serial: arm: Implement CONFIG_SERIAL_MULTI into altera serial driver

Implement support for CONFIG_SERIAL_MULTI into altera 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 altera 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: Scott McNutt <smcnutt@psyent.com>

common/serial.c

@@ -71,6 +71,7 @@ serial_initfunc(ml2_serial_initialize);
 serial_initfunc(sconsole_serial_initialize);
 serial_initfunc(p3mx_serial_initialize);
 serial_initfunc(altera_jtag_serial_initialize);
+serial_initfunc(altera_serial_initialize);
 
 void serial_register(struct serial_device *dev)
 {
@@ -120,6 +121,7 @@ void serial_initialize(void)
 	sconsole_serial_initialize();
 	p3mx_serial_initialize();
 	altera_jtag_serial_initialize();
+	altera_serial_initialize();
 
 	serial_assign(default_serial_console()->name);
 }

drivers/serial/altera_uart.c

@@ -26,6 +26,8 @@
 #include <watchdog.h>
 #include <asm/io.h>
 #include <nios2-io.h>
+#include <linux/compiler.h>
+#include <serial.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -37,27 +39,33 @@ static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;
 
 #if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
 
-/* Everything's already setup for fixed-baud PTF
+/*
+ * Everything's already setup for fixed-baud PTF
  * assignment
  */
-void serial_setbrg (void){ return; }
-int serial_init (void) { return (0);}
+static void altera_serial_setbrg(void)
+{
+}
+
+static int altera_serial_init(void)
+{
+	return 0;
+}
 
 #else
 
-void serial_setbrg (void)
+static void altera_serial_setbrg(void)
 {
 	unsigned div;
 
 	div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
 	writel (div, &uart->divisor);
-	return;
 }
 
-int serial_init (void)
+static int altera_serial_init(void)
 {
-	serial_setbrg ();
-	return (0);
+	serial_setbrg();
+	return 0;
 }
 
 #endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
@@ -65,7 +73,7 @@ int serial_init (void)
 /*-----------------------------------------------------------------------
  * UART CONSOLE
  *---------------------------------------------------------------------*/
-void serial_putc (char c)
+static void altera_serial_putc(char c)
 {
 	if (c == '\n')
 		serial_putc ('\r');
@@ -74,21 +82,74 @@ void serial_putc (char c)
 	writel ((unsigned char)c, &uart->txdata);
 }
 
-void serial_puts (const char *s)
+static void altera_serial_puts(const char *s)
 {
 	while (*s != 0) {
 		serial_putc (*s++);
 	}
 }
 
-int serial_tstc (void)
+static int altera_serial_tstc(void)
 {
 	return (readl (&uart->status) & NIOS_UART_RRDY);
 }
 
-int serial_getc (void)
+static int altera_serial_getc(void)
 {
 	while (serial_tstc () == 0)
 		WATCHDOG_RESET ();
 	return (readl (&uart->rxdata) & 0x00ff );
 }
+
+#ifdef CONFIG_SERIAL_MULTI
+static struct serial_device altera_serial_drv = {
+	.name	= "altera_serial",
+	.start	= altera_serial_init,
+	.stop	= NULL,
+	.setbrg	= altera_serial_setbrg,
+	.putc	= altera_serial_putc,
+	.puts	= altera_serial_puts,
+	.getc	= altera_serial_getc,
+	.tstc	= altera_serial_tstc,
+};
+
+void altera_serial_initialize(void)
+{
+	serial_register(&altera_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+	return &altera_serial_drv;
+}
+#else
+int serial_init(void)
+{
+	return altera_serial_init();
+}
+
+void serial_setbrg(void)
+{
+	altera_serial_setbrg();
+}
+
+void serial_putc(const char c)
+{
+	altera_serial_putc(c);
+}
+
+void serial_puts(const char *s)
+{
+	altera_serial_puts(s);
+}
+
+int serial_getc(void)
+{
+	return altera_serial_getc();
+}
+
+int serial_tstc(void)
+{
+	return altera_serial_tstc();
+}
+#endif