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  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 /*
  26  * National LM63 Temperature Sensor
  27  */
  28
  29 #include <common.h>
  30 #include <i2c.h>
  31 #include <dtt.h>
  32
  33 #define DTT_I2C_DEV_CODE 0x4C   /* National LM63 device */
  34
  35 #define DTT_READ_TEMP_RMT_MSB   0x01
  36 #define DTT_CONFIG              0x03
  37 #define DTT_READ_TEMP_RMT_LSB   0x10
  38 #define DTT_TACHLIM_LSB         0x48
  39 #define DTT_TACHLIM_MSB         0x49
  40 #define DTT_FAN_CONFIG          0x4A
  41 #define DTT_PWM_FREQ            0x4D
  42 #define DTT_PWM_LOOKUP_BASE     0x50
  43
  44 struct pwm_lookup_entry {
  45         u8 temp;
  46         u8 pwm;
  47 };
  48
  49 /*
  50  * Device code
  51  */
  52
  53 int dtt_read(int sensor, int reg)
  54 {
  55         int dlen;
  56         uchar data[2];
  57
  58         /*
  59          * Calculate sensor address and register.
  60          */
  61         sensor = DTT_I2C_DEV_CODE;      /* address of lm63 is not adjustable */
  62
  63         dlen = 1;
  64
  65         /*
  66          * Now try to read the register.
  67          */
  68         if (i2c_read(sensor, reg, 1, data, dlen) != 0)
  69                 return -1;
  70
  71         return (int)data[0];
  72 }                               /* dtt_read() */
  73
  74 int dtt_write(int sensor, int reg, int val)
  75 {
  76         int dlen;
  77         uchar data[2];
  78
  79         /*
  80          * Calculate sensor address and register.
  81          */
  82         sensor = DTT_I2C_DEV_CODE;      /* address of lm63 is not adjustable */
  83
  84         dlen = 1;
  85         data[0] = (char)(val & 0xff);
  86
  87         /*
  88          * Write value to register.
  89          */
  90         if (i2c_write(sensor, reg, 1, data, dlen) != 0)
  91                 return 1;
  92
  93         return 0;
  94 }                               /* dtt_write() */
  95
  96 static int _dtt_init(int sensor)
  97 {
  98         int i;
  99         int val;
 100
 101         struct pwm_lookup_entry pwm_lookup[] = CONFIG_DTT_PWM_LOOKUPTABLE;
 102
 103         /*
 104          * Set PWM Frequency to 2.5% resolution
 105          */
 106         val = 20;
 107         if (dtt_write(sensor, DTT_PWM_FREQ, val) != 0)
 108                 return 1;
 109
 110         /*
 111          * Set Tachometer Limit
 112          */
 113         val = CONFIG_DTT_TACH_LIMIT;
 114         if (dtt_write(sensor, DTT_TACHLIM_LSB, val & 0xff) != 0)
 115                 return 1;
 116         if (dtt_write(sensor, DTT_TACHLIM_MSB, (val >> 8) & 0xff) != 0)
 117                 return 1;
 118
 119         /*
 120          * Setup PWM Lookup-Table
 121          */
 122         for (i = 0; i < sizeof(pwm_lookup) / sizeof(struct pwm_lookup_entry);
 123              i++) {
 124                 int address = DTT_PWM_LOOKUP_BASE + 2 * i;
 125                 val = pwm_lookup[i].temp;
 126                 if (dtt_write(sensor, address, val) != 0)
 127                         return 1;
 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         /* Ignore LSB for now, U-Boot only prints natural numbers */
 156         return temp >> 8;
 157 }
 158
 159 int dtt_init(void)
 160 {
 161         int i;
 162         unsigned char sensors[] = CONFIG_DTT_SENSORS;
 163         const char *const header = "DTT:   ";
 164
 165         for (i = 0; i < sizeof(sensors); i++) {
 166                 if (_dtt_init(sensors[i]) != 0)
 167                         printf("%s%d FAILED INIT\n", header, i + 1);
 168                 else
 169                         printf("%s%d is %i C\n", header, i + 1,
 170                                dtt_get_temp(sensors[i]));
 171         }
 172
 173         return 0;
 174 }