stm32: add synchronous debug printf

Allow use of a synchronous debug printf instead of using the
full console task to save space. This can be turned on with
CONFIG_DEBUG_PRINTF, and will provide essentially a one-way
console for debugging. This is essentially expanding upon
the debug_printf work done for zinger.

BUG=chrome-os-partner:41959
BRANCH=none
TEST=tested with following CLs on glados_pd by verifying we
get a one-way console.

Change-Id: If028b5d873261890de5b270bbc00e06bdcaa7431
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/306782
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

6 files changed, 3 insertions, 57 deletions

diff --git a/board/zinger/board.c b/board/zinger/board.c
index ac3b95db20..bf4b51d5c7 100644
--- a/board/zinger/board.c
+++ b/board/zinger/board.c
@@ -5,7 +5,7 @@
 /* Tiny charger configuration */
 
 #include "common.h"
-#include "debug.h"
+#include "debug_printf.h"
 #include "ec_commands.h"
 #include "registers.h"
 #include "rsa.h"
diff --git a/board/zinger/build.mk b/board/zinger/build.mk
index 4e9e2f1f6d..249f8a3e1b 100644
--- a/board/zinger/build.mk
+++ b/board/zinger/build.mk
@@ -11,4 +11,3 @@ CHIP_FAMILY:=stm32f0
 CHIP_VARIANT:=stm32f03x
 
 board-y=board.o hardware.o runtime.o usb_pd_policy.o
-board-$(CONFIG_DEBUG_PRINTF)+=debug.o
diff --git a/board/zinger/debug.c b/board/zinger/debug.c
deleted file mode 100644
index 48c2259083..0000000000
--- a/board/zinger/debug.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-/* Synchronous UART debug printf */
-
-#include "common.h"
-#include "printf.h"
-#include "registers.h"
-#include "util.h"
-
-static int debug_txchar(void *context, int c)
-{
-	if (c == '\n') {
-		while (!(STM32_USART_SR(UARTN_BASE) & STM32_USART_SR_TXE))
-			;
-		STM32_USART_TDR(UARTN_BASE) = '\r';
-	}
-
-	/* Wait for space to transmit */
-	while (!(STM32_USART_SR(UARTN_BASE) & STM32_USART_SR_TXE))
-		;
-	STM32_USART_TDR(UARTN_BASE) = c;
-
-	return 0;
-}
-
-
-
-void debug_printf(const char *format, ...)
-{
-	va_list args;
-
-	va_start(args, format);
-	vfnprintf(debug_txchar, NULL, format, args);
-	va_end(args);
-}
diff --git a/board/zinger/debug.h b/board/zinger/debug.h
deleted file mode 100644
index 38cea6fb28..0000000000
--- a/board/zinger/debug.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-/* Synchronous UART debug printf */
-
-#ifndef __CROS_EC_DEBUG_H
-#define __CROS_EC_DEBUG_H
-
-#ifdef CONFIG_DEBUG_PRINTF
-void debug_printf(const char *format, ...);
-#else
-#define debug_printf(...)
-#endif
-
-#endif /* __CROS_EC_DEBUG_H */
diff --git a/board/zinger/runtime.c b/board/zinger/runtime.c
index 8631eea74e..502d6649de 100644
--- a/board/zinger/runtime.c
+++ b/board/zinger/runtime.c
@@ -7,7 +7,7 @@
 #include "clock.h"
 #include "common.h"
 #include "cpu.h"
-#include "debug.h"
+#include "debug_printf.h"
 #include "registers.h"
 #include "system.h"
 #include "task.h"
diff --git a/board/zinger/usb_pd_policy.c b/board/zinger/usb_pd_policy.c
index 477060d17d..fd9cf8be7b 100644
--- a/board/zinger/usb_pd_policy.c
+++ b/board/zinger/usb_pd_policy.c
@@ -6,7 +6,7 @@
 #include "adc.h"
 #include "common.h"
 #include "console.h"
-#include "debug.h"
+#include "debug_printf.h"
 #include "ec_commands.h"
 #include "hooks.h"
 #include "registers.h"