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Diffstat (limited to 'drivers/hwmon/lm73.c')
| -rw-r--r-- | drivers/hwmon/lm73.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c new file mode 100644 index 0000000..f9ae012 --- /dev/null +++ b/drivers/hwmon/lm73.c @@ -0,0 +1,181 @@ +/* + * (C) Copyright 2007 + * Larry Johnson, lrj@acm.org + * + * 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 + */ + +/* + * National Semiconductor LM73 Temperature Sensor + */ + +#include <common.h> + +#ifdef CONFIG_DTT_LM73 +#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_LM73" +#endif + +#include <i2c.h> +#include <dtt.h> + +/* + * Device code + */ +#define DTT_I2C_DEV_CODE 0x48 /* National Semi's LM73 device */ + +int dtt_read(int sensor, int reg) +{ + int dlen; + uchar data[2]; + + /* + * Validate 'reg' param and get register size. + */ + switch (reg) { + case DTT_CONFIG: + case DTT_CONTROL: + dlen = 1; + break; + case DTT_READ_TEMP: + case DTT_TEMP_HIGH: + case DTT_TEMP_LOW: + case DTT_ID: + dlen = 2; + break; + default: + return -1; + } + /* + * Calculate sensor address and register. + */ + sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate LM73 addr */ + /* + * Now try to read the register. + */ + if (i2c_read(sensor, reg, 1, data, dlen) != 0) + return -1; + /* + * Handle 2 byte result. + */ + if (2 == dlen) + 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 and handle register size + */ + switch (reg) { + case DTT_CONFIG: + case DTT_CONTROL: + dlen = 1; + data[0] = (char)(val & 0xff); + break; + case DTT_TEMP_HIGH: + case DTT_TEMP_LOW: + dlen = 2; + data[0] = (char)((val >> 8) & 0xff); /* MSB first */ + data[1] = (char)(val & 0xff); + break; + default: + return -1; + } + /* + * Calculate sensor address and register. + */ + sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate LM73 addr */ + /* + * Write value to register. + */ + return i2c_write(sensor, reg, 1, data, dlen) != 0; +} /* dtt_write() */ + +static int _dtt_init(int sensor) +{ + int val; + + /* + * Validate the Identification register + */ + if (0x0190 != dtt_read(sensor, DTT_ID)) + return 1; + /* + * Setup THIGH (upper-limit) and TLOW (lower-limit) registers + */ + val = CFG_DTT_MAX_TEMP << 7; + if (dtt_write(sensor, DTT_TEMP_HIGH, val)) + return 1; + + val = CFG_DTT_MIN_TEMP << 7; + if (dtt_write(sensor, DTT_TEMP_LOW, val)) + return 1; + /* + * Setup configuraton register + */ + /* config = alert active low, disabled, and reset */ + val = 0x64; + if (dtt_write(sensor, DTT_CONFIG, val)) + return 1; + /* + * Setup control/status register + */ + /* control = temp resolution 0.25C */ + val = 0x00; + if (dtt_write(sensor, DTT_CONTROL, val)) + return 1; + + dtt_read(sensor, DTT_CONTROL); /* clear temperature flags */ + 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) + 0x0040) >> 7; +} /* dtt_get_temp() */ + +#endif /* CONFIG_DTT_LM73 */ |