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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/i2c/chips/smsc47b397.txt |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'Documentation/i2c/chips/smsc47b397.txt')
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1 | November 23, 2004 | ||
2 | |||
3 | The following specification describes the SMSC LPC47B397-NC sensor chip | ||
4 | (for which there is no public datasheet available). This document was | ||
5 | provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected | ||
6 | by Mark M. Hoffman <mhoffman@lightlink.com>. | ||
7 | |||
8 | * * * * * | ||
9 | |||
10 | Methods for detecting the HP SIO and reading the thermal data on a dc7100. | ||
11 | |||
12 | The thermal information on the dc7100 is contained in the SIO Hardware Monitor | ||
13 | (HWM). The information is accessed through an index/data pair. The index/data | ||
14 | pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The | ||
15 | HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB) | ||
16 | and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and | ||
17 | 0x480 and 0x481 for the index/data pair. | ||
18 | |||
19 | Reading temperature information. | ||
20 | The temperature information is located in the following registers: | ||
21 | Temp1 0x25 (Currently, this reflects the CPU temp on all systems). | ||
22 | Temp2 0x26 | ||
23 | Temp3 0x27 | ||
24 | Temp4 0x80 | ||
25 | |||
26 | Programming Example | ||
27 | The following is an example of how to read the HWM temperature registers: | ||
28 | MOV DX,480H | ||
29 | MOV AX,25H | ||
30 | OUT DX,AL | ||
31 | MOV DX,481H | ||
32 | IN AL,DX | ||
33 | |||
34 | AL contains the data in hex, the temperature in Celsius is the decimal | ||
35 | equivalent. | ||
36 | |||
37 | Ex: If AL contains 0x2A, the temperature is 42 degrees C. | ||
38 | |||
39 | Reading tach information. | ||
40 | The fan speed information is located in the following registers: | ||
41 | LSB MSB | ||
42 | Tach1 0x28 0x29 (Currently, this reflects the CPU | ||
43 | fan speed on all systems). | ||
44 | Tach2 0x2A 0x2B | ||
45 | Tach3 0x2C 0x2D | ||
46 | Tach4 0x2E 0x2F | ||
47 | |||
48 | Important!!! | ||
49 | Reading the tach LSB locks the tach MSB. | ||
50 | The LSB Must be read first. | ||
51 | |||
52 | How to convert the tach reading to RPM. | ||
53 | The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB) | ||
54 | The SIO counts the number of 90kHz (11.111us) pulses per revolution. | ||
55 | RPM = 60/(TCount * 11.111us) | ||
56 | |||
57 | Example: | ||
58 | Reg 0x28 = 0x9B | ||
59 | Reg 0x29 = 0x08 | ||
60 | |||
61 | TCount = 0x89B = 2203 | ||
62 | |||
63 | RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM | ||
64 | |||
65 | Obtaining the SIO version. | ||
66 | |||
67 | CONFIGURATION SEQUENCE | ||
68 | To program the configuration registers, the following sequence must be followed: | ||
69 | 1. Enter Configuration Mode | ||
70 | 2. Configure the Configuration Registers | ||
71 | 3. Exit Configuration Mode. | ||
72 | |||
73 | Enter Configuration Mode | ||
74 | To place the chip into the Configuration State The config key (0x55) is written | ||
75 | to the CONFIG PORT (0x2E). | ||
76 | |||
77 | Configuration Mode | ||
78 | In configuration mode, the INDEX PORT is located at the CONFIG PORT address and | ||
79 | the DATA PORT is at INDEX PORT address + 1. | ||
80 | |||
81 | The desired configuration registers are accessed in two steps: | ||
82 | a. Write the index of the Logical Device Number Configuration Register | ||
83 | (i.e., 0x07) to the INDEX PORT and then write the number of the | ||
84 | desired logical device to the DATA PORT. | ||
85 | |||
86 | b. Write the address of the desired configuration register within the | ||
87 | logical device to the INDEX PORT and then write or read the config- | ||
88 | uration register through the DATA PORT. | ||
89 | |||
90 | Note: If accessing the Global Configuration Registers, step (a) is not required. | ||
91 | |||
92 | Exit Configuration Mode | ||
93 | To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E). | ||
94 | The chip returns to the RUN State. (This is important). | ||
95 | |||
96 | Programming Example | ||
97 | The following is an example of how to read the SIO Device ID located at 0x20 | ||
98 | |||
99 | ; ENTER CONFIGURATION MODE | ||
100 | MOV DX,02EH | ||
101 | MOV AX,055H | ||
102 | OUT DX,AL | ||
103 | ; GLOBAL CONFIGURATION REGISTER | ||
104 | MOV DX,02EH | ||
105 | MOV AL,20H | ||
106 | OUT DX,AL | ||
107 | ; READ THE DATA | ||
108 | MOV DX,02FH | ||
109 | IN AL,DX | ||
110 | ; EXIT CONFIGURATION MODE | ||
111 | MOV DX,02EH | ||
112 | MOV AX,0AAH | ||
113 | OUT DX,AL | ||
114 | |||
115 | The registers of interest for identifying the SIO on the dc7100 are Device ID | ||
116 | (0x20) and Device Rev (0x21). | ||
117 | |||
118 | The Device ID will read 0X6F | ||
119 | The Device Rev currently reads 0x01 | ||
120 | |||
121 | Obtaining the HWM Base Address. | ||
122 | The following is an example of how to read the HWM Base Address located in | ||
123 | Logical Device 8. | ||
124 | |||
125 | ; ENTER CONFIGURATION MODE | ||
126 | MOV DX,02EH | ||
127 | MOV AX,055H | ||
128 | OUT DX,AL | ||
129 | ; CONFIGURE REGISTER CRE0, | ||
130 | ; LOGICAL DEVICE 8 | ||
131 | MOV DX,02EH | ||
132 | MOV AL,07H | ||
133 | OUT DX,AL ;Point to LD# Config Reg | ||
134 | MOV DX,02FH | ||
135 | MOV AL, 08H | ||
136 | OUT DX,AL;Point to Logical Device 8 | ||
137 | ; | ||
138 | MOV DX,02EH | ||
139 | MOV AL,60H | ||
140 | OUT DX,AL ; Point to HWM Base Addr MSB | ||
141 | MOV DX,02FH | ||
142 | IN AL,DX ; Get MSB of HWM Base Addr | ||
143 | ; EXIT CONFIGURATION MODE | ||
144 | MOV DX,02EH | ||
145 | MOV AX,0AAH | ||
146 | OUT DX,AL | ||