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Diffstat (limited to 'Documentation/arm/SA1100/serial_UART')
| -rw-r--r-- | Documentation/arm/SA1100/serial_UART | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/arm/SA1100/serial_UART b/Documentation/arm/SA1100/serial_UART new file mode 100644 index 000000000000..aea2e91ca0ef --- /dev/null +++ b/Documentation/arm/SA1100/serial_UART @@ -0,0 +1,47 @@ +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 +> + +If you're not using devfs, 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. + + |