diff options
author | Jean Delvare <khali@linux-fr.org> | 2009-12-06 21:30:44 -0500 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-09 21:59:52 -0500 |
commit | 5327b9b83a9c45a3fcbcda224a2b02d9eea9f6bb (patch) | |
tree | 757452708d27b1459945d651aae064e15f9ccfe4 /Documentation/misc-devices | |
parent | e3cc2226e99cfadbf300dde892c4a16d742a0856 (diff) |
Doc: use misc-devices/ dir for drivers
We have a directory for misc drivers documentation, let's use it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/misc-devices')
-rw-r--r-- | Documentation/misc-devices/c2port.txt | 90 | ||||
-rw-r--r-- | Documentation/misc-devices/ics932s401 | 31 |
2 files changed, 121 insertions, 0 deletions
diff --git a/Documentation/misc-devices/c2port.txt b/Documentation/misc-devices/c2port.txt new file mode 100644 index 000000000000..d9bf93ea4398 --- /dev/null +++ b/Documentation/misc-devices/c2port.txt | |||
@@ -0,0 +1,90 @@ | |||
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 | ||
35 | http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and | ||
36 | |||
37 | - C2 Specification at | ||
38 | http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf, | ||
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 | ||
diff --git a/Documentation/misc-devices/ics932s401 b/Documentation/misc-devices/ics932s401 new file mode 100644 index 000000000000..07a739f406d8 --- /dev/null +++ b/Documentation/misc-devices/ics932s401 | |||
@@ -0,0 +1,31 @@ | |||
1 | Kernel driver ics932s401 | ||
2 | ====================== | ||
3 | |||
4 | Supported chips: | ||
5 | * IDT ICS932S401 | ||
6 | Prefix: 'ics932s401' | ||
7 | Addresses scanned: I2C 0x69 | ||
8 | Datasheet: Publically available at the IDT website | ||
9 | |||
10 | Author: Darrick J. Wong | ||
11 | |||
12 | Description | ||
13 | ----------- | ||
14 | |||
15 | This driver implements support for the IDT ICS932S401 chip family. | ||
16 | |||
17 | This chip has 4 clock outputs--a base clock for the CPU (which is likely | ||
18 | multiplied to get the real CPU clock), a system clock, a PCI clock, a USB | ||
19 | clock, and a reference clock. The driver reports selected and actual | ||
20 | frequency. If spread spectrum mode is enabled, the driver also reports by what | ||
21 | percent the clock signal is being spread, which should be between 0 and -0.5%. | ||
22 | All frequencies are reported in KHz. | ||
23 | |||
24 | The ICS932S401 monitors all inputs continuously. The driver will not read | ||
25 | the registers more often than once every other second. | ||
26 | |||
27 | Special Features | ||
28 | ---------------- | ||
29 | |||
30 | The clocks could be reprogrammed to increase system speed. I will not help you | ||
31 | do this, as you risk damaging your system! | ||