From 24d528e3fa3a8370aa5263592c362b7d61642340 Mon Sep 17 00:00:00 2001
From: "Albert ARIBAUD \\(3ADEV\\)" <albert.aribaud@3adev.fr>
Date: Tue, 31 Mar 2015 11:40:48 +0200
Subject: dtt: add ds620 support

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
---
 drivers/hwmon/ds620.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 drivers/hwmon/ds620.c

(limited to 'drivers/hwmon/ds620.c')

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;
+}
-- 
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