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Diffstat (limited to 'dtt/lm81.c')
| -rw-r--r-- | dtt/lm81.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/dtt/lm81.c b/dtt/lm81.c new file mode 100644 index 0000000..c83a3cd --- /dev/null +++ b/dtt/lm81.c @@ -0,0 +1,148 @@ +/* + * (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> + +#ifdef CONFIG_DTT_LM81 +#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_LM81" +#endif + +#include <i2c.h> +#include <dtt.h> + +/* + * Device code + */ +#define DTT_I2C_DEV_CODE 0x2c /* ON Semi's LM81 device */ + +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; + + printf ("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() */ + +#endif /* CONFIG_DTT_LM81 */ |