[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;
	struct device		*hwmon_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_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);
	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 ssize_t ad7314_show_name(struct device *dev,
				struct device_attribute *devattr, char *buf)
{
	return sprintf(buf, "%s\n", to_spi_device(dev)->modalias);
}

static DEVICE_ATTR(name, S_IRUGO, ad7314_show_name, NULL);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
			  ad7314_show_temperature, NULL, 0);

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

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

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

	chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL);
	if (chip == NULL)
		return -ENOMEM;

	spi_set_drvdata(spi_dev, chip);

	ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group);
	if (ret < 0)
		return ret;

	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;
	}
	chip->spi_dev = spi_dev;

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

static int ad7314_remove(struct spi_device *spi_dev)
{
	struct ad7314_data *chip = spi_get_drvdata(spi_dev);

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

	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",
	},
	.probe = ad7314_probe,
	.remove = ad7314_remove,
	.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;
	40	struct device *hwmon_dev;
	41	u16 rx ____cacheline_aligned;
	42	};
	43
eae1415d	44	static int ad7314_spi_read(struct ad7314_data *chip)
4f3a6595 JC	45	{
	46	int ret;
	47
	48	ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx));
	49	if (ret < 0) {
	50	dev_err(&chip->spi_dev->dev, "SPI read error\n");
	51	return ret;
	52	}
	53
eae1415d	54	return be16_to_cpu(chip->rx);
4f3a6595 JC	55	}
	56
	57	static ssize_t ad7314_show_temperature(struct device *dev,
	58	struct device_attribute *attr,
	59	char *buf)
	60	{
	61	struct ad7314_data *chip = dev_get_drvdata(dev);
	62	s16 data;
	63	int ret;
	64
eae1415d	65	ret = ad7314_spi_read(chip);
4f3a6595 JC	66	if (ret < 0)
	67	return ret;
	68	switch (spi_get_device_id(chip->spi_dev)->driver_data) {
	69	case ad7314:
1137a9a6	70	data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT;
984faa1f	71	data = sign_extend32(data, 9);
4f3a6595 JC	72
	73	return sprintf(buf, "%d\n", 250 * data);
	74	case adt7301:
	75	case adt7302:
	76	/*
	77	* Documented as a 13 bit twos complement register
	78	* with a sign bit - which is a 14 bit 2's complement
	79	* register. 1lsb - 31.25 milli degrees centigrade
	80	*/
eae1415d	81	data = ret & ADT7301_TEMP_MASK;
984faa1f	82	data = sign_extend32(data, 13);
4f3a6595 JC	83
	84	return sprintf(buf, "%d\n",
	85	DIV_ROUND_CLOSEST(data * 3125, 100));
	86	default:
	87	return -EINVAL;
	88	}
	89	}
	90
3ceefe43 GR	91	static ssize_t ad7314_show_name(struct device *dev,
	92	struct device_attribute devattr, char buf)
	93	{
	94	return sprintf(buf, "%s\n", to_spi_device(dev)->modalias);
	95	}
	96
	97	static DEVICE_ATTR(name, S_IRUGO, ad7314_show_name, NULL);
4f3a6595 JC	98	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
	99	ad7314_show_temperature, NULL, 0);
	100
	101	static struct attribute *ad7314_attributes[] = {
3ceefe43	102	&dev_attr_name.attr,
4f3a6595 JC	103	&sensor_dev_attr_temp1_input.dev_attr.attr,
	104	NULL,
	105	};
	106
	107	static const struct attribute_group ad7314_group = {
	108	.attrs = ad7314_attributes,
	109	};
	110
6c931ae1	111	static int ad7314_probe(struct spi_device *spi_dev)
4f3a6595 JC	112	{
	113	int ret;
	114	struct ad7314_data *chip;
	115
be923040 GR	116	chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL);
	117	if (chip == NULL)
	118	return -ENOMEM;
	119
debe597c	120	spi_set_drvdata(spi_dev, chip);
4f3a6595 JC	121
	122	ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group);
	123	if (ret < 0)
be923040 GR	124	return ret;
be923040 GR	125
4f3a6595 JC	126	chip->hwmon_dev = hwmon_device_register(&spi_dev->dev);
	127	if (IS_ERR(chip->hwmon_dev)) {
	128	ret = PTR_ERR(chip->hwmon_dev);
	129	goto error_remove_group;
	130	}
e16de913	131	chip->spi_dev = spi_dev;
4f3a6595 JC	132
	133	return 0;
	134	error_remove_group:
	135	sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
4f3a6595 JC	136	return ret;
	137	}
	138
281dfd0b	139	static int ad7314_remove(struct spi_device *spi_dev)
4f3a6595	140	{
debe597c	141	struct ad7314_data *chip = spi_get_drvdata(spi_dev);
4f3a6595 JC	142
	143	hwmon_device_unregister(chip->hwmon_dev);
	144	sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
4f3a6595 JC	145
	146	return 0;
	147	}
	148
	149	static const struct spi_device_id ad7314_id[] = {
	150	{ "adt7301", adt7301 },
	151	{ "adt7302", adt7302 },
	152	{ "ad7314", ad7314 },
	153	{ }
	154	};
	155	MODULE_DEVICE_TABLE(spi, ad7314_id);
	156
	157	static struct spi_driver ad7314_driver = {
	158	.driver = {
	159	.name = "ad7314",
4f3a6595 JC	160	},
4f3a6595 JC	161	.probe = ad7314_probe,
9e5e9b7a	162	.remove = ad7314_remove,
4f3a6595 JC	163	.id_table = ad7314_id,
	164	};
	165
91efffe2	166	module_spi_driver(ad7314_driver);
4f3a6595 JC	167
4f3a6595 JC	168	MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
b55f3757	169	MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver");
4f3a6595	170	MODULE_LICENSE("GPL v2");