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-rw-r--r--drivers/hwmon/ad7314.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/drivers/hwmon/ad7314.c b/drivers/hwmon/ad7314.c
new file mode 100644
index 000000000..7802bbf5f
--- /dev/null
+++ b/drivers/hwmon/ad7314.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Conversion to hwmon from IIO done by Jonathan Cameron <jic23@cam.ac.uk>
+ */
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/bitops.h>
+
+/*
+ * AD7314 temperature masks
+ */
+#define AD7314_TEMP_MASK 0x7FE0
+#define AD7314_TEMP_SHIFT 5
+
+/*
+ * ADT7301 and ADT7302 temperature masks
+ */
+#define ADT7301_TEMP_MASK 0x3FFF
+
+enum ad7314_variant {
+ adt7301,
+ adt7302,
+ ad7314,
+};
+
+struct ad7314_data {
+ struct spi_device *spi_dev;
+ u16 rx ____cacheline_aligned;
+};
+
+static int ad7314_spi_read(struct ad7314_data *chip)
+{
+ int ret;
+
+ ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx));
+ if (ret < 0) {
+ dev_err(&chip->spi_dev->dev, "SPI read error\n");
+ return ret;
+ }
+
+ return be16_to_cpu(chip->rx);
+}
+
+static ssize_t ad7314_temperature_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct ad7314_data *chip = dev_get_drvdata(dev);
+ s16 data;
+ int ret;
+
+ ret = ad7314_spi_read(chip);
+ if (ret < 0)
+ return ret;
+ switch (spi_get_device_id(chip->spi_dev)->driver_data) {
+ case ad7314:
+ data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT;
+ data = sign_extend32(data, 9);
+
+ return sprintf(buf, "%d\n", 250 * data);
+ case adt7301:
+ case adt7302:
+ /*
+ * Documented as a 13 bit twos complement register
+ * with a sign bit - which is a 14 bit 2's complement
+ * register. 1lsb - 31.25 milli degrees centigrade
+ */
+ data = ret & ADT7301_TEMP_MASK;
+ data = sign_extend32(data, 13);
+
+ return sprintf(buf, "%d\n",
+ DIV_ROUND_CLOSEST(data * 3125, 100));
+ default:
+ return -EINVAL;
+ }
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, ad7314_temperature, 0);
+
+static struct attribute *ad7314_attrs[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ NULL,
+};
+
+ATTRIBUTE_GROUPS(ad7314);
+
+static int ad7314_probe(struct spi_device *spi_dev)
+{
+ struct ad7314_data *chip;
+ struct device *hwmon_dev;
+
+ chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL);
+ if (chip == NULL)
+ return -ENOMEM;
+
+ chip->spi_dev = spi_dev;
+ hwmon_dev = devm_hwmon_device_register_with_groups(&spi_dev->dev,
+ spi_dev->modalias,
+ chip, ad7314_groups);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct spi_device_id ad7314_id[] = {
+ { "adt7301", adt7301 },
+ { "adt7302", adt7302 },
+ { "ad7314", ad7314 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad7314_id);
+
+static struct spi_driver ad7314_driver = {
+ .driver = {
+ .name = "ad7314",
+ },
+ .probe = ad7314_probe,
+ .id_table = ad7314_id,
+};
+
+module_spi_driver(ad7314_driver);
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver");
+MODULE_LICENSE("GPL v2");