diff options
Diffstat (limited to 'Documentation/hwmon')
| -rw-r--r-- | Documentation/hwmon/pcf8591 | 28 | ||||
| -rw-r--r-- | Documentation/hwmon/tmp421 | 36 |
2 files changed, 51 insertions, 13 deletions
diff --git a/Documentation/hwmon/pcf8591 b/Documentation/hwmon/pcf8591 index 5628fcf..e76a789 100644 --- 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 + 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 : @@ -58,8 +59,8 @@ 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 +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. @@ -67,19 +68,20 @@ for your others chips. On detection (i.e. insmod, modprobe et al.), directories are being created for each detected PCF8591: -/sys/bus/devices/<0>-<1>/ +/sys/bus/i2c/devices/<0>-<1>/ where <0> is the bus the chip was detected on (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. diff --git a/Documentation/hwmon/tmp421 b/Documentation/hwmon/tmp421 new file mode 100644 index 0000000..0cf07f82 --- /dev/null +++ b/Documentation/hwmon/tmp421 @@ -0,0 +1,36 @@ +Kernel driver tmp421 +==================== + +Supported chips: + * Texas Instruments TMP421 + Prefix: 'tmp421' + Addresses scanned: I2C 0x2a, 0x4c, 0x4d, 0x4e and 0x4f + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp421.html + * Texas Instruments TMP422 + Prefix: 'tmp422' + Addresses scanned: I2C 0x2a, 0x4c, 0x4d, 0x4e and 0x4f + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp421.html + * Texas Instruments TMP423 + Prefix: 'tmp423' + Addresses scanned: I2C 0x2a, 0x4c, 0x4d, 0x4e and 0x4f + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp421.html + +Authors: + Andre Prendel <andre.prendel@gmx.de> + +Description +----------- + +This driver implements support for Texas Instruments TMP421, TMP422 +and TMP423 temperature sensor chips. These chips implement one local +and up to one (TMP421), up to two (TMP422) or up to three (TMP423) +remote sensors. Temperature is measured in degrees Celsius. The chips +are wired over I2C/SMBus and specified over a temperature range of -40 +to +125 degrees Celsius. Resolution for both the local and remote +channels is 0.0625 degree C. + +The chips support only temperature measurement. The driver exports +the temperature values via the following sysfs files: + +temp[1-4]_input +temp[2-4]_fault |
