diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/i2c/chips/max6875 | 2 | ||||
-rw-r--r-- | Documentation/i2c/chips/pca9539 | 10 | ||||
-rw-r--r-- | Documentation/i2c/chips/pcf8574 | 12 | ||||
-rw-r--r-- | Documentation/i2c/chips/pcf8575 | 9 |
4 files changed, 18 insertions, 15 deletions
diff --git a/Documentation/i2c/chips/max6875 b/Documentation/i2c/chips/max6875 index a0cd8af2f408..10ca43cd1a72 100644 --- a/Documentation/i2c/chips/max6875 +++ b/Documentation/i2c/chips/max6875 | |||
@@ -49,7 +49,7 @@ $ modprobe max6875 force=0,0x50 | |||
49 | 49 | ||
50 | The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple | 50 | The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple |
51 | addresses. For example, for address 0x50, it also reserves 0x51. | 51 | addresses. For example, for address 0x50, it also reserves 0x51. |
52 | The even-address instance is called 'max6875', the odd one is 'max6875 subclient'. | 52 | The even-address instance is called 'max6875', the odd one is 'dummy'. |
53 | 53 | ||
54 | 54 | ||
55 | Programming the chip using i2c-dev | 55 | Programming the chip using i2c-dev |
diff --git a/Documentation/i2c/chips/pca9539 b/Documentation/i2c/chips/pca9539 index 1d81c530c4a5..6aff890088b1 100644 --- a/Documentation/i2c/chips/pca9539 +++ b/Documentation/i2c/chips/pca9539 | |||
@@ -7,7 +7,7 @@ drivers/gpio/pca9539.c instead. | |||
7 | Supported chips: | 7 | Supported chips: |
8 | * Philips PCA9539 | 8 | * Philips PCA9539 |
9 | Prefix: 'pca9539' | 9 | Prefix: 'pca9539' |
10 | Addresses scanned: 0x74 - 0x77 | 10 | Addresses scanned: none |
11 | Datasheet: | 11 | Datasheet: |
12 | http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf | 12 | http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf |
13 | 13 | ||
@@ -23,6 +23,14 @@ The input sense can also be inverted. | |||
23 | The 16 lines are split between two bytes. | 23 | The 16 lines are split between two bytes. |
24 | 24 | ||
25 | 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 | |||
26 | Sysfs entries | 34 | Sysfs entries |
27 | ------------- | 35 | ------------- |
28 | 36 | ||
diff --git a/Documentation/i2c/chips/pcf8574 b/Documentation/i2c/chips/pcf8574 index 5c1ad1376b62..235815c075ff 100644 --- a/Documentation/i2c/chips/pcf8574 +++ b/Documentation/i2c/chips/pcf8574 | |||
@@ -4,13 +4,13 @@ Kernel driver pcf8574 | |||
4 | Supported chips: | 4 | Supported chips: |
5 | * Philips PCF8574 | 5 | * Philips PCF8574 |
6 | Prefix: 'pcf8574' | 6 | Prefix: 'pcf8574' |
7 | Addresses scanned: I2C 0x20 - 0x27 | 7 | Addresses scanned: none |
8 | Datasheet: Publicly available at the Philips Semiconductors website | 8 | Datasheet: Publicly available at the Philips Semiconductors website |
9 | http://www.semiconductors.philips.com/pip/PCF8574P.html | 9 | http://www.semiconductors.philips.com/pip/PCF8574P.html |
10 | 10 | ||
11 | * Philips PCF8574A | 11 | * Philips PCF8574A |
12 | Prefix: 'pcf8574a' | 12 | Prefix: 'pcf8574a' |
13 | Addresses scanned: I2C 0x38 - 0x3f | 13 | Addresses scanned: none |
14 | Datasheet: Publicly available at the Philips Semiconductors website | 14 | Datasheet: Publicly available at the Philips Semiconductors website |
15 | http://www.semiconductors.philips.com/pip/PCF8574P.html | 15 | http://www.semiconductors.philips.com/pip/PCF8574P.html |
16 | 16 | ||
@@ -38,12 +38,10 @@ For more informations see the datasheet. | |||
38 | Accessing PCF8574(A) via /sys interface | 38 | Accessing PCF8574(A) via /sys interface |
39 | ------------------------------------- | 39 | ------------------------------------- |
40 | 40 | ||
41 | ! Be careful ! | ||
42 | The PCF8574(A) is plainly impossible to detect ! Stupid chip. | 41 | The PCF8574(A) is plainly impossible to detect ! Stupid chip. |
43 | So every chip with address in the interval [20..27] and [38..3f] are | 42 | So, you have to pass the I2C bus and address of the installed PCF857A |
44 | detected as PCF8574(A). If you have other chips in this address | 43 | and PCF8574A devices explicitly to the driver at load time via the |
45 | range, the workaround is to load this module after the one | 44 | force=... parameter. |
46 | for your others chips. | ||
47 | 45 | ||
48 | On detection (i.e. insmod, modprobe et al.), directories are being | 46 | On detection (i.e. insmod, modprobe et al.), directories are being |
49 | created for each detected PCF8574(A): | 47 | created for each detected PCF8574(A): |
diff --git a/Documentation/i2c/chips/pcf8575 b/Documentation/i2c/chips/pcf8575 index 25f5698a61cf..40b268eb276f 100644 --- a/Documentation/i2c/chips/pcf8575 +++ b/Documentation/i2c/chips/pcf8575 | |||
@@ -40,12 +40,9 @@ Detection | |||
40 | --------- | 40 | --------- |
41 | 41 | ||
42 | There is no method known to detect whether a chip on a given I2C address is | 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 there are two alternatives | 43 | a PCF8575 or whether it is any other I2C device, so you have to pass the I2C |
44 | to let the driver find the installed PCF8575 devices: | 44 | bus and address of the installed PCF8575 devices explicitly to the driver at |
45 | - Load this driver after any other I2C driver for I2C devices with addresses | 45 | load time via the force=... parameter. |
46 | in the range 0x20 .. 0x27. | ||
47 | - Pass the I2C bus and address of the installed PCF8575 devices explicitly to | ||
48 | the driver at load time via the probe=... or force=... parameters. | ||
49 | 46 | ||
50 | /sys interface | 47 | /sys interface |
51 | -------------- | 48 | -------------- |