pkg/tinyusb: implement stdio via CDC ACM

makefiles/stdio.inc.mk

@@ -9,6 +9,7 @@ STDIO_MODULES = \
   stdio_semihosting \
   stdio_uart \
   stdio_telnet \
+  stdio_tinyusb_cdc_acm \
   #
 
 # select stdio_uart if no other stdio module is slected
@@ -22,6 +23,10 @@ ifneq (,$(filter stdio_cdc_acm,$(USEMODULE)))
   USEMODULE += stdio_available
 endif
 
+ifneq (,$(filter stdio_tinyusb_cdc_acm,$(USEMODULE)))
+  USEPKG += tinyusb
+endif
+
 ifneq (,$(filter stdio_rtt,$(USEMODULE)))
   USEMODULE += ztimer_msec
 endif

pkg/tinyusb/Makefile

@@ -11,9 +11,12 @@ PSRC = $(PKG_SOURCE_DIR)/src
 
 .PHONY: all
 
-all: $(filter tinyusb_%,$(USEMODULE))
+all: $(filter tinyusb_% stdio_tinyusb_cdc_acm,$(USEMODULE))
 	$(QQ)"$(MAKE)" -C $(PSRC) -f $(RIOTBASE)/Makefile.base MODULE=tinyusb
 
+stdio_tinyusb_cdc_acm:
+	$(QQ)"$(MAKE)" -C $(RIOTPKG)/$(PKG_NAME)/cdc_acm_stdio
+
 tinyusb_contrib:
 	$(QQ)"$(MAKE)" -C $(RIOTPKG)/$(PKG_NAME)/contrib
 

pkg/tinyusb/Makefile.dep

@@ -8,6 +8,11 @@ USEMODULE += tinyusb_hw
 
 DEFAULT_MODULE += auto_init_tinyusb
 
+ifneq (,$(filter stdio_tinyusb_cdc_acm, $(USEMODULE)))
+  USEMODULE += tinyusb_class_cdc
+  USEMODULE += tinyusb_device
+endif
+
 ifeq (,$(filter tinyusb_class_%,$(USEMODULE)))
   $(error At least one tinyusb_class_* module has to be enabled)
 endif

pkg/tinyusb/cdc_acm_stdio/Makefile

@@ -0,0 +1,3 @@
+MODULE = stdio_tinyusb_cdc_acm
+
+include $(RIOTBASE)/Makefile.base

pkg/tinyusb/cdc_acm_stdio/cdc_acm_stdio.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2022 ML!PA Consulting GmbH
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup pkg_tinyusb
+ * @{
+ *
+ * @file
+ * @brief CDC ACM stdio implementation for tinyUSB CDC ACM
+ *
+ * This file implements a USB CDC ACM callback and read/write functions.
+ *
+ * @author      Benjamin Valentin <[email protected]>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "tusb.h"
+#include "tinyusb.h"
+
+#if MODULE_VFS
+#include "vfs.h"
+#endif
+
+#ifdef MODULE_USB_BOARD_RESET
+#include "usb_board_reset_internal.h"
+#endif
+
+static mutex_t data_lock = MUTEX_INIT_LOCKED;
+
+void stdio_init(void)
+{
+    /* Initialize this side of the CDC ACM pipe */
+#if MODULE_VFS
+    vfs_bind_stdio();
+#endif
+}
+
+#if IS_USED(MODULE_STDIO_AVAILABLE)
+int stdio_available(void)
+{
+    return tud_cdc_available();
+}
+#endif
+
+ssize_t stdio_read(void* buffer, size_t len)
+{
+    mutex_lock(&data_lock);
+    return tud_cdc_read(buffer, len);
+}
+
+ssize_t stdio_write(const void* buffer, size_t len)
+{
+    const char *start = buffer;
+
+    while (tud_cdc_connected() && len) {
+        size_t n = tud_cdc_write(buffer, len);
+        buffer = (char *)buffer + n;
+        len -= n;
+    };
+
+    tud_cdc_write_flush();
+
+    return (char *)buffer - start;
+}
+
+void tud_cdc_rx_cb(uint8_t itf)
+{
+    (void)itf;
+
+    mutex_unlock(&data_lock);
+}