678fdb401d1d681000fc3a6e273c7374656957 100644 (file)
--- a/hardware/common/usb.c
+++ b/hardware/common/usb.c
@@ -33,14 +33,7 @@
 #define SUBCLASS_USBTMC 0x03
 #define USBTMC_USB488   0x01
 
-/* Message logging helpers with subsystem-specific prefix string. */
-#define LOG_PREFIX "usb: "
-#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
-#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
-#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
-#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
-#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
-#define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
+#define LOG_PREFIX "usb"
 
 /**
  * Find USB devices according to a connection string.
@@ -267,8 +260,11 @@ SR_PRIV int usb_callback(int fd, int revents, void *cb_data)
 
        g_mutex_lock(&ctx->usb_mutex);
        ret = ctx->usb_cb(fd, revents, ctx->usb_cb_data);
-       ResetEvent(ctx->usb_event);
-       g_mutex_unlock(&ctx->usb_mutex);
+
+       if (ctx->usb_thread_running) {
+               ResetEvent(ctx->usb_event);
+               g_mutex_unlock(&ctx->usb_mutex);
+       }
 
        return ret;
 }
@@ -277,6 +273,11 @@ SR_PRIV int usb_callback(int fd, int revents, void *cb_data)
 SR_PRIV int usb_source_add(struct sr_context *ctx, int timeout,
                sr_receive_data_callback_t cb, void *cb_data)
 {
+       if (ctx->usb_source_present) {
+               sr_err("A USB event source is already present.");
+               return SR_ERR;
+       }
+
 #ifdef _WIN32
        ctx->usb_event = CreateEvent(NULL, TRUE, FALSE, NULL);
        g_mutex_init(&ctx->usb_mutex);
@@ -296,12 +297,16 @@ SR_PRIV int usb_source_add(struct sr_context *ctx, int timeout,
                sr_source_add(lupfd[i]->fd, lupfd[i]->events, timeout, cb, cb_data);
        free(lupfd);
 #endif
+       ctx->usb_source_present = TRUE;
 
        return SR_OK;
 }
 
 SR_PRIV int usb_source_remove(struct sr_context *ctx)
 {
+       if (!ctx->usb_source_present)
+               return SR_OK;
+
 #ifdef _WIN32
        ctx->usb_thread_running = FALSE;
        g_mutex_unlock(&ctx->usb_mutex);
@@ -319,6 +324,7 @@ SR_PRIV int usb_source_remove(struct sr_context *ctx)
                sr_source_remove(lupfd[i]->fd);
        free(lupfd);
 #endif
+       ctx->usb_source_present = FALSE;
 
        return SR_OK;
 }