diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-23 12:30:48 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-23 12:30:48 -0400 |
commit | 40aba218969914d1b225e742617adb921cf94eae (patch) | |
tree | 663ec9cdadbedec5f8eab754cbc590298c1d40be /Documentation | |
parent | b64ada6b23d4a305fb3ca59b79dd38707fc53b69 (diff) | |
parent | cfd550ed3d3bd509b475c7a9d425fc63bf843a7c (diff) |
Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c: Clearly mark ACPI drivers as such
i2c: Add driver for SMBus Control Method Interface
i2c-pnx: Correct use of request_region/request_mem_region
MAINTAINERS: Add maintainer for AT24 and PCA9564/PCA9665
i2c-piix4: Add AMD SB900 SMBus device ID
i2c/chips: Remove deprecated pcf8574 driver
i2c/chips: Remove deprecated pca9539 driver
i2c/chips: Remove deprecated pcf8575 driver
gpio/pcf857x: Copy i2c_device_id from old pcf8574 driver
i2c/scx200_acb: Provide more information on bus errors
i2c: Provide compatibility links for i2c adapters
i2c: Convert i2c adapters to bus devices
i2c: Convert i2c clients to a device type
i2c/tsl2550: Use combined SMBus transactions
i2c-taos-evm: Switch echo off to improve performance
i2c: Drop unused i2c_driver.id field
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/i2c/busses/i2c-piix4 | 2 | ||||
-rw-r--r-- | Documentation/i2c/chips/pca9539 | 58 | ||||
-rw-r--r-- | Documentation/i2c/chips/pcf8574 | 65 | ||||
-rw-r--r-- | Documentation/i2c/chips/pcf8575 | 69 |
4 files changed, 2 insertions, 192 deletions
diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4 index f889481762b5..c5b37c570554 100644 --- a/Documentation/i2c/busses/i2c-piix4 +++ b/Documentation/i2c/busses/i2c-piix4 | |||
@@ -8,6 +8,8 @@ Supported adapters: | |||
8 | Datasheet: Only available via NDA from ServerWorks | 8 | Datasheet: Only available via NDA from ServerWorks |
9 | * ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges | 9 | * ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges |
10 | Datasheet: Not publicly available | 10 | Datasheet: Not publicly available |
11 | * AMD SB900 | ||
12 | Datasheet: Not publicly available | ||
11 | * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge | 13 | * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge |
12 | Datasheet: Publicly available at the SMSC website http://www.smsc.com | 14 | Datasheet: Publicly available at the SMSC website http://www.smsc.com |
13 | 15 | ||
diff --git a/Documentation/i2c/chips/pca9539 b/Documentation/i2c/chips/pca9539 deleted file mode 100644 index 6aff890088b1..000000000000 --- a/Documentation/i2c/chips/pca9539 +++ /dev/null | |||
@@ -1,58 +0,0 @@ | |||
1 | Kernel driver pca9539 | ||
2 | ===================== | ||
3 | |||
4 | NOTE: this driver is deprecated and will be dropped soon, use | ||
5 | drivers/gpio/pca9539.c instead. | ||
6 | |||
7 | Supported chips: | ||
8 | * Philips PCA9539 | ||
9 | Prefix: 'pca9539' | ||
10 | Addresses scanned: none | ||
11 | Datasheet: | ||
12 | http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf | ||
13 | |||
14 | Author: Ben Gardner <bgardner@wabtec.com> | ||
15 | |||
16 | |||
17 | Description | ||
18 | ----------- | ||
19 | |||
20 | The Philips PCA9539 is a 16 bit low power I/O device. | ||
21 | All 16 lines can be individually configured as an input or output. | ||
22 | The input sense can also be inverted. | ||
23 | The 16 lines are split between two bytes. | ||
24 | |||
25 | |||
26 | Detection | ||
27 | --------- | ||
28 | |||
29 | The PCA9539 is difficult to detect and not commonly found in PC machines, | ||
30 | so you have to pass the I2C bus and address of the installed PCA9539 | ||
31 | devices explicitly to the driver at load time via the force=... parameter. | ||
32 | |||
33 | |||
34 | Sysfs entries | ||
35 | ------------- | ||
36 | |||
37 | Each is a byte that maps to the 8 I/O bits. | ||
38 | A '0' suffix is for bits 0-7, while '1' is for bits 8-15. | ||
39 | |||
40 | input[01] - read the current value | ||
41 | output[01] - sets the output value | ||
42 | direction[01] - direction of each bit: 1=input, 0=output | ||
43 | invert[01] - toggle the input bit sense | ||
44 | |||
45 | input reads the actual state of the line and is always available. | ||
46 | The direction defaults to input for all channels. | ||
47 | |||
48 | |||
49 | General Remarks | ||
50 | --------------- | ||
51 | |||
52 | Note that each output, direction, and invert entry controls 8 lines. | ||
53 | You should use the read, modify, write sequence. | ||
54 | For example. to set output bit 0 of 1. | ||
55 | val=$(cat output0) | ||
56 | val=$(( $val | 1 )) | ||
57 | echo $val > output0 | ||
58 | |||
diff --git a/Documentation/i2c/chips/pcf8574 b/Documentation/i2c/chips/pcf8574 deleted file mode 100644 index 235815c075ff..000000000000 --- a/Documentation/i2c/chips/pcf8574 +++ /dev/null | |||
@@ -1,65 +0,0 @@ | |||
1 | Kernel driver pcf8574 | ||
2 | ===================== | ||
3 | |||
4 | Supported chips: | ||
5 | * Philips PCF8574 | ||
6 | Prefix: 'pcf8574' | ||
7 | Addresses scanned: none | ||
8 | Datasheet: Publicly available at the Philips Semiconductors website | ||
9 | http://www.semiconductors.philips.com/pip/PCF8574P.html | ||
10 | |||
11 | * Philips PCF8574A | ||
12 | Prefix: 'pcf8574a' | ||
13 | Addresses scanned: none | ||
14 | Datasheet: Publicly available at the Philips Semiconductors website | ||
15 | http://www.semiconductors.philips.com/pip/PCF8574P.html | ||
16 | |||
17 | Authors: | ||
18 | Frodo Looijaard <frodol@dds.nl>, | ||
19 | Philip Edelbrock <phil@netroedge.com>, | ||
20 | Dan Eaton <dan.eaton@rocketlogix.com>, | ||
21 | Aurelien Jarno <aurelien@aurel32.net>, | ||
22 | Jean Delvare <khali@linux-fr.org>, | ||
23 | |||
24 | |||
25 | Description | ||
26 | ----------- | ||
27 | The PCF8574(A) is an 8-bit I/O expander for the I2C bus produced by Philips | ||
28 | Semiconductors. It is designed to provide a byte I2C interface to up to 16 | ||
29 | separate devices (8 x PCF8574 and 8 x PCF8574A). | ||
30 | |||
31 | This device consists of a quasi-bidirectional port. Each of the eight I/Os | ||
32 | can be independently used as an input or output. To setup an I/O as an | ||
33 | input, you have to write a 1 to the corresponding output. | ||
34 | |||
35 | For more informations see the datasheet. | ||
36 | |||
37 | |||
38 | Accessing PCF8574(A) via /sys interface | ||
39 | ------------------------------------- | ||
40 | |||
41 | The PCF8574(A) is plainly impossible to detect ! Stupid chip. | ||
42 | So, you have to pass the I2C bus and address of the installed PCF857A | ||
43 | and PCF8574A devices explicitly to the driver at load time via the | ||
44 | force=... parameter. | ||
45 | |||
46 | On detection (i.e. insmod, modprobe et al.), directories are being | ||
47 | created for each detected PCF8574(A): | ||
48 | |||
49 | /sys/bus/i2c/devices/<0>-<1>/ | ||
50 | where <0> is the bus the chip was detected on (e. g. i2c-0) | ||
51 | and <1> the chip address ([20..27] or [38..3f]): | ||
52 | |||
53 | (example: /sys/bus/i2c/devices/1-0020/) | ||
54 | |||
55 | Inside these directories, there are two files each: | ||
56 | read and write (and one file with chip name). | ||
57 | |||
58 | The read file is read-only. Reading gives you the current I/O input | ||
59 | if the corresponding output is set as 1, otherwise the current output | ||
60 | value, that is to say 0. | ||
61 | |||
62 | The write file is read/write. Writing a value outputs it on the I/O | ||
63 | port. Reading returns the last written value. As it is not possible | ||
64 | to read this value from the chip, you need to write at least once to | ||
65 | this file before you can read back from it. | ||
diff --git a/Documentation/i2c/chips/pcf8575 b/Documentation/i2c/chips/pcf8575 deleted file mode 100644 index 40b268eb276f..000000000000 --- a/Documentation/i2c/chips/pcf8575 +++ /dev/null | |||
@@ -1,69 +0,0 @@ | |||
1 | About the PCF8575 chip and the pcf8575 kernel driver | ||
2 | ==================================================== | ||
3 | |||
4 | The PCF8575 chip is produced by the following manufacturers: | ||
5 | |||
6 | * Philips NXP | ||
7 | http://www.nxp.com/#/pip/cb=[type=product,path=50807/41735/41850,final=PCF8575_3]|pip=[pip=PCF8575_3][0] | ||
8 | |||
9 | * Texas Instruments | ||
10 | http://focus.ti.com/docs/prod/folders/print/pcf8575.html | ||
11 | |||
12 | |||
13 | Some vendors sell small PCB's with the PCF8575 mounted on it. You can connect | ||
14 | such a board to a Linux host via e.g. an USB to I2C interface. Examples of | ||
15 | PCB boards with a PCF8575: | ||
16 | |||
17 | * SFE Breakout Board for PCF8575 I2C Expander by RobotShop | ||
18 | http://www.robotshop.ca/home/products/robot-parts/electronics/adapters-converters/sfe-pcf8575-i2c-expander-board.html | ||
19 | |||
20 | * Breakout Board for PCF8575 I2C Expander by Spark Fun Electronics | ||
21 | http://www.sparkfun.com/commerce/product_info.php?products_id=8130 | ||
22 | |||
23 | |||
24 | Description | ||
25 | ----------- | ||
26 | The PCF8575 chip is a 16-bit I/O expander for the I2C bus. Up to eight of | ||
27 | these chips can be connected to the same I2C bus. You can find this | ||
28 | chip on some custom designed hardware, but you won't find it on PC | ||
29 | motherboards. | ||
30 | |||
31 | The PCF8575 chip consists of a 16-bit quasi-bidirectional port and an I2C-bus | ||
32 | interface. Each of the sixteen I/O's can be independently used as an input or | ||
33 | an output. To set up an I/O pin as an input, you have to write a 1 to the | ||
34 | corresponding output. | ||
35 | |||
36 | For more information please see the datasheet. | ||
37 | |||
38 | |||
39 | Detection | ||
40 | --------- | ||
41 | |||
42 | There is no method known to detect whether a chip on a given I2C address is | ||
43 | a PCF8575 or whether it is any other I2C device, so you have to pass the I2C | ||
44 | bus and address of the installed PCF8575 devices explicitly to the driver at | ||
45 | load time via the force=... parameter. | ||
46 | |||
47 | /sys interface | ||
48 | -------------- | ||
49 | |||
50 | For each address on which a PCF8575 chip was found or forced the following | ||
51 | files will be created under /sys: | ||
52 | * /sys/bus/i2c/devices/<bus>-<address>/read | ||
53 | * /sys/bus/i2c/devices/<bus>-<address>/write | ||
54 | where bus is the I2C bus number (0, 1, ...) and address is the four-digit | ||
55 | hexadecimal representation of the 7-bit I2C address of the PCF8575 | ||
56 | (0020 .. 0027). | ||
57 | |||
58 | The read file is read-only. Reading it will trigger an I2C read and will hence | ||
59 | report the current input state for the pins configured as inputs, and the | ||
60 | current output value for the pins configured as outputs. | ||
61 | |||
62 | The write file is read-write. Writing a value to it will configure all pins | ||
63 | as output for which the corresponding bit is zero. Reading the write file will | ||
64 | return the value last written, or -EAGAIN if no value has yet been written to | ||
65 | the write file. | ||
66 | |||
67 | On module initialization the configuration of the chip is not changed -- the | ||
68 | chip is left in the state it was already configured in through either power-up | ||
69 | or through previous I2C write actions. | ||