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Diffstat (limited to 'u-boot/drivers/hwmon/lm73.c')
| -rw-r--r-- | u-boot/drivers/hwmon/lm73.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/u-boot/drivers/hwmon/lm73.c b/u-boot/drivers/hwmon/lm73.c new file mode 100644 index 0000000..7b5d893 --- /dev/null +++ b/u-boot/drivers/hwmon/lm73.c @@ -0,0 +1,178 @@ +/* + * (C) Copyright 2007-2008 + * 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> +#include <i2c.h> +#include <dtt.h> + +/* + * Device code + */ +#define DTT_I2C_DEV_CODE 0x48 /* National Semi's LM73 device */ +#define DTT_READ_TEMP 0x0 +#define DTT_CONFIG 0x1 +#define DTT_TEMP_HIGH 0x2 +#define DTT_TEMP_LOW 0x3 +#define DTT_CONTROL 0x4 +#define DTT_ID 0x7 + +int dtt_read(int const sensor, int const reg) +{ + int dlen; + uint8_t 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; + } + /* + * Try to read the register at the calculated sensor address. + */ + if (0 != + i2c_read(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, dlen)) + return -1; + /* + * Handle 2 byte result. + */ + if (2 == dlen) + return (int)((unsigned)data[0] << 8 | (unsigned)data[1]); + + return (int)data[0]; +} /* dtt_read() */ + +int dtt_write(int const sensor, int const reg, int const val) +{ + int dlen; + uint8_t data[2]; + + /* + * Validate 'reg' param and handle register size + */ + switch (reg) { + case DTT_CONFIG: + case DTT_CONTROL: + dlen = 1; + data[0] = (uint8_t) val; + break; + case DTT_TEMP_HIGH: + case DTT_TEMP_LOW: + dlen = 2; + data[0] = (uint8_t) (val >> 8); /* MSB first */ + data[1] = (uint8_t) val; + break; + default: + return -1; + } + /* + * Write value to register at the calculated sensor address. + */ + return 0 != i2c_write(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, + dlen); +} /* dtt_write() */ + +static int _dtt_init(int const 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 = CONFIG_SYS_DTT_MAX_TEMP << 7; + if (dtt_write(sensor, DTT_TEMP_HIGH, val)) + return -1; + + val = CONFIG_SYS_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 (0 != _dtt_init(sensors[i])) + 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 const sensor) +{ + int const ret = dtt_read(sensor, DTT_READ_TEMP); + + if (ret < 0) { + printf("DTT temperature read failed.\n"); + return 0; + } + return (int)((int16_t) ret + 0x0040) >> 7; +} /* dtt_get_temp() */ |