ASoC: Amstrad Delta: add info about the line discipline requirement to Kconfig help...

I thought it could be usefull to add some information on how to get the device
fully supported by loading a line discipline on the modem line.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/omap/Kconfig b/sound/soc/omap/Kconfig
index 2dee9839be86035f6b668655dcf84aa12d9e843c..653a362425dfd265b70068361495c0404908df60 100644 (file)
--- a/sound/soc/omap/Kconfig
+++ b/sound/soc/omap/Kconfig
@@ -21,7 +21,18 @@ config SND_OMAP_SOC_AMS_DELTA
        select SND_OMAP_SOC_MCBSP
        select SND_SOC_CX20442
        help
-         Say Y if you want to add support for SoC audio on Amstrad Delta.
+         Say Y  if you want to add support  for SoC audio device  connected to
+         a handset and a speakerphone found on Amstrad E3 (Delta) videophone.
+
+         Note that in order to get those devices fully supported,  you have to
+         build  the kernel  with  standard  serial port  driver  included  and
+         configured for at least 4 ports.  Then, from userspace, you must load
+         a line discipline #19 on the modem (ttyS3) serial line.  The simplest
+         way to achieve this is to install util-linux-ng  and use the included
+         ldattach  utility.  This  can be  started  automatically  from  udev,
+         a simple rule like this one should do the trick (it does for me):
+               ACTION=="add", KERNEL=="controlC0", \
+                               RUN+="/usr/sbin/ldattach 19 /dev/ttyS3"
 
 config SND_OMAP_SOC_OSK5912
        tristate "SoC Audio support for omap osk5912"