dtt: add ds620 support
Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
diff --git a/drivers/hwmon/ds620.c b/drivers/hwmon/ds620.c
new file mode 100644
index 0000000..1ecc3da
--- /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;
+}