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author | Ingo Molnar <mingo@elte.hu> | 2008-12-16 22:04:48 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-12-16 22:04:48 +0100 |
commit | 78f902ccc597d6ce3e8d1477d70f2d79e960ba7a (patch) | |
tree | c6ceab663de16501d1dda1c1596fe2dacaaef8e3 /Documentation/c2port.txt | |
parent | 9ee670fd87b7d69c8633b94c42aadcbbcb96f28e (diff) | |
parent | 8b1fae4e4200388b64dd88065639413cb3f1051c (diff) |
Merge commit 'v2.6.28-rc8' into x86/doc
Diffstat (limited to 'Documentation/c2port.txt')
-rw-r--r-- | Documentation/c2port.txt | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/Documentation/c2port.txt b/Documentation/c2port.txt new file mode 100644 index 00000000000..d9bf93ea439 --- /dev/null +++ b/Documentation/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/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and + +- C2 Specification at +http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf, + +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 |