From 60a1859008c35e715d868939875f6a761a8b4ab5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Sun, 14 Jun 2020 18:57:05 +0200
Subject: [PATCH] usb_cdcacm: add flush method to wait for empty buffer

---
 lib/usb_cdcacm.c | 8 +++++++-
 lib/usb_cdcacm.h | 3 +++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/usb_cdcacm.c b/lib/usb_cdcacm.c
index 4dca758..6516e5a 100644
--- a/lib/usb_cdcacm.c
+++ b/lib/usb_cdcacm.c
@@ -479,7 +479,13 @@ void usb_cdcacm_putchar(char c)
 	usb_cdcacm_data_tx_cb(NULL, 0); // send data over USB when possible
 }
 
+void usb_cdcacm_flush(void)
+{
+	while (tx_used);
+}
+
 /** USB interrupt service routine called when data is received */
-void usb_lp_can_rx0_isr(void) {
+void usb_lp_can_rx0_isr(void)
+{
 	usbd_poll(usb_device);
 }
diff --git a/lib/usb_cdcacm.h b/lib/usb_cdcacm.h
index 92177cf..ffc0289 100644
--- a/lib/usb_cdcacm.h
+++ b/lib/usb_cdcacm.h
@@ -16,3 +16,6 @@ void usb_cdcacm_setup(void);
  *  @note blocks if transmit buffer is full, else puts in buffer and returns
  */
 void usb_cdcacm_putchar(char c);
+/** wait until all is transmitted (blocking)
+ */
+void usb_cdcacm_flush(void);