[linux-2.6-block.git] / drivers / hwmon / max31722.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * max31722 - hwmon driver for Maxim Integrated MAX31722/MAX31723 SPI
 * digital thermometer and thermostats.
 *
 * Copyright (c) 2016, Intel Corporation.
 */

#include <linux/acpi.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>

#define MAX31722_REG_CFG				0x00
#define MAX31722_REG_TEMP_LSB				0x01

#define MAX31722_MODE_CONTINUOUS			0x00
#define MAX31722_MODE_STANDBY				0x01
#define MAX31722_MODE_MASK				0xFE
#define MAX31722_RESOLUTION_12BIT			0x06
#define MAX31722_WRITE_MASK				0x80

struct max31722_data {
	struct device *hwmon_dev;
	struct spi_device *spi_device;
	u8 mode;
};

static int max31722_set_mode(struct max31722_data *data, u8 mode)
{
	int ret;
	struct spi_device *spi = data->spi_device;
	u8 buf[2] = {
		MAX31722_REG_CFG | MAX31722_WRITE_MASK,
		(data->mode & MAX31722_MODE_MASK) | mode
	};

	ret = spi_write(spi, &buf, sizeof(buf));
	if (ret < 0) {
		dev_err(&spi->dev, "failed to set sensor mode.\n");
		return ret;
	}
	data->mode = (data->mode & MAX31722_MODE_MASK) | mode;

	return 0;
}

static ssize_t max31722_temp_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	ssize_t ret;
	struct max31722_data *data = dev_get_drvdata(dev);

	ret = spi_w8r16(data->spi_device, MAX31722_REG_TEMP_LSB);
	if (ret < 0)
		return ret;
	/* Keep 12 bits and multiply by the scale of 62.5 millidegrees/bit. */
	return sprintf(buf, "%d\n", (s16)le16_to_cpu(ret) * 125 / 32);
}

static SENSOR_DEVICE_ATTR_RO(temp1_input, max31722_temp, 0);

static struct attribute *max31722_attrs[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	NULL,
};

ATTRIBUTE_GROUPS(max31722);

static int max31722_probe(struct spi_device *spi)
{
	int ret;
	struct max31722_data *data;

	data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	spi_set_drvdata(spi, data);
	data->spi_device = spi;
	/*
	 * Set SD bit to 0 so we can have continuous measurements.
	 * Set resolution to 12 bits for maximum precision.
	 */
	data->mode = MAX31722_MODE_CONTINUOUS | MAX31722_RESOLUTION_12BIT;
	ret = max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
	if (ret < 0)
		return ret;

	data->hwmon_dev = hwmon_device_register_with_groups(&spi->dev,
							    spi->modalias,
							    data,
							    max31722_groups);
	if (IS_ERR(data->hwmon_dev)) {
		max31722_set_mode(data, MAX31722_MODE_STANDBY);
		return PTR_ERR(data->hwmon_dev);
	}

	return 0;
}

static int max31722_remove(struct spi_device *spi)
{
	struct max31722_data *data = spi_get_drvdata(spi);

	hwmon_device_unregister(data->hwmon_dev);

	return max31722_set_mode(data, MAX31722_MODE_STANDBY);
}

static int __maybe_unused max31722_suspend(struct device *dev)
{
	struct spi_device *spi_device = to_spi_device(dev);
	struct max31722_data *data = spi_get_drvdata(spi_device);

	return max31722_set_mode(data, MAX31722_MODE_STANDBY);
}

static int __maybe_unused max31722_resume(struct device *dev)
{
	struct spi_device *spi_device = to_spi_device(dev);
	struct max31722_data *data = spi_get_drvdata(spi_device);

	return max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
}

static SIMPLE_DEV_PM_OPS(max31722_pm_ops, max31722_suspend, max31722_resume);

static const struct spi_device_id max31722_spi_id[] = {
	{"max31722", 0},
	{"max31723", 0},
	{}
};

static const struct acpi_device_id __maybe_unused max31722_acpi_id[] = {
	{"MAX31722", 0},
	{"MAX31723", 0},
	{}
};

MODULE_DEVICE_TABLE(spi, max31722_spi_id);

static struct spi_driver max31722_driver = {
	.driver = {
		.name = "max31722",
		.pm = &max31722_pm_ops,
		.acpi_match_table = ACPI_PTR(max31722_acpi_id),
	},
	.probe =            max31722_probe,
	.remove =           max31722_remove,
	.id_table =         max31722_spi_id,
};

module_spi_driver(max31722_driver);

MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
MODULE_DESCRIPTION("max31722 sensor driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
36edc939	1	// SPDX-License-Identifier: GPL-2.0-only
04e1e70a TB	2	/*
	3	* max31722 - hwmon driver for Maxim Integrated MAX31722/MAX31723 SPI
	4	* digital thermometer and thermostats.
	5	*
	6	* Copyright (c) 2016, Intel Corporation.
04e1e70a TB	7	*/
	8
	9	#include <linux/acpi.h>
	10	#include <linux/hwmon.h>
	11	#include <linux/hwmon-sysfs.h>
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/spi/spi.h>
	15
	16	#define MAX31722_REG_CFG 0x00
	17	#define MAX31722_REG_TEMP_LSB 0x01
	18
	19	#define MAX31722_MODE_CONTINUOUS 0x00
	20	#define MAX31722_MODE_STANDBY 0x01
	21	#define MAX31722_MODE_MASK 0xFE
	22	#define MAX31722_RESOLUTION_12BIT 0x06
	23	#define MAX31722_WRITE_MASK 0x80
	24
	25	struct max31722_data {
	26	struct device *hwmon_dev;
	27	struct spi_device *spi_device;
	28	u8 mode;
	29	};
	30
	31	static int max31722_set_mode(struct max31722_data *data, u8 mode)
	32	{
	33	int ret;
	34	struct spi_device *spi = data->spi_device;
	35	u8 buf[2] = {
	36	MAX31722_REG_CFG \| MAX31722_WRITE_MASK,
	37	(data->mode & MAX31722_MODE_MASK) \| mode
	38	};
	39
	40	ret = spi_write(spi, &buf, sizeof(buf));
	41	if (ret < 0) {
	42	dev_err(&spi->dev, "failed to set sensor mode.\n");
	43	return ret;
	44	}
	45	data->mode = (data->mode & MAX31722_MODE_MASK) \| mode;
	46
	47	return 0;
	48	}
	49
845ee709 GR	50	static ssize_t max31722_temp_show(struct device *dev,
845ee709 GR	51	struct device_attribute attr, char buf)
04e1e70a TB	52	{
	53	ssize_t ret;
	54	struct max31722_data *data = dev_get_drvdata(dev);
	55
	56	ret = spi_w8r16(data->spi_device, MAX31722_REG_TEMP_LSB);
	57	if (ret < 0)
	58	return ret;
	59	/* Keep 12 bits and multiply by the scale of 62.5 millidegrees/bit. */
	60	return sprintf(buf, "%d\n", (s16)le16_to_cpu(ret) * 125 / 32);
	61	}
	62
845ee709	63	static SENSOR_DEVICE_ATTR_RO(temp1_input, max31722_temp, 0);
04e1e70a TB	64
	65	static struct attribute *max31722_attrs[] = {
	66	&sensor_dev_attr_temp1_input.dev_attr.attr,
	67	NULL,
	68	};
	69
	70	ATTRIBUTE_GROUPS(max31722);
	71
	72	static int max31722_probe(struct spi_device *spi)
	73	{
	74	int ret;
	75	struct max31722_data *data;
	76
	77	data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
	78	if (!data)
	79	return -ENOMEM;
	80
	81	spi_set_drvdata(spi, data);
	82	data->spi_device = spi;
	83	/*
	84	* Set SD bit to 0 so we can have continuous measurements.
	85	* Set resolution to 12 bits for maximum precision.
	86	*/
	87	data->mode = MAX31722_MODE_CONTINUOUS \| MAX31722_RESOLUTION_12BIT;
	88	ret = max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
	89	if (ret < 0)
	90	return ret;
	91
	92	data->hwmon_dev = hwmon_device_register_with_groups(&spi->dev,
	93	spi->modalias,
	94	data,
	95	max31722_groups);
	96	if (IS_ERR(data->hwmon_dev)) {
	97	max31722_set_mode(data, MAX31722_MODE_STANDBY);
	98	return PTR_ERR(data->hwmon_dev);
	99	}
	100
	101	return 0;
	102	}
	103
	104	static int max31722_remove(struct spi_device *spi)
	105	{
	106	struct max31722_data *data = spi_get_drvdata(spi);
	107
	108	hwmon_device_unregister(data->hwmon_dev);
	109
	110	return max31722_set_mode(data, MAX31722_MODE_STANDBY);
	111	}
	112
	113	static int __maybe_unused max31722_suspend(struct device *dev)
	114	{
	115	struct spi_device *spi_device = to_spi_device(dev);
	116	struct max31722_data *data = spi_get_drvdata(spi_device);
	117
	118	return max31722_set_mode(data, MAX31722_MODE_STANDBY);
	119	}
	120
	121	static int __maybe_unused max31722_resume(struct device *dev)
	122	{
	123	struct spi_device *spi_device = to_spi_device(dev);
	124	struct max31722_data *data = spi_get_drvdata(spi_device);
	125
	126	return max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
	127	}
128
129	static SIMPLE_DEV_PM_OPS(max31722_pm_ops, max31722_suspend, max31722_resume);
130
131	static const struct spi_device_id max31722_spi_id[] = {
132	{"max31722", 0},
133	{"max31723", 0},
134	{}
135	};
136
137	static const struct acpi_device_id __maybe_unused max31722_acpi_id[] = {
138	{"MAX31722", 0},
139	{"MAX31723", 0},
140	{}
141	};
142
143	MODULE_DEVICE_TABLE(spi, max31722_spi_id);
144
145	static struct spi_driver max31722_driver = {
146	.driver = {
147	.name = "max31722",
148	.pm = &max31722_pm_ops,
149	.acpi_match_table = ACPI_PTR(max31722_acpi_id),
150	},
151	.probe = max31722_probe,
152	.remove = max31722_remove,
153	.id_table = max31722_spi_id,
154	};
155
156	module_spi_driver(max31722_driver);
157
158	MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
159	MODULE_DESCRIPTION("max31722 sensor driver");
160	MODULE_LICENSE("GPL v2");