serial: arm: Implement CONFIG_SERIAL_MULTI into atmel serial driver

Implement support for CONFIG_SERIAL_MULTI into atmel 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 atmel 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: Xu, Hong <Hong.Xu@atmel.com>

common/serial.c

@@ -72,6 +72,7 @@ serial_initfunc(sconsole_serial_initialize);
 serial_initfunc(p3mx_serial_initialize);
 serial_initfunc(altera_jtag_serial_initialize);
 serial_initfunc(altera_serial_initialize);
+serial_initfunc(atmel_serial_initialize);
 
 void serial_register(struct serial_device *dev)
 {
@@ -122,6 +123,7 @@ void serial_initialize(void)
 	p3mx_serial_initialize();
 	altera_jtag_serial_initialize();
 	altera_serial_initialize();
+	atmel_serial_initialize();
 
 	serial_assign(default_serial_console()->name);
 }

drivers/serial/atmel_usart.c

@@ -20,6 +20,8 @@
  */
 #include <common.h>
 #include <watchdog.h>
+#include <serial.h>
+#include <linux/compiler.h>
 
 #include <asm/io.h>
 #include <asm/arch/clk.h>
@@ -29,7 +31,7 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-void serial_setbrg(void)
+static void atmel_serial_setbrg(void)
 {
 	atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 	unsigned long divisor;
@@ -45,7 +47,7 @@ void serial_setbrg(void)
 	writel(USART3_BF(CD, divisor), &usart->brgr);
 }
 
-int serial_init(void)
+static int atmel_serial_init(void)
 {
 	atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 
@@ -73,7 +75,7 @@ int serial_init(void)
 	return 0;
 }
 
-void serial_putc(char c)
+static void atmel_serial_putc(char c)
 {
 	atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 
@@ -84,13 +86,13 @@ void serial_putc(char c)
 	writel(c, &usart->thr);
 }
 
-void serial_puts(const char *s)
+static void atmel_serial_puts(const char *s)
 {
 	while (*s)
 		serial_putc(*s++);
 }
 
-int serial_getc(void)
+static int atmel_serial_getc(void)
 {
 	atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 
@@ -99,8 +101,61 @@ int serial_getc(void)
 	return readl(&usart->rhr);
 }
 
-int serial_tstc(void)
+static int atmel_serial_tstc(void)
 {
 	atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 	return (readl(&usart->csr) & USART3_BIT(RXRDY)) != 0;
 }
+
+#ifdef CONFIG_SERIAL_MULTI
+static struct serial_device atmel_serial_drv = {
+	.name	= "atmel_serial",
+	.start	= atmel_serial_init,
+	.stop	= NULL,
+	.setbrg	= atmel_serial_setbrg,
+	.putc	= atmel_serial_putc,
+	.puts	= atmel_serial_puts,
+	.getc	= atmel_serial_getc,
+	.tstc	= atmel_serial_tstc,
+};
+
+void atmel_serial_initialize(void)
+{
+	serial_register(&atmel_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+	return &atmel_serial_drv;
+}
+#else
+int serial_init(void)
+{
+	return atmel_serial_init();
+}
+
+void serial_setbrg(void)
+{
+	atmel_serial_setbrg();
+}
+
+void serial_putc(const char c)
+{
+	atmel_serial_putc(c);
+}
+
+void serial_puts(const char *s)
+{
+	atmel_serial_puts(s);
+}
+
+int serial_getc(void)
+{
+	return atmel_serial_getc();
+}
+
+int serial_tstc(void)
+{
+	return atmel_serial_tstc();
+}
+#endif