[PATCH] I2C: documentation update 2/3

This patch adds missing documentation for system health monitoring chips.
I would like to thank all people, who helped me with this project.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

31 files changed, 2849 insertions, 5 deletions

diff --git a/Documentation/i2c/chips/adm1021 b/Documentation/i2c/chips/adm1021
new file mode 100644
index 00000000000..03d02bfb3df
--- /dev/null
+++ b/Documentation/i2c/chips/adm1021
@@ -0,0 +1,111 @@
+Kernel driver adm1021
+=====================
+
+Supported chips:
+  * Analog Devices ADM1021
+    Prefix: 'adm1021'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Analog Devices website
+  * Analog Devices ADM1021A/ADM1023
+    Prefix: 'adm1023'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Analog Devices website
+  * Genesys Logic GL523SM
+    Prefix: 'gl523sm'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet:
+  * Intel Xeon Processor
+    Prefix: - any other - may require 'force_adm1021' parameter
+    Addresses scanned: none
+    Datasheet: Publicly available at Intel website
+  * Maxim MAX1617
+    Prefix: 'max1617'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Maxim website
+  * Maxim MAX1617A
+    Prefix: 'max1617a'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Maxim website
+  * National Semiconductor LM84
+    Prefix: 'lm84'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the National Semiconductor website
+  * Philips NE1617
+    Prefix: 'max1617' (probably detected as a max1617)
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Philips website
+  * Philips NE1617A
+    Prefix: 'max1617' (probably detected as a max1617)
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Philips website
+  * TI THMC10
+    Prefix: 'thmc10'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the TI website
+  * Onsemi MC1066
+    Prefix: 'mc1066'
+    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
+    Datasheet: Publicly available at the Onsemi website
+
+
+Authors:
+        Frodo Looijaard <frodol@dds.nl>,
+        Philip Edelbrock <phil@netroedge.com>
+
+Module Parameters
+-----------------
+
+* read_only: int
+  Don't set any values, read only mode
+
+
+Description
+-----------
+
+The chips supported by this driver are very similar. The Maxim MAX1617 is
+the oldest; it has the problem that it is not very well detectable. The
+MAX1617A solves that. The ADM1021 is a straight clone of the MAX1617A.
+Ditto for the THMC10. From here on, we will refer to all these chips as
+ADM1021-clones.
+
+The ADM1021 and MAX1617A reports a die code, which is a sort of revision
+code. This can help us pinpoint problems; it is not very useful
+otherwise.
+
+ADM1021-clones implement two temperature sensors. One of them is internal,
+and measures the temperature of the chip itself; the other is external and
+is realised in the form of a transistor-like device. A special alarm
+indicates whether the remote sensor is connected.
+
+Each sensor has its own low and high limits. When they are crossed, the
+corresponding alarm is set and remains on as long as the temperature stays
+out of range. Temperatures are measured in degrees Celsius. Measurements
+are possible between -65 and +127 degrees, with a resolution of one degree.
+
+If an alarm triggers, it will remain triggered until the hardware register
+is read at least once. This means that the cause for the alarm may already
+have disappeared!
+
+This driver only updates its values each 1.5 seconds; reading it more often
+will do no harm, but will return 'old' values. It is possible to make
+ADM1021-clones do faster measurements, but there is really no good reason
+for that.
+
+Xeon support
+------------
+
+Some Xeon processors have real max1617, adm1021, or compatible chips
+within them, with two temperature sensors.
+
+Other Xeons have chips with only one sensor.
+
+If you have a Xeon, and the adm1021 module loads, and both temperatures
+appear valid, then things are good.
+
+If the adm1021 module doesn't load, you should try this:
+	modprobe adm1021 force_adm1021=BUS,ADDRESS
+	ADDRESS can only be 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e.
+
+If you have dual Xeons you may have appear to have two separate
+adm1021-compatible chips, or two single-temperature sensors, at distinct
+addresses.
diff --git a/Documentation/i2c/chips/adm1025 b/Documentation/i2c/chips/adm1025
new file mode 100644
index 00000000000..39d2b781b5d
--- /dev/null
+++ b/Documentation/i2c/chips/adm1025
@@ -0,0 +1,51 @@
+Kernel driver adm1025
+=====================
+
+Supported chips:
+  * Analog Devices ADM1025, ADM1025A
+    Prefix: 'adm1025'
+    Addresses scanned: I2C 0x2c - 0x2e
+    Datasheet: Publicly available at the Analog Devices website
+  * Philips NE1619
+    Prefix: 'ne1619'
+    Addresses scanned: I2C 0x2c - 0x2d
+    Datasheet: Publicly available at the Philips website
+
+The NE1619 presents some differences with the original ADM1025:
+  * Only two possible addresses (0x2c - 0x2d).
+  * No temperature offset register, but we don't use it anyway.
+  * No INT mode for pin 16. We don't play with it anyway.
+
+Authors:
+        Chen-Yuan Wu <gwu@esoft.com>,
+        Jean Delvare <khali@linux-fr.org>
+
+Description
+-----------
+
+(This is from Analog Devices.) The ADM1025 is a complete system hardware
+monitor for microprocessor-based systems, providing measurement and limit
+comparison of various system parameters. Five voltage measurement inputs
+are provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and
+the processor core voltage. The ADM1025 can monitor a sixth power-supply
+voltage by measuring its own VCC. One input (two pins) is dedicated to a
+remote temperature-sensing diode and an on-chip temperature sensor allows
+ambient temperature to be monitored.
+
+One specificity of this chip is that the pin 11 can be hardwired in two
+different manners. It can act as the +12V power-supply voltage analog
+input, or as the a fifth digital entry for the VID reading (bit 4). It's
+kind of strange since both are useful, and the reason for designing the
+chip that way is obscure at least to me. The bit 5 of the configuration
+register can be used to define how the chip is hardwired. Please note that
+it is not a choice you have to make as the user. The choice was already
+made by your motherboard's maker. If the configuration bit isn't set
+properly, you'll have a wrong +12V reading or a wrong VID reading. The way
+the driver handles that is to preserve this bit through the initialization
+process, assuming that the BIOS set it up properly beforehand. If it turns
+out not to be true in some cases, we'll provide a module parameter to force
+modes.
+
+This driver also supports the ADM1025A, which differs from the ADM1025
+only in that it has "open-drain VID inputs while the ADM1025 has on-chip
+100k pull-ups on the VID inputs". It doesn't make any difference for us.
diff --git a/Documentation/i2c/chips/adm1026 b/Documentation/i2c/chips/adm1026
new file mode 100644
index 00000000000..473c689d792
--- /dev/null
+++ b/Documentation/i2c/chips/adm1026
@@ -0,0 +1,93 @@
+Kernel driver adm1026
+=====================
+
+Supported chips:
+  * Analog Devices ADM1026
+    Prefix: 'adm1026'
+    Addresses scanned: I2C 0x2c, 0x2d, 0x2e
+    Datasheet: Publicly available at the Analog Devices website
+               http://www.analog.com/en/prod/0,,766_825_ADM1026,00.html
+
+Authors:
+        Philip Pokorny <ppokorny@penguincomputing.com> for Penguin Computing
+        Justin Thiessen <jthiessen@penguincomputing.com>
+
+Module Parameters
+-----------------
+
+* gpio_input: int array (min = 1, max = 17)
+  List of GPIO pins (0-16) to program as inputs
+* gpio_output: int array (min = 1, max = 17)
+  List of GPIO pins (0-16) to program as outputs
+* gpio_inverted: int array (min = 1, max = 17)
+  List of GPIO pins (0-16) to program as inverted
+* gpio_normal: int array (min = 1, max = 17)
+  List of GPIO pins (0-16) to program as normal/non-inverted
+* gpio_fan: int array (min = 1, max = 8)
+  List of GPIO pins (0-7) to program as fan tachs
+
+
+Description
+-----------
+
+This driver implements support for the Analog Devices ADM1026. Analog
+Devices calls it a "complete thermal system management controller."
+
+The ADM1026 implements three (3) temperature sensors, 17 voltage sensors,
+16 general purpose digital I/O lines, eight (8) fan speed sensors (8-bit),
+an analog output and a PWM output along with limit, alarm and mask bits for
+all of the above. There is even 8k bytes of EEPROM memory on chip.
+
+Temperatures are measured in degrees Celsius. There are two external
+sensor inputs and one internal sensor. Each sensor has a high and low
+limit. If the limit is exceeded, an interrupt (#SMBALERT) can be
+generated. The interrupts can be masked. In addition, there are over-temp
+limits for each sensor. If this limit is exceeded, the #THERM output will
+be asserted. The current temperature and limits have a resolution of 1
+degree.
+
+Fan rotation speeds are reported in RPM (rotations per minute) but measured
+in counts of a 22.5kHz internal clock. Each fan has a high limit which
+corresponds to a minimum fan speed. If the limit is exceeded, an interrupt
+can be generated. Each fan can be programmed to divide the reference clock
+by 1, 2, 4 or 8. Not all RPM values can accurately be represented, so some
+rounding is done. With a divider of 8, the slowest measurable speed of a
+two pulse per revolution fan is 661 RPM.
+
+There are 17 voltage sensors. An alarm is triggered if the voltage has
+crossed a programmable minimum or maximum limit. Note that minimum in this
+case always means 'closest to zero'; this is important for negative voltage
+measurements. Several inputs have integrated attenuators so they can measure
+higher voltages directly. 3.3V, 5V, 12V, -12V and battery voltage all have
+dedicated inputs. There are several inputs scaled to 0-3V full-scale range
+for SCSI terminator power. The remaining inputs are not scaled and have
+a 0-2.5V full-scale range. A 2.5V or 1.82V reference voltage is provided
+for negative voltage measurements.
+
+If an alarm triggers, it will remain triggered until the hardware register
+is read at least once. This means that the cause for the alarm may already
+have disappeared! Note that in the current implementation, all hardware
+registers are read whenever any data is read (unless it is less than 2.0
+seconds since the last update). This means that you can easily miss
+once-only alarms.
+
+The ADM1026 measures continuously. Analog inputs are measured about 4
+times a second. Fan speed measurement time depends on fan speed and
+divisor. It can take as long as 1.5 seconds to measure all fan speeds.
+
+The ADM1026 has the ability to automatically control fan speed based on the
+temperature sensor inputs. Both the PWM output and the DAC output can be
+used to control fan speed. Usually only one of these two outputs will be
+used. Write the minimum PWM or DAC value to the appropriate control
+register. Then set the low temperature limit in the tmin values for each
+temperature sensor. The range of control is fixed at 20 °C, and the
+largest difference between current and tmin of the temperature sensors sets
+the control output. See the datasheet for several example circuits for
+controlling fan speed with the PWM and DAC outputs. The fan speed sensors
+do not have PWM compensation, so it is probably best to control the fan
+voltage from the power lead rather than on the ground lead.
+
+The datasheet shows an example application with VID signals attached to
+GPIO lines. Unfortunately, the chip may not be connected to the VID lines
+in this way. The driver assumes that the chips *is* connected this way to
+get a VID voltage.
diff --git a/Documentation/i2c/chips/adm1031 b/Documentation/i2c/chips/adm1031
new file mode 100644
index 00000000000..130a38382b9
--- /dev/null
+++ b/Documentation/i2c/chips/adm1031
@@ -0,0 +1,35 @@
+Kernel driver adm1031
+=====================
+
+Supported chips:
+  * Analog Devices ADM1030
+    Prefix: 'adm1030'
+    Addresses scanned: I2C 0x2c to 0x2e
+    Datasheet: Publicly available at the Analog Devices website
+               http://products.analog.com/products/info.asp?product=ADM1030
+
+  * Analog Devices ADM1031
+    Prefix: 'adm1031'
+    Addresses scanned: I2C 0x2c to 0x2e
+    Datasheet: Publicly available at the Analog Devices website
+               http://products.analog.com/products/info.asp?product=ADM1031
+
+Authors:
+        Alexandre d'Alton <alex@alexdalton.org>
+        Jean Delvare <khali@linux-fr.org>
+
+Description
+-----------
+
+The ADM1030 and ADM1031 are digital temperature sensors and fan controllers.
+They sense their own temperature as well as the temperature of up to one
+(ADM1030) or two (ADM1031) external diodes.
+
+All temperature values are given in degrees Celsius. Resolution is 0.5
+degree for the local temperature, 0.125 degree for the remote temperatures.
+
+Each temperature channel has its own high and low limits, plus a critical
+limit.
+
+The ADM1030 monitors a single fan speed, while the ADM1031 monitors up to
+two. Each fan channel has its own low speed limit.
diff --git a/Documentation/i2c/chips/asb100 b/Documentation/i2c/chips/asb100
new file mode 100644
index 00000000000..ab7365e139b
--- /dev/null
+++ b/Documentation/i2c/chips/asb100
@@ -0,0 +1,72 @@
+Kernel driver asb100
+====================
+
+Supported Chips:
+  * Asus ASB100 and ASB100-A "Bach"
+    Prefix: 'asb100'
+    Addresses scanned: I2C 0x2d
+    Datasheet: none released
+
+Author: Mark M. Hoffman <mhoffman@lightlink.com>
+
+Description
+-----------
+
+This driver implements support for the Asus ASB100 and ASB100-A "Bach".
+These are custom ASICs available only on Asus mainboards. Asus refuses to
+supply a datasheet for these chips. Thanks go to many people who helped
+investigate their hardware, including:
+
+Vitaly V. Bursov
+Alexander van Kaam (author of MBM for Windows)
+Bertrik Sikken
+
+The ASB100 implements seven voltage sensors, three fan rotation speed
+sensors, four temperature sensors, VID lines and alarms. In addition to
+these, the ASB100-A also implements a single PWM controller for fans 2 and
+3 (i.e. one setting controls both.) If you have a plain ASB100, the PWM
+controller will simply not work (or maybe it will for you... it doesn't for
+me).
+
+Temperatures are measured and reported in degrees Celsius.
+
+Fan speeds are reported in RPM (rotations per minute). An alarm is
+triggered if the rotation speed has dropped below a programmable limit.
+
+Voltage sensors (also known as IN sensors) report values in volts.
+
+The VID lines encode the core voltage value: the voltage level your
+processor should work with. This is hardcoded by the mainboard and/or
+processor itself. It is a value in volts.
+
+Alarms: (TODO question marks indicate may or may not work)
+
+0x0001 => in0 (?)
+0x0002 => in1 (?)
+0x0004 => in2
+0x0008 => in3
+0x0010 => temp1 (1)
+0x0020 => temp2
+0x0040 => fan1
+0x0080 => fan2
+0x0100 => in4
+0x0200 => in5 (?) (2)
+0x0400 => in6 (?) (2)
+0x0800 => fan3
+0x1000 => chassis switch
+0x2000 => temp3
+
+Alarm Notes:
+
+(1) This alarm will only trigger if the hysteresis value is 127C.
+I.e. it behaves the same as w83781d.
+
+(2) The min and max registers for these values appear to
+be read-only or otherwise stuck at 0x00.
+
+TODO:
+* Experiment with fan divisors > 8.
+* Experiment with temp. sensor types.
+* Are there really 13 voltage inputs? Probably not...
+* Cleanups, no doubt...
+
diff --git a/Documentation/i2c/chips/ds1621 b/Documentation/i2c/chips/ds1621
new file mode 100644
index 00000000000..1fee6f1e6bc
--- /dev/null
+++ b/Documentation/i2c/chips/ds1621
@@ -0,0 +1,108 @@
+Kernel driver ds1621
+====================
+
+Supported chips:
+  * Dallas Semiconductor DS1621
+    Prefix: 'ds1621'
+    Addresses scanned: I2C 0x48 - 0x4f
+    Datasheet: Publicly available at the Dallas Semiconductor website
+               http://www.dalsemi.com/
+  * Dallas Semiconductor DS1625
+    Prefix: 'ds1621'
+    Addresses scanned: I2C 0x48 - 0x4f
+    Datasheet: Publicly available at the Dallas Semiconductor website
+               http://www.dalsemi.com/
+
+Authors:
+        Christian W. Zuckschwerdt <zany@triq.net>
+        valuable contributions by Jan M. Sendler <sendler@sendler.de>
+        ported to 2.6 by Aurelien Jarno <aurelien@aurel32.net>
+        with the help of Jean Delvare <khali@linux-fr.org>
+
+Module Parameters
+------------------
+
+* polarity int
+  Output's polarity: 0 = active high, 1 = active low
+
+Description
+-----------
+
+The DS1621 is a (one instance) digital thermometer and thermostat. It has
+both high and low temperature limits which can be user defined (i.e.
+programmed into non-volatile on-chip registers). Temperature range is -55
+degree Celsius to +125 in 0.5 increments. You may convert this into a
+Fahrenheit range of -67 to +257 degrees with 0.9 steps. If polarity
+parameter is not provided, original value is used.
+
+As for the thermostat, behavior can also be programmed using the polarity
+toggle. On the one hand ("heater"), the thermostat output of the chip,
+Tout, will trigger when the low limit temperature is met or underrun and
+stays high until the high limit is met or exceeded. On the other hand
+("cooler"), vice versa. That way "heater" equals "active low", whereas
+"conditioner" equals "active high". Please note that the DS1621 data sheet
+is somewhat misleading in this point since setting the polarity bit does
+not simply invert Tout.
+
+A second thing is that, during extensive testing, Tout showed a tolerance
+of up to +/- 0.5 degrees even when compared against precise temperature
+readings. Be sure to have a high vs. low temperature limit gap of al least
+1.0 degree Celsius to avoid Tout "bouncing", though!
+
+As for alarms, you can read the alarm status of the DS1621 via the 'alarms'
+/sys file interface. The result consists mainly of bit 6 and 5 of the
+configuration register of the chip; bit 6 (0x40 or 64) is the high alarm
+bit and bit 5 (0x20 or 32) the low one. These bits are set when the high or
+low limits are met or exceeded and are reset by the module as soon as the
+respective temperature ranges are left.
+
+The alarm registers are in no way suitable to find out about the actual
+status of Tout. They will only tell you about its history, whether or not
+any of the limits have ever been met or exceeded since last power-up or
+reset. Be aware: When testing, it showed that the status of Tout can change
+with neither of the alarms set.
+
+Temperature conversion of the DS1621 takes up to 1000ms; internal access to
+non-volatile registers may last for 10ms or below.
+
+High Accuracy Temperature Reading
+---------------------------------
+
+As said before, the temperature issued via the 9-bit i2c-bus data is
+somewhat arbitrary. Internally, the temperature conversion is of a
+different kind that is explained (not so...) well in the DS1621 data sheet.
+To cut the long story short: Inside the DS1621 there are two oscillators,
+both of them biassed by a temperature coefficient.
+
+Higher resolution of the temperature reading can be achieved using the
+internal projection, which means taking account of REG_COUNT and REG_SLOPE
+(the driver manages them):
+
+Taken from Dallas Semiconductors App Note 068: 'Increasing Temperature
+Resolution on the DS1620' and App Note 105: 'High Resolution Temperature
+Measurement with Dallas Direct-to-Digital Temperature Sensors'
+
+- Read the 9-bit temperature and strip the LSB (Truncate the .5 degs)
+- The resulting value is TEMP_READ.
+- Then, read REG_COUNT.
+- And then, REG_SLOPE.
+
+      TEMP = TEMP_READ - 0.25 + ((REG_SLOPE - REG_COUNT) / REG_SLOPE)
+
+Note that this is what the DONE bit in the DS1621 configuration register is
+good for: Internally, one temperature conversion takes up to 1000ms. Before
+that conversion is complete you will not be able to read valid things out
+of REG_COUNT and REG_SLOPE. The DONE bit, as you may have guessed by now,
+tells you whether the conversion is complete ("done", in plain English) and
+thus, whether the values you read are good or not.
+
+The DS1621 has two modes of operation: "Continuous" conversion, which can
+be understood as the default stand-alone mode where the chip gets the
+temperature and controls external devices via its Tout pin or tells other
+i2c's about it if they care. The other mode is called "1SHOT", that means
+that it only figures out about the temperature when it is explicitly told
+to do so; this can be seen as power saving mode.
+
+Now if you want to read REG_COUNT and REG_SLOPE, you have to either stop
+the continuous conversions until the contents of these registers are valid,
+or, in 1SHOT mode, you have to have one conversion made.
diff --git a/Documentation/i2c/chips/eeprom b/Documentation/i2c/chips/eeprom
new file mode 100644
index 00000000000..f7e8104b576
--- /dev/null
+++ b/Documentation/i2c/chips/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/i2c/chips/fscher b/Documentation/i2c/chips/fscher
new file mode 100644
index 00000000000..64031659aff
--- /dev/null
+++ b/Documentation/i2c/chips/fscher
@@ -0,0 +1,169 @@
+Kernel driver fscher
+====================
+
+Supported chips:
+  * Fujitsu-Siemens Hermes chip
+    Prefix: 'fscher'
+    Addresses scanned: I2C 0x73
+
+Authors:
+        Reinhard Nissl <rnissl@gmx.de> based on work
+        from Hermann Jung <hej@odn.de>,
+        Frodo Looijaard <frodol@dds.nl>,
+        Philip Edelbrock <phil@netroedge.com>
+
+Description
+-----------
+
+This driver implements support for the Fujitsu-Siemens Hermes chip. It is
+described in the 'Register Set Specification BMC Hermes based Systemboard'
+from Fujitsu-Siemens.
+
+The Hermes chip implements a hardware-based system management, e.g. for
+controlling fan speed and core voltage. There is also a watchdog counter on
+the chip which can trigger an alarm and even shut the system down.
+
+The chip provides three temperature values (CPU, motherboard and
+auxiliary), three voltage values (+12V, +5V and battery) and three fans
+(power supply, CPU and auxiliary).
+
+Temperatures are measured in degrees Celsius. The resolution is 1 degree.
+
+Fan rotation speeds are reported in RPM (rotations per minute). The value
+can be divided by a programmable divider (1, 2 or 4) which is stored on
+the chip.
+
+Voltage sensors (also known as "in" sensors) report their values in volts.
+
+All values are reported as final values from the driver. There is no need
+for further calculations.
+
+
+Detailed description
+--------------------
+
+Below you'll find a single line description of all the bit values. With
+this information, you're able to decode e. g. alarms, wdog, etc. To make
+use of the watchdog, you'll need to set the watchdog time and enable the
+watchdog. After that it is necessary to restart the watchdog time within
+the specified period of time, or a system reset will occur.
+
+* revision
+  READING & 0xff = 0x??: HERMES revision identification
+
+* alarms
+  READING & 0x80 = 0x80: CPU throttling active
+  READING & 0x80 = 0x00: CPU running at full speed
+
+  READING & 0x10 = 0x10: software event (see control:1)
+  READING & 0x10 = 0x00: no software event
+
+  READING & 0x08 = 0x08: watchdog event (see wdog:2)
+  READING & 0x08 = 0x00: no watchdog event
+
+  READING & 0x02 = 0x02: thermal event (see temp*:1)
+  READING & 0x02 = 0x00: no thermal event
+
+  READING & 0x01 = 0x01: fan event (see fan*:1)
+  READING & 0x01 = 0x00: no fan event
+
+  READING & 0x13 ! 0x00: ALERT LED is flashing
+
+* control
+  READING & 0x01 = 0x01: software event
+  READING & 0x01 = 0x00: no software event
+
+  WRITING & 0x01 = 0x01: set software event
+  WRITING & 0x01 = 0x00: clear software event
+
+* watchdog_control
+  READING & 0x80 = 0x80: power off on watchdog event while thermal event
+  READING & 0x80 = 0x00: watchdog power off disabled (just system reset enabled)
+
+  READING & 0x40 = 0x40: watchdog timebase 60 seconds (see also wdog:1)
+  READING & 0x40 = 0x00: watchdog timebase  2 seconds
+
+  READING & 0x10 = 0x10: watchdog enabled
+  READING & 0x10 = 0x00: watchdog disabled
+
+  WRITING & 0x80 = 0x80: enable "power off on watchdog event while thermal event"
+  WRITING & 0x80 = 0x00: disable "power off on watchdog event while thermal event"
+
+  WRITING & 0x40 = 0x40: set watchdog timebase to 60 seconds
+  WRITING & 0x40 = 0x00: set watchdog timebase to  2 seconds
+
+  WRITING & 0x20 = 0x20: disable watchdog
+
+  WRITING & 0x10 = 0x10: enable watchdog / restart watchdog time
+
+* watchdog_state
+  READING & 0x02 = 0x02: watchdog system reset occurred
+  READING & 0x02 = 0x00: no watchdog system reset occurred
+
+  WRITING & 0x02 = 0x02: clear watchdog event
+
+* watchdog_preset
+  READING & 0xff = 0x??: configured watch dog time in units (see wdog:3 0x40)
+
+  WRITING & 0xff = 0x??: configure watch dog time in units