[mirror_ubuntu-jammy-kernel.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/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},
	{}
};
MODULE_DEVICE_TABLE(spi, max31722_spi_id);

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