Basic braille screen reader support

This adds a minimalistic braille screen reader support.  This is meant to
be used by blind people e.g.  on boot failures or when / cannot be mounted
etc and thus the userland screen readers can not work.

[akpm@linux-foundation.org: fix exports]
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Jiri Kosina <jikos@jikos.cz>
Cc: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3ce193f86565..0ba0861b5d18 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -496,6 +496,11 @@ and is between 256 and 4096 characters. It is defined in the file
                         switching to the matching ttyS device later.  The
                         options are the same as for ttyS, above.
 
+                If the device connected to the port is not a TTY but a braille
+                device, prepend "brl," before the device type, for instance
+                        console=brl,ttyS0
+                For now, only VisioBraille is supported.
+
         earlycon=       [KNL] Output early console device and options.
                 uart[8250],io,<addr>[,options]
                 uart[8250],mmio,<addr>[,options]