linux/Documentation/hwmon/smsc47b397
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   1Kernel driver smsc47b397
   2========================
   3
   4Supported chips:
   5  * SMSC LPC47B397-NC
   6  * SMSC SCH5307-NS
   7  * SMSC SCH5317
   8    Prefix: 'smsc47b397'
   9    Addresses scanned: none, address read from Super I/O config space
  10    Datasheet: In this file
  11
  12Authors: Mark M. Hoffman <mhoffman@lightlink.com>
  13         Utilitek Systems, Inc.
  14
  15November 23, 2004
  16
  17The following specification describes the SMSC LPC47B397-NC[1] sensor chip
  18(for which there is no public datasheet available). This document was
  19provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected
  20by Mark M. Hoffman <mhoffman@lightlink.com>.
  21
  22[1] And SMSC SCH5307-NS and SCH5317, which have different device IDs but are
  23otherwise compatible.
  24
  25* * * * *
  26
  27Methods for detecting the HP SIO and reading the thermal data on a dc7100.
  28
  29The thermal information on the dc7100 is contained in the SIO Hardware Monitor
  30(HWM). The information is accessed through an index/data pair. The index/data
  31pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The
  32HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB)
  33and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and
  340x480 and 0x481 for the index/data pair.
  35
  36Reading temperature information.
  37The temperature information is located in the following registers:
  38Temp1           0x25    (Currently, this reflects the CPU temp on all systems).
  39Temp2           0x26
  40Temp3           0x27
  41Temp4           0x80
  42
  43Programming Example
  44The following is an example of how to read the HWM temperature registers:
  45MOV     DX,480H
  46MOV     AX,25H
  47OUT     DX,AL
  48MOV     DX,481H
  49IN      AL,DX
  50
  51AL contains the data in hex, the temperature in Celsius is the decimal
  52equivalent.
  53
  54Ex: If AL contains 0x2A, the temperature is 42 degrees C.
  55
  56Reading tach information.
  57The fan speed information is located in the following registers:
  58                LSB     MSB
  59Tach1           0x28    0x29    (Currently, this reflects the CPU
  60                                fan speed on all systems).
  61Tach2           0x2A    0x2B
  62Tach3           0x2C    0x2D
  63Tach4           0x2E    0x2F
  64
  65Important!!!
  66Reading the tach LSB locks the tach MSB.
  67The LSB Must be read first.
  68
  69How to convert the tach reading to RPM.
  70The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB)
  71The SIO counts the number of 90kHz (11.111us) pulses per revolution.
  72RPM = 60/(TCount * 11.111us)
  73
  74Example:
  75Reg 0x28 = 0x9B
  76Reg 0x29 = 0x08
  77
  78TCount = 0x89B = 2203
  79
  80RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM
  81
  82Obtaining the SIO version.
  83
  84CONFIGURATION SEQUENCE
  85To program the configuration registers, the following sequence must be followed:
  861. Enter Configuration Mode
  872. Configure the Configuration Registers
  883. Exit Configuration Mode.
  89
  90Enter Configuration Mode
  91To place the chip into the Configuration State The config key (0x55) is written
  92to the CONFIG PORT (0x2E).
  93
  94Configuration Mode
  95In configuration mode, the INDEX PORT is located at the CONFIG PORT address and
  96the DATA PORT is at INDEX PORT address + 1.
  97
  98The desired configuration registers are accessed in two steps:
  99a.      Write the index of the Logical Device Number Configuration Register
 100        (i.e., 0x07) to the INDEX PORT and then write the number of the
 101        desired logical device to the DATA PORT.
 102
 103b.      Write the address of the desired configuration register within the
 104        logical device to the INDEX PORT and then write or read the config-
 105        uration register through the DATA PORT.
 106
 107Note: If accessing the Global Configuration Registers, step (a) is not required.
 108
 109Exit Configuration Mode
 110To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E).
 111The chip returns to the RUN State.  (This is important).
 112
 113Programming Example
 114The following is an example of how to read the SIO Device ID located at 0x20
 115
 116; ENTER CONFIGURATION MODE
 117MOV     DX,02EH
 118MOV     AX,055H
 119OUT     DX,AL
 120; GLOBAL CONFIGURATION  REGISTER
 121MOV     DX,02EH
 122MOV     AL,20H
 123OUT     DX,AL
 124; READ THE DATA
 125MOV     DX,02FH
 126IN      AL,DX
 127; EXIT CONFIGURATION MODE
 128MOV     DX,02EH
 129MOV     AX,0AAH
 130OUT     DX,AL
 131
 132The registers of interest for identifying the SIO on the dc7100 are Device ID
 133(0x20) and Device Rev  (0x21).
 134
 135The Device ID will read 0x6F (0x81 for SCH5307-NS, and 0x85 for SCH5317)
 136The Device Rev currently reads 0x01
 137
 138Obtaining the HWM Base Address.
 139The following is an example of how to read the HWM Base Address located in
 140Logical Device 8.
 141
 142; ENTER CONFIGURATION MODE
 143MOV     DX,02EH
 144MOV     AX,055H
 145OUT     DX,AL
 146; CONFIGURE REGISTER CRE0,
 147; LOGICAL DEVICE 8
 148MOV     DX,02EH
 149MOV     AL,07H
 150OUT     DX,AL ;Point to LD# Config Reg
 151MOV     DX,02FH
 152MOV     AL, 08H
 153OUT     DX,AL;Point to Logical Device 8
 154;
 155MOV     DX,02EH
 156MOV     AL,60H
 157OUT     DX,AL   ; Point to HWM Base Addr MSB
 158MOV     DX,02FH
 159IN      AL,DX   ; Get MSB of HWM Base Addr
 160; EXIT CONFIGURATION MODE
 161MOV     DX,02EH
 162MOV     AX,0AAH
 163OUT     DX,AL
 164
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