Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6

[firefly-linux-kernel-4.4.55.git] / Documentation / hwmon / pcf8591

diff --git a/Documentation/hwmon/pcf8591 b/Documentation/hwmon/pcf8591
index 5628fcf4207f787fa3ab33fc07c377f4e1c8e196..ac020b3bb7b3769939a3574505ab1d3a0b173900 100644 (file)
--- a/Documentation/hwmon/pcf8591
+++ b/Documentation/hwmon/pcf8591
@@ -2,11 +2,11 @@ Kernel driver pcf8591
 =====================
 
 Supported chips:
-  * Philips PCF8591
+  * Philips/NXP PCF8591
     Prefix: 'pcf8591'
-    Addresses scanned: I2C 0x48 - 0x4f
-    Datasheet: Publicly available at the Philips Semiconductor website
-               http://www.semiconductors.philips.com/pip/PCF8591P.html
+    Addresses scanned: none
+    Datasheet: Publicly available at the NXP website
+               http://www.nxp.com/pip/PCF8591_6.html
 
 Authors:
         Aurelien Jarno <aurelien@aurel32.net>
@@ -16,9 +16,10 @@ Authors:
 
 Description
 -----------
+
 The PCF8591 is an 8-bit A/D and D/A converter (4 analog inputs and one
-analog output) for the I2C bus produced by Philips Semiconductors. It
-is designed to provide a byte I2C interface to up to 4 separate devices.
+analog output) for the I2C bus produced by Philips Semiconductors (now NXP).
+It is designed to provide a byte I2C interface to up to 4 separate devices.
 
 The PCF8591 has 4 analog inputs programmable as single-ended or
 differential inputs :
@@ -57,29 +58,28 @@ 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 [48..4f] 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/devices/<0>-<1>/
-where <0> is the bus the chip was detected on (e. g. i2c-0)
+/sys/bus/i2c/devices/<0>-<1>/
+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:
-in0, in1, in2, in3, out0_enable, out0_output, name
+in0_input, in1_input, in2_input, in3_input, out0_enable, out0_output, name
 
 Name contains chip name.
 
-The in0, in1, in2 and in3 files are RO. Reading gives the value of the
-corresponding channel. Depending on the current analog inputs configuration,
-files in2 and/or in3 do not exist. Values range are from 0 to 255 for single
-ended inputs and -128 to +127 for differential inputs (8-bit ADC).
+The in0_input, in1_input, in2_input and in3_input files are RO. Reading gives
+the value of the corresponding channel. Depending on the current analog inputs
+configuration, files in2_input and in3_input may not exist. Values range
+from 0 to 255 for single ended inputs and -128 to +127 for differential inputs
+(8-bit ADC).
 
 The out0_enable file is RW. Reading gives "1" for analog output enabled and
 "0" for analog output disabled. Writing accepts "0" and "1" accordingly.