aboutsummaryrefslogtreecommitdiff
path: root/Documentation/arm/SA1100/serial_UART
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/arm/SA1100/serial_UART
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'Documentation/arm/SA1100/serial_UART')
-rw-r--r--Documentation/arm/SA1100/serial_UART47
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.
+
+