Eric Lee / smarc-fsl-linux-kernel

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drivers/hwmon/max31722.c 3.9 KB
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36edc9395   Thomas Gleixner   treewide: Replace... 
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  // SPDX-License-Identifier: GPL-2.0-only
04e1e70af   Tiberiu Breana   hwmon: (max31722)... 
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  /*
   * max31722 - hwmon driver for Maxim Integrated MAX31722/MAX31723 SPI
   * digital thermometer and thermostats.
   *
   * Copyright (c) 2016, Intel Corporation.
04e1e70af   Tiberiu Breana   hwmon: (max31722)... 
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   */
  
  #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.
  ");
  		return ret;
  	}
  	data->mode = (data->mode & MAX31722_MODE_MASK) | mode;
  
  	return 0;
  }
845ee7092   Guenter Roeck   hwmon: (max31722)... 
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  static ssize_t max31722_temp_show(struct device *dev,
  				  struct device_attribute *attr, char *buf)
04e1e70af   Tiberiu Breana   hwmon: (max31722)... 
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  {
  	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
  ", (s16)le16_to_cpu(ret) * 125 / 32);
  }
845ee7092   Guenter Roeck   hwmon: (max31722)... 
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  static SENSOR_DEVICE_ATTR_RO(temp1_input, max31722_temp, 0);
04e1e70af   Tiberiu Breana   hwmon: (max31722)... 
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  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");