mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-14 17:07:38 +00:00
65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
/*
|
|
* DS620 DTT support
|
|
*
|
|
* (C) Copyright 2014 3ADEV <http://www.3adev.com>
|
|
* Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
/*
|
|
* Dallas Semiconductor's DS1621/1631 Digital Thermometer and Thermostat.
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <i2c.h>
|
|
#include <dtt.h>
|
|
|
|
/*
|
|
* Device code
|
|
*/
|
|
#define DTT_I2C_DEV_CODE 0x48
|
|
#define DTT_START_CONVERT 0x51
|
|
#define DTT_TEMP 0xAA
|
|
#define DTT_CONFIG 0xAC
|
|
|
|
/*
|
|
* Config register MSB bits
|
|
*/
|
|
#define DTT_CONFIG_1SHOT 0x01
|
|
#define DTT_CONFIG_AUTOC 0x02
|
|
#define DTT_CONFIG_R0 0x04 /* always 1 */
|
|
#define DTT_CONFIG_R1 0x08 /* always 1 */
|
|
#define DTT_CONFIG_TLF 0x10
|
|
#define DTT_CONFIG_THF 0x20
|
|
#define DTT_CONFIG_NVB 0x40
|
|
#define DTT_CONFIG_DONE 0x80
|
|
|
|
#define CHIP(sensor) (DTT_I2C_DEV_CODE + (sensor & 0x07))
|
|
|
|
int dtt_init_one(int sensor)
|
|
{
|
|
uint8_t config = DTT_CONFIG_1SHOT
|
|
| DTT_CONFIG_R0
|
|
| DTT_CONFIG_R1;
|
|
return i2c_write(CHIP(sensor), DTT_CONFIG, 1, &config, 1);
|
|
}
|
|
|
|
int dtt_get_temp(int sensor)
|
|
{
|
|
uint8_t status;
|
|
uint8_t temp[2];
|
|
|
|
/* Start a conversion, may take up to 1 second. */
|
|
i2c_write(CHIP(sensor), DTT_START_CONVERT, 1, NULL, 0);
|
|
do {
|
|
if (i2c_read(CHIP(sensor), DTT_CONFIG, 1, &status, 1))
|
|
/* bail out if I2C error */
|
|
status |= DTT_CONFIG_DONE;
|
|
} while (!(status & DTT_CONFIG_DONE));
|
|
if (i2c_read(CHIP(sensor), DTT_TEMP, 1, temp, 2))
|
|
/* bail out if I2C error */
|
|
return -274; /* below absolute zero == error */
|
|
|
|
return ((int16_t)(temp[1] | (temp[0] << 8))) >> 7;
|
|
}
|