[PATCH v3 4/6] serial: Implement serial_flush() function for console flush() fallback

[Pali Rohár]

Like in all other console functions, implement also serial_flush() function
as a fallback int console flush() function.

Flush support is available only when config option CONSOLE_FLUSH_SUPPORT is
enabled. So when it is disabled then provides just empty static inline
function serial_flush().

Signed-off-by: Pali Rohár <pali at kernel.org>
---
 common/console.c               |  3 +++
 common/stdio.c                 |  8 ++++++++
 drivers/serial/serial-uclass.c | 10 ++++++++++
 include/serial.h               |  5 +++++
 4 files changed, 26 insertions(+)

diff --git a/common/console.c b/common/console.c
index 0abfc224b53b..e4dc1da44a35 100644
--- a/common/console.c
+++ b/common/console.c
@@ -797,6 +797,9 @@ void flush(void)
 	if (gd->flags & GD_FLG_DEVINIT) {
 		/* Send to the standard output */
 		fflush(stdout);
+	} else {
+		/* Send directly to the handler */
+		serial_flush();
 	}
 }
 #endif
diff --git a/common/stdio.c b/common/stdio.c
index 92161a0df87d..13083842cbd9 100644
--- a/common/stdio.c
+++ b/common/stdio.c
@@ -87,6 +87,13 @@ static void stdio_serial_puts(struct stdio_dev *dev, const char *s)
 	serial_puts(s);
 }
 
+#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
+static void stdio_serial_flush(struct stdio_dev *dev)
+{
+	serial_flush();
+}
+#endif
+
 static int stdio_serial_getc(struct stdio_dev *dev)
 {
 	return serial_getc();
@@ -112,6 +119,7 @@ static void drv_system_init (void)
 	dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
 	dev.putc = stdio_serial_putc;
 	dev.puts = stdio_serial_puts;
+	STDIO_DEV_ASSIGN_FLUSH(&dev, stdio_serial_flush);
 	dev.getc = stdio_serial_getc;
 	dev.tstc = stdio_serial_tstc;
 	stdio_register (&dev);
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
index be6502f3d24c..f028da0900cd 100644
--- a/drivers/serial/serial-uclass.c
+++ b/drivers/serial/serial-uclass.c
@@ -327,6 +327,16 @@ void serial_puts(const char *str)
 		_serial_puts(gd->cur_serial_dev, str);
 }
 
+#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
+void serial_flush(void)
+{
+	if (!gd->cur_serial_dev)
+		return;
+
+	_serial_flush(gd->cur_serial_dev);
+}
+#endif
+
 int serial_getc(void)
 {
 	if (!gd->cur_serial_dev)
diff --git a/include/serial.h b/include/serial.h
index 8c2e7adbc321..f9009d4046e3 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -362,6 +362,11 @@ void serial_setbrg(void);
 void serial_putc(const char ch);
 void serial_putc_raw(const char ch);
 void serial_puts(const char *str);
+#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
+void serial_flush(void);
+#else
+static inline void serial_flush(void) {}
+#endif
 int serial_getc(void);
 int serial_tstc(void);
 
-- 
2.20.1