/* * (C) Copyright 2006 * Heiko Schocher, DENX Software Enginnering <hs@denx.de> * * based on dtt/lm75.c which is ... * * (C) Copyright 2001 * Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ /* * On Semiconductor's LM81 Temperature Sensor */ #include <common.h> #include <i2c.h> #include <dtt.h> /* * Device code */ #define DTT_I2C_DEV_CODE 0x2c /* ON Semi's LM81 device */ #define DTT_READ_TEMP 0x27 #define DTT_CONFIG_TEMP 0x4b #define DTT_TEMP_MAX 0x39 #define DTT_TEMP_HYST 0x3a #define DTT_CONFIG 0x40 int dtt_read(int sensor, int reg) { int dlen = 1; uchar data[2]; /* * Calculate sensor address and register. */ sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */ /* * Now try to read the register. */ if (i2c_read(sensor, reg, 1, data, dlen) != 0) return -1; return (int)data[0]; } /* dtt_read() */ int dtt_write(int sensor, int reg, int val) { uchar data; /* * Calculate sensor address and register. */ sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */ data = (char)(val & 0xff); /* * Write value to register. */ if (i2c_write(sensor, reg, 1, &data, 1) != 0) return 1; return 0; } /* dtt_write() */ #define DTT_MANU 0x3e #define DTT_REV 0x3f #define DTT_CONFIG 0x40 #define DTT_ADR 0x48 static int _dtt_init(int sensor) { int man; int adr; int rev; if (dtt_write (sensor, DTT_CONFIG, 0x01) < 0) return 1; /* The LM81 needs 400ms to get the correct values ... */ udelay (400000); man = dtt_read (sensor, DTT_MANU); if (man != 0x01) return 1; adr = dtt_read (sensor, DTT_ADR); if (adr < 0) return 1; rev = dtt_read (sensor, DTT_REV); if (adr < 0) return 1; debug ("DTT: Found LM81@%x Rev: %d\n", adr, rev); return 0; } /* _dtt_init() */ int dtt_init (void) { int i; unsigned char sensors[] = CONFIG_DTT_SENSORS; const char *const header = "DTT: "; for (i = 0; i < sizeof(sensors); i++) { if (_dtt_init(sensors[i]) != 0) printf("%s%d FAILED INIT\n", header, i+1); else printf("%s%d is %i C\n", header, i+1, dtt_get_temp(sensors[i])); } return (0); } /* dtt_init() */ #define TEMP_FROM_REG(temp) \ ((temp)<256?((((temp)&0x1fe) >> 1) * 10) + ((temp) & 1) * 5: \ ((((temp)&0x1fe) >> 1) -255) * 10 - ((temp) & 1) * 5) \ int dtt_get_temp(int sensor) { int val = dtt_read (sensor, DTT_READ_TEMP); int tmpcnf = dtt_read (sensor, DTT_CONFIG_TEMP); return (TEMP_FROM_REG((val << 1) + ((tmpcnf & 0x80) >> 7))) / 10; } /* dtt_get_temp() */