From 59743aed13a4240e03f28c38231dc96b3c2cce6e Mon Sep 17 00:00:00 2001
From: Koen Zandberg <koen@bergzand.net>
Date: Thu, 28 Feb 2019 21:40:35 +0100
Subject: [PATCH] USBUS cdc acm: Add STDIO wrapper for CDC ACM

---
 Makefile.dep                          | 17 +++---
 makefiles/pseudomodules.inc.mk        |  1 +
 sys/auto_init/usb/auto_init_usb.c     |  8 +++
 sys/usb/usbus/cdc/acm/Makefile        |  3 ++
 sys/usb/usbus/cdc/acm/cdc_acm_stdio.c | 74 +++++++++++++++++++++++++++
 5 files changed, 97 insertions(+), 6 deletions(-)
 create mode 100644 sys/usb/usbus/cdc/acm/cdc_acm_stdio.c

diff --git a/Makefile.dep b/Makefile.dep
index cc006103c8..1339dbca5c 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -401,7 +401,7 @@ ifneq (,$(filter newlib,$(USEMODULE)))
   ifeq (,$(filter newlib_syscalls_%,$(USEMODULE)))
     USEMODULE += newlib_syscalls_default
   endif
-  ifeq (,$(filter stdio_rtt,$(USEMODULE)))
+  ifeq (,$(filter stdio_rtt stdio_cdc_acm,$(USEMODULE)))
     USEMODULE += stdio_uart
   endif
 endif
@@ -414,6 +414,11 @@ ifneq (,$(filter posix_sockets,$(USEMODULE)))
   USEMODULE += xtimer
 endif
 
+ifneq (,$(filter stdio_cdc_acm,$(USEMODULE)))
+  USEMODULE += usbus_cdc_acm
+  USEMODULE += isrpipe
+endif
+
 ifneq (,$(filter stdio_rtt,$(USEMODULE)))
   USEMODULE += xtimer
 endif
@@ -874,17 +879,17 @@ ifneq (,$(filter tlsf-malloc,$(USEMODULE)))
   USEPKG += tlsf
 endif
 
-ifneq (,$(filter usbus_cdc_acm,$(USEMODULE)))
-  USEMODULE += tsrb
-  USEMODULE += usbus
-endif
-
 ifneq (,$(filter usbus,$(USEMODULE)))
   FEATURES_REQUIRED += periph_usbdev
   USEMODULE += core_thread_flags
   USEMODULE += event
 endif
 
+ifneq (,$(filter usbus_cdc_acm,$(USEMODULE)))
+  USEMODULE += tsrb
+  USEMODULE += usbus
+endif
+
 ifneq (,$(filter usbus_cdc_ecm,$(USEMODULE)))
   USEMODULE += iolist
   USEMODULE += fmt
diff --git a/makefiles/pseudomodules.inc.mk b/makefiles/pseudomodules.inc.mk
index 818839dbe5..e9462ecac8 100644
--- a/makefiles/pseudomodules.inc.mk
+++ b/makefiles/pseudomodules.inc.mk
@@ -80,6 +80,7 @@ PSEUDOMODULES += sock_tcp
 PSEUDOMODULES += sock_udp
 PSEUDOMODULES += stdin
 PSEUDOMODULES += stdio_ethos
+PSEUDOMODULES += stdio_cdc_acm
 PSEUDOMODULES += stdio_uart_rx
 PSEUDOMODULES += sock_dtls
 
diff --git a/sys/auto_init/usb/auto_init_usb.c b/sys/auto_init/usb/auto_init_usb.c
index 6d85d3622b..dfaf2d848e 100644
--- a/sys/auto_init/usb/auto_init_usb.c
+++ b/sys/auto_init/usb/auto_init_usb.c
@@ -28,6 +28,9 @@
 #include "usb/usbus/cdc/ecm.h"
 usbus_cdcecm_device_t cdcecm;
 #endif
+#ifdef MODULE_USBUS_CDC_ACM
+#include "usb/usbus/cdc/acm.h"
+#endif
 
 static char _stack[USBUS_STACKSIZE];
 static usbus_t usbus;
@@ -42,6 +45,11 @@ void auto_init_usb(void)
     usbus_init(&usbus, usbdev);
 
     /* USBUS function handlers initialization */
+#ifdef MODULE_STDIO_CDC_ACM
+    void usb_cdc_acm_stdio_init(usbus_t *usbus);
+    usb_cdc_acm_stdio_init(&usbus);
+#endif
+
 #ifdef MODULE_USBUS_CDC_ECM
     usbus_cdcecm_init(&usbus, &cdcecm);
 #endif
diff --git a/sys/usb/usbus/cdc/acm/Makefile b/sys/usb/usbus/cdc/acm/Makefile
index 7624bfb51e..dac9843796 100644
--- a/sys/usb/usbus/cdc/acm/Makefile
+++ b/sys/usb/usbus/cdc/acm/Makefile
@@ -1,4 +1,7 @@
 MODULE = usbus_cdc_acm
 SRC = cdc_acm.c
 
+ifneq (,$(filter stdio_cdc_acm,$(USEMODULE)))
+  SRC += cdc_acm_stdio.c
+endif
 include $(RIOTBASE)/Makefile.base
diff --git a/sys/usb/usbus/cdc/acm/cdc_acm_stdio.c b/sys/usb/usbus/cdc/acm/cdc_acm_stdio.c
new file mode 100644
index 0000000000..c61af0b223
--- /dev/null
+++ b/sys/usb/usbus/cdc/acm/cdc_acm_stdio.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2018 Koen Zandberg
+ *
+ * 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 sys
+ * @{
+ *
+ * @file
+ * @brief CDC ACM stdio implementation for USBUS CDC ACM
+ *
+ * This file implements a USB CDC ACM callback and read/write functions.
+ *
+ *
+ * @}
+ */
+
+#include <stdio.h>
+
+#include "isrpipe.h"
+
+#include "usb/usbus.h"
+#include "usb/usbus/cdc/acm.h"
+
+#if MODULE_VFS
+#include "vfs.h"
+#endif
+
+static usbus_cdcacm_device_t cdcacm;
+static uint8_t _cdc_tx_buf_mem[USBUS_CDC_ACM_STDIO_BUF_SIZE];
+static uint8_t _cdc_rx_buf_mem[USBUS_CDC_ACM_STDIO_BUF_SIZE];
+static isrpipe_t _cdc_stdio_isrpipe = ISRPIPE_INIT(_cdc_rx_buf_mem);
+
+void stdio_init(void)
+{
+    /* Initialize this side of the CDC ACM pipe */
+#if MODULE_VFS
+    vfs_bind_stdio();
+#endif
+}
+
+ssize_t stdio_read(void* buffer, size_t len)
+{
+    (void)buffer;
+    (void)len;
+    return isrpipe_read(&_cdc_stdio_isrpipe, buffer, len);
+}
+
+ssize_t stdio_write(const void* buffer, size_t len)
+{
+    usbus_cdc_acm_submit(&cdcacm, buffer, len);
+    usbus_cdc_acm_flush(&cdcacm);
+    /* Use tsrb and flush */
+    return len;
+}
+
+static void _cdc_acm_rx_pipe(usbus_cdcacm_device_t *cdcacm,
+                             uint8_t *data, size_t len)
+{
+    (void)cdcacm;
+    for (size_t i = 0; i < len; i++) {
+        isrpipe_write_one(&_cdc_stdio_isrpipe, data[i]);
+    }
+}
+
+void usb_cdc_acm_stdio_init(usbus_t *usbus)
+{
+    usbus_cdc_acm_init(usbus, &cdcacm, _cdc_acm_rx_pipe, NULL,
+                       _cdc_tx_buf_mem, sizeof(_cdc_tx_buf_mem));
+}