plugins: add USB TSR test plugin

This is intended for testing USB event delivery to TSR plugins.
Usage:

1. enter plugin -> select Start
2. plug and unplug USB
3. reenter plugin -> select Status
   it should display "State: disconnected" then "Prev: connected"
4. when done -> select Stop Plugin

Change-Id: I6c70f452db642f3fcbfbcb4f06c57f93e60f4cfd

apps/plugins/CATEGORIES

@@ -178,6 +178,7 @@ test_resize,apps
 test_sampr,apps
 test_scanrate,apps
 test_touchscreen,apps
+test_usb,apps
 test_viewports,apps
 test_greylib_bitmap_scale,viewers
 text_editor,apps

apps/plugins/SOURCES

@@ -226,5 +226,6 @@ test_sampr.c
 #ifdef HAVE_TOUCHSCREEN
 test_touchscreen.c
 #endif
+test_usb.c
 test_viewports.c
 #endif /* HAVE_TEST_PLUGINS */

apps/plugins/test_usb.c

@@ -0,0 +1,136 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2022 Aidan MacDonald
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "plugin.h"
+#include "logf.h"
+
+#undef DEBUGF
+#define DEBUGF(...)
+//#define DEBUGF printf
+
+#define EV_EXIT MAKE_SYS_EVENT(SYS_EVENT_CLS_PRIVATE, 0xFF)
+
+unsigned char stack[DEFAULT_STACK_SIZE];
+struct event_queue queue;
+int thread_id;
+const char* state = "none";
+const char* prev_state = "none";
+
+static void main_loop(void)
+{
+    bool exiting = false;
+    struct queue_event ev;
+
+    while(true) {
+        rb->queue_wait(&queue, &ev);
+
+        /* events that are handled whether exiting or not */
+        switch(ev.id) {
+        case EV_EXIT:
+            return;
+        }
+
+        if(exiting)
+            continue;
+
+        /* events handled only when not exiting */
+        switch(ev.id) {
+        case SYS_USB_CONNECTED:
+            prev_state = state;
+            state = "connected";
+            logf("test_usb: connect ack %ld", *rb->current_tick);
+            DEBUGF("test_usb: connect ack %ld\n", *rb->current_tick);
+            rb->usb_acknowledge(SYS_USB_CONNECTED_ACK);
+            break;
+
+        case SYS_USB_DISCONNECTED:
+            prev_state = state;
+            state = "disconnected";
+            logf("test_usb: disconnect %ld", *rb->current_tick);
+            DEBUGF("test_usb: disconnect %ld\n", *rb->current_tick);
+            break;
+
+        case SYS_POWEROFF:
+        case SYS_REBOOT:
+            prev_state = state;
+            state = "exiting";
+            exiting = true;
+            break;
+        }
+    }
+}
+
+static void kill_tsr(void)
+{
+    rb->queue_post(&queue, EV_EXIT, 0);
+    rb->thread_wait(thread_id);
+    rb->queue_delete(&queue);
+}
+
+static bool exit_tsr(bool reenter)
+{
+    MENUITEM_STRINGLIST(menu, "USB test menu", NULL,
+                        "Status", "Stop plugin", "Back");
+
+    while(true) {
+        int result = reenter ? rb->do_menu(&menu, NULL, NULL, false) : 1;
+        switch(result) {
+        case 0:
+            rb->splashf(HZ, "State: %s", state);
+            rb->splashf(HZ, "Prev: %s", prev_state);
+            break;
+        case 1:
+            rb->splashf(HZ, "Stopping USB test thread");
+            kill_tsr();
+            return true;
+        case 2:
+            return false;
+        }
+    }
+}
+
+static void run_tsr(void)
+{
+    rb->queue_init(&queue, true);
+    thread_id = rb->create_thread(main_loop, stack, sizeof(stack),
+                                  0, "test_usb TSR"
+                                  IF_PRIO(, PRIORITY_BACKGROUND)
+                                  IF_COP(, CPU));
+    rb->plugin_tsr(exit_tsr);
+}
+
+enum plugin_status plugin_start(const void* parameter)
+{
+    (void)parameter;
+    MENUITEM_STRINGLIST(menu, "USB test menu", NULL,
+                        "Start", "Quit");
+
+    switch(rb->do_menu(&menu, NULL, NULL, false)) {
+    case 0:
+        run_tsr();
+        rb->splashf(HZ, "Thread started");
+        return PLUGIN_OK;
+    case 1:
+        return PLUGIN_OK;
+    default:
+        return PLUGIN_ERROR;
+    }
+}