LXR uboot/drivers/hwmon/lm81.c

   1/*
   2 * (C) Copyright 2006
   3 * Heiko Schocher, DENX Software Enginnering <hs@denx.de>
   4 *
   5 * based on dtt/lm75.c which is ...
   6 *
   7 * (C) Copyright 2001
   8 * Bill Hunter,  Wave 7 Optics, williamhunter@mediaone.net
   9 *
  10 * SPDX-License-Identifier:     GPL-2.0+
  11 */
  12
  13/*
  14 * On Semiconductor's LM81 Temperature Sensor
  15 */
  16
  17#include <common.h>
  18#include <i2c.h>
  19#include <dtt.h>
  20
  21/*
  22 * Device code
  23 */
  24#define DTT_I2C_DEV_CODE 0x2c                   /* ON Semi's LM81 device */
  25#define DTT_READ_TEMP           0x27
  26#define DTT_CONFIG_TEMP         0x4b
  27#define DTT_TEMP_MAX            0x39
  28#define DTT_TEMP_HYST           0x3a
  29#define DTT_CONFIG              0x40
  30
  31int dtt_read(int sensor, int reg)
  32{
  33    int dlen = 1;
  34    uchar data[2];
  35
  36    /*
  37     * Calculate sensor address and register.
  38     */
  39    sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */
  40
  41    /*
  42     * Now try to read the register.
  43     */
  44    if (i2c_read(sensor, reg, 1, data, dlen) != 0)
  45        return -1;
  46
  47    return (int)data[0];
  48} /* dtt_read() */
  49
  50
  51int dtt_write(int sensor, int reg, int val)
  52{
  53    uchar data;
  54
  55    /*
  56     * Calculate sensor address and register.
  57     */
  58    sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */
  59
  60    data = (char)(val & 0xff);
  61
  62    /*
  63     * Write value to register.
  64     */
  65    if (i2c_write(sensor, reg, 1, &data, 1) != 0)
  66        return 1;
  67
  68    return 0;
  69} /* dtt_write() */
  70
  71#define DTT_MANU        0x3e
  72#define DTT_REV         0x3f
  73#define DTT_CONFIG      0x40
  74#define DTT_ADR         0x48
  75
  76int dtt_init_one(int sensor)
  77{
  78        int     man;
  79        int     adr;
  80        int     rev;
  81
  82        if (dtt_write (sensor, DTT_CONFIG, 0x01) < 0)
  83                return 1;
  84        /* The LM81 needs 400ms to get the correct values ... */
  85        udelay (400000);
  86        man = dtt_read (sensor, DTT_MANU);
  87        if (man != 0x01)
  88                return 1;
  89        adr = dtt_read (sensor, DTT_ADR);
  90        if (adr < 0)
  91                return 1;
  92        rev = dtt_read (sensor, DTT_REV);
  93        if (adr < 0)
  94                return 1;
  95
  96        debug ("DTT:   Found LM81@%x Rev: %d\n", adr, rev);
  97        return 0;
  98} /* dtt_init_one() */
  99
 100
 101#define TEMP_FROM_REG(temp) \
 102   ((temp)<256?((((temp)&0x1fe) >> 1) * 10)      + ((temp) & 1) * 5:  \
 103               ((((temp)&0x1fe) >> 1) -255) * 10 - ((temp) & 1) * 5)  \
 104
 105int dtt_get_temp(int sensor)
 106{
 107        int val = dtt_read (sensor, DTT_READ_TEMP);
 108        int tmpcnf = dtt_read (sensor, DTT_CONFIG_TEMP);
 109
 110        return (TEMP_FROM_REG((val << 1) + ((tmpcnf & 0x80) >> 7))) / 10;
 111} /* dtt_get_temp() */
 112