aboutsummaryrefslogtreecommitdiff
path: root/Documentation/misc-devices/c2port.txt
diff options
context:
space:
mode:
authorFathi Boudra <fathi.boudra@linaro.org>2013-04-28 09:33:08 +0300
committerFathi Boudra <fathi.boudra@linaro.org>2013-04-28 09:33:08 +0300
commit3b4bd47f8f4ed3aaf7c81c9b5d2d37ad79fadf4a (patch)
treeb9996006addfd7ae70a39672b76843b49aebc189 /Documentation/misc-devices/c2port.txt
downloadlinux-linaro-highbank-3b4bd47f8f4ed3aaf7c81c9b5d2d37ad79fadf4a.tar.gz
Imported Upstream version 3.9.0HEADupstream/3.9.0upstreammaster
Diffstat (limited to 'Documentation/misc-devices/c2port.txt')
-rw-r--r--Documentation/misc-devices/c2port.txt90
1 files changed, 90 insertions, 0 deletions
diff --git a/Documentation/misc-devices/c2port.txt b/Documentation/misc-devices/c2port.txt
new file mode 100644
index 00000000..ea734446
--- /dev/null
+++ b/Documentation/misc-devices/c2port.txt
@@ -0,0 +1,90 @@
+ C2 port support
+ ---------------
+
+(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+
+
+Overview
+--------
+
+This driver implements the support for Linux of Silicon Labs (Silabs)
+C2 Interface used for in-system programming of micro controllers.
+
+By using this driver you can reprogram the in-system flash without EC2
+or EC3 debug adapter. This solution is also useful in those systems
+where the micro controller is connected via special GPIOs pins.
+
+References
+----------
+
+The C2 Interface main references are at (http://www.silabs.com)
+Silicon Laboratories site], see:
+
+- AN127: FLASH Programming via the C2 Interface at
+http://www.silabs.com/Support Documents/TechnicalDocs/an127.pdf
+
+- C2 Specification at
+http://www.silabs.com/pages/DownloadDoc.aspx?FILEURL=Support%20Documents/TechnicalDocs/an127.pdf&src=SearchResults
+
+however it implements a two wire serial communication protocol (bit
+banging) designed to enable in-system programming, debugging, and
+boundary-scan testing on low pin-count Silicon Labs devices. Currently
+this code supports only flash programming but extensions are easy to
+add.
+
+Using the driver
+----------------
+
+Once the driver is loaded you can use sysfs support to get C2port's
+info or read/write in-system flash.
+
+# ls /sys/class/c2port/c2port0/
+access flash_block_size flash_erase rev_id
+dev_id flash_blocks_num flash_size subsystem/
+flash_access flash_data reset uevent
+
+Initially the C2port access is disabled since you hardware may have
+such lines multiplexed with other devices so, to get access to the
+C2port, you need the command:
+
+# echo 1 > /sys/class/c2port/c2port0/access
+
+after that you should read the device ID and revision ID of the
+connected micro controller:
+
+# cat /sys/class/c2port/c2port0/dev_id
+8
+# cat /sys/class/c2port/c2port0/rev_id
+1
+
+However, for security reasons, the in-system flash access in not
+enabled yet, to do so you need the command:
+
+# echo 1 > /sys/class/c2port/c2port0/flash_access
+
+After that you can read the whole flash:
+
+# cat /sys/class/c2port/c2port0/flash_data > image
+
+erase it:
+
+# echo 1 > /sys/class/c2port/c2port0/flash_erase
+
+and write it:
+
+# cat image > /sys/class/c2port/c2port0/flash_data
+
+after writing you have to reset the device to execute the new code:
+
+# echo 1 > /sys/class/c2port/c2port0/reset