serial: powerpc: Implement CONFIG_SERIAL_MULTI into p3mx serial driver

Implement support for CONFIG_SERIAL_MULTI into p3mx serial driver.
This driver was so far only usable directly, but this patch also adds
support for the multi method. This allows using more than one serial
driver alongside the p3mx driver. Also, add a weak implementation
of default_serial_console() returning this driver.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Tom Rini <trini@ti.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Stefan Roese <sr@denx.de>
diff --git a/board/prodrive/p3mx/serial.c b/board/prodrive/p3mx/serial.c
index e1af37e..d3591b4 100644
--- a/board/prodrive/p3mx/serial.c
+++ b/board/prodrive/p3mx/serial.c
@@ -35,6 +35,9 @@
 
 #include <common.h>
 #include <command.h>
+#include <serial.h>
+#include <linux/compiler.h>
+
 #include "../../Marvell/include/memory.h"
 #include "serial.h"
 
@@ -42,14 +45,14 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-int serial_init (void)
+static int p3mx_serial_init(void)
 {
 	mpsc_init (gd->baudrate);
 
 	return (0);
 }
 
-void serial_putc (const char c)
+static void p3mx_serial_putc(const char c)
 {
 	if (c == '\n')
 		mpsc_putchar ('\r');
@@ -57,28 +60,81 @@
 	mpsc_putchar (c);
 }
 
-int serial_getc (void)
+static int p3mx_serial_getc(void)
 {
 	return mpsc_getchar ();
 }
 
-int serial_tstc (void)
+static int p3mx_serial_tstc(void)
 {
 	return mpsc_test_char ();
 }
 
-void serial_setbrg (void)
+static void p3mx_serial_setbrg(void)
 {
 	galbrg_set_baudrate (CONFIG_MPSC_PORT, gd->baudrate);
 }
 
 
-void serial_puts (const char *s)
+static void p3mx_serial_puts(const char *s)
 {
 	while (*s) {
 		serial_putc (*s++);
 	}
 }
+
+#ifdef CONFIG_SERIAL_MULTI
+static struct serial_device p3mx_serial_drv = {
+	.name	= "p3mx_serial",
+	.start	= p3mx_serial_init,
+	.stop	= NULL,
+	.setbrg	= p3mx_serial_setbrg,
+	.putc	= p3mx_serial_putc,
+	.puts	= p3mx_serial_puts,
+	.getc	= p3mx_serial_getc,
+	.tstc	= p3mx_serial_tstc,
+};
+
+void p3mx_serial_initialize(void)
+{
+	serial_register(&p3mx_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+	return &p3mx_serial_drv;
+}
+#else
+int serial_init(void)
+{
+	return p3mx_serial_init();
+}
+
+void serial_setbrg(void)
+{
+	p3mx_serial_setbrg();
+}
+
+void serial_putc(const char c)
+{
+	p3mx_serial_putc(c);
+}
+
+void serial_puts(const char *s)
+{
+	p3mx_serial_puts(s);
+}
+
+int serial_getc(void)
+{
+	return p3mx_serial_getc();
+}
+
+int serial_tstc(void)
+{
+	return p3mx_serial_tstc();
+}
+#endif
 
 #if defined(CONFIG_CMD_KGDB)
 void kgdb_serial_init (void)
diff --git a/common/serial.c b/common/serial.c
index e4b566e..5129837 100644
--- a/common/serial.c
+++ b/common/serial.c
@@ -69,6 +69,7 @@
 serial_initfunc(evb64260_serial_initialize);
 serial_initfunc(ml2_serial_initialize);
 serial_initfunc(sconsole_serial_initialize);
+serial_initfunc(p3mx_serial_initialize);
 
 void serial_register(struct serial_device *dev)
 {
@@ -116,6 +117,7 @@
 	evb64260_serial_initialize();
 	ml2_serial_initialize();
 	sconsole_serial_initialize();
+	p3mx_serial_initialize();
 
 	serial_assign(default_serial_console()->name);
 }