docs: admin-guide: kernel-parameters: Document earlycon options for i.MX UARTs

drivers/tty/serial/imx.c implements these earlycon options.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20200229132750.2783-1-j.neuschaefer@gmx.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 56bf9b2a9ddf08ce838793f577fe069deb639fd3..3e3fd0d19e53e51a272d8f42fffbaf6506a7bcc0 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1095,6 +1095,12 @@
                        A valid base address must be provided, and the serial
                        port must already be setup and configured.
 
+               ec_imx21,<addr>
+               ec_imx6q,<addr>
+                       Start an early, polled-mode, output-only console on the
+                       Freescale i.MX UART at the specified address. The UART
+                       must already be setup and configured.
+
                ar3700_uart,<addr>
                        Start an early, polled-mode console on the
                        Armada 3700 serial port at the specified