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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Maxim MAX197 A/D Converter driver
 *
 * Copyright (c) 2012 Savoir-faire Linux Inc.
 *          Vivien Didelot <[email protected]>
 *
 * For further information, see the Documentation/hwmon/max197.rst 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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
6c1fe725 VD	2	/*
	3	* Maxim MAX197 A/D Converter driver
	4	*
	5	* Copyright (c) 2012 Savoir-faire Linux Inc.
	6	* Vivien Didelot <[email protected]>
	7	*
7ebd8b66	8	* For further information, see the Documentation/hwmon/max197.rst file.
6c1fe725 VD	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
ac316725	13	#include <linux/mod_devicetable.h>
6c1fe725 VD	14	#include <linux/init.h>
	15	#include <linux/err.h>
	16	#include <linux/slab.h>
	17	#include <linux/mutex.h>
	18	#include <linux/device.h>
	19	#include <linux/sysfs.h>
	20	#include <linux/hwmon.h>
	21	#include <linux/hwmon-sysfs.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/platform_data/max197.h>
	24
	25	#define MAX199_LIMIT 4000 /* 4V */
	26	#define MAX197_LIMIT 10000 /* 10V */
	27
	28	#define MAX197_NUM_CH 8 /* 8 Analog Input Channels */
	29
	30	/* Control byte format */
	31	#define MAX197_BIP (1 << 3) /* Bipolarity */
	32	#define MAX197_RNG (1 << 4) /* Full range */
	33
	34	#define MAX197_SCALE 12207 /* Scale coefficient for raw data */
	35
	36	/* List of supported chips */
	37	enum max197_chips { max197, max199 };
	38
	39	/**
	40	* struct max197_data - device instance specific data
	41	* @pdata: Platform data.
	42	* @hwmon_dev: The hwmon device.
	43	* @lock: Read/Write mutex.
	44	* @limit: Max range value (10V for MAX197, 4V for MAX199).
	45	* @scale: Need to scale.
	46	* @ctrl_bytes: Channels control byte.
	47	*/
	48	struct max197_data {
	49	struct max197_platform_data *pdata;
	50	struct device *hwmon_dev;
	51	struct mutex lock;
	52	int limit;
	53	bool scale;
	54	u8 ctrl_bytes[MAX197_NUM_CH];
	55	};
	56
	57	static inline void max197_set_unipolarity(struct max197_data *data, int channel)
	58	{
	59	data->ctrl_bytes[channel] &= ~MAX197_BIP;
	60	}
	61
	62	static inline void max197_set_bipolarity(struct max197_data *data, int channel)
	63	{
	64	data->ctrl_bytes[channel] \|= MAX197_BIP;
	65	}
	66
	67	static inline void max197_set_half_range(struct max197_data *data, int channel)
	68	{
	69	data->ctrl_bytes[channel] &= ~MAX197_RNG;
	70	}
	71
	72	static inline void max197_set_full_range(struct max197_data *data, int channel)
	73	{
	74	data->ctrl_bytes[channel] \|= MAX197_RNG;
	75	}
	76
	77	static inline bool max197_is_bipolar(struct max197_data *data, int channel)
78	{
79	return data->ctrl_bytes[channel] & MAX197_BIP;
80	}
81
82	static inline bool max197_is_full_range(struct max197_data *data, int channel)
83	{
84	return data->ctrl_bytes[channel] & MAX197_RNG;
85	}
86
87	/* Function called on read access on in{0,1,2,3,4,5,6,7}_{min,max} */
88	static ssize_t max197_show_range(struct device *dev,
89	struct device_attribute devattr, char buf)
90	{
91	struct max197_data *data = dev_get_drvdata(dev);
92	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
93	int channel = attr->index;
94	bool is_min = attr->nr;
95	int range;
96
97	if (mutex_lock_interruptible(&data->lock))
98	return -ERESTARTSYS;
99
100	range = max197_is_full_range(data, channel) ?
101	data->limit : data->limit / 2;
102	if (is_min) {
103	if (max197_is_bipolar(data, channel))
104	range = -range;
105	else
106	range = 0;
107	}
108
109	mutex_unlock(&data->lock);
110
111	return sprintf(buf, "%d\n", range);
112	}
113
114	/* Function called on write access on in{0,1,2,3,4,5,6,7}_{min,max} */
115	static ssize_t max197_store_range(struct device *dev,
116	struct device_attribute *devattr,
117	const char *buf, size_t count)
118	{
119	struct max197_data *data = dev_get_drvdata(dev);
120	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
121	int channel = attr->index;
122	bool is_min = attr->nr;
123	long value;
124	int half = data->limit / 2;
125	int full = data->limit;
126
127	if (kstrtol(buf, 10, &value))
128	return -EINVAL;
129
130	if (is_min) {
131	if (value <= -full)
132	value = -full;
133	else if (value < 0)
134	value = -half;
135	else
136	value = 0;
137	} else {
138	if (value >= full)
139	value = full;
140	else
141	value = half;
142	}
143
144	if (mutex_lock_interruptible(&data->lock))
145	return -ERESTARTSYS;
146
147	if (value == 0) {
148	/* We can deduce only the polarity */
149	max197_set_unipolarity(data, channel);
150	} else if (value == -half) {
151	max197_set_bipolarity(data, channel);
152	max197_set_half_range(data, channel);
153	} else if (value == -full) {
154	max197_set_bipolarity(data, channel);
155	max197_set_full_range(data, channel);
156	} else if (value == half) {
157	/* We can deduce only the range */
158	max197_set_half_range(data, channel);
159	} else if (value == full) {
160	/* We can deduce only the range */
161	max197_set_full_range(data, channel);
162	}
163
164	mutex_unlock(&data->lock);
165
166	return count;
167	}
168
169	/* Function called on read access on in{0,1,2,3,4,5,6,7}_input */
170	static ssize_t max197_show_input(struct device *dev,
171	struct device_attribute *devattr,
172	char *buf)
173	{
174	struct max197_data *data = dev_get_drvdata(dev);
175	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
176	int channel = attr->index;
177	s32 value;
178	int ret;
179
180	if (mutex_lock_interruptible(&data->lock))
181	return -ERESTARTSYS;
182
183	ret = data->pdata->convert(data->ctrl_bytes[channel]);
184	if (ret < 0) {
185	dev_err(dev, "conversion failed\n");
186	goto unlock;
187	}
188	value = ret;
189
190	/*
191	* Coefficient to apply on raw value.
192	* See Table 1. Full Scale and Zero Scale in the MAX197 datasheet.
193	*/
194	if (data->scale) {
195	value *= MAX197_SCALE;
196	if (max197_is_full_range(data, channel))
197	value *= 2;
198	value /= 10000;
199	}
200
201	ret = sprintf(buf, "%d\n", value);
202
203	unlock:
204	mutex_unlock(&data->lock);
205	return ret;
206	}
207
a93c843b JL	208	static ssize_t name_show(struct device dev, struct device_attribute attr,
a93c843b JL	209	char *buf)
6c1fe725 VD	210	{
	211	struct platform_device *pdev = to_platform_device(dev);
	212	return sprintf(buf, "%s\n", pdev->name);
	213	}
	214
	215	#define MAX197_SENSOR_DEVICE_ATTR_CH(chan) \
	216	static SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO, \
	217	max197_show_input, NULL, chan); \
	218	static SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO \| S_IWUSR, \
	219	max197_show_range, \
	220	max197_store_range, \
	221	true, chan); \
	222	static SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO \| S_IWUSR, \
	223	max197_show_range, \
	224	max197_store_range, \
	225	false, chan)
	226
	227	#define MAX197_SENSOR_DEV_ATTR_IN(chan) \
	228	&sensor_dev_attr_in##chan##_input.dev_attr.attr, \
	229	&sensor_dev_attr_in##chan##_max.dev_attr.attr, \
	230	&sensor_dev_attr_in##chan##_min.dev_attr.attr
	231
a93c843b	232	static DEVICE_ATTR_RO(name);
6c1fe725 VD	233
	234	MAX197_SENSOR_DEVICE_ATTR_CH(0);
	235	MAX197_SENSOR_DEVICE_ATTR_CH(1);
	236	MAX197_SENSOR_DEVICE_ATTR_CH(2);
	237	MAX197_SENSOR_DEVICE_ATTR_CH(3);
	238	MAX197_SENSOR_DEVICE_ATTR_CH(4);
	239	MAX197_SENSOR_DEVICE_ATTR_CH(5);
	240	MAX197_SENSOR_DEVICE_ATTR_CH(6);
	241	MAX197_SENSOR_DEVICE_ATTR_CH(7);
	242
	243	static const struct attribute_group max197_sysfs_group = {
	244	.attrs = (struct attribute *[]) {
	245	&dev_attr_name.attr,
	246	MAX197_SENSOR_DEV_ATTR_IN(0),
	247	MAX197_SENSOR_DEV_ATTR_IN(1),
	248	MAX197_SENSOR_DEV_ATTR_IN(2),
	249	MAX197_SENSOR_DEV_ATTR_IN(3),
	250	MAX197_SENSOR_DEV_ATTR_IN(4),
	251	MAX197_SENSOR_DEV_ATTR_IN(5),
	252	MAX197_SENSOR_DEV_ATTR_IN(6),
	253	MAX197_SENSOR_DEV_ATTR_IN(7),
	254	NULL
	255	},
	256	};
	257
6c931ae1	258	static int max197_probe(struct platform_device *pdev)
6c1fe725 VD	259	{
	260	int ch, ret;
	261	struct max197_data *data;
a8b3a3a5	262	struct max197_platform_data *pdata = dev_get_platdata(&pdev->dev);
6c1fe725 VD	263	enum max197_chips chip = platform_get_device_id(pdev)->driver_data;
	264
	265	if (pdata == NULL) {
	266	dev_err(&pdev->dev, "no platform data supplied\n");
	267	return -EINVAL;
	268	}
	269
	270	if (pdata->convert == NULL) {
	271	dev_err(&pdev->dev, "no convert function supplied\n");
	272	return -EINVAL;
	273	}
	274
	275	data = devm_kzalloc(&pdev->dev, sizeof(struct max197_data), GFP_KERNEL);
6122de8f	276	if (!data)
6c1fe725	277	return -ENOMEM;
6c1fe725 VD	278
	279	data->pdata = pdata;
	280	mutex_init(&data->lock);
	281
	282	if (chip == max197) {
	283	data->limit = MAX197_LIMIT;
	284	data->scale = true;
	285	} else {
	286	data->limit = MAX199_LIMIT;
	287	data->scale = false;
	288	}
	289
	290	for (ch = 0; ch < MAX197_NUM_CH; ch++)
	291	data->ctrl_bytes[ch] = (u8) ch;
	292
	293	platform_set_drvdata(pdev, data);
	294
	295	ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group);
	296	if (ret) {
	297	dev_err(&pdev->dev, "sysfs create group failed\n");
	298	return ret;
	299	}
	300
	301	data->hwmon_dev = hwmon_device_register(&pdev->dev);
	302	if (IS_ERR(data->hwmon_dev)) {
	303	ret = PTR_ERR(data->hwmon_dev);
	304	dev_err(&pdev->dev, "hwmon device register failed\n");
	305	goto error;
	306	}
	307
	308	return 0;
	309
	310	error:
	311	sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
	312	return ret;
	313	}
	314
281dfd0b	315	static int max197_remove(struct platform_device *pdev)
6c1fe725 VD	316	{
	317	struct max197_data *data = platform_get_drvdata(pdev);
	318
	319	hwmon_device_unregister(data->hwmon_dev);
	320	sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
	321
	322	return 0;
	323	}
	324
9c2cbcec	325	static const struct platform_device_id max197_device_ids[] = {
6c1fe725 VD	326	{ "max197", max197 },
	327	{ "max199", max199 },
	328	{ }
	329	};
	330	MODULE_DEVICE_TABLE(platform, max197_device_ids);
	331
	332	static struct platform_driver max197_driver = {
	333	.driver = {
	334	.name = "max197",
6c1fe725 VD	335	},
6c1fe725 VD	336	.probe = max197_probe,
9e5e9b7a	337	.remove = max197_remove,
6c1fe725 VD	338	.id_table = max197_device_ids,
	339	};
	340	module_platform_driver(max197_driver);
	341
	342	MODULE_LICENSE("GPL");
	343	MODULE_AUTHOR("Savoir-faire Linux Inc. <[email protected]>");
	344	MODULE_DESCRIPTION("Maxim MAX197 A/D Converter driver");