[linux-2.6-block.git] / drivers / hwmon / tc74.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * An hwmon driver for the Microchip TC74
 *
 * Copyright 2015 Maciej Szmigiero <mail@maciej.szmigiero.name>
 *
 * Based on ad7414.c:
 *	Copyright 2006 Stefan Roese, DENX Software Engineering
 *	Copyright 2008 Sean MacLennan, PIKA Technologies
 *	Copyright 2008 Frank Edelhaeuser, Spansion Inc.
 */

#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/sysfs.h>

/* TC74 registers */
#define TC74_REG_TEMP		0x00
#define TC74_REG_CONFIG		0x01

struct tc74_data {
	struct i2c_client	*client;
	struct mutex		lock;	/* atomic read data updates */
	bool			valid;	/* validity of fields below */
	unsigned long		next_update;	/* In jiffies */
	s8			temp_input;	/* Temp value in dC */
};

static int tc74_update_device(struct device *dev)
{
	struct tc74_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	ret = mutex_lock_interruptible(&data->lock);
	if (ret)
		return ret;

	if (time_after(jiffies, data->next_update) || !data->valid) {
		s32 value;

		value = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
		if (value < 0) {
			dev_dbg(&client->dev, "TC74_REG_CONFIG read err %d\n",
				(int)value);

			ret = value;
			goto ret_unlock;
		}

		if (!(value & BIT(6))) {
			/* not ready yet */

			ret = -EAGAIN;
			goto ret_unlock;
		}

		value = i2c_smbus_read_byte_data(client, TC74_REG_TEMP);
		if (value < 0) {
			dev_dbg(&client->dev, "TC74_REG_TEMP read err %d\n",
				(int)value);

			ret = value;
			goto ret_unlock;
		}

		data->temp_input = value;
		data->next_update = jiffies + HZ / 4;
		data->valid = true;
	}

ret_unlock:
	mutex_unlock(&data->lock);

	return ret;
}

static ssize_t temp_input_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct tc74_data *data = dev_get_drvdata(dev);
	int ret;

	ret = tc74_update_device(dev);
	if (ret)
		return ret;

	return sprintf(buf, "%d\n", data->temp_input * 1000);
}
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);

static struct attribute *tc74_attrs[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	NULL
};

ATTRIBUTE_GROUPS(tc74);

static int tc74_probe(struct i2c_client *client,
		      const struct i2c_device_id *dev_id)
{
	struct device *dev = &client->dev;
	struct tc74_data *data;
	struct device *hwmon_dev;
	s32 conf;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -EOPNOTSUPP;

	data = devm_kzalloc(dev, sizeof(struct tc74_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	/* Make sure the chip is powered up. */
	conf = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
	if (conf < 0) {
		dev_err(dev, "unable to read config register\n");

		return conf;
	}

	if (conf & 0x3f) {
		dev_err(dev, "invalid config register value\n");

		return -ENODEV;
	}

	if (conf & BIT(7)) {
		s32 ret;

		conf &= ~BIT(7);

		ret = i2c_smbus_write_byte_data(client, TC74_REG_CONFIG, conf);
		if (ret)
			dev_warn(dev, "unable to disable STANDBY\n");
	}

	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
							   client->name,
							   data, tc74_groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id tc74_id[] = {
	{ "tc74", 0 },
	{}
};
MODULE_DEVICE_TABLE(i2c, tc74_id);

static struct i2c_driver tc74_driver = {
	.driver = {
		.name	= "tc74",
	},
	.probe	= tc74_probe,
	.id_table = tc74_id,
};

module_i2c_driver(tc74_driver);

MODULE_AUTHOR("Maciej Szmigiero <mail@maciej.szmigiero.name>");

MODULE_DESCRIPTION("TC74 driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
761c1770 MS	2	/*
	3	* An hwmon driver for the Microchip TC74
	4	*
	5	* Copyright 2015 Maciej Szmigiero <mail@maciej.szmigiero.name>
	6	*
	7	* Based on ad7414.c:
	8	* Copyright 2006 Stefan Roese, DENX Software Engineering
	9	* Copyright 2008 Sean MacLennan, PIKA Technologies
	10	* Copyright 2008 Frank Edelhaeuser, Spansion Inc.
761c1770 MS	11	*/
	12
	13	#include <linux/bitops.h>
	14	#include <linux/err.h>
	15	#include <linux/hwmon.h>
	16	#include <linux/hwmon-sysfs.h>
	17	#include <linux/i2c.h>
	18	#include <linux/jiffies.h>
	19	#include <linux/module.h>
	20	#include <linux/mutex.h>
	21	#include <linux/slab.h>
	22	#include <linux/sysfs.h>
	23
	24	/* TC74 registers */
	25	#define TC74_REG_TEMP 0x00
	26	#define TC74_REG_CONFIG 0x01
	27
	28	struct tc74_data {
	29	struct i2c_client *client;
	30	struct mutex lock; /* atomic read data updates */
	31	bool valid; /* validity of fields below */
	32	unsigned long next_update; /* In jiffies */
	33	s8 temp_input; /* Temp value in dC */
	34	};
	35
	36	static int tc74_update_device(struct device *dev)
	37	{
	38	struct tc74_data *data = dev_get_drvdata(dev);
	39	struct i2c_client *client = data->client;
	40	int ret;
	41
	42	ret = mutex_lock_interruptible(&data->lock);
	43	if (ret)
	44	return ret;
	45
	46	if (time_after(jiffies, data->next_update) \|\| !data->valid) {
	47	s32 value;
	48
	49	value = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
	50	if (value < 0) {
	51	dev_dbg(&client->dev, "TC74_REG_CONFIG read err %d\n",
	52	(int)value);
	53
	54	ret = value;
	55	goto ret_unlock;
	56	}
	57
	58	if (!(value & BIT(6))) {
	59	/* not ready yet */
	60
	61	ret = -EAGAIN;
	62	goto ret_unlock;
	63	}
	64
	65	value = i2c_smbus_read_byte_data(client, TC74_REG_TEMP);
	66	if (value < 0) {
	67	dev_dbg(&client->dev, "TC74_REG_TEMP read err %d\n",
	68	(int)value);
	69
	70	ret = value;
	71	goto ret_unlock;
	72	}
	73
	74	data->temp_input = value;
75	data->next_update = jiffies + HZ / 4;
76	data->valid = true;
77	}
78
79	ret_unlock:
80	mutex_unlock(&data->lock);
81
82	return ret;
83	}
84
5abcbc7b	85	static ssize_t temp_input_show(struct device *dev,
761c1770 MS	86	struct device_attribute attr, char buf)
	87	{
	88	struct tc74_data *data = dev_get_drvdata(dev);
	89	int ret;
	90
	91	ret = tc74_update_device(dev);
	92	if (ret)
	93	return ret;
	94
	95	return sprintf(buf, "%d\n", data->temp_input * 1000);
	96	}
5abcbc7b	97	static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
761c1770 MS	98
	99	static struct attribute *tc74_attrs[] = {
	100	&sensor_dev_attr_temp1_input.dev_attr.attr,
	101	NULL
	102	};
	103
	104	ATTRIBUTE_GROUPS(tc74);
	105
	106	static int tc74_probe(struct i2c_client *client,
	107	const struct i2c_device_id *dev_id)
	108	{
	109	struct device *dev = &client->dev;
	110	struct tc74_data *data;
	111	struct device *hwmon_dev;
	112	s32 conf;
	113
	114	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	115	return -EOPNOTSUPP;
	116
	117	data = devm_kzalloc(dev, sizeof(struct tc74_data), GFP_KERNEL);
	118	if (!data)
	119	return -ENOMEM;
	120
	121	data->client = client;
	122	mutex_init(&data->lock);
	123
	124	/* Make sure the chip is powered up. */
	125	conf = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
	126	if (conf < 0) {
	127	dev_err(dev, "unable to read config register\n");
	128
	129	return conf;
	130	}
	131
	132	if (conf & 0x3f) {
	133	dev_err(dev, "invalid config register value\n");
	134
	135	return -ENODEV;
	136	}
	137
	138	if (conf & BIT(7)) {
	139	s32 ret;
	140
	141	conf &= ~BIT(7);
	142
	143	ret = i2c_smbus_write_byte_data(client, TC74_REG_CONFIG, conf);
	144	if (ret)
	145	dev_warn(dev, "unable to disable STANDBY\n");
	146	}
	147
	148	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
	149	client->name,
	150	data, tc74_groups);
	151	return PTR_ERR_OR_ZERO(hwmon_dev);
	152	}
	153
	154	static const struct i2c_device_id tc74_id[] = {
	155	{ "tc74", 0 },
	156	{}
	157	};
	158	MODULE_DEVICE_TABLE(i2c, tc74_id);
	159
	160	static struct i2c_driver tc74_driver = {
	161	.driver = {
162	.name = "tc74",
163	},
164	.probe = tc74_probe,
165	.id_table = tc74_id,
166	};
167
168	module_i2c_driver(tc74_driver);
169
170	MODULE_AUTHOR("Maciej Szmigiero <mail@maciej.szmigiero.name>");
171
172	MODULE_DESCRIPTION("TC74 driver");
173	MODULE_LICENSE("GPL");