diff options
Diffstat (limited to 'Documentation/misc-devices')
| -rw-r--r-- | Documentation/misc-devices/ad525x_dpot.txt | 57 | ||||
| -rw-r--r-- | Documentation/misc-devices/c2port.txt | 90 | ||||
| -rw-r--r-- | Documentation/misc-devices/eeprom | 96 | ||||
| -rw-r--r-- | Documentation/misc-devices/ics932s401 | 31 | ||||
| -rw-r--r-- | Documentation/misc-devices/isl29003 | 62 | ||||
| -rw-r--r-- | Documentation/misc-devices/max6875 | 110 |
6 files changed, 446 insertions, 0 deletions
diff --git a/Documentation/misc-devices/ad525x_dpot.txt b/Documentation/misc-devices/ad525x_dpot.txt new file mode 100644 index 00000000000..0c9413b1cbf --- /dev/null +++ b/Documentation/misc-devices/ad525x_dpot.txt @@ -0,0 +1,57 @@ +--------------------------------- + AD525x Digital Potentiometers +--------------------------------- + +The ad525x_dpot driver exports a simple sysfs interface. This allows you to +work with the immediate resistance settings as well as update the saved startup +settings. Access to the factory programmed tolerance is also provided, but +interpretation of this settings is required by the end application according to +the specific part in use. + +--------- + Files +--------- + +Each dpot device will have a set of eeprom, rdac, and tolerance files. How +many depends on the actual part you have, as will the range of allowed values. + +The eeprom files are used to program the startup value of the device. + +The rdac files are used to program the immediate value of the device. + +The tolerance files are the read-only factory programmed tolerance settings +and may vary greatly on a part-by-part basis. For exact interpretation of +this field, please consult the datasheet for your part. This is presented +as a hex file for easier parsing. + +----------- + Example +----------- + +Locate the device in your sysfs tree. This is probably easiest by going into +the common i2c directory and locating the device by the i2c slave address. + + # ls /sys/bus/i2c/devices/ + 0-0022 0-0027 0-002f + +So assuming the device in question is on the first i2c bus and has the slave +address of 0x2f, we descend (unrelated sysfs entries have been trimmed). + + # ls /sys/bus/i2c/devices/0-002f/ + eeprom0 rdac0 tolerance0 + +You can use simple reads/writes to access these files: + + # cd /sys/bus/i2c/devices/0-002f/ + + # cat eeprom0 + 0 + # echo 10 > eeprom0 + # cat eeprom0 + 10 + + # cat rdac0 + 5 + # echo 3 > rdac0 + # cat rdac0 + 3 diff --git a/Documentation/misc-devices/c2port.txt b/Documentation/misc-devices/c2port.txt new file mode 100644 index 00000000000..d9bf93ea439 --- /dev/null +++ b/Documentation/misc-devices/c2port.txt @@ -0,0 +1,90 @@ + C2 port support + --------------- + +(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com> + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + + + +Overview +-------- + +This driver implements the support for Linux of Silicon Labs (Silabs) +C2 Interface used for in-system programming of micro controllers. + +By using this driver you can reprogram the in-system flash without EC2 +or EC3 debug adapter. This solution is also useful in those systems +where the micro controller is connected via special GPIOs pins. + +References +---------- + +The C2 Interface main references are at (http://www.silabs.com) +Silicon Laboratories site], see: + +- AN127: FLASH Programming via the C2 Interface at +http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and + +- C2 Specification at +http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf, + +however it implements a two wire serial communication protocol (bit +banging) designed to enable in-system programming, debugging, and +boundary-scan testing on low pin-count Silicon Labs devices. Currently +this code supports only flash programming but extensions are easy to +add. + +Using the driver +---------------- + +Once the driver is loaded you can use sysfs support to get C2port's +info or read/write in-system flash. + +# ls /sys/class/c2port/c2port0/ +access flash_block_size flash_erase rev_id +dev_id flash_blocks_num flash_size subsystem/ +flash_access flash_data reset uevent + +Initially the C2port access is disabled since you hardware may have +such lines multiplexed with other devices so, to get access to the +C2port, you need the command: + +# echo 1 > /sys/class/c2port/c2port0/access + +after that you should read the device ID and revision ID of the +connected micro controller: + +# cat /sys/class/c2port/c2port0/dev_id +8 +# cat /sys/class/c2port/c2port0/rev_id +1 + +However, for security reasons, the in-system flash access in not +enabled yet, to do so you need the command: + +# echo 1 > /sys/class/c2port/c2port0/flash_access + +After that you can read the whole flash: + +# cat /sys/class/c2port/c2port0/flash_data > image + +erase it: + +# echo 1 > /sys/class/c2port/c2port0/flash_erase + +and write it: + +# cat image > /sys/class/c2port/c2port0/flash_data + +after writing you have to reset the device to execute the new code: + +# echo 1 > /sys/class/c2port/c2port0/reset diff --git a/Documentation/misc-devices/eeprom b/Documentation/misc-devices/eeprom new file mode 100644 index 00000000000..f7e8104b576 --- /dev/null +++ b/Documentation/misc-devices/eeprom @@ -0,0 +1,96 @@ +Kernel driver eeprom +==================== + +Supported chips: + * Any EEPROM chip in the designated address range + Prefix: 'eeprom' + Addresses scanned: I2C 0x50 - 0x57 + Datasheets: Publicly available from: + Atmel (www.atmel.com), + Catalyst (www.catsemi.com), + Fairchild (www.fairchildsemi.com), + Microchip (www.microchip.com), + Philips (www.semiconductor.philips.com), + Rohm (www.rohm.com), + ST (www.st.com), + Xicor (www.xicor.com), + and others. + + Chip Size (bits) Address + 24C01 1K 0x50 (shadows at 0x51 - 0x57) + 24C01A 1K 0x50 - 0x57 (Typical device on DIMMs) + 24C02 2K 0x50 - 0x57 + 24C04 4K 0x50, 0x52, 0x54, 0x56 + (additional data at 0x51, 0x53, 0x55, 0x57) + 24C08 8K 0x50, 0x54 (additional data at 0x51, 0x52, + 0x53, 0x55, 0x56, 0x57) + 24C16 16K 0x50 (additional data at 0x51 - 0x57) + Sony 2K 0x57 + + Atmel 34C02B 2K 0x50 - 0x57, SW write protect at 0x30-37 + Catalyst 34FC02 2K 0x50 - 0x57, SW write protect at 0x30-37 + Catalyst 34RC02 2K 0x50 - 0x57, SW write protect at 0x30-37 + Fairchild 34W02 2K 0x50 - 0x57, SW write protect at 0x30-37 + Microchip 24AA52 2K 0x50 - 0x57, SW write protect at 0x30-37 + ST M34C02 2K 0x50 - 0x57, SW write protect at 0x30-37 + + +Authors: + Frodo Looijaard <frodol@dds.nl>, + Philip Edelbrock <phil@netroedge.com>, + Jean Delvare <khali@linux-fr.org>, + Greg Kroah-Hartman <greg@kroah.com>, + IBM Corp. + +Description +----------- + +This is a simple EEPROM module meant to enable reading the first 256 bytes +of an EEPROM (on a SDRAM DIMM for example). However, it will access serial +EEPROMs on any I2C adapter. The supported devices are generically called +24Cxx, and are listed above; however the numbering for these +industry-standard devices may vary by manufacturer. + +This module was a programming exercise to get used to the new project +organization laid out by Frodo, but it should be at least completely +effective for decoding the contents of EEPROMs on DIMMs. + +DIMMS will typically contain a 24C01A or 24C02, or the 34C02 variants. +The other devices will not be found on a DIMM because they respond to more +than one address. + +DDC Monitors may contain any device. Often a 24C01, which responds to all 8 +addresses, is found. + +Recent Sony Vaio laptops have an EEPROM at 0x57. We couldn't get the +specification, so it is guess work and far from being complete. + +The Microchip 24AA52/24LCS52, ST M34C02, and others support an additional +software write protect register at 0x30 - 0x37 (0x20 less than the memory +location). The chip responds to "write quick" detection at this address but +does not respond to byte reads. If this register is present, the lower 128 +bytes of the memory array are not write protected. Any byte data write to +this address will write protect the memory array permanently, and the +device will no longer respond at the 0x30-37 address. The eeprom driver +does not support this register. + +Lacking functionality: + +* Full support for larger devices (24C04, 24C08, 24C16). These are not +typically found on a PC. These devices will appear as separate devices at +multiple addresses. + +* Support for really large devices (24C32, 24C64, 24C128, 24C256, 24C512). +These devices require two-byte address fields and are not supported. + +* Enable Writing. Again, no technical reason why not, but making it easy +to change the contents of the EEPROMs (on DIMMs anyway) also makes it easy +to disable the DIMMs (potentially preventing the computer from booting) +until the values are restored somehow. + +Use: + +After inserting the module (and any other required SMBus/i2c modules), you +should have some EEPROM directories in /sys/bus/i2c/devices/* of names such +as "0-0050". Inside each of these is a series of files, the eeprom file +contains the binary data from EEPROM. diff --git a/Documentation/misc-devices/ics932s401 b/Documentation/misc-devices/ics932s401 new file mode 100644 index 00000000000..07a739f406d --- /dev/null +++ b/Documentation/misc-devices/ics932s401 @@ -0,0 +1,31 @@ +Kernel driver ics932s401 +====================== + +Supported chips: + * IDT ICS932S401 + Prefix: 'ics932s401' + Addresses scanned: I2C 0x69 + Datasheet: Publically available at the IDT website + +Author: Darrick J. Wong + +Description +----------- + +This driver implements support for the IDT ICS932S401 chip family. + +This chip has 4 clock outputs--a base clock for the CPU (which is likely +multiplied to get the real CPU clock), a system clock, a PCI clock, a USB +clock, and a reference clock. The driver reports selected and actual +frequency. If spread spectrum mode is enabled, the driver also reports by what +percent the clock signal is being spread, which should be between 0 and -0.5%. +All frequencies are reported in KHz. + +The ICS932S401 monitors all inputs continuously. The driver will not read +the registers more often than once every other second. + +Special Features +---------------- + +The clocks could be reprogrammed to increase system speed. I will not help you +do this, as you risk damaging your system! diff --git a/Documentation/misc-devices/isl29003 b/Documentation/misc-devices/isl29003 new file mode 100644 index 00000000000..c4ff5f38e01 --- /dev/null +++ b/Documentation/misc-devices/isl29003 @@ -0,0 +1,62 @@ +Kernel driver isl29003 +===================== + +Supported chips: +* Intersil ISL29003 +Prefix: 'isl29003' +Addresses scanned: none +Datasheet: +http://www.intersil.com/data/fn/fn7464.pdf + +Author: Daniel Mack <daniel@caiaq.de> + + +Description +----------- +The ISL29003 is an integrated light sensor with a 16-bit integrating type +ADC, I2C user programmable lux range select for optimized counts/lux, and +I2C multi-function control and monitoring capabilities. The internal ADC +provides 16-bit resolution while rejecting 50Hz and 60Hz flicker caused by +artificial light sources. + +The driver allows to set the lux range, the bit resolution, the operational +mode (see below) and the power state of device and can read the current lux +value, of course. + + +Detection +--------- + +The ISL29003 does not have an ID register which could be used to identify +it, so the detection routine will just try to read from the configured I2C +addess and consider the device to be present as soon as it ACKs the +transfer. + + +Sysfs entries +------------- + +range: + 0: 0 lux to 1000 lux (default) + 1: 0 lux to 4000 lux + 2: 0 lux to 16,000 lux + 3: 0 lux to 64,000 lux + +resolution: + 0: 2^16 cycles (default) + 1: 2^12 cycles + 2: 2^8 cycles + 3: 2^4 cycles + +mode: + 0: diode1's current (unsigned 16bit) (default) + 1: diode1's current (unsigned 16bit) + 2: difference between diodes (l1 - l2, signed 15bit) + +power_state: + 0: device is disabled (default) + 1: device is enabled + +lux (read only): + returns the value from the last sensor reading + diff --git a/Documentation/misc-devices/max6875 b/Documentation/misc-devices/max6875 new file mode 100644 index 00000000000..1e89ee3ccc1 --- /dev/null +++ b/Documentation/misc-devices/max6875 @@ -0,0 +1,110 @@ +Kernel driver max6875 +===================== + +Supported chips: + * Maxim MAX6874, MAX6875 + Prefix: 'max6875' + Addresses scanned: None (see below) + Datasheet: + http://pdfserv.maxim-ic.com/en/ds/MAX6874-MAX6875.pdf + +Author: Ben Gardner <bgardner@wabtec.com> + + +Description +----------- + +The Maxim MAX6875 is an EEPROM-programmable power-supply sequencer/supervisor. +It provides timed outputs that can be used as a watchdog, if properly wired. +It also provides 512 bytes of user EEPROM. + +At reset, the MAX6875 reads the configuration EEPROM into its configuration +registers. The chip then begins to operate according to the values in the +registers. + +The Maxim MAX6874 is a similar, mostly compatible device, with more intputs +and outputs: + vin gpi vout +MAX6874 6 4 8 +MAX6875 4 3 5 + +See the datasheet for more information. + + +Sysfs entries +------------- + +eeprom - 512 bytes of user-defined EEPROM space. + + +General Remarks +--------------- + +Valid addresses for the MAX6875 are 0x50 and 0x52. +Valid addresses for the MAX6874 are 0x50, 0x52, 0x54 and 0x56. +The driver does not probe any address, so you explicitly instantiate the +devices. + +Example: +$ modprobe max6875 +$ echo max6875 0x50 > /sys/bus/i2c/devices/i2c-0/new_device + +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 'dummy'. + + +Programming the chip using i2c-dev +---------------------------------- + +Use the i2c-dev interface to access and program the chips. +Reads and writes are performed differently depending on the address range. + +The configuration registers are at addresses 0x00 - 0x45. +Use i2c_smbus_write_byte_data() to write a register and +i2c_smbus_read_byte_data() to read a register. +The command is the register number. + +Examples: +To write a 1 to register 0x45: + i2c_smbus_write_byte_data(fd, 0x45, 1); + +To read register 0x45: + value = i2c_smbus_read_byte_data(fd, 0x45); + + +The configuration EEPROM is at addresses 0x8000 - 0x8045. +The user EEPROM is at addresses 0x8100 - 0x82ff. + +Use i2c_smbus_write_word_data() to write a byte to EEPROM. + +The command is the upper byte of the address: 0x80, 0x81, or 0x82. +The data word is the lower part of the address or'd with data << 8. + cmd = address >> 8; + val = (address & 0xff) | (data << 8); + +Example: +To write 0x5a to address 0x8003: + i2c_smbus_write_word_data(fd, 0x80, 0x5a03); + + +Reading data from the EEPROM is a little more complicated. +Use i2c_smbus_write_byte_data() to set the read address and then +i2c_smbus_read_byte() or i2c_smbus_read_i2c_block_data() to read the data. + +Example: +To read data starting at offset 0x8100, first set the address: + i2c_smbus_write_byte_data(fd, 0x81, 0x00); + +And then read the data + value = i2c_smbus_read_byte(fd); + + or + + count = i2c_smbus_read_i2c_block_data(fd, 0x84, 16, buffer); + +The block read should read 16 bytes. +0x84 is the block read command. + +See the datasheet for more details. + |