diff options
Diffstat (limited to 'Documentation/i2c/chips/adm9240')
| -rw-r--r-- | Documentation/i2c/chips/adm9240 | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/Documentation/i2c/chips/adm9240 b/Documentation/i2c/chips/adm9240 deleted file mode 100644 index 35f618f3289..00000000000 --- a/Documentation/i2c/chips/adm9240 +++ /dev/null @@ -1,177 +0,0 @@ -Kernel driver adm9240 -===================== - -Supported chips: - * Analog Devices ADM9240 - Prefix: 'adm9240' - Addresses scanned: I2C 0x2c - 0x2f - Datasheet: Publicly available at the Analog Devices website - http://www.analog.com/UploadedFiles/Data_Sheets/79857778ADM9240_0.pdf - - * Dallas Semiconductor DS1780 - Prefix: 'ds1780' - Addresses scanned: I2C 0x2c - 0x2f - Datasheet: Publicly available at the Dallas Semiconductor (Maxim) website - http://pdfserv.maxim-ic.com/en/ds/DS1780.pdf - - * National Semiconductor LM81 - Prefix: 'lm81' - Addresses scanned: I2C 0x2c - 0x2f - Datasheet: Publicly available at the National Semiconductor website - http://www.national.com/ds.cgi/LM/LM81.pdf - -Authors: - Frodo Looijaard <frodol@dds.nl>, - Philip Edelbrock <phil@netroedge.com>, - Michiel Rook <michiel@grendelproject.nl>, - Grant Coady <gcoady@gmail.com> with guidance - from Jean Delvare <khali@linux-fr.org> - -Interface ---------- -The I2C addresses listed above assume BIOS has not changed the -chip MSB 5-bit address. Each chip reports a unique manufacturer -identification code as well as the chip revision/stepping level. - -Description ------------ -[From ADM9240] The ADM9240 is a complete system hardware monitor for -microprocessor-based systems, providing measurement and limit comparison -of up to four power supplies and two processor core voltages, plus -temperature, two fan speeds and chassis intrusion. Measured values can -be read out via an I2C-compatible serial System Management Bus, and values -for limit comparisons can be programmed in over the same serial bus. The -high speed successive approximation ADC allows frequent sampling of all -analog channels to ensure a fast interrupt response to any out-of-limit -measurement. - -The ADM9240, DS1780 and LM81 are register compatible, the following -details are common to the three chips. Chip differences are described -after this section. - - -Measurements ------------- -The measurement cycle - -The adm9240 driver will take a measurement reading no faster than once -each two seconds. User-space may read sysfs interface faster than the -measurement update rate and will receive cached data from the most -recent measurement. - -ADM9240 has a very fast 320us temperature and voltage measurement cycle -with independent fan speed measurement cycles counting alternating rising -edges of the fan tacho inputs. - -DS1780 measurement cycle is about once per second including fan speed. - -LM81 measurement cycle is about once per 400ms including fan speed. -The LM81 12-bit extended temperature measurement mode is not supported. - -Temperature ------------ -On chip temperature is reported as degrees Celsius as 9-bit signed data -with resolution of 0.5 degrees Celsius. High and low temperature limits -are 8-bit signed data with resolution of one degree Celsius. - -Temperature alarm is asserted once the temperature exceeds the high limit, -and is cleared when the temperature falls below the temp1_max_hyst value. - -Fan Speed ---------- -Two fan tacho inputs are provided, the ADM9240 gates an internal 22.5kHz -clock via a divider to an 8-bit counter. Fan speed (rpm) is calculated by: - -rpm = (22500 * 60) / (count * divider) - -Automatic fan clock divider - - * User sets 0 to fan_min limit - - low speed alarm is disabled - - fan clock divider not changed - - auto fan clock adjuster enabled for valid fan speed reading - - * User sets fan_min limit too low - - low speed alarm is enabled - - fan clock divider set to max - - fan_min set to register value 254 which corresponds - to 664 rpm on adm9240 - - low speed alarm will be asserted if fan speed is - less than minimum measurable speed - - auto fan clock adjuster disabled - - * User sets reasonable fan speed - - low speed alarm is enabled - - fan clock divider set to suit fan_min - - auto fan clock adjuster enabled: adjusts fan_min - - * User sets unreasonably high low fan speed limit - - resolution of the low speed limit may be reduced - - alarm will be asserted - - auto fan clock adjuster enabled: adjusts fan_min - - * fan speed may be displayed as zero until the auto fan clock divider - adjuster brings fan speed clock divider back into chip measurement - range, this will occur within a few measurement cycles. - -Analog Output -------------- -An analog output provides a 0 to 1.25 volt signal intended for an external -fan speed amplifier circuit. The analog output is set to maximum value on -power up or reset. This doesn't do much on the test Intel SE440BX-2. - -Voltage Monitor - -Voltage (IN) measurement is internally scaled: - - nr label nominal maximum resolution - mV mV mV - 0 +2.5V 2500 3320 13.0 - 1 Vccp1 2700 3600 14.1 - 2 +3.3V 3300 4380 17.2 - 3 +5V 5000 6640 26.0 - 4 +12V 12000 15940 62.5 - 5 Vccp2 2700 3600 14.1 - -The reading is an unsigned 8-bit value, nominal voltage measurement is -represented by a reading of 192, being 3/4 of the measurement range. - -An alarm is asserted for any voltage going below or above the set limits. - -The driver reports and accepts voltage limits scaled to the above table. - -VID Monitor ------------ -The chip has five inputs to read the 5-bit VID and reports the mV value -based on detected CPU type. - -Chassis Intrusion ------------------ -An alarm is asserted when the CI pin goes active high. The ADM9240 -Datasheet has an example of an external temperature sensor driving -this pin. On an Intel SE440BX-2 the Chassis Intrusion header is -connected to a normally open switch. - -The ADM9240 provides an internal open drain on this line, and may output -a 20 ms active low pulse to reset an external Chassis Intrusion latch. - -Clear the CI latch by writing value 1 to the sysfs chassis_clear file. - -Alarm flags reported as 16-bit word - - bit label comment - --- ------------- -------------------------- - 0 +2.5 V_Error high or low limit exceeded - 1 VCCP_Error high or low limit exceeded - 2 +3.3 V_Error high or low limit exceeded - 3 +5 V_Error high or low limit exceeded - 4 Temp_Error temperature error - 6 FAN1_Error fan low limit exceeded - 7 FAN2_Error fan low limit exceeded - 8 +12 V_Error high or low limit exceeded - 9 VCCP2_Error high or low limit exceeded - 12 Chassis_Error CI pin went high - -Remaining bits are reserved and thus undefined. It is important to note -that alarm bits may be cleared on read, user-space may latch alarms and -provide the end-user with a method to clear alarm memory. |