mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-25 14:10:43 +00:00
156 lines
3.2 KiB
C
156 lines
3.2 KiB
C
/*
|
|
* 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
|
|
*/
|
|
|
|
/*
|
|
* Dallas Semiconductor's DS1775 Digital Thermometer and Thermostat
|
|
*/
|
|
|
|
#include <common.h>
|
|
|
|
#ifdef CONFIG_DTT_DS1775
|
|
#include <i2c.h>
|
|
#include <dtt.h>
|
|
|
|
#define DTT_I2C_DEV_CODE 0x49 /* Dallas Semi's DS1775 device code */
|
|
|
|
int dtt_read(int sensor, int reg)
|
|
{
|
|
int dlen;
|
|
uchar data[2];
|
|
|
|
/*
|
|
* Calculate sensor address and command
|
|
*/
|
|
sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* Calculate addr of ds1775 */
|
|
|
|
/*
|
|
* Prepare to handle 2 byte result
|
|
*/
|
|
if ((reg == DTT_READ_TEMP) ||
|
|
(reg == DTT_TEMP_OS) || (reg == DTT_TEMP_HYST))
|
|
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];
|
|
}
|
|
|
|
|
|
int dtt_write(int sensor, int reg, int val)
|
|
{
|
|
int dlen;
|
|
uchar data[2];
|
|
|
|
/*
|
|
* Calculate sensor address and register
|
|
*/
|
|
sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
|
|
|
|
/*
|
|
* Handle various data sizes
|
|
*/
|
|
if ((reg == DTT_READ_TEMP) ||
|
|
(reg == DTT_TEMP_OS) || (reg == DTT_TEMP_HYST)) {
|
|
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 device
|
|
*/
|
|
if (i2c_write(sensor, reg, 1, data, dlen) != 0)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int _dtt_init(int sensor)
|
|
{
|
|
int val;
|
|
|
|
/*
|
|
* Setup High Temp
|
|
*/
|
|
val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80;
|
|
if (dtt_write(sensor, DTT_TEMP_OS, val) != 0)
|
|
return 1;
|
|
udelay(50000); /* Max 50ms */
|
|
|
|
/*
|
|
* Setup Low Temp - hysteresis
|
|
*/
|
|
val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
|
|
if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0)
|
|
return 1;
|
|
udelay(50000); /* Max 50ms */
|
|
|
|
/*
|
|
* Setup configuraton register
|
|
*
|
|
* Fault Tolerance limits 4, Thermometer resolution bits is 9,
|
|
* Polarity = Active Low,continuous conversion mode, Thermostat
|
|
* mode is interrupt mode
|
|
*/
|
|
val = 0xa;
|
|
if (dtt_write(sensor, DTT_CONFIG, val) != 0)
|
|
return 1;
|
|
udelay(50000); /* Max 50ms */
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int dtt_init (void)
|
|
{
|
|
int i;
|
|
unsigned char sensors[] = CONFIG_DTT_SENSORS;
|
|
|
|
for (i = 0; i < sizeof(sensors); i++) {
|
|
if (_dtt_init(sensors[i]) != 0)
|
|
printf("DTT%d: FAILED\n", i+1);
|
|
else
|
|
printf("DTT%d: %i C\n", i+1, dtt_get_temp(sensors[i]));
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
|
|
int dtt_get_temp(int sensor)
|
|
{
|
|
return (dtt_read(sensor, DTT_READ_TEMP) / 256);
|
|
}
|
|
|
|
|
|
#endif /* CONFIG_DTT_DS1775 */
|