/* * (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 LM75 Temperature Sensor */ #include <common.h> #ifdef CONFIG_DTT_LM75 #if !defined(CFG_EEPROM_PAGE_WRITE_ENABLE) || \ (CFG_EEPROM_PAGE_WRITE_BITS < 1) # error "CFG_EEPROM_PAGE_WRITE_ENABLE must be defined and CFG_EEPROM_PAGE_WRITE_BITS must be greater than 1 to use CONFIG_DTT_LM75" #endif #include <i2c.h> #include <dtt.h> /* * Device code */ #define DTT_I2C_DEV_CODE 0x48 /* ON Semi's LM75 device */ int dtt_read(int sensor, int reg) { int dlen; uchar data[2]; /* * Validate 'reg' param */ if((reg < 0) || (reg > 3)) return -1; /* * Calculate sensor address and register. */ sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate address of lm75 */ /* * Prepare to handle 2 byte result. */ if ((reg == DTT_READ_TEMP) || (reg == DTT_TEMP_HYST) || (reg == DTT_TEMP_SET)) dlen = 2; else dlen = 1; /* * Now try to read the register. */ if (i2c_read(sensor, reg, 1, data, dlen) != 0) return -1; /* * Handle 2 byte result. */ if (dlen == 2) return ((int)((short)data[1] + (((short)data[0]) << 8))); return (int)data[0]; } /* dtt_read() */ int dtt_write(int sensor, int reg, int val) { int dlen; uchar data[2]; /* * Validate 'reg' param */ if ((reg < 0) || (reg > 3)) return 1; /* * Calculate sensor address and register. */ sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate address of lm75 */ /* * Handle 2 byte values. */ if ((reg == DTT_READ_TEMP) || (reg == DTT_TEMP_HYST) || (reg == DTT_TEMP_SET)) { dlen = 2; data[0] = (char)((val >> 8) & 0xff); /* MSB first */ data[1] = (char)(val & 0xff); } else { dlen = 1; data[0] = (char)(val & 0xff); } /* * Write value to register. */ if (i2c_write(sensor, reg, 1, data, dlen) != 0) return 1; return 0; } /* dtt_write() */ static int _dtt_init(int sensor) { int val; /* * Setup TSET ( trip point ) register */ val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80; /* trip */ if (dtt_write(sensor, DTT_TEMP_SET, val) != 0) return 1; /* * Setup THYST ( untrip point ) register - Hysteresis */ val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80; if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0) return 1; /* * Setup configuraton register */ #ifdef CONFIG_DTT_AD7414 /* config = alert active low and disabled */ val = 0x60; #else /* config = 6 sample integration, int mode, active low, and enable */ val = 0x18; #endif if (dtt_write(sensor, DTT_CONFIG, val) != 0) return 1; 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() */ int dtt_get_temp(int sensor) { return (dtt_read(sensor, DTT_READ_TEMP) / 256); } /* dtt_get_temp() */ #endif /* CONFIG_DTT_LM75 */