[linux.git] / drivers / hwmon / max197.c

/*
 * Maxim MAX197 A/D Converter driver
 *
 * Copyright (c) 2012 Savoir-faire Linux Inc.
 *          Vivien Didelot <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * For further information, see the Documentation/hwmon/max197 file.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/platform_device.h>
#include <linux/platform_data/max197.h>

#define MAX199_LIMIT	4000		/* 4V */
#define MAX197_LIMIT	10000		/* 10V */

#define MAX197_NUM_CH	8		/* 8 Analog Input Channels */

/* Control byte format */
#define MAX197_BIP	(1 << 3)	/* Bipolarity */
#define MAX197_RNG	(1 << 4)	/* Full range */

#define MAX197_SCALE	12207		/* Scale coefficient for raw data */

/* List of supported chips */
enum max197_chips { max197, max199 };

/**
 * struct max197_data - device instance specific data
 * @pdata:		Platform data.
 * @hwmon_dev:		The hwmon device.
 * @lock:		Read/Write mutex.
 * @limit:		Max range value (10V for MAX197, 4V for MAX199).
 * @scale:		Need to scale.
 * @ctrl_bytes:		Channels control byte.
 */
struct max197_data {
	struct max197_platform_data *pdata;
	struct device *hwmon_dev;
	struct mutex lock;
	int limit;
	bool scale;
	u8 ctrl_bytes[MAX197_NUM_CH];
};

static inline void max197_set_unipolarity(struct max197_data *data, int channel)
{
	data->ctrl_bytes[channel] &= ~MAX197_BIP;
}

static inline void max197_set_bipolarity(struct max197_data *data, int channel)
{
	data->ctrl_bytes[channel] |= MAX197_BIP;
}

static inline void max197_set_half_range(struct max197_data *data, int channel)
{
	data->ctrl_bytes[channel] &= ~MAX197_RNG;
}

static inline void max197_set_full_range(struct max197_data *data, int channel)
{
	data->ctrl_bytes[channel] |= MAX197_RNG;
}

static inline bool max197_is_bipolar(struct max197_data *data, int channel)
{
	return data->ctrl_bytes[channel] & MAX197_BIP;
}

static inline bool max197_is_full_range(struct max197_data *data, int channel)
{
	return data->ctrl_bytes[channel] & MAX197_RNG;
}

/* Function called on read access on in{0,1,2,3,4,5,6,7}_{min,max} */
static ssize_t max197_show_range(struct device *dev,
				 struct device_attribute *devattr, char *buf)
{
	struct max197_data *data = dev_get_drvdata(dev);
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
	int channel = attr->index;
	bool is_min = attr->nr;
	int range;

	if (mutex_lock_interruptible(&data->lock))
		return -ERESTARTSYS;

	range = max197_is_full_range(data, channel) ?
		data->limit : data->limit / 2;
	if (is_min) {
		if (max197_is_bipolar(data, channel))
			range = -range;
		else
			range = 0;
	}

	mutex_unlock(&data->lock);

	return sprintf(buf, "%d\n", range);
}

/* Function called on write access on in{0,1,2,3,4,5,6,7}_{min,max} */
static ssize_t max197_store_range(struct device *dev,
				  struct device_attribute *devattr,
				  const char *buf, size_t count)
{
	struct max197_data *data = dev_get_drvdata(dev);
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
	int channel = attr->index;
	bool is_min = attr->nr;
	long value;
	int half = data->limit / 2;
	int full = data->limit;

	if (kstrtol(buf, 10, &value))
		return -EINVAL;

	if (is_min) {
		if (value <= -full)
			value = -full;
		else if (value < 0)
			value = -half;
		else
			value = 0;
	} else {
		if (value >= full)
			value = full;
		else
			value = half;
	}

	if (mutex_lock_interruptible(&data->lock))
		return -ERESTARTSYS;

	if (value == 0) {
		/* We can deduce only the polarity */
		max197_set_unipolarity(data, channel);
	} else if (value == -half) {
		max197_set_bipolarity(data, channel);
		max197_set_half_range(data, channel);
	} else if (value == -full) {
		max197_set_bipolarity(data, channel);
		max197_set_full_range(data, channel);
	} else if (value == half) {
		/* We can deduce only the range */
		max197_set_half_range(data, channel);
	} else if (value == full) {
		/* We can deduce only the range */
		max197_set_full_range(data, channel);
	}

	mutex_unlock(&data->lock);

	return count;
}

/* Function called on read access on in{0,1,2,3,4,5,6,7}_input */
static ssize_t max197_show_input(struct device *dev,
				 struct device_attribute *devattr,
				 char *buf)
{
	struct max197_data *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	int channel = attr->index;
	s32 value;
	int ret;

	if (mutex_lock_interruptible(&data->lock))
		return -ERESTARTSYS;

	ret = data->pdata->convert(data->ctrl_bytes[channel]);
	if (ret < 0) {
		dev_err(dev, "conversion failed\n");
		goto unlock;
	}
	value = ret;

	/*
	 * Coefficient to apply on raw value.
	 * See Table 1. Full Scale and Zero Scale in the MAX197 datasheet.
	 */
	if (data->scale) {
		value *= MAX197_SCALE;
		if (max197_is_full_range(data, channel))
			value *= 2;
		value /= 10000;
	}

	ret = sprintf(buf, "%d\n", value);

unlock:
	mutex_unlock(&data->lock);
	return ret;
}

static ssize_t name_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct platform_device *pdev = to_platform_device(dev);
	return sprintf(buf, "%s\n", pdev->name);
}

#define MAX197_SENSOR_DEVICE_ATTR_CH(chan)				\
	static SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO,		\
				  max197_show_input, NULL, chan);	\
	static SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO | S_IWUSR,	\
				    max197_show_range,			\
				    max197_store_range,			\
				    true, chan);			\
	static SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO | S_IWUSR,	\
				    max197_show_range,			\
				    max197_store_range,			\
				    false, chan)

#define MAX197_SENSOR_DEV_ATTR_IN(chan)					\
	&sensor_dev_attr_in##chan##_input.dev_attr.attr,		\
	&sensor_dev_attr_in##chan##_max.dev_attr.attr,			\
	&sensor_dev_attr_in##chan##_min.dev_attr.attr

static DEVICE_ATTR_RO(name);

MAX197_SENSOR_DEVICE_ATTR_CH(0);
MAX197_SENSOR_DEVICE_ATTR_CH(1);
MAX197_SENSOR_DEVICE_ATTR_CH(2);
MAX197_SENSOR_DEVICE_ATTR_CH(3);
MAX197_SENSOR_DEVICE_ATTR_CH(4);
MAX197_SENSOR_DEVICE_ATTR_CH(5);
MAX197_SENSOR_DEVICE_ATTR_CH(6);
MAX197_SENSOR_DEVICE_ATTR_CH(7);

static const struct attribute_group max197_sysfs_group = {
	.attrs = (struct attribute *[]) {
		&dev_attr_name.attr,
		MAX197_SENSOR_DEV_ATTR_IN(0),
		MAX197_SENSOR_DEV_ATTR_IN(1),
		MAX197_SENSOR_DEV_ATTR_IN(2),
		MAX197_SENSOR_DEV_ATTR_IN(3),
		MAX197_SENSOR_DEV_ATTR_IN(4),
		MAX197_SENSOR_DEV_ATTR_IN(5),
		MAX197_SENSOR_DEV_ATTR_IN(6),
		MAX197_SENSOR_DEV_ATTR_IN(7),
		NULL
	},
};

static int max197_probe(struct platform_device *pdev)
{
	int ch, ret;
	struct max197_data *data;
	struct max197_platform_data *pdata = dev_get_platdata(&pdev->dev);
	enum max197_chips chip = platform_get_device_id(pdev)->driver_data;

	if (pdata == NULL) {
		dev_err(&pdev->dev, "no platform data supplied\n");
		return -EINVAL;
	}

	if (pdata->convert == NULL) {
		dev_err(&pdev->dev, "no convert function supplied\n");
		return -EINVAL;
	}

	data = devm_kzalloc(&pdev->dev, sizeof(struct max197_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->pdata = pdata;
	mutex_init(&data->lock);

	if (chip == max197) {
		data->limit = MAX197_LIMIT;
		data->scale = true;
	} else {
		data->limit = MAX199_LIMIT;
		data->scale = false;
	}

	for (ch = 0; ch < MAX197_NUM_CH; ch++)
		data->ctrl_bytes[ch] = (u8) ch;

	platform_set_drvdata(pdev, data);

	ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group);
	if (ret) {
		dev_err(&pdev->dev, "sysfs create group failed\n");
		return ret;
	}

	data->hwmon_dev = hwmon_device_register(&pdev->dev);
	if (IS_ERR(data->hwmon_dev)) {
		ret = PTR_ERR(data->hwmon_dev);
		dev_err(&pdev->dev, "hwmon device register failed\n");
		goto error;
	}

	return 0;

error:
	sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
	return ret;
}

static int max197_remove(struct platform_device *pdev)
{
	struct max197_data *data = platform_get_drvdata(pdev);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);

	return 0;
}

static const struct platform_device_id max197_device_ids[] = {
	{ "max197", max197 },
	{ "max199", max199 },
	{ }
};
MODULE_DEVICE_TABLE(platform, max197_device_ids);

static struct platform_driver max197_driver = {
	.driver = {
		.name = "max197",
	},
	.probe = max197_probe,
	.remove = max197_remove,
	.id_table = max197_device_ids,
};
module_platform_driver(max197_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Savoir-faire Linux Inc. <[email protected]>");
MODULE_DESCRIPTION("Maxim MAX197 A/D Converter driver");
Commit	Line	Data
6c1fe725 VD	1	/*
	2	* Maxim MAX197 A/D Converter driver
	3	*
	4	* Copyright (c) 2012 Savoir-faire Linux Inc.
	5	* Vivien Didelot <[email protected]>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* For further information, see the Documentation/hwmon/max197 file.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
ac316725	16	#include <linux/mod_devicetable.h>
6c1fe725 VD	17	#include <linux/init.h>
	18	#include <linux/err.h>
	19	#include <linux/slab.h>
	20	#include <linux/mutex.h>
	21	#include <linux/device.h>
	22	#include <linux/sysfs.h>
	23	#include <linux/hwmon.h>
	24	#include <linux/hwmon-sysfs.h>
	25	#include <linux/platform_device.h>
	26	#include <linux/platform_data/max197.h>
	27
	28	#define MAX199_LIMIT 4000 /* 4V */
	29	#define MAX197_LIMIT 10000 /* 10V */
	30
	31	#define MAX197_NUM_CH 8 /* 8 Analog Input Channels */
	32
	33	/* Control byte format */
	34	#define MAX197_BIP (1 << 3) /* Bipolarity */
	35	#define MAX197_RNG (1 << 4) /* Full range */
	36
	37	#define MAX197_SCALE 12207 /* Scale coefficient for raw data */
	38
	39	/* List of supported chips */
	40	enum max197_chips { max197, max199 };
	41
	42	/**
	43	* struct max197_data - device instance specific data
	44	* @pdata: Platform data.
	45	* @hwmon_dev: The hwmon device.
	46	* @lock: Read/Write mutex.
	47	* @limit: Max range value (10V for MAX197, 4V for MAX199).
	48	* @scale: Need to scale.
	49	* @ctrl_bytes: Channels control byte.
	50	*/
	51	struct max197_data {
	52	struct max197_platform_data *pdata;
	53	struct device *hwmon_dev;
	54	struct mutex lock;
	55	int limit;
	56	bool scale;
	57	u8 ctrl_bytes[MAX197_NUM_CH];
	58	};
	59
	60	static inline void max197_set_unipolarity(struct max197_data *data, int channel)
	61	{
	62	data->ctrl_bytes[channel] &= ~MAX197_BIP;
	63	}
	64
	65	static inline void max197_set_bipolarity(struct max197_data *data, int channel)
	66	{
	67	data->ctrl_bytes[channel] \|= MAX197_BIP;
	68	}
	69
	70	static inline void max197_set_half_range(struct max197_data *data, int channel)
	71	{
	72	data->ctrl_bytes[channel] &= ~MAX197_RNG;
	73	}
	74
	75	static inline void max197_set_full_range(struct max197_data *data, int channel)
	76	{
	77	data->ctrl_bytes[channel] \|= MAX197_RNG;
	78	}
	79
	80	static inline bool max197_is_bipolar(struct max197_data *data, int channel)
81	{
82	return data->ctrl_bytes[channel] & MAX197_BIP;
83	}
84
85	static inline bool max197_is_full_range(struct max197_data *data, int channel)
86	{
87	return data->ctrl_bytes[channel] & MAX197_RNG;
88	}
89
90	/* Function called on read access on in{0,1,2,3,4,5,6,7}_{min,max} */
91	static ssize_t max197_show_range(struct device *dev,
92	struct device_attribute devattr, char buf)
93	{
94	struct max197_data *data = dev_get_drvdata(dev);
95	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
96	int channel = attr->index;
97	bool is_min = attr->nr;
98	int range;
99
100	if (mutex_lock_interruptible(&data->lock))
101	return -ERESTARTSYS;
102
103	range = max197_is_full_range(data, channel) ?
104	data->limit : data->limit / 2;
105	if (is_min) {
106	if (max197_is_bipolar(data, channel))
107	range = -range;
108	else
109	range = 0;
110	}
111
112	mutex_unlock(&data->lock);
113
114	return sprintf(buf, "%d\n", range);
115	}
116
117	/* Function called on write access on in{0,1,2,3,4,5,6,7}_{min,max} */
118	static ssize_t max197_store_range(struct device *dev,
119	struct device_attribute *devattr,
120	const char *buf, size_t count)
121	{
122	struct max197_data *data = dev_get_drvdata(dev);
123	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
124	int channel = attr->index;
125	bool is_min = attr->nr;
126	long value;
127	int half = data->limit / 2;
128	int full = data->limit;
129
130	if (kstrtol(buf, 10, &value))
131	return -EINVAL;
132
133	if (is_min) {
134	if (value <= -full)
135	value = -full;
136	else if (value < 0)
137	value = -half;
138	else
139	value = 0;
140	} else {
141	if (value >= full)
142	value = full;
143	else
144	value = half;
145	}
146
147	if (mutex_lock_interruptible(&data->lock))
148	return -ERESTARTSYS;
149
150	if (value == 0) {
151	/* We can deduce only the polarity */
152	max197_set_unipolarity(data, channel);
153	} else if (value == -half) {
154	max197_set_bipolarity(data, channel);
155	max197_set_half_range(data, channel);
156	} else if (value == -full) {
157	max197_set_bipolarity(data, channel);
158	max197_set_full_range(data, channel);
159	} else if (value == half) {
160	/* We can deduce only the range */
161	max197_set_half_range(data, channel);
162	} else if (value == full) {
163	/* We can deduce only the range */
164	max197_set_full_range(data, channel);
165	}
166
167	mutex_unlock(&data->lock);
168
169	return count;
170	}
171
172	/* Function called on read access on in{0,1,2,3,4,5,6,7}_input */
173	static ssize_t max197_show_input(struct device *dev,
174	struct device_attribute *devattr,
175	char *buf)
176	{
177	struct max197_data *data = dev_get_drvdata(dev);
178	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
179	int channel = attr->index;
180	s32 value;
181	int ret;
182
183	if (mutex_lock_interruptible(&data->lock))
184	return -ERESTARTSYS;
185
186	ret = data->pdata->convert(data->ctrl_bytes[channel]);
187	if (ret < 0) {
188	dev_err(dev, "conversion failed\n");
189	goto unlock;
190	}
191	value = ret;
192
193	/*
194	* Coefficient to apply on raw value.
195	* See Table 1. Full Scale and Zero Scale in the MAX197 datasheet.
196	*/
197	if (data->scale) {
198	value *= MAX197_SCALE;
199	if (max197_is_full_range(data, channel))
200	value *= 2;
201	value /= 10000;
202	}
203
204	ret = sprintf(buf, "%d\n", value);
205
206	unlock:
207	mutex_unlock(&data->lock);
208	return ret;
209	}
210
a93c843b JL	211	static ssize_t name_show(struct device dev, struct device_attribute attr,
a93c843b JL	212	char *buf)
6c1fe725 VD	213	{
	214	struct platform_device *pdev = to_platform_device(dev);
	215	return sprintf(buf, "%s\n", pdev->name);
	216	}
	217
	218	#define MAX197_SENSOR_DEVICE_ATTR_CH(chan) \
	219	static SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO, \
	220	max197_show_input, NULL, chan); \
	221	static SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO \| S_IWUSR, \
	222	max197_show_range, \
	223	max197_store_range, \
	224	true, chan); \
	225	static SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO \| S_IWUSR, \
	226	max197_show_range, \
	227	max197_store_range, \
	228	false, chan)
	229
	230	#define MAX197_SENSOR_DEV_ATTR_IN(chan) \
	231	&sensor_dev_attr_in##chan##_input.dev_attr.attr, \
	232	&sensor_dev_attr_in##chan##_max.dev_attr.attr, \
	233	&sensor_dev_attr_in##chan##_min.dev_attr.attr
	234
a93c843b	235	static DEVICE_ATTR_RO(name);
6c1fe725 VD	236
	237	MAX197_SENSOR_DEVICE_ATTR_CH(0);
	238	MAX197_SENSOR_DEVICE_ATTR_CH(1);
	239	MAX197_SENSOR_DEVICE_ATTR_CH(2);
	240	MAX197_SENSOR_DEVICE_ATTR_CH(3);
	241	MAX197_SENSOR_DEVICE_ATTR_CH(4);
	242	MAX197_SENSOR_DEVICE_ATTR_CH(5);
	243	MAX197_SENSOR_DEVICE_ATTR_CH(6);
	244	MAX197_SENSOR_DEVICE_ATTR_CH(7);
	245
	246	static const struct attribute_group max197_sysfs_group = {
	247	.attrs = (struct attribute *[]) {
	248	&dev_attr_name.attr,
	249	MAX197_SENSOR_DEV_ATTR_IN(0),
	250	MAX197_SENSOR_DEV_ATTR_IN(1),
	251	MAX197_SENSOR_DEV_ATTR_IN(2),
	252	MAX197_SENSOR_DEV_ATTR_IN(3),
	253	MAX197_SENSOR_DEV_ATTR_IN(4),
	254	MAX197_SENSOR_DEV_ATTR_IN(5),
	255	MAX197_SENSOR_DEV_ATTR_IN(6),
	256	MAX197_SENSOR_DEV_ATTR_IN(7),
	257	NULL
	258	},
	259	};
	260
6c931ae1	261	static int max197_probe(struct platform_device *pdev)
6c1fe725 VD	262	{
	263	int ch, ret;
	264	struct max197_data *data;
a8b3a3a5	265	struct max197_platform_data *pdata = dev_get_platdata(&pdev->dev);
6c1fe725 VD	266	enum max197_chips chip = platform_get_device_id(pdev)->driver_data;
	267
	268	if (pdata == NULL) {
	269	dev_err(&pdev->dev, "no platform data supplied\n");
	270	return -EINVAL;
	271	}
	272
	273	if (pdata->convert == NULL) {
	274	dev_err(&pdev->dev, "no convert function supplied\n");
	275	return -EINVAL;
	276	}
	277
	278	data = devm_kzalloc(&pdev->dev, sizeof(struct max197_data), GFP_KERNEL);
6122de8f	279	if (!data)
6c1fe725	280	return -ENOMEM;
6c1fe725 VD	281
	282	data->pdata = pdata;
	283	mutex_init(&data->lock);
	284
	285	if (chip == max197) {
	286	data->limit = MAX197_LIMIT;
	287	data->scale = true;
	288	} else {
	289	data->limit = MAX199_LIMIT;
	290	data->scale = false;
	291	}
	292
	293	for (ch = 0; ch < MAX197_NUM_CH; ch++)
	294	data->ctrl_bytes[ch] = (u8) ch;
	295
	296	platform_set_drvdata(pdev, data);
	297
	298	ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group);
	299	if (ret) {
	300	dev_err(&pdev->dev, "sysfs create group failed\n");
	301	return ret;
	302	}
	303
	304	data->hwmon_dev = hwmon_device_register(&pdev->dev);
	305	if (IS_ERR(data->hwmon_dev)) {
	306	ret = PTR_ERR(data->hwmon_dev);
	307	dev_err(&pdev->dev, "hwmon device register failed\n");
	308	goto error;
	309	}
	310
	311	return 0;
	312
	313	error:
	314	sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
	315	return ret;
	316	}
	317
281dfd0b	318	static int max197_remove(struct platform_device *pdev)
6c1fe725 VD	319	{
	320	struct max197_data *data = platform_get_drvdata(pdev);
	321
	322	hwmon_device_unregister(data->hwmon_dev);
	323	sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
	324
	325	return 0;
	326	}
	327
9c2cbcec	328	static const struct platform_device_id max197_device_ids[] = {
6c1fe725 VD	329	{ "max197", max197 },
	330	{ "max199", max199 },
	331	{ }
	332	};
	333	MODULE_DEVICE_TABLE(platform, max197_device_ids);
	334
	335	static struct platform_driver max197_driver = {
	336	.driver = {
	337	.name = "max197",
6c1fe725 VD	338	},
6c1fe725 VD	339	.probe = max197_probe,
9e5e9b7a	340	.remove = max197_remove,
6c1fe725 VD	341	.id_table = max197_device_ids,
	342	};
	343	module_platform_driver(max197_driver);
	344
	345	MODULE_LICENSE("GPL");
	346	MODULE_AUTHOR("Savoir-faire Linux Inc. <[email protected]>");
	347	MODULE_DESCRIPTION("Maxim MAX197 A/D Converter driver");