hwmon: AD7314 driver (ported from IIO) (4f3a6595) · Commits · e / devices / android_kernel_samsung_universal8895

Documentation/hwmon/ad7314

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		Kernel driver ad7314
		====================

		Supported chips:
		* Analog Devices AD7314
		Prefix: 'ad7314'
		Datasheet: Publicly available at Analog Devices website.
		* Analog Devices ADT7301
		Prefix: 'adt7301'
		Datasheet: Publicly available at Analog Devices website.
		* Analog Devices ADT7302
		Prefix: 'adt7302'
		Datasheet: Publicly available at Analog Devices website.

		Description
		-----------

		Driver supports the above parts. The ad7314 has a 10 bit
		sensor with 1lsb = 0.25 degrees centigrade. The adt7301 and
		adt7302 have 14 bit sensors with 1lsb = 0.03125 degrees centigrade.

		Notes
		-----

		Currently power down mode is not supported.

drivers/hwmon/Kconfig

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		@@ -68,6 +68,16 @@ config SENSORS_ABITUGURU3
		This driver can also be built as a module. If so, the module
		will be called abituguru3.

		config SENSORS_AD7314
		tristate "Analog Devices AD7314 and compatibles"
		depends on SPI && EXPERIMENTAL
		help
		If you say yes here you get support for the Analog Devices
		AD7314, ADT7301 and ADT7302 temperature sensors.

		This driver can also be built as a module. If so, the module
		will be called ad7314.

		config SENSORS_AD7414
		tristate "Analog Devices AD7414"
		depends on I2C && EXPERIMENTAL

drivers/hwmon/Makefile

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		@@ -21,6 +21,7 @@ obj-$(CONFIG_SENSORS_W83791D) += w83791d.o

		obj-$(CONFIG_SENSORS_ABITUGURU) += abituguru.o
		obj-$(CONFIG_SENSORS_ABITUGURU3)+= abituguru3.o
		obj-$(CONFIG_SENSORS_AD7314) += ad7314.o
		obj-$(CONFIG_SENSORS_AD7414) += ad7414.o
		obj-$(CONFIG_SENSORS_AD7418) += ad7418.o
		obj-$(CONFIG_SENSORS_ADCXX) += adcxx.o

drivers/hwmon/ad7314.c

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		/*
		* AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
		*
		* Copyright 2010 Analog Devices Inc.
		*
		* Licensed under the GPL-2 or later.
		*
		* 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>

		/*
		* AD7314 power mode
		*/
		#define AD7314_PD 0x2000

		/*
		* AD7314 temperature masks
		*/
		#define AD7314_TEMP_SIGN 0x200
		#define AD7314_TEMP_MASK 0x7FE0
		#define AD7314_TEMP_OFFSET 5

		/*
		* ADT7301 and ADT7302 temperature masks
		*/
		#define ADT7301_TEMP_SIGN 0x2000
		#define ADT7301_TEMP_MASK 0x3FFF

		enum ad7314_variant {
		adt7301,
		adt7302,
		ad7314,
		};

		struct ad7314_data {
		struct spi_device *spi_dev;
		struct device *hwmon_dev;
		u16 rx ____cacheline_aligned;
		};

		static int ad7314_spi_read(struct ad7314_data chip, s16 data)
		{
		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;
		}

		*data = be16_to_cpu(chip->rx);

		return ret;
		}

		static ssize_t ad7314_show_temperature(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, &data);
		if (ret < 0)
		return ret;
		switch (spi_get_device_id(chip->spi_dev)->driver_data) {
		case ad7314:
		data = (data & AD7314_TEMP_MASK) >> AD7314_TEMP_OFFSET;
		data = (data << 6) >> 6;

		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 &= ADT7301_TEMP_MASK;
		data = (data << 2) >> 2;

		return sprintf(buf, "%d\n",
		DIV_ROUND_CLOSEST(data * 3125, 100));
		default:
		return -EINVAL;
		}
		}

		static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
		ad7314_show_temperature, NULL, 0);

		static struct attribute *ad7314_attributes[] = {
		&sensor_dev_attr_temp1_input.dev_attr.attr,
		NULL,
		};

		static const struct attribute_group ad7314_group = {
		.attrs = ad7314_attributes,
		};

		static int __devinit ad7314_probe(struct spi_device *spi_dev)
		{
		int ret;
		struct ad7314_data *chip;

		chip = kzalloc(sizeof(*chip), GFP_KERNEL);
		if (chip == NULL) {
		ret = -ENOMEM;
		goto error_ret;
		}
		dev_set_drvdata(&spi_dev->dev, chip);

		ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group);
		if (ret < 0)
		goto error_free_chip;
		chip->hwmon_dev = hwmon_device_register(&spi_dev->dev);
		if (IS_ERR(chip->hwmon_dev)) {
		ret = PTR_ERR(chip->hwmon_dev);
		goto error_remove_group;
		}

		return 0;
		error_remove_group:
		sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
		error_free_chip:
		kfree(chip);
		error_ret:
		return ret;
		}

		static int __devexit ad7314_remove(struct spi_device *spi_dev)
		{
		struct ad7314_data *chip = dev_get_drvdata(&spi_dev->dev);

		hwmon_device_unregister(chip->hwmon_dev);
		sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
		kfree(chip);

		return 0;
		}

		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",
		.bus = &spi_bus_type,
		.owner = THIS_MODULE,
		},
		.probe = ad7314_probe,
		.remove = __devexit_p(ad7314_remove),
		.id_table = ad7314_id,
		};

		static __init int ad7314_init(void)
		{
		return spi_register_driver(&ad7314_driver);
		}
		module_init(ad7314_init);

		static __exit void ad7314_exit(void)
		{
		spi_unregister_driver(&ad7314_driver);
		}
		module_exit(ad7314_exit);

		MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
		MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital"
		" temperature sensor driver");
		MODULE_LICENSE("GPL v2");