AMBA PL011 looks like PL010 with a minor change in the registers. I'd
like to move both to amba-pl01x-earlycon.c but I cannot because the
EARLYCON_START() macro always uses the same symbol name.

Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>

---
 drivers/tty/serial/amba-pl011.c |   41 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

Index: b/drivers/tty/serial/amba-pl011.c
===================================================================
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -43,6 +43,7 @@
 #include <linux/tty_flip.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
+#include <linux/earlycon.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/serial.h>
 #include <linux/clk.h>
@@ -2020,6 +2021,46 @@ static void __exit pl011_exit(void)
 arch_initcall(pl011_init);
 module_exit(pl011_exit);
 
+static int __earlyconinit pl011_earlycon_probe(struct earlycon_drv *drv)
+{
+	volatile uint32_t *cr;
+
+	/* this driver doesn't support probing of the base address */
+	if (!drv->base)
+		return -EINVAL;
+
+	cr = (volatile uint32_t *) (drv->base + UART011_CR);
+	return (*cr & UART01x_CR_UARTEN) ? 0 : -1;
+}
+
+static void __earlyconinit pl011_earlycon_putc(struct earlycon_drv *drv, int ch)
+{
+	volatile uint32_t *fr, *dr;
+
+	fr = (volatile uint32_t *) (drv->base + UART01x_FR);
+	while (*fr & UART01x_FR_TXFF)
+		barrier();
+
+	dr = (volatile uint32_t *) (drv->base + UART01x_DR);
+	*dr = ch;
+}
+
+static void __earlyconinit pl011_earlycon_flush(struct earlycon_drv *drv)
+{
+	volatile uint32_t *fr;
+
+	fr = (volatile uint32_t *) (drv->base + UART01x_FR);
+	while (*fr & UART01x_FR_BUSY)
+		barrier();
+}
+
+
+EARLYCON_START("amba-pl011")
+	.probe = pl011_earlycon_probe,
+	.putc = pl011_earlycon_putc,
+	.flush = pl011_earlycon_flush,
+EARLYCON_END
+
 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
 MODULE_DESCRIPTION("ARM AMBA serial port driver");
 MODULE_LICENSE("GPL");