console: add a flag to prepend '\r' in the multi-console framework

Currently, console drivers prepend '\r' to '\n' by themselves. This is
common enough to be supported in the framework.

Add a new flag, CONSOLE_FLAG_TRANSLATE_CRLF. A driver can set this
flag to ask the framework to transform LF into CRLF instead of doing
it by itself.

Change-Id: I4f5c5887591bc0a8749a105abe62b6562eaf503b
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

drivers/console/multi_console.c

@@ -70,6 +70,20 @@ void console_set_scope(console_t *console, unsigned int scope)
 	console->flags = (console->flags & ~CONSOLE_FLAG_SCOPE_MASK) | scope;
 }
 
+static int do_putc(int c, console_t *console)
+{
+	int ret;
+
+	if ((c == '\n') &&
+	    ((console->flags & CONSOLE_FLAG_TRANSLATE_CRLF) != 0)) {
+		ret = console->putc('\r', console);
+		if (ret < 0)
+			return ret;
+	}
+
+	return console->putc(c, console);
+}
+
 int console_putc(int c)
 {
 	int err = ERROR_NO_VALID_CONSOLE;
@@ -77,7 +91,7 @@ int console_putc(int c)
 
 	for (console = console_list; console != NULL; console = console->next)
 		if ((console->flags & console_state) && console->putc) {
-			int ret = console->putc(c, console);
+			int ret = do_putc(c, console);
 			if ((err == ERROR_NO_VALID_CONSOLE) || (ret < err))
 				err = ret;
 		}

include/drivers/console.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -21,7 +21,8 @@
 #define CONSOLE_FLAG_CRASH		(U(1) << 2)
 /* Bits 3 to 7 reserved for additional scopes in future expansion. */
 #define CONSOLE_FLAG_SCOPE_MASK		((U(1) << 8) - 1)
-/* Bits 8 to 31 reserved for non-scope use in future expansion. */
+/* Bits 8 to 31 for non-scope use. */
+#define CONSOLE_FLAG_TRANSLATE_CRLF	(U(1) << 8)
 
 /* Returned by getc callbacks when receive FIFO is empty. */
 #define ERROR_NO_PENDING_CHAR		(-1)

plat/common/aarch64/crash_console_helpers.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -125,9 +125,18 @@ putc_loop:
 	b.eq	putc_continue
 	ldr	x2, [x15, #CONSOLE_T_PUTC]
 	cbz	x2, putc_continue
+	cmp	w14, #'\n'
+	b.ne	putc
+	tst	w1, #CONSOLE_FLAG_TRANSLATE_CRLF
+	b.eq	putc
 	mov	x1, x15
+	mov	w0, #'\r'
 	blr	x2
+	ldr	x2, [x15, #CONSOLE_T_PUTC]
+putc:
+	mov	x1, x15
 	mov	w0, w14
+	blr	x2
 putc_continue:
 	ldr	x15, [x15]			/* X15 = next struct */
 	b	putc_loop