text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   *
   * Copyright (C) 2012 ARM Limited
   */
  
  #define DRVNAME "vexpress-hwmon"
  #define pr_fmt(fmt) DRVNAME ": " fmt
  
  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/hwmon.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  #include <linux/platform_device.h>
  #include <linux/vexpress.h>
  
  struct vexpress_hwmon_data {
  	struct device *hwmon_dev;
  	struct regmap *reg;
  };
  
  static ssize_t vexpress_hwmon_label_show(struct device *dev,
  		struct device_attribute *dev_attr, char *buffer)
  {
  	const char *label = of_get_property(dev->of_node, "label", NULL);
  
  	return sysfs_emit(buffer, "%s\n", label);
  }
  
  static ssize_t vexpress_hwmon_u32_show(struct device *dev,
  		struct device_attribute *dev_attr, char *buffer)
  {
  	struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
  	int err;
  	u32 value;
  
  	err = regmap_read(data->reg, 0, &value);
  	if (err)
  		return err;
  
  	return sysfs_emit(buffer, "%u\n", value /
  			  to_sensor_dev_attr(dev_attr)->index);
  }
  
  static ssize_t vexpress_hwmon_u64_show(struct device *dev,
  		struct device_attribute *dev_attr, char *buffer)
  {
  	struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
  	int err;
  	u32 value_hi, value_lo;
  
  	err = regmap_read(data->reg, 0, &value_lo);
  	if (err)
  		return err;
  
  	err = regmap_read(data->reg, 1, &value_hi);
  	if (err)
  		return err;
  
  	return sysfs_emit(buffer, "%llu\n",
  			  div_u64(((u64)value_hi << 32) | value_lo,
  				  to_sensor_dev_attr(dev_attr)->index));
  }
  
  static umode_t vexpress_hwmon_attr_is_visible(struct kobject *kobj,
  		struct attribute *attr, int index)
  {
  	struct device *dev = kobj_to_dev(kobj);
  	struct device_attribute *dev_attr = container_of(attr,
  				struct device_attribute, attr);
  
  	if (dev_attr->show == vexpress_hwmon_label_show &&
  			!of_get_property(dev->of_node, "label", NULL))
  		return 0;
  
  	return attr->mode;
  }
  
  struct vexpress_hwmon_type {
  	const char *name;
  	const struct attribute_group **attr_groups;
  };
  
  #if !defined(CONFIG_REGULATOR_VEXPRESS)
  static DEVICE_ATTR(in1_label, 0444, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR_RO(in1_input, vexpress_hwmon_u32, 1000);
  static struct attribute *vexpress_hwmon_attrs_volt[] = {
  	&dev_attr_in1_label.attr,
  	&sensor_dev_attr_in1_input.dev_attr.attr,
  	NULL
  };
  static struct attribute_group vexpress_hwmon_group_volt = {
  	.is_visible = vexpress_hwmon_attr_is_visible,
  	.attrs = vexpress_hwmon_attrs_volt,
  };
  static struct vexpress_hwmon_type vexpress_hwmon_volt = {
  	.name = "vexpress_volt",
  	.attr_groups = (const struct attribute_group *[]) {
  		&vexpress_hwmon_group_volt,
  		NULL,
  	},
  };
  #endif
  
  static DEVICE_ATTR(curr1_label, 0444, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR_RO(curr1_input, vexpress_hwmon_u32, 1000);
  static struct attribute *vexpress_hwmon_attrs_amp[] = {
  	&dev_attr_curr1_label.attr,
  	&sensor_dev_attr_curr1_input.dev_attr.attr,
  	NULL
  };
  static struct attribute_group vexpress_hwmon_group_amp = {
  	.is_visible = vexpress_hwmon_attr_is_visible,
  	.attrs = vexpress_hwmon_attrs_amp,
  };
  static struct vexpress_hwmon_type vexpress_hwmon_amp = {
  	.name = "vexpress_amp",
  	.attr_groups = (const struct attribute_group *[]) {
  		&vexpress_hwmon_group_amp,
  		NULL
  	},
  };
  
  static DEVICE_ATTR(temp1_label, 0444, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR_RO(temp1_input, vexpress_hwmon_u32, 1000);
  static struct attribute *vexpress_hwmon_attrs_temp[] = {
  	&dev_attr_temp1_label.attr,
  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	NULL
  };
  static struct attribute_group vexpress_hwmon_group_temp = {
  	.is_visible = vexpress_hwmon_attr_is_visible,
  	.attrs = vexpress_hwmon_attrs_temp,
  };
  static struct vexpress_hwmon_type vexpress_hwmon_temp = {
  	.name = "vexpress_temp",
  	.attr_groups = (const struct attribute_group *[]) {
  		&vexpress_hwmon_group_temp,
  		NULL
  	},
  };
  
  static DEVICE_ATTR(power1_label, 0444, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR_RO(power1_input, vexpress_hwmon_u32, 1);
  static struct attribute *vexpress_hwmon_attrs_power[] = {
  	&dev_attr_power1_label.attr,
  	&sensor_dev_attr_power1_input.dev_attr.attr,
  	NULL
  };
  static struct attribute_group vexpress_hwmon_group_power = {
  	.is_visible = vexpress_hwmon_attr_is_visible,
  	.attrs = vexpress_hwmon_attrs_power,
  };
  static struct vexpress_hwmon_type vexpress_hwmon_power = {
  	.name = "vexpress_power",
  	.attr_groups = (const struct attribute_group *[]) {
  		&vexpress_hwmon_group_power,
  		NULL
  	},
  };
  
  static DEVICE_ATTR(energy1_label, 0444, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR_RO(energy1_input, vexpress_hwmon_u64, 1);
  static struct attribute *vexpress_hwmon_attrs_energy[] = {
  	&dev_attr_energy1_label.attr,
  	&sensor_dev_attr_energy1_input.dev_attr.attr,
  	NULL
  };
  static struct attribute_group vexpress_hwmon_group_energy = {
  	.is_visible = vexpress_hwmon_attr_is_visible,
  	.attrs = vexpress_hwmon_attrs_energy,
  };
  static struct vexpress_hwmon_type vexpress_hwmon_energy = {
  	.name = "vexpress_energy",
  	.attr_groups = (const struct attribute_group *[]) {
  		&vexpress_hwmon_group_energy,
  		NULL
  	},
  };
  
  static const struct of_device_id vexpress_hwmon_of_match[] = {
  #if !defined(CONFIG_REGULATOR_VEXPRESS)
  	{
  		.compatible = "arm,vexpress-volt",
  		.data = &vexpress_hwmon_volt,
  	},
  #endif
  	{
  		.compatible = "arm,vexpress-amp",
  		.data = &vexpress_hwmon_amp,
  	}, {
  		.compatible = "arm,vexpress-temp",
  		.data = &vexpress_hwmon_temp,
  	}, {
  		.compatible = "arm,vexpress-power",
  		.data = &vexpress_hwmon_power,
  	}, {
  		.compatible = "arm,vexpress-energy",
  		.data = &vexpress_hwmon_energy,
  	},
  	{}
  };
  MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
  
  static int vexpress_hwmon_probe(struct platform_device *pdev)
  {
  	const struct of_device_id *match;
  	struct vexpress_hwmon_data *data;
  	const struct vexpress_hwmon_type *type;
  
  	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  	platform_set_drvdata(pdev, data);
  
  	match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
  	if (!match)
  		return -ENODEV;
  	type = match->data;
  
  	data->reg = devm_regmap_init_vexpress_config(&pdev->dev);
  	if (IS_ERR(data->reg))
  		return PTR_ERR(data->reg);
  
  	data->hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
  			type->name, data, type->attr_groups);
  
  	return PTR_ERR_OR_ZERO(data->hwmon_dev);
  }
  
  static struct platform_driver vexpress_hwmon_driver = {
  	.probe = vexpress_hwmon_probe,
  	.driver	= {
  		.name = DRVNAME,
  		.of_match_table = vexpress_hwmon_of_match,
  	},
  };
  
  module_platform_driver(vexpress_hwmon_driver);
  
  MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
  MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:vexpress-hwmon");
  