aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/misc-devices
diff options
context:
space:
mode:
authorJean Delvare <khali@linux-fr.org>2009-12-06 21:30:44 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-09 21:59:52 -0500
commit5327b9b83a9c45a3fcbcda224a2b02d9eea9f6bb (patch)
tree757452708d27b1459945d651aae064e15f9ccfe4 /Documentation/misc-devices
parente3cc2226e99cfadbf300dde892c4a16d742a0856 (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.txt90
-rw-r--r--Documentation/misc-devices/ics932s40131
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
6This program is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2 of the License, or
9(at your option) any later version.
10
11This program is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public License for more details.
15
16
17
18Overview
19--------
20
21This driver implements the support for Linux of Silicon Labs (Silabs)
22C2 Interface used for in-system programming of micro controllers.
23
24By using this driver you can reprogram the in-system flash without EC2
25or EC3 debug adapter. This solution is also useful in those systems
26where the micro controller is connected via special GPIOs pins.
27
28References
29----------
30
31The C2 Interface main references are at (http://www.silabs.com)
32Silicon Laboratories site], see:
33
34- AN127: FLASH Programming via the C2 Interface at
35http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and
36
37- C2 Specification at
38http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf,
39
40however it implements a two wire serial communication protocol (bit
41banging) designed to enable in-system programming, debugging, and
42boundary-scan testing on low pin-count Silicon Labs devices. Currently
43this code supports only flash programming but extensions are easy to
44add.
45
46Using the driver
47----------------
48
49Once the driver is loaded you can use sysfs support to get C2port's
50info or read/write in-system flash.
51
52# ls /sys/class/c2port/c2port0/
53access flash_block_size flash_erase rev_id
54dev_id flash_blocks_num flash_size subsystem/
55flash_access flash_data reset uevent
56
57Initially the C2port access is disabled since you hardware may have
58such lines multiplexed with other devices so, to get access to the
59C2port, you need the command:
60
61# echo 1 > /sys/class/c2port/c2port0/access
62
63after that you should read the device ID and revision ID of the
64connected micro controller:
65
66# cat /sys/class/c2port/c2port0/dev_id
678
68# cat /sys/class/c2port/c2port0/rev_id
691
70
71However, for security reasons, the in-system flash access in not
72enabled yet, to do so you need the command:
73
74# echo 1 > /sys/class/c2port/c2port0/flash_access
75
76After that you can read the whole flash:
77
78# cat /sys/class/c2port/c2port0/flash_data > image
79
80erase it:
81
82# echo 1 > /sys/class/c2port/c2port0/flash_erase
83
84and write it:
85
86# cat image > /sys/class/c2port/c2port0/flash_data
87
88after 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 @@
1Kernel driver ics932s401
2======================
3
4Supported chips:
5 * IDT ICS932S401
6 Prefix: 'ics932s401'
7 Addresses scanned: I2C 0x69
8 Datasheet: Publically available at the IDT website
9
10Author: Darrick J. Wong
11
12Description
13-----------
14
15This driver implements support for the IDT ICS932S401 chip family.
16
17This chip has 4 clock outputs--a base clock for the CPU (which is likely
18multiplied to get the real CPU clock), a system clock, a PCI clock, a USB
19clock, and a reference clock. The driver reports selected and actual
20frequency. If spread spectrum mode is enabled, the driver also reports by what
21percent the clock signal is being spread, which should be between 0 and -0.5%.
22All frequencies are reported in KHz.
23
24The ICS932S401 monitors all inputs continuously. The driver will not read
25the registers more often than once every other second.
26
27Special Features
28----------------
29
30The clocks could be reprogrammed to increase system speed. I will not help you
31do this, as you risk damaging your system!