diff options
author | Tom Rini <trini@konsulko.com> | 2015-04-10 09:38:38 -0400 |
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committer | Tom Rini <trini@konsulko.com> | 2015-04-10 11:54:07 -0400 |
commit | 59064346dd2713e5259a32d5ef55792a8f91171b (patch) | |
tree | 2192fa718f041119e9ba64a9d76f7fe7c546d480 /drivers/hwmon/ds620.c | |
parent | 6d0f45260846b8cafcae6a815178ff8ece7dea7a (diff) | |
parent | 412ae53aadb53cd63e754d638bafe6e426aeafee (diff) |
Merge branch 'master' of git://git.denx.de/u-boot-arm
Diffstat (limited to 'drivers/hwmon/ds620.c')
-rw-r--r-- | drivers/hwmon/ds620.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/hwmon/ds620.c b/drivers/hwmon/ds620.c new file mode 100644 index 0000000000..1ecc3da799 --- /dev/null +++ b/drivers/hwmon/ds620.c @@ -0,0 +1,65 @@ +/* + * 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; +} |