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1 | C2 port support |
2 | --------------- | |
3 | ||
4 | (C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com> | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | ||
17 | ||
18 | Overview | |
19 | -------- | |
20 | ||
21 | This driver implements the support for Linux of Silicon Labs (Silabs) | |
22 | C2 Interface used for in-system programming of micro controllers. | |
23 | ||
24 | By using this driver you can reprogram the in-system flash without EC2 | |
25 | or EC3 debug adapter. This solution is also useful in those systems | |
26 | where the micro controller is connected via special GPIOs pins. | |
27 | ||
28 | References | |
29 | ---------- | |
30 | ||
31 | The C2 Interface main references are at (http://www.silabs.com) | |
32 | Silicon Laboratories site], see: | |
33 | ||
34 | - AN127: FLASH Programming via the C2 Interface at | |
0ea6e611 | 35 | http://www.silabs.com/Support Documents/TechnicalDocs/an127.pdf |
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36 | |
37 | - C2 Specification at | |
0ea6e611 | 38 | http://www.silabs.com/pages/DownloadDoc.aspx?FILEURL=Support%20Documents/TechnicalDocs/an127.pdf&src=SearchResults |
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39 | |
40 | however it implements a two wire serial communication protocol (bit | |
41 | banging) designed to enable in-system programming, debugging, and | |
42 | boundary-scan testing on low pin-count Silicon Labs devices. Currently | |
43 | this code supports only flash programming but extensions are easy to | |
44 | add. | |
45 | ||
46 | Using the driver | |
47 | ---------------- | |
48 | ||
49 | Once the driver is loaded you can use sysfs support to get C2port's | |
50 | info or read/write in-system flash. | |
51 | ||
52 | # ls /sys/class/c2port/c2port0/ | |
53 | access flash_block_size flash_erase rev_id | |
54 | dev_id flash_blocks_num flash_size subsystem/ | |
55 | flash_access flash_data reset uevent | |
56 | ||
57 | Initially the C2port access is disabled since you hardware may have | |
58 | such lines multiplexed with other devices so, to get access to the | |
59 | C2port, you need the command: | |
60 | ||
61 | # echo 1 > /sys/class/c2port/c2port0/access | |
62 | ||
63 | after that you should read the device ID and revision ID of the | |
64 | connected micro controller: | |
65 | ||
66 | # cat /sys/class/c2port/c2port0/dev_id | |
67 | 8 | |
68 | # cat /sys/class/c2port/c2port0/rev_id | |
69 | 1 | |
70 | ||
71 | However, for security reasons, the in-system flash access in not | |
72 | enabled yet, to do so you need the command: | |
73 | ||
74 | # echo 1 > /sys/class/c2port/c2port0/flash_access | |
75 | ||
76 | After that you can read the whole flash: | |
77 | ||
78 | # cat /sys/class/c2port/c2port0/flash_data > image | |
79 | ||
80 | erase it: | |
81 | ||
82 | # echo 1 > /sys/class/c2port/c2port0/flash_erase | |
83 | ||
84 | and write it: | |
85 | ||
86 | # cat image > /sys/class/c2port/c2port0/flash_data | |
87 | ||
88 | after writing you have to reset the device to execute the new code: | |
89 | ||
90 | # echo 1 > /sys/class/c2port/c2port0/reset |