[linux-2.6-block.git] / drivers / hwmon / ad7314.c

/*
 * 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>
#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");
Commit	Line	Data
4f3a6595 JC	1	/*
	2	* AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
	3	*
	4	* Copyright 2010 Analog Devices Inc.
	5	*
	6	* Licensed under the GPL-2 or later.
	7	*
	8	* Conversion to hwmon from IIO done by Jonathan Cameron <jic23@cam.ac.uk>
	9	*/
	10	#include <linux/device.h>
	11	#include <linux/kernel.h>
	12	#include <linux/slab.h>
	13	#include <linux/sysfs.h>
	14	#include <linux/spi/spi.h>
	15	#include <linux/module.h>
	16	#include <linux/err.h>
	17	#include <linux/hwmon.h>
	18	#include <linux/hwmon-sysfs.h>
984faa1f	19	#include <linux/bitops.h>
4f3a6595	20
4f3a6595 JC	21	/*
	22	* AD7314 temperature masks
	23	*/
4f3a6595	24	#define AD7314_TEMP_MASK 0x7FE0
1137a9a6	25	#define AD7314_TEMP_SHIFT 5
4f3a6595 JC	26
	27	/*
	28	* ADT7301 and ADT7302 temperature masks
	29	*/
4f3a6595 JC	30	#define ADT7301_TEMP_MASK 0x3FFF
	31
	32	enum ad7314_variant {
	33	adt7301,
	34	adt7302,
	35	ad7314,
	36	};
	37
	38	struct ad7314_data {
	39	struct spi_device *spi_dev;
4f3a6595 JC	40	u16 rx ____cacheline_aligned;
	41	};
	42
eae1415d	43	static int ad7314_spi_read(struct ad7314_data *chip)
4f3a6595 JC	44	{
	45	int ret;
	46
	47	ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx));
	48	if (ret < 0) {
	49	dev_err(&chip->spi_dev->dev, "SPI read error\n");
	50	return ret;
	51	}
	52
eae1415d	53	return be16_to_cpu(chip->rx);
4f3a6595 JC	54	}
4f3a6595 JC	55
1ba3e023 GR	56	static ssize_t ad7314_temperature_show(struct device *dev,
	57	struct device_attribute *attr,
	58	char *buf)
4f3a6595 JC	59	{
	60	struct ad7314_data *chip = dev_get_drvdata(dev);
	61	s16 data;
	62	int ret;
	63
eae1415d	64	ret = ad7314_spi_read(chip);
4f3a6595 JC	65	if (ret < 0)
	66	return ret;
	67	switch (spi_get_device_id(chip->spi_dev)->driver_data) {
	68	case ad7314:
1137a9a6	69	data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT;
984faa1f	70	data = sign_extend32(data, 9);
4f3a6595 JC	71
	72	return sprintf(buf, "%d\n", 250 * data);
	73	case adt7301:
	74	case adt7302:
	75	/*
	76	* Documented as a 13 bit twos complement register
	77	* with a sign bit - which is a 14 bit 2's complement
	78	* register. 1lsb - 31.25 milli degrees centigrade
	79	*/
eae1415d	80	data = ret & ADT7301_TEMP_MASK;
984faa1f	81	data = sign_extend32(data, 13);
4f3a6595 JC	82
	83	return sprintf(buf, "%d\n",
	84	DIV_ROUND_CLOSEST(data * 3125, 100));
	85	default:
	86	return -EINVAL;
	87	}
	88	}
	89
1ba3e023	90	static SENSOR_DEVICE_ATTR_RO(temp1_input, ad7314_temperature, 0);
4f3a6595	91
157926c0	92	static struct attribute *ad7314_attrs[] = {
4f3a6595 JC	93	&sensor_dev_attr_temp1_input.dev_attr.attr,
	94	NULL,
	95	};
	96
157926c0	97	ATTRIBUTE_GROUPS(ad7314);
4f3a6595	98
6c931ae1	99	static int ad7314_probe(struct spi_device *spi_dev)
4f3a6595	100	{
4f3a6595	101	struct ad7314_data *chip;
157926c0	102	struct device *hwmon_dev;
4f3a6595	103
be923040 GR	104	chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL);
	105	if (chip == NULL)
	106	return -ENOMEM;
	107
e16de913	108	chip->spi_dev = spi_dev;
157926c0 AL	109	hwmon_dev = devm_hwmon_device_register_with_groups(&spi_dev->dev,
	110	spi_dev->modalias,
	111	chip, ad7314_groups);
	112	return PTR_ERR_OR_ZERO(hwmon_dev);
4f3a6595 JC	113	}
	114
	115	static const struct spi_device_id ad7314_id[] = {
	116	{ "adt7301", adt7301 },
	117	{ "adt7302", adt7302 },
	118	{ "ad7314", ad7314 },
	119	{ }
	120	};
	121	MODULE_DEVICE_TABLE(spi, ad7314_id);
	122
	123	static struct spi_driver ad7314_driver = {
	124	.driver = {
	125	.name = "ad7314",
4f3a6595 JC	126	},
4f3a6595 JC	127	.probe = ad7314_probe,
4f3a6595 JC	128	.id_table = ad7314_id,
	129	};
	130
91efffe2	131	module_spi_driver(ad7314_driver);
4f3a6595 JC	132
4f3a6595 JC	133	MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
b55f3757	134	MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver");
4f3a6595	135	MODULE_LICENSE("GPL v2");