3 files changed, 37 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 43842177b771..2609ead7ff55 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -883,6 +883,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         which are not unmapped.
 
         earlycon=       [KNL] Output early console device and options.
+
                 uart[8250],io,<addr>[,options]
                 uart[8250],mmio,<addr>[,options]
                 uart[8250],mmio32,<addr>[,options]
@@ -892,6 +893,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         (mmio) or 32-bit (mmio32).
                         The options are the same as for ttyS, above.
 
+                pl011,<addr>
+                        Start an early, polled-mode console on a pl011 serial
+                        port at the specified address. The pl011 serial port
+                        must already be setup and configured. Options are not
+                        yet supported.
+
         earlyprintk=    [X86,SH,BLACKFIN,ARM]
                         earlyprintk=vga
                         earlyprintk=efi
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 9fb6028ad900..4290d05875b1 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -60,6 +60,7 @@ config SERIAL_AMBA_PL011_CONSOLE
         bool "Support for console on AMBA serial port"
         depends on SERIAL_AMBA_PL011=y
         select SERIAL_CORE_CONSOLE
+        select SERIAL_EARLYCON
         ---help---
           Say Y here if you wish to use an AMBA PrimeCell UART as the system
           console (the system console is the device which receives all kernel
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index dacf0a09ab24..ee3d80346780 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -303,7 +303,7 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *
 
         /* Optionally make use of an RX channel as well */
         chan = dma_request_slave_channel(dev, "rx");
-        
+
         if (!chan && plat->dma_rx_param) {
                 chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
 
@@ -2045,6 +2045,34 @@ static struct console amba_console = {
 };
 
 #define AMBA_CONSOLE    (&amba_console)
+
+static void pl011_putc(struct uart_port *port, int c)
+{
+        while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
+                ;
+        writeb(c, port->membase + UART01x_DR);
+        while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
+                ;
+}
+
+static void pl011_early_write(struct console *con, const char *s, unsigned n)
+{
+        struct earlycon_device *dev = con->data;
+
+        uart_console_write(&dev->port, s, n, pl011_putc);
+}
+
+static int __init pl011_early_console_setup(struct earlycon_device *device,
+                                            const char *opt)
+{
+        if (!device->port.membase)
+                return -ENODEV;
+
+        device->con->write = pl011_early_write;
+        return 0;
+}
+EARLYCON_DECLARE(pl011, pl011_early_console_setup);
+
 #else
 #define AMBA_CONSOLE    NULL
 #endif