Documentation/hwmon/smsc47b397

   1 Kernel driver smsc47b397
   2 ========================
   3
   4 Supported chips:
   5
   6   * SMSC LPC47B397-NC
   7
   8   * SMSC SCH5307-NS
   9
  10   * SMSC SCH5317
  11
  12     Prefix: 'smsc47b397'
  13
  14     Addresses scanned: none, address read from Super I/O config space
  15
  16     Datasheet: In this file
  17
  18 Authors:
  19
  20        - Mark M. Hoffman <mhoffman@lightlink.com>
  21        - Utilitek Systems, Inc.
  22
  23 November 23, 2004
  24
  25 The following specification describes the SMSC LPC47B397-NC [1]_ sensor chip
  26 (for which there is no public datasheet available). This document was
  27 provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected
  28 by Mark M. Hoffman <mhoffman@lightlink.com>.
  29
  30 .. [1] And SMSC SCH5307-NS and SCH5317, which have different device IDs but are
  31        otherwise compatible.
  32
  33 -------------------------------------------------------------------------
  34
  35 Methods for detecting the HP SIO and reading the thermal data on a dc7100
  36 -------------------------------------------------------------------------
  37
  38 The thermal information on the dc7100 is contained in the SIO Hardware Monitor
  39 (HWM). The information is accessed through an index/data pair. The index/data
  40 pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The
  41 HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB)
  42 and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and
  43 0x480 and 0x481 for the index/data pair.
  44
  45 Reading temperature information.
  46 The temperature information is located in the following registers:
  47
  48 =============== ======= =======================================================
  49 Temp1           0x25    (Currently, this reflects the CPU temp on all systems).
  50 Temp2           0x26
  51 Temp3           0x27
  52 Temp4           0x80
  53 =============== ======= =======================================================
  54
  55 Programming Example
  56 The following is an example of how to read the HWM temperature registers::
  57
  58         MOV     DX,480H
  59         MOV     AX,25H
  60         OUT     DX,AL
  61         MOV     DX,481H
  62         IN      AL,DX
  63
  64 AL contains the data in hex, the temperature in Celsius is the decimal
  65 equivalent.
  66
  67 Ex: If AL contains 0x2A, the temperature is 42 degrees C.
  68
  69 Reading tach information.
  70 The fan speed information is located in the following registers:
  71
  72 =============== ======= ======= =================================
  73                 LSB     MSB
  74 Tach1           0x28    0x29    (Currently, this reflects the CPU
  75                                 fan speed on all systems).
  76 Tach2           0x2A    0x2B
  77 Tach3           0x2C    0x2D
  78 Tach4           0x2E    0x2F
  79 =============== ======= ======= =================================
  80
  81 .. Important::
  82
  83         Reading the tach LSB locks the tach MSB.
  84         The LSB Must be read first.
  85
  86 How to convert the tach reading to RPM
  87 --------------------------------------
  88
  89 The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB)
  90 The SIO counts the number of 90kHz (11.111us) pulses per revolution.
  91 RPM = 60/(TCount * 11.111us)
  92
  93 Example::
  94
  95         Reg 0x28 = 0x9B
  96         Reg 0x29 = 0x08
  97
  98 TCount = 0x89B = 2203
  99
 100 RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM
 101
 102 Obtaining the SIO version.
 103
 104 Configuration Sequence
 105 ----------------------
 106
 107 To program the configuration registers, the following sequence must be followed:
 108 1. Enter Configuration Mode
 109 2. Configure the Configuration Registers
 110 3. Exit Configuration Mode.
 111
 112 Enter Configuration Mode
 113 ^^^^^^^^^^^^^^^^^^^^^^^^
 114
 115 To place the chip into the Configuration State The config key (0x55) is written
 116 to the CONFIG PORT (0x2E).
 117
 118 Configuration Mode
 119 ^^^^^^^^^^^^^^^^^^
 120
 121 In configuration mode, the INDEX PORT is located at the CONFIG PORT address and
 122 the DATA PORT is at INDEX PORT address + 1.
 123
 124 The desired configuration registers are accessed in two steps:
 125
 126 a.      Write the index of the Logical Device Number Configuration Register
 127         (i.e., 0x07) to the INDEX PORT and then write the number of the
 128         desired logical device to the DATA PORT.
 129
 130 b.      Write the address of the desired configuration register within the
 131         logical device to the INDEX PORT and then write or read the config-
 132         uration register through the DATA PORT.
 133
 134 Note:
 135         If accessing the Global Configuration Registers, step (a) is not required.
 136
 137 Exit Configuration Mode
 138 ^^^^^^^^^^^^^^^^^^^^^^^
 139
 140 To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E).
 141 The chip returns to the RUN State.  (This is important).
 142
 143 Programming Example
 144 ^^^^^^^^^^^^^^^^^^^
 145
 146 The following is an example of how to read the SIO Device ID located at 0x20:
 147
 148         ; ENTER CONFIGURATION MODE
 149         MOV     DX,02EH
 150         MOV     AX,055H
 151         OUT     DX,AL
 152         ; GLOBAL CONFIGURATION  REGISTER
 153         MOV     DX,02EH
 154         MOV     AL,20H
 155         OUT     DX,AL
 156         ; READ THE DATA
 157         MOV     DX,02FH
 158         IN      AL,DX
 159         ; EXIT CONFIGURATION MODE
 160         MOV     DX,02EH
 161         MOV     AX,0AAH
 162         OUT     DX,AL
 163
 164 The registers of interest for identifying the SIO on the dc7100 are Device ID
 165 (0x20) and Device Rev  (0x21).
 166
 167 The Device ID will read 0x6F (0x81 for SCH5307-NS, and 0x85 for SCH5317)
 168 The Device Rev currently reads 0x01
 169
 170 Obtaining the HWM Base Address
 171 ------------------------------
 172
 173 The following is an example of how to read the HWM Base Address located in
 174 Logical Device 8::
 175
 176         ; ENTER CONFIGURATION MODE
 177         MOV     DX,02EH
 178         MOV     AX,055H
 179         OUT     DX,AL
 180         ; CONFIGURE REGISTER CRE0,
 181         ; LOGICAL DEVICE 8
 182         MOV     DX,02EH
 183         MOV     AL,07H
 184         OUT     DX,AL ;Point to LD# Config Reg
 185         MOV     DX,02FH
 186         MOV     AL, 08H
 187         OUT     DX,AL;Point to Logical Device 8
 188         ;
 189         MOV     DX,02EH
 190         MOV     AL,60H
 191         OUT     DX,AL   ; Point to HWM Base Addr MSB
 192         MOV     DX,02FH
 193         IN      AL,DX   ; Get MSB of HWM Base Addr
 194         ; EXIT CONFIGURATION MODE
 195         MOV     DX,02EH
 196         MOV     AX,0AAH
 197         OUT     DX,AL