Documentation/hwmon/smsc47b397

   1 Kernel driver smsc47b397
   2 ========================
   3
   4 Supported chips:
   5   * SMSC LPC47B397-NC
   6     Prefix: 'smsc47b397'
   7     Addresses scanned: none, address read from Super I/O config space
   8     Datasheet: In this file
   9
  10 Authors: Mark M. Hoffman <mhoffman@lightlink.com>
  11          Utilitek Systems, Inc.
  12
  13 November 23, 2004
  14
  15 The following specification describes the SMSC LPC47B397-NC sensor chip
  16 (for which there is no public datasheet available). This document was
  17 provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected
  18 by Mark M. Hoffman <mhoffman@lightlink.com>.
  19
  20 * * * * *
  21
  22 Methods for detecting the HP SIO and reading the thermal data on a dc7100.
  23
  24 The thermal information on the dc7100 is contained in the SIO Hardware Monitor
  25 (HWM). The information is accessed through an index/data pair. The index/data
  26 pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The
  27 HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB)
  28 and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and
  29 0x480 and 0x481 for the index/data pair.
  30
  31 Reading temperature information.
  32 The temperature information is located in the following registers:
  33 Temp1           0x25    (Currently, this reflects the CPU temp on all systems).
  34 Temp2           0x26
  35 Temp3           0x27
  36 Temp4           0x80
  37
  38 Programming Example
  39 The following is an example of how to read the HWM temperature registers:
  40 MOV     DX,480H
  41 MOV     AX,25H
  42 OUT     DX,AL
  43 MOV     DX,481H
  44 IN      AL,DX
  45
  46 AL contains the data in hex, the temperature in Celsius is the decimal
  47 equivalent.
  48
  49 Ex: If AL contains 0x2A, the temperature is 42 degrees C.
  50
  51 Reading tach information.
  52 The fan speed information is located in the following registers:
  53                 LSB     MSB
  54 Tach1           0x28    0x29    (Currently, this reflects the CPU
  55                                 fan speed on all systems).
  56 Tach2           0x2A    0x2B
  57 Tach3           0x2C    0x2D
  58 Tach4           0x2E    0x2F
  59
  60 Important!!!
  61 Reading the tach LSB locks the tach MSB.
  62 The LSB Must be read first.
  63
  64 How to convert the tach reading to RPM.
  65 The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB)
  66 The SIO counts the number of 90kHz (11.111us) pulses per revolution.
  67 RPM = 60/(TCount * 11.111us)
  68
  69 Example:
  70 Reg 0x28 = 0x9B
  71 Reg 0x29 = 0x08
  72
  73 TCount = 0x89B = 2203
  74
  75 RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM
  76
  77 Obtaining the SIO version.
  78
  79 CONFIGURATION SEQUENCE
  80 To program the configuration registers, the following sequence must be followed:
  81 1. Enter Configuration Mode
  82 2. Configure the Configuration Registers
  83 3. Exit Configuration Mode.
  84
  85 Enter Configuration Mode
  86 To place the chip into the Configuration State The config key (0x55) is written
  87 to the CONFIG PORT (0x2E).
  88
  89 Configuration Mode
  90 In configuration mode, the INDEX PORT is located at the CONFIG PORT address and
  91 the DATA PORT is at INDEX PORT address + 1.
  92
  93 The desired configuration registers are accessed in two steps:
  94 a.      Write the index of the Logical Device Number Configuration Register
  95         (i.e., 0x07) to the INDEX PORT and then write the number of the
  96         desired logical device to the DATA PORT.
  97
  98 b.      Write the address of the desired configuration register within the
  99         logical device to the INDEX PORT and then write or read the config-
 100         uration register through the DATA PORT.
 101
 102 Note: If accessing the Global Configuration Registers, step (a) is not required.
 103
 104 Exit Configuration Mode
 105 To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E).
 106 The chip returns to the RUN State.  (This is important).
 107
 108 Programming Example
 109 The following is an example of how to read the SIO Device ID located at 0x20
 110
 111 ; ENTER CONFIGURATION MODE
 112 MOV     DX,02EH
 113 MOV     AX,055H
 114 OUT     DX,AL
 115 ; GLOBAL CONFIGURATION  REGISTER
 116 MOV     DX,02EH
 117 MOV     AL,20H
 118 OUT     DX,AL
 119 ; READ THE DATA
 120 MOV     DX,02FH
 121 IN      AL,DX
 122 ; EXIT CONFIGURATION MODE
 123 MOV     DX,02EH
 124 MOV     AX,0AAH
 125 OUT     DX,AL
 126
 127 The registers of interest for identifying the SIO on the dc7100 are Device ID
 128 (0x20) and Device Rev  (0x21).
 129
 130 The Device ID will read 0X6F
 131 The Device Rev currently reads 0x01
 132
 133 Obtaining the HWM Base Address.
 134 The following is an example of how to read the HWM Base Address located in
 135 Logical Device 8.
 136
 137 ; ENTER CONFIGURATION MODE
 138 MOV     DX,02EH
 139 MOV     AX,055H
 140 OUT     DX,AL
 141 ; CONFIGURE REGISTER CRE0,
 142 ; LOGICAL DEVICE 8
 143 MOV     DX,02EH
 144 MOV     AL,07H
 145 OUT     DX,AL ;Point to LD# Config Reg
 146 MOV     DX,02FH
 147 MOV     AL, 08H
 148 OUT     DX,AL;Point to Logical Device 8
 149 ;
 150 MOV     DX,02EH
 151 MOV     AL,60H
 152 OUT     DX,AL   ; Point to HWM Base Addr MSB
 153 MOV     DX,02FH
 154 IN      AL,DX   ; Get MSB of HWM Base Addr
 155 ; EXIT CONFIGURATION MODE
 156 MOV     DX,02EH
 157 MOV     AX,0AAH
 158 OUT     DX,AL