serial: fsl_lpuart: add earlycon support

Add support for DT and command line based earlycon support for
lpuart and lpuart32 used on Freescale Vybrid and and QorIQ LS1021A
processors.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 08ce76f4f261..3d790033744e 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1746,6 +1746,45 @@ static struct console lpuart32_console = {
 	.data		= &lpuart_reg,
 };
 
+static void lpuart_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, lpuart_console_putchar);
+}
+
+static void lpuart32_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, lpuart32_console_putchar);
+}
+
+static int __init lpuart_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = lpuart_early_write;
+	return 0;
+}
+
+static int __init lpuart32_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = lpuart32_early_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
+EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
+EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
+
 #define LPUART_CONSOLE	(&lpuart_console)
 #define LPUART32_CONSOLE	(&lpuart32_console)
 #else