diff options
Diffstat (limited to 'Documentation/misc-devices')
| -rw-r--r-- | Documentation/misc-devices/ad525x_dpot.txt | 57 | ||||
| -rw-r--r-- | Documentation/misc-devices/apds990x.txt | 111 | ||||
| -rw-r--r-- | Documentation/misc-devices/bh1770glc.txt | 116 | ||||
| -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/lis3lv02d | 92 | ||||
| -rw-r--r-- | Documentation/misc-devices/max6875 | 110 | ||||
| -rw-r--r-- | Documentation/misc-devices/spear-pcie-gadget.txt | 130 |
10 files changed, 895 insertions, 0 deletions
diff --git a/Documentation/misc-devices/ad525x_dpot.txt b/Documentation/misc-devices/ad525x_dpot.txt new file mode 100644 index 00000000..0c9413b1 --- /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/apds990x.txt b/Documentation/misc-devices/apds990x.txt new file mode 100644 index 00000000..d5408cad --- /dev/null +++ b/Documentation/misc-devices/apds990x.txt @@ -0,0 +1,111 @@ +Kernel driver apds990x +====================== + +Supported chips: +Avago APDS990X + +Data sheet: +Not freely available + +Author: +Samu Onkalo <samu.p.onkalo@nokia.com> + +Description +----------- + +APDS990x is a combined ambient light and proximity sensor. ALS and proximity +functionality are highly connected. ALS measurement path must be running +while the proximity functionality is enabled. + +ALS produces raw measurement values for two channels: Clear channel +(infrared + visible light) and IR only. However, threshold comparisons happen +using clear channel only. Lux value and the threshold level on the HW +might vary quite much depending the spectrum of the light source. + +Driver makes necessary conversions to both directions so that user handles +only lux values. Lux value is calculated using information from the both +channels. HW threshold level is calculated from the given lux value to match +with current type of the lightning. Sometimes inaccuracy of the estimations +lead to false interrupt, but that doesn't harm. + +ALS contains 4 different gain steps. Driver automatically +selects suitable gain step. After each measurement, reliability of the results +is estimated and new measurement is trigged if necessary. + +Platform data can provide tuned values to the conversion formulas if +values are known. Otherwise plain sensor default values are used. + +Proximity side is little bit simpler. There is no need for complex conversions. +It produces directly usable values. + +Driver controls chip operational state using pm_runtime framework. +Voltage regulators are controlled based on chip operational state. + +SYSFS +----- + + +chip_id + RO - shows detected chip type and version + +power_state + RW - enable / disable chip. Uses counting logic + 1 enables the chip + 0 disables the chip +lux0_input + RO - measured lux value + sysfs_notify called when threshold interrupt occurs + +lux0_sensor_range + RO - lux0_input max value. Actually never reaches since sensor tends + to saturate much before that. Real max value varies depending + on the light spectrum etc. + +lux0_rate + RW - measurement rate in Hz + +lux0_rate_avail + RO - supported measurement rates + +lux0_calibscale + RW - calibration value. Set to neutral value by default. + Output results are multiplied with calibscale / calibscale_default + value. + +lux0_calibscale_default + RO - neutral calibration value + +lux0_thresh_above_value + RW - HI level threshold value. All results above the value + trigs an interrupt. 65535 (i.e. sensor_range) disables the above + interrupt. + +lux0_thresh_below_value + RW - LO level threshold value. All results below the value + trigs an interrupt. 0 disables the below interrupt. + +prox0_raw + RO - measured proximity value + sysfs_notify called when threshold interrupt occurs + +prox0_sensor_range + RO - prox0_raw max value (1023) + +prox0_raw_en + RW - enable / disable proximity - uses counting logic + 1 enables the proximity + 0 disables the proximity + +prox0_reporting_mode + RW - trigger / periodic. In "trigger" mode the driver tells two possible + values: 0 or prox0_sensor_range value. 0 means no proximity, + 1023 means proximity. This causes minimal number of interrupts. + In "periodic" mode the driver reports all values above + prox0_thresh_above. This causes more interrupts, but it can give + _rough_ estimate about the distance. + +prox0_reporting_mode_avail + RO - accepted values to prox0_reporting_mode (trigger, periodic) + +prox0_thresh_above_value + RW - threshold level which trigs proximity events. diff --git a/Documentation/misc-devices/bh1770glc.txt b/Documentation/misc-devices/bh1770glc.txt new file mode 100644 index 00000000..7d64c014 --- /dev/null +++ b/Documentation/misc-devices/bh1770glc.txt @@ -0,0 +1,116 @@ +Kernel driver bh1770glc +======================= + +Supported chips: +ROHM BH1770GLC +OSRAM SFH7770 + +Data sheet: +Not freely available + +Author: +Samu Onkalo <samu.p.onkalo@nokia.com> + +Description +----------- +BH1770GLC and SFH7770 are combined ambient light and proximity sensors. +ALS and proximity parts operates on their own, but they shares common I2C +interface and interrupt logic. In principle they can run on their own, +but ALS side results are used to estimate reliability of the proximity sensor. + +ALS produces 16 bit lux values. The chip contains interrupt logic to produce +low and high threshold interrupts. + +Proximity part contains IR-led driver up to 3 IR leds. The chip measures +amount of reflected IR light and produces proximity result. Resolution is +8 bit. Driver supports only one channel. Driver uses ALS results to estimate +reliability of the proximity results. Thus ALS is always running while +proximity detection is needed. + +Driver uses threshold interrupts to avoid need for polling the values. +Proximity low interrupt doesn't exists in the chip. This is simulated +by using a delayed work. As long as there is proximity threshold above +interrupts the delayed work is pushed forward. So, when proximity level goes +below the threshold value, there is no interrupt and the delayed work will +finally run. This is handled as no proximity indication. + +Chip state is controlled via runtime pm framework when enabled in config. + +Calibscale factor is used to hide differences between the chips. By default +value set to neutral state meaning factor of 1.00. To get proper values, +calibrated source of light is needed as a reference. Calibscale factor is set +so that measurement produces about the expected lux value. + +SYSFS +----- + +chip_id + RO - shows detected chip type and version + +power_state + RW - enable / disable chip. Uses counting logic + 1 enables the chip + 0 disables the chip + +lux0_input + RO - measured lux value + sysfs_notify called when threshold interrupt occurs + +lux0_sensor_range + RO - lux0_input max value + +lux0_rate + RW - measurement rate in Hz + +lux0_rate_avail + RO - supported measurement rates + +lux0_thresh_above_value + RW - HI level threshold value. All results above the value + trigs an interrupt. 65535 (i.e. sensor_range) disables the above + interrupt. + +lux0_thresh_below_value + RW - LO level threshold value. All results below the value + trigs an interrupt. 0 disables the below interrupt. + +lux0_calibscale + RW - calibration value. Set to neutral value by default. + Output results are multiplied with calibscale / calibscale_default + value. + +lux0_calibscale_default + RO - neutral calibration value + +prox0_raw + RO - measured proximity value + sysfs_notify called when threshold interrupt occurs + +prox0_sensor_range + RO - prox0_raw max value + +prox0_raw_en + RW - enable / disable proximity - uses counting logic + 1 enables the proximity + 0 disables the proximity + +prox0_thresh_above_count + RW - number of proximity interrupts needed before triggering the event + +prox0_rate_above + RW - Measurement rate (in Hz) when the level is above threshold + i.e. when proximity on has been reported. + +prox0_rate_below + RW - Measurement rate (in Hz) when the level is below threshold + i.e. when proximity off has been reported. + +prox0_rate_avail + RO - Supported proximity measurement rates in Hz + +prox0_thresh_above0_value + RW - threshold level which trigs proximity events. + Filtered by persistence filter (prox0_thresh_above_count) + +prox0_thresh_above1_value + RW - threshold level which trigs event immediately diff --git a/Documentation/misc-devices/c2port.txt b/Documentation/misc-devices/c2port.txt new file mode 100644 index 00000000..ea734446 --- /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/Support Documents/TechnicalDocs/an127.pdf + +- C2 Specification at +http://www.silabs.com/pages/DownloadDoc.aspx?FILEURL=Support%20Documents/TechnicalDocs/an127.pdf&src=SearchResults + +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 00000000..f7e8104b --- /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 00000000..bdac67ff --- /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: Publicly 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 00000000..c4ff5f38 --- /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/lis3lv02d b/Documentation/misc-devices/lis3lv02d new file mode 100644 index 00000000..f1a4ec84 --- /dev/null +++ b/Documentation/misc-devices/lis3lv02d @@ -0,0 +1,92 @@ +Kernel driver lis3lv02d +======================= + +Supported chips: + + * STMicroelectronics LIS3LV02DL, LIS3LV02DQ (12 bits precision) + * STMicroelectronics LIS302DL, LIS3L02DQ, LIS331DL (8 bits) + +Authors: + Yan Burman <burman.yan@gmail.com> + Eric Piel <eric.piel@tremplin-utc.net> + + +Description +----------- + +This driver provides support for the accelerometer found in various HP laptops +sporting the feature officially called "HP Mobile Data Protection System 3D" or +"HP 3D DriveGuard". It detects automatically laptops with this sensor. Known +models (full list can be found in drivers/platform/x86/hp_accel.c) will have +their axis automatically oriented on standard way (eg: you can directly play +neverball). The accelerometer data is readable via +/sys/devices/platform/lis3lv02d. Reported values are scaled +to mg values (1/1000th of earth gravity). + +Sysfs attributes under /sys/devices/platform/lis3lv02d/: +position - 3D position that the accelerometer reports. Format: "(x,y,z)" +rate - read reports the sampling rate of the accelerometer device in HZ. + write changes sampling rate of the accelerometer device. + Only values which are supported by HW are accepted. +selftest - performs selftest for the chip as specified by chip manufacturer. + +This driver also provides an absolute input class device, allowing +the laptop to act as a pinball machine-esque joystick. Joystick device can be +calibrated. Joystick device can be in two different modes. +By default output values are scaled between -32768 .. 32767. In joystick raw +mode, joystick and sysfs position entry have the same scale. There can be +small difference due to input system fuzziness feature. +Events are also available as input event device. + +Selftest is meant only for hardware diagnostic purposes. It is not meant to be +used during normal operations. Position data is not corrupted during selftest +but interrupt behaviour is not guaranteed to work reliably. In test mode, the +sensing element is internally moved little bit. Selftest measures difference +between normal mode and test mode. Chip specifications tell the acceptance +limit for each type of the chip. Limits are provided via platform data +to allow adjustment of the limits without a change to the actual driver. +Seltest returns either "OK x y z" or "FAIL x y z" where x, y and z are +measured difference between modes. Axes are not remapped in selftest mode. +Measurement values are provided to help HW diagnostic applications to make +final decision. + +On HP laptops, if the led infrastructure is activated, support for a led +indicating disk protection will be provided as /sys/class/leds/hp::hddprotect. + +Another feature of the driver is misc device called "freefall" that +acts similar to /dev/rtc and reacts on free-fall interrupts received +from the device. It supports blocking operations, poll/select and +fasync operation modes. You must read 1 bytes from the device. The +result is number of free-fall interrupts since the last successful +read (or 255 if number of interrupts would not fit). See the hpfall.c +file for an example on using the device. + + +Axes orientation +---------------- + +For better compatibility between the various laptops. The values reported by +the accelerometer are converted into a "standard" organisation of the axes +(aka "can play neverball out of the box"): + * When the laptop is horizontal the position reported is about 0 for X and Y + and a positive value for Z + * If the left side is elevated, X increases (becomes positive) + * If the front side (where the touchpad is) is elevated, Y decreases + (becomes negative) + * If the laptop is put upside-down, Z becomes negative + +If your laptop model is not recognized (cf "dmesg"), you can send an +email to the maintainer to add it to the database. When reporting a new +laptop, please include the output of "dmidecode" plus the value of +/sys/devices/platform/lis3lv02d/position in these four cases. + +Q&A +--- + +Q: How do I safely simulate freefall? I have an HP "portable +workstation" which has about 3.5kg and a plastic case, so letting it +fall to the ground is out of question... + +A: The sensor is pretty sensitive, so your hands can do it. Lift it +into free space, follow the fall with your hands for like 10 +centimeters. That should be enough to trigger the detection. diff --git a/Documentation/misc-devices/max6875 b/Documentation/misc-devices/max6875 new file mode 100644 index 00000000..1e89ee3c --- /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. + diff --git a/Documentation/misc-devices/spear-pcie-gadget.txt b/Documentation/misc-devices/spear-pcie-gadget.txt new file mode 100644 index 00000000..02c13ef5 --- /dev/null +++ b/Documentation/misc-devices/spear-pcie-gadget.txt @@ -0,0 +1,130 @@ +Spear PCIe Gadget Driver: + +Author +============= +Pratyush Anand (pratyush.anand@st.com) + +Location +============ +driver/misc/spear13xx_pcie_gadget.c + +Supported Chip: +=================== +SPEAr1300 +SPEAr1310 + +Menuconfig option: +========================== +Device Drivers + Misc devices + PCIe gadget support for SPEAr13XX platform +purpose +=========== +This driver has several nodes which can be read/written by configfs interface. +Its main purpose is to configure selected dual mode PCIe controller as device +and then program its various registers to configure it as a particular device +type. This driver can be used to show spear's PCIe device capability. + +Description of different nodes: +================================= + +read behavior of nodes: +------------------------------ +link :gives ltssm status. +int_type :type of supported interrupt +no_of_msi :zero if MSI is not enabled by host. A positive value is the + number of MSI vector granted. +vendor_id :returns programmed vendor id (hex) +device_id :returns programmed device id(hex) +bar0_size: :returns size of bar0 in hex. +bar0_address :returns address of bar0 mapped area in hex. +bar0_rw_offset :returns offset of bar0 for which bar0_data will return value. +bar0_data :returns data at bar0_rw_offset. + +write behavior of nodes: +------------------------------ +link :write UP to enable ltsmm DOWN to disable +int_type :write interrupt type to be configured and (int_type could be + INTA, MSI or NO_INT). Select MSI only when you have programmed + no_of_msi node. +no_of_msi :number of MSI vector needed. +inta :write 1 to assert INTA and 0 to de-assert. +send_msi :write MSI vector to be sent. +vendor_id :write vendor id(hex) to be programmed. +device_id :write device id(hex) to be programmed. +bar0_size :write size of bar0 in hex. default bar0 size is 1000 (hex) + bytes. +bar0_address :write address of bar0 mapped area in hex. (default mapping of + bar0 is SYSRAM1(E0800000). Always program bar size before bar + address. Kernel might modify bar size and address for alignment, so + read back bar size and address after writing to cross check. +bar0_rw_offset :write offset of bar0 for which bar0_data will write value. +bar0_data :write data to be written at bar0_rw_offset. + +Node programming example +=========================== +Program all PCIe registers in such a way that when this device is connected +to the PCIe host, then host sees this device as 1MB RAM. +#mount -t configfs none /Config +For nth PCIe Device Controller +# cd /config/pcie_gadget.n/ +Now you have all the nodes in this directory. +program vendor id as 0x104a +# echo 104A >> vendor_id + +program device id as 0xCD80 +# echo CD80 >> device_id + +program BAR0 size as 1MB +# echo 100000 >> bar0_size + +check for programmed bar0 size +# cat bar0_size + +Program BAR0 Address as DDR (0x2100000). This is the physical address of +memory, which is to be made visible to PCIe host. Similarly any other peripheral +can also be made visible to PCIe host. E.g., if you program base address of UART +as BAR0 address then when this device will be connected to a host, it will be +visible as UART. +# echo 2100000 >> bar0_address + +program interrupt type : INTA +# echo INTA >> int_type + +go for link up now. +# echo UP >> link + +It will have to be insured that, once link up is done on gadget, then only host +is initialized and start to search PCIe devices on its port. + +/*wait till link is up*/ +# cat link +wait till it returns UP. + +To assert INTA +# echo 1 >> inta + +To de-assert INTA +# echo 0 >> inta + +if MSI is to be used as interrupt, program no of msi vector needed (say4) +# echo 4 >> no_of_msi + +select MSI as interrupt type +# echo MSI >> int_type + +go for link up now +# echo UP >> link + +wait till link is up +# cat link +An application can repetitively read this node till link is found UP. It can +sleep between two read. + +wait till msi is enabled +# cat no_of_msi +Should return 4 (number of requested MSI vector) + +to send msi vector 2 +# echo 2 >> send_msi +#cd - |