1 files changed, 56 insertions, 1 deletions

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index a2a529994ba5..6c6f82ad8d5c 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1234,6 +1234,61 @@ out:
 
 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
 
+#ifdef CONFIG_SERIAL_EARLYCON
+static unsigned int __init omap_serial_early_in(struct uart_port *port,
+                                                int offset)
+{
+        offset <<= port->regshift;
+        return readw(port->membase + offset);
+}
+
+static void __init omap_serial_early_out(struct uart_port *port, int offset,
+                                         int value)
+{
+        offset <<= port->regshift;
+        writew(value, port->membase + offset);
+}
+
+static void __init omap_serial_early_putc(struct uart_port *port, int c)
+{
+        unsigned int status;
+
+        for (;;) {
+                status = omap_serial_early_in(port, UART_LSR);
+                if ((status & BOTH_EMPTY) == BOTH_EMPTY)
+                        break;
+                cpu_relax();
+        }
+        omap_serial_early_out(port, UART_TX, c);
+}
+
+static void __init early_omap_serial_write(struct console *console,
+                                           const char *s, unsigned int count)
+{
+        struct earlycon_device *device = console->data;
+        struct uart_port *port = &device->port;
+
+        uart_console_write(port, s, count, omap_serial_early_putc);
+}
+
+static int __init early_omap_serial_setup(struct earlycon_device *device,
+                                          const char *options)
+{
+        struct uart_port *port = &device->port;
+
+        if (!(device->port.membase || device->port.iobase))
+                return -ENODEV;
+
+        port->regshift = 2;
+        device->con->write = early_omap_serial_write;
+        return 0;
+}
+
+OF_EARLYCON_DECLARE(omapserial, "ti,omap2-uart", early_omap_serial_setup);
+OF_EARLYCON_DECLARE(omapserial, "ti,omap3-uart", early_omap_serial_setup);
+OF_EARLYCON_DECLARE(omapserial, "ti,omap4-uart", early_omap_serial_setup);
+#endif /* CONFIG_SERIAL_EARLYCON */
+
 static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
 
 static struct uart_driver serial_omap_reg;
@@ -1395,7 +1450,7 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
         return 0;
 }
 
-static struct uart_ops serial_omap_pops = {
+static const struct uart_ops serial_omap_pops = {
         .tx_empty       = serial_omap_tx_empty,
         .set_mctrl      = serial_omap_set_mctrl,
         .get_mctrl      = serial_omap_get_mctrl,