Alexander Graf 601147b06a serial: bcm283x_mu: Detect disabled serial device ... On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times. However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today. This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly. That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Reviewed-by: Simon Glass <sjg@chromium.org>		2016-09-06 13:18:19 -04:00
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rpi	serial: bcm283x_mu: Detect disabled serial device	2016-09-06 13:18:19 -04:00