1 .. SPDX-License-Identifier: GPL-2.0 2 .. include:: <isonum.txt> 3 4 =============== 5 C2 port support 6 =============== 7 8 (C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com> 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 2 of the License, or 13 (at your option) any later version. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 21 22 Overview 23 -------- 24 25 This driver implements the support for Linux of Silicon Labs (Silabs) 26 C2 Interface used for in-system programming of micro controllers. 27 28 By using this driver you can reprogram the in-system flash without EC2 29 or EC3 debug adapter. This solution is also useful in those systems 30 where the micro controller is connected via special GPIOs pins. 31 32 References 33 ---------- 34 35 The C2 Interface main references are at (https://www.silabs.com) 36 Silicon Laboratories site], see: 37 38 - AN127: FLASH Programming via the C2 Interface at 39 https://www.silabs.com/Support Documents/TechnicalDocs/an127.pdf 40 41 - C2 Specification at 42 https://www.silabs.com/pages/DownloadDoc.aspx?FILEURL=Support%20Documents/TechnicalDocs/an127.pdf&src=SearchResults 43 44 however it implements a two wire serial communication protocol (bit 45 banging) designed to enable in-system programming, debugging, and 46 boundary-scan testing on low pin-count Silicon Labs devices. Currently 47 this code supports only flash programming but extensions are easy to 48 add. 49 50 Using the driver 51 ---------------- 52 53 Once the driver is loaded you can use sysfs support to get C2port's 54 info or read/write in-system flash:: 55 56 # ls /sys/class/c2port/c2port0/ 57 access flash_block_size flash_erase rev_id 58 dev_id flash_blocks_num flash_size subsystem/ 59 flash_access flash_data reset uevent 60 61 Initially the C2port access is disabled since you hardware may have 62 such lines multiplexed with other devices so, to get access to the 63 C2port, you need the command:: 64 65 # echo 1 > /sys/class/c2port/c2port0/access 66 67 after that you should read the device ID and revision ID of the 68 connected micro controller:: 69 70 # cat /sys/class/c2port/c2port0/dev_id 71 8 72 # cat /sys/class/c2port/c2port0/rev_id 73 1 74 75 However, for security reasons, the in-system flash access in not 76 enabled yet, to do so you need the command:: 77 78 # echo 1 > /sys/class/c2port/c2port0/flash_access 79 80 After that you can read the whole flash:: 81 82 # cat /sys/class/c2port/c2port0/flash_data > image 83 84 erase it:: 85 86 # echo 1 > /sys/class/c2port/c2port0/flash_erase 87 88 and write it:: 89 90 # cat image > /sys/class/c2port/c2port0/flash_data 91 92 after writing you have to reset the device to execute the new code:: 93 94 # echo 1 > /sys/class/c2port/c2port0/reset
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.