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| author | Jean Delvare <khali@linux-fr.org> | 2010-10-28 20:31:50 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2010-10-28 20:31:50 +0200 |
| commit | 6dfee85397a47063291fe199eaf950bee7944454 (patch) | |
| tree | a0938da1f748f16621238e047a93f052fbd9adb2 /Documentation | |
| parent | 4275fcd65d3b4a504b7779e532c81a927afd28c0 (diff) | |
| download | lwn-6dfee85397a47063291fe199eaf950bee7944454.tar.gz lwn-6dfee85397a47063291fe199eaf950bee7944454.zip | |
hwmon: (pcf8591) Don't attempt to detect devices
The PCF8591 can't be detected, don't even try. There are plenty of
other means to instantiate i2c devices these days.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/hwmon/pcf8591 | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/Documentation/hwmon/pcf8591 b/Documentation/hwmon/pcf8591 index e76a7892f68e..ac020b3bb7b3 100644 --- a/Documentation/hwmon/pcf8591 +++ b/Documentation/hwmon/pcf8591 @@ -4,7 +4,7 @@ Kernel driver pcf8591 Supported chips: * Philips/NXP PCF8591 Prefix: 'pcf8591' - Addresses scanned: I2C 0x48 - 0x4f + Addresses scanned: none Datasheet: Publicly available at the NXP website http://www.nxp.com/pip/PCF8591_6.html @@ -58,18 +58,16 @@ Module parameters Accessing PCF8591 via /sys interface ------------------------------------- -! Be careful ! -The PCF8591 is plainly impossible to detect! Stupid chip. -So every chip with address in the interval [0x48..0x4f] is -detected as PCF8591. If you have other chips in this address -range, the workaround is to load this module after the one -for your others chips. +The PCF8591 is plainly impossible to detect! Thus the driver won't even +try. You have to explicitly instantiate the device at the relevant +address (in the interval [0x48..0x4f]) either through platform data, or +using the sysfs interface. See Documentation/i2c/instantiating-devices +for details. -On detection (i.e. insmod, modprobe et al.), directories are being -created for each detected PCF8591: +Directories are being created for each instantiated PCF8591: /sys/bus/i2c/devices/<0>-<1>/ -where <0> is the bus the chip was detected on (e. g. i2c-0) +where <0> is the bus the chip is connected to (e. g. i2c-0) and <1> the chip address ([48..4f]) Inside these directories, there are such files: |