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diff --git a/Documentation/i2c/chips/smsc47b397.txt b/Documentation/i2c/chips/smsc47b397.txt new file mode 100644 index 000000000000..389edae7f8df --- /dev/null +++ b/Documentation/i2c/chips/smsc47b397.txt @@ -0,0 +1,146 @@ +November 23, 2004 + +The following specification describes the SMSC LPC47B397-NC sensor chip +(for which there is no public datasheet available). This document was +provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected +by Mark M. Hoffman <mhoffman@lightlink.com>. + +* * * * * + +Methods for detecting the HP SIO and reading the thermal data on a dc7100. + +The thermal information on the dc7100 is contained in the SIO Hardware Monitor +(HWM). The information is accessed through an index/data pair. The index/data +pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The +HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB) +and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and +0x480 and 0x481 for the index/data pair. + +Reading temperature information. +The temperature information is located in the following registers: +Temp1 0x25 (Currently, this reflects the CPU temp on all systems). +Temp2 0x26 +Temp3 0x27 +Temp4 0x80 + +Programming Example +The following is an example of how to read the HWM temperature registers: +MOV DX,480H +MOV AX,25H +OUT DX,AL +MOV DX,481H +IN AL,DX + +AL contains the data in hex, the temperature in Celsius is the decimal +equivalent. + +Ex: If AL contains 0x2A, the temperature is 42 degrees C. + +Reading tach information. +The fan speed information is located in the following registers: + LSB MSB +Tach1 0x28 0x29 (Currently, this reflects the CPU + fan speed on all systems). +Tach2 0x2A 0x2B +Tach3 0x2C 0x2D +Tach4 0x2E 0x2F + +Important!!! +Reading the tach LSB locks the tach MSB. +The LSB Must be read first. + +How to convert the tach reading to RPM. +The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB) +The SIO counts the number of 90kHz (11.111us) pulses per revolution. +RPM = 60/(TCount * 11.111us) + +Example: +Reg 0x28 = 0x9B +Reg 0x29 = 0x08 + +TCount = 0x89B = 2203 + +RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM + +Obtaining the SIO version. + +CONFIGURATION SEQUENCE +To program the configuration registers, the following sequence must be followed: +1. Enter Configuration Mode +2. Configure the Configuration Registers +3. Exit Configuration Mode. + +Enter Configuration Mode +To place the chip into the Configuration State The config key (0x55) is written +to the CONFIG PORT (0x2E). + +Configuration Mode +In configuration mode, the INDEX PORT is located at the CONFIG PORT address and +the DATA PORT is at INDEX PORT address + 1. + +The desired configuration registers are accessed in two steps: +a. Write the index of the Logical Device Number Configuration Register + (i.e., 0x07) to the INDEX PORT and then write the number of the + desired logical device to the DATA PORT. + +b. Write the address of the desired configuration register within the + logical device to the INDEX PORT and then write or read the config- + uration register through the DATA PORT. + +Note: If accessing the Global Configuration Registers, step (a) is not required. + +Exit Configuration Mode +To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E). +The chip returns to the RUN State. (This is important). + +Programming Example +The following is an example of how to read the SIO Device ID located at 0x20 + +; ENTER CONFIGURATION MODE +MOV DX,02EH +MOV AX,055H +OUT DX,AL +; GLOBAL CONFIGURATION REGISTER +MOV DX,02EH +MOV AL,20H +OUT DX,AL +; READ THE DATA +MOV DX,02FH +IN AL,DX +; EXIT CONFIGURATION MODE +MOV DX,02EH +MOV AX,0AAH +OUT DX,AL + +The registers of interest for identifying the SIO on the dc7100 are Device ID +(0x20) and Device Rev (0x21). + +The Device ID will read 0X6F +The Device Rev currently reads 0x01 + +Obtaining the HWM Base Address. +The following is an example of how to read the HWM Base Address located in +Logical Device 8. + +; ENTER CONFIGURATION MODE +MOV DX,02EH +MOV AX,055H +OUT DX,AL +; CONFIGURE REGISTER CRE0, +; LOGICAL DEVICE 8 +MOV DX,02EH +MOV AL,07H +OUT DX,AL ;Point to LD# Config Reg +MOV DX,02FH +MOV AL, 08H +OUT DX,AL;Point to Logical Device 8 +; +MOV DX,02EH +MOV AL,60H +OUT DX,AL ; Point to HWM Base Addr MSB +MOV DX,02FH +IN AL,DX ; Get MSB of HWM Base Addr +; EXIT CONFIGURATION MODE +MOV DX,02EH +MOV AX,0AAH +OUT DX,AL |