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diff --git a/Documentation/arm/sa1100/serial_uart.rst b/Documentation/arm/sa1100/serial_uart.rst new file mode 100644 index 000000000000..ea983642b9be --- /dev/null +++ b/Documentation/arm/sa1100/serial_uart.rst @@ -0,0 +1,51 @@ +================== +SA1100 serial port +================== + +The SA1100 serial port had its major/minor numbers officially assigned:: + + > Date: Sun, 24 Sep 2000 21:40:27 -0700 + > From: H. Peter Anvin <hpa@transmeta.com> + > To: Nicolas Pitre <nico@CAM.ORG> + > Cc: Device List Maintainer <device@lanana.org> + > Subject: Re: device + > + > Okay. Note that device numbers 204 and 205 are used for "low density + > serial devices", so you will have a range of minors on those majors (the + > tty device layer handles this just fine, so you don't have to worry about + > doing anything special.) + > + > So your assignments are: + > + > 204 char Low-density serial ports + > 5 = /dev/ttySA0 SA1100 builtin serial port 0 + > 6 = /dev/ttySA1 SA1100 builtin serial port 1 + > 7 = /dev/ttySA2 SA1100 builtin serial port 2 + > + > 205 char Low-density serial ports (alternate device) + > 5 = /dev/cusa0 Callout device for ttySA0 + > 6 = /dev/cusa1 Callout device for ttySA1 + > 7 = /dev/cusa2 Callout device for ttySA2 + > + +You must create those inodes in /dev on the root filesystem used +by your SA1100-based device:: + + mknod ttySA0 c 204 5 + mknod ttySA1 c 204 6 + mknod ttySA2 c 204 7 + mknod cusa0 c 205 5 + mknod cusa1 c 205 6 + mknod cusa2 c 205 7 + +In addition to the creation of the appropriate device nodes above, you +must ensure your user space applications make use of the correct device +name. The classic example is the content of the /etc/inittab file where +you might have a getty process started on ttyS0. + +In this case: + +- replace occurrences of ttyS0 with ttySA0, ttyS1 with ttySA1, etc. + +- don't forget to add 'ttySA0', 'console', or the appropriate tty name + in /etc/securetty for root to be allowed to login as well. |