diff options
Diffstat (limited to 'Documentation/i2c')
-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 a0cd8af2f40..10ca43cd1a7 100644 --- a/Documentation/i2c/chips/max6875 +++ b/Documentation/i2c/chips/max6875 @@ -49,7 +49,7 @@ $ modprobe max6875 force=0,0x50 The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple addresses. For example, for address 0x50, it also reserves 0x51. -The even-address instance is called 'max6875', the odd one is 'max6875 subclient'. +The even-address instance is called 'max6875', the odd one is 'dummy'. Programming the chip using i2c-dev diff --git a/Documentation/i2c/chips/pca9539 b/Documentation/i2c/chips/pca9539 index 1d81c530c4a..6aff890088b 100644 --- a/Documentation/i2c/chips/pca9539 +++ b/Documentation/i2c/chips/pca9539 @@ -7,7 +7,7 @@ drivers/gpio/pca9539.c instead. Supported chips: * Philips PCA9539 Prefix: 'pca9539' - Addresses scanned: 0x74 - 0x77 + Addresses scanned: none Datasheet: http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf @@ -23,6 +23,14 @@ The input sense can also be inverted. The 16 lines are split between two bytes. +Detection +--------- + +The PCA9539 is difficult to detect and not commonly found in PC machines, +so you have to pass the I2C bus and address of the installed PCA9539 +devices explicitly to the driver at load time via the force=... parameter. + + Sysfs entries ------------- diff --git a/Documentation/i2c/chips/pcf8574 b/Documentation/i2c/chips/pcf8574 index 5c1ad1376b6..235815c075f 100644 --- a/Documentation/i2c/chips/pcf8574 +++ b/Documentation/i2c/chips/pcf8574 @@ -4,13 +4,13 @@ Kernel driver pcf8574 Supported chips: * Philips PCF8574 Prefix: 'pcf8574' - Addresses scanned: I2C 0x20 - 0x27 + Addresses scanned: none Datasheet: Publicly available at the Philips Semiconductors website http://www.semiconductors.philips.com/pip/PCF8574P.html * Philips PCF8574A Prefix: 'pcf8574a' - Addresses scanned: I2C 0x38 - 0x3f + Addresses scanned: none Datasheet: Publicly available at the Philips Semiconductors website http://www.semiconductors.philips.com/pip/PCF8574P.html @@ -38,12 +38,10 @@ For more informations see the datasheet. Accessing PCF8574(A) via /sys interface ------------------------------------- -! Be careful ! The PCF8574(A) is plainly impossible to detect ! Stupid chip. -So every chip with address in the interval [20..27] and [38..3f] are -detected as PCF8574(A). If you have other chips in this address -range, the workaround is to load this module after the one -for your others chips. +So, you have to pass the I2C bus and address of the installed PCF857A +and PCF8574A devices explicitly to the driver at load time via the +force=... parameter. On detection (i.e. insmod, modprobe et al.), directories are being created for each detected PCF8574(A): diff --git a/Documentation/i2c/chips/pcf8575 b/Documentation/i2c/chips/pcf8575 index 25f5698a61c..40b268eb276 100644 --- a/Documentation/i2c/chips/pcf8575 +++ b/Documentation/i2c/chips/pcf8575 @@ -40,12 +40,9 @@ Detection --------- There is no method known to detect whether a chip on a given I2C address is -a PCF8575 or whether it is any other I2C device. So there are two alternatives -to let the driver find the installed PCF8575 devices: -- Load this driver after any other I2C driver for I2C devices with addresses - in the range 0x20 .. 0x27. -- Pass the I2C bus and address of the installed PCF8575 devices explicitly to - the driver at load time via the probe=... or force=... parameters. +a PCF8575 or whether it is any other I2C device, so you have to pass the I2C +bus and address of the installed PCF8575 devices explicitly to the driver at +load time via the force=... parameter. /sys interface -------------- |