drivers/hwmon/lm63.c

   1 /*
   2  * (C) Copyright 2007-2008
   3  * Dirk Eibach,  Guntermann & Drunck GmbH, eibach@gdsys.de
   4  * based on lm75.c by Bill Hunter
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 /*
  10  * National LM63/LM64 Temperature Sensor
  11  * Main difference: LM 64 has -16 Kelvin temperature offset
  12  */
  13
  14 #include <common.h>
  15 #include <i2c.h>
  16 #include <dtt.h>
  17
  18 #define DTT_I2C_LM63_ADDR       0x4C    /* National LM63 device */
  19
  20 #define DTT_READ_TEMP_RMT_MSB   0x01
  21 #define DTT_CONFIG              0x03
  22 #define DTT_READ_TEMP_RMT_LSB   0x10
  23 #define DTT_TACHLIM_LSB         0x48
  24 #define DTT_TACHLIM_MSB         0x49
  25 #define DTT_FAN_CONFIG          0x4A
  26 #define DTT_PWM_FREQ            0x4D
  27 #define DTT_PWM_LOOKUP_BASE     0x50
  28
  29 struct pwm_lookup_entry {
  30         u8 temp;
  31         u8 pwm;
  32 };
  33
  34 /*
  35  * Device code
  36  */
  37
  38 int dtt_read(int sensor, int reg)
  39 {
  40         int dlen;
  41         uchar data[2];
  42
  43         /*
  44          * Calculate sensor address and register.
  45          */
  46         if (!sensor)
  47                 sensor = DTT_I2C_LM63_ADDR;     /* legacy config */
  48
  49         dlen = 1;
  50
  51         /*
  52          * Now try to read the register.
  53          */
  54         if (i2c_read(sensor, reg, 1, data, dlen) != 0)
  55                 return -1;
  56
  57         return (int)data[0];
  58 }                               /* dtt_read() */
  59
  60 int dtt_write(int sensor, int reg, int val)
  61 {
  62         int dlen;
  63         uchar data[2];
  64
  65         /*
  66          * Calculate sensor address and register.
  67          */
  68         if (!sensor)
  69                 sensor = DTT_I2C_LM63_ADDR;     /* legacy config */
  70
  71         dlen = 1;
  72         data[0] = (char)(val & 0xff);
  73
  74         /*
  75          * Write value to register.
  76          */
  77         if (i2c_write(sensor, reg, 1, data, dlen) != 0)
  78                 return 1;
  79
  80         return 0;
  81 }                               /* dtt_write() */
  82
  83 static int is_lm64(int sensor)
  84 {
  85         return sensor && (sensor != DTT_I2C_LM63_ADDR);
  86 }
  87
  88 int dtt_init_one(int sensor)
  89 {
  90         int i;
  91         int val;
  92
  93         struct pwm_lookup_entry pwm_lookup[] = CONFIG_DTT_PWM_LOOKUPTABLE;
  94
  95         /*
  96          * Set PWM Frequency to 2.5% resolution
  97          */
  98         val = 20;
  99         if (dtt_write(sensor, DTT_PWM_FREQ, val) != 0)
 100                 return 1;
 101
 102         /*
 103          * Set Tachometer Limit
 104          */
 105         val = CONFIG_DTT_TACH_LIMIT;
 106         if (dtt_write(sensor, DTT_TACHLIM_LSB, val & 0xff) != 0)
 107                 return 1;
 108         if (dtt_write(sensor, DTT_TACHLIM_MSB, (val >> 8) & 0xff) != 0)
 109                 return 1;
 110
 111         /*
 112          * Make sure PWM Lookup-Table is writeable
 113          */
 114         if (dtt_write(sensor, DTT_FAN_CONFIG, 0x20) != 0)
 115                 return 1;
 116
 117         /*
 118          * Setup PWM Lookup-Table
 119          */
 120         for (i = 0; i < ARRAY_SIZE(pwm_lookup); i++) {
 121                 int address = DTT_PWM_LOOKUP_BASE + 2 * i;
 122                 val = pwm_lookup[i].temp;
 123                 if (is_lm64(sensor))
 124                         val -= 16;
 125                 if (dtt_write(sensor, address, val) != 0)
 126                         return 1;
 127                 val = dtt_read(sensor, address);
 128                 val = pwm_lookup[i].pwm;
 129                 if (dtt_write(sensor, address + 1, val) != 0)
 130                         return 1;
 131         }
 132
 133         /*
 134          * Enable PWM Lookup-Table, PWM Clock 360 kHz, Tachometer Mode 2
 135          */
 136         val = 0x02;
 137         if (dtt_write(sensor, DTT_FAN_CONFIG, val) != 0)
 138                 return 1;
 139
 140         /*
 141          * Enable Tach input
 142          */
 143         val = dtt_read(sensor, DTT_CONFIG) | 0x04;
 144         if (dtt_write(sensor, DTT_CONFIG, val) != 0)
 145                 return 1;
 146
 147         return 0;
 148 }
 149
 150 int dtt_get_temp(int sensor)
 151 {
 152         s16 temp = (dtt_read(sensor, DTT_READ_TEMP_RMT_MSB) << 8)
 153             | (dtt_read(sensor, DTT_READ_TEMP_RMT_LSB));
 154
 155         if (is_lm64(sensor))
 156                 temp += 16 << 8;
 157
 158         /* Ignore LSB for now, U-Boot only prints natural numbers */
 159         return temp >> 8;
 160 }