Documentation/hwmon/smsc47b397

   1 Kernel driver smsc47b397
   2 ========================
   3
   4 Supported 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
  12 Authors: Mark M. Hoffman <mhoffman@lightlink.com>
  13          Utilitek Systems, Inc.
  14
  15 November 23, 2004
  16
  17 The following specification describes the SMSC LPC47B397-NC[1] sensor chip
  18 (for which there is no public datasheet available). This document was
  19 provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected
  20 by Mark M. Hoffman <mhoffman@lightlink.com>.
  21
  22 [1] And SMSC SCH5307-NS and SCH5317, which have different device IDs but are
  23 otherwise compatible.
  24
  25 * * * * *
  26
  27 Methods for detecting the HP SIO and reading the thermal data on a dc7100.
  28
  29 The 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
  31 pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The
  32 HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB)
  33 and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and
  34 0x480 and 0x481 for the index/data pair.
  35
  36 Reading temperature information.
  37 The temperature information is located in the following registers:
  38 Temp1           0x25    (Currently, this reflects the CPU temp on all systems).
  39 Temp2           0x26
  40 Temp3           0x27
  41 Temp4           0x80
  42
  43 Programming Example
  44 The following is an example of how to read the HWM temperature registers:
  45 MOV     DX,480H
  46 MOV     AX,25H
  47 OUT     DX,AL
  48 MOV     DX,481H
  49 IN      AL,DX
  50
  51 AL contains the data in hex, the temperature in Celsius is the decimal
  52 equivalent.
  53
  54 Ex: If AL contains 0x2A, the temperature is 42 degrees C.
  55
  56 Reading tach information.
  57 The fan speed information is located in the following registers:
  58                 LSB     MSB
  59 Tach1           0x28    0x29    (Currently, this reflects the CPU
  60                                 fan speed on all systems).
  61 Tach2           0x2A    0x2B
  62 Tach3           0x2C    0x2D
  63 Tach4           0x2E    0x2F
  64
  65 Important!!!
  66 Reading the tach LSB locks the tach MSB.
  67 The LSB Must be read first.
  68
  69 How to convert the tach reading to RPM.
  70 The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB)
  71 The SIO counts the number of 90kHz (11.111us) pulses per revolution.
  72 RPM = 60/(TCount * 11.111us)
  73
  74 Example:
  75 Reg 0x28 = 0x9B
  76 Reg 0x29 = 0x08
  77
  78 TCount = 0x89B = 2203
  79
  80 RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM
  81
  82 Obtaining the SIO version.
  83
  84 CONFIGURATION SEQUENCE
  85 To program the configuration registers, the following sequence must be followed:
  86 1. Enter Configuration Mode
  87 2. Configure the Configuration Registers
  88 3. Exit Configuration Mode.
  89
  90 Enter Configuration Mode
  91 To place the chip into the Configuration State The config key (0x55) is written
  92 to the CONFIG PORT (0x2E).
  93
  94 Configuration Mode
  95 In configuration mode, the INDEX PORT is located at the CONFIG PORT address and
  96 the DATA PORT is at INDEX PORT address + 1.
  97
  98 The desired configuration registers are accessed in two steps:
  99 a.      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
 103 b.      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
 107 Note: If accessing the Global Configuration Registers, step (a) is not required.
 108
 109 Exit Configuration Mode
 110 To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E).
 111 The chip returns to the RUN State.  (This is important).
 112
 113 Programming Example
 114 The following is an example of how to read the SIO Device ID located at 0x20
 115
 116 ; ENTER CONFIGURATION MODE
 117 MOV     DX,02EH
 118 MOV     AX,055H
 119 OUT     DX,AL
 120 ; GLOBAL CONFIGURATION  REGISTER
 121 MOV     DX,02EH
 122 MOV     AL,20H
 123 OUT     DX,AL
 124 ; READ THE DATA
 125 MOV     DX,02FH
 126 IN      AL,DX
 127 ; EXIT CONFIGURATION MODE
 128 MOV     DX,02EH
 129 MOV     AX,0AAH
 130 OUT     DX,AL
 131
 132 The registers of interest for identifying the SIO on the dc7100 are Device ID
 133 (0x20) and Device Rev  (0x21).
 134
 135 The Device ID will read 0x6F (0x81 for SCH5307-NS, and 0x85 for SCH5317)
 136 The Device Rev currently reads 0x01
 137
 138 Obtaining the HWM Base Address.
 139 The following is an example of how to read the HWM Base Address located in
 140 Logical Device 8.
 141
 142 ; ENTER CONFIGURATION MODE
 143 MOV     DX,02EH
 144 MOV     AX,055H
 145 OUT     DX,AL
 146 ; CONFIGURE REGISTER CRE0,
 147 ; LOGICAL DEVICE 8
 148 MOV     DX,02EH
 149 MOV     AL,07H
 150 OUT     DX,AL ;Point to LD# Config Reg
 151 MOV     DX,02FH
 152 MOV     AL, 08H
 153 OUT     DX,AL;Point to Logical Device 8
 154 ;
 155 MOV     DX,02EH
 156 MOV     AL,60H
 157 OUT     DX,AL   ; Point to HWM Base Addr MSB
 158 MOV     DX,02FH
 159 IN      AL,DX   ; Get MSB of HWM Base Addr
 160 ; EXIT CONFIGURATION MODE
 161 MOV     DX,02EH
 162 MOV     AX,0AAH
 163 OUT     DX,AL