/*
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * 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 vexpress_config_func *func;
  };
  
  static ssize_t vexpress_hwmon_name_show(struct device *dev,
  		struct device_attribute *dev_attr, char *buffer)
  {
  	const char *compatible = of_get_property(dev->of_node, "compatible",
  			NULL);
  
  	return sprintf(buffer, "%s
  ", compatible);
  }
  
  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);
  
  	if (!label)
  		return -ENOENT;
  
  	return snprintf(buffer, PAGE_SIZE, "%s
  ", 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 = vexpress_config_read(data->func, 0, &value);
  	if (err)
  		return err;
  
  	return snprintf(buffer, PAGE_SIZE, "%u
  ", 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 = vexpress_config_read(data->func, 0, &value_lo);
  	if (err)
  		return err;
  
  	err = vexpress_config_read(data->func, 1, &value_hi);
  	if (err)
  		return err;
  
  	return snprintf(buffer, PAGE_SIZE, "%llu
  ",
  			div_u64(((u64)value_hi << 32) | value_lo,
  			to_sensor_dev_attr(dev_attr)->index));
  }
  
  static DEVICE_ATTR(name, S_IRUGO, vexpress_hwmon_name_show, NULL);
  
  #define VEXPRESS_HWMON_ATTRS(_name, _label_attr, _input_attr)	\
  struct attribute *vexpress_hwmon_attrs_##_name[] = {		\
  	&dev_attr_name.attr,					\
  	&dev_attr_##_label_attr.attr,				\
  	&sensor_dev_attr_##_input_attr.dev_attr.attr,		\
  	NULL							\
  }
  
  #if !defined(CONFIG_REGULATOR_VEXPRESS)
  static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
  		NULL, 1000);
  static VEXPRESS_HWMON_ATTRS(volt, in1_label, in1_input);
  static struct attribute_group vexpress_hwmon_group_volt = {
  	.attrs = vexpress_hwmon_attrs_volt,
  };
  #endif
  
  static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
  		NULL, 1000);
  static VEXPRESS_HWMON_ATTRS(amp, curr1_label, curr1_input);
  static struct attribute_group vexpress_hwmon_group_amp = {
  	.attrs = vexpress_hwmon_attrs_amp,
  };
  
  static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
  		NULL, 1000);
  static VEXPRESS_HWMON_ATTRS(temp, temp1_label, temp1_input);
  static struct attribute_group vexpress_hwmon_group_temp = {
  	.attrs = vexpress_hwmon_attrs_temp,
  };
  
  static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
  		NULL, 1);
  static VEXPRESS_HWMON_ATTRS(power, power1_label, power1_input);
  static struct attribute_group vexpress_hwmon_group_power = {
  	.attrs = vexpress_hwmon_attrs_power,
  };
  
  static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
  		NULL, 1);
  static VEXPRESS_HWMON_ATTRS(energy, energy1_label, energy1_input);
  static struct attribute_group vexpress_hwmon_group_energy = {
  	.attrs = vexpress_hwmon_attrs_energy,
  };
  
  static struct of_device_id vexpress_hwmon_of_match[] = {
  #if !defined(CONFIG_REGULATOR_VEXPRESS)
  	{
  		.compatible = "arm,vexpress-volt",
  		.data = &vexpress_hwmon_group_volt,
  	},
  #endif
  	{
  		.compatible = "arm,vexpress-amp",
  		.data = &vexpress_hwmon_group_amp,
  	}, {
  		.compatible = "arm,vexpress-temp",
  		.data = &vexpress_hwmon_group_temp,
  	}, {
  		.compatible = "arm,vexpress-power",
  		.data = &vexpress_hwmon_group_power,
  	}, {
  		.compatible = "arm,vexpress-energy",
  		.data = &vexpress_hwmon_group_energy,
  	},
  	{}
  };
  MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
  
  static int vexpress_hwmon_probe(struct platform_device *pdev)
  {
  	int err;
  	const struct of_device_id *match;
  	struct vexpress_hwmon_data *data;
  
  	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;
  
  	data->func = vexpress_config_func_get_by_dev(&pdev->dev);
  	if (!data->func)
  		return -ENODEV;
  
  	err = sysfs_create_group(&pdev->dev.kobj, match->data);
  	if (err)
  		goto error;
  
  	data->hwmon_dev = hwmon_device_register(&pdev->dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);
  		goto error;
  	}
  
  	return 0;
  
  error:
  	sysfs_remove_group(&pdev->dev.kobj, match->data);
  	vexpress_config_func_put(data->func);
  	return err;
  }
  
  static int vexpress_hwmon_remove(struct platform_device *pdev)
  {
  	struct vexpress_hwmon_data *data = platform_get_drvdata(pdev);
  	const struct of_device_id *match;
  
  	hwmon_device_unregister(data->hwmon_dev);
  
  	match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
  	sysfs_remove_group(&pdev->dev.kobj, match->data);
  
  	vexpress_config_func_put(data->func);
  
  	return 0;
  }
  
  static struct platform_driver vexpress_hwmon_driver = {
  	.probe = vexpress_hwmon_probe,
  	.remove = vexpress_hwmon_remove,
  	.driver	= {
  		.name = DRVNAME,
  		.owner = THIS_MODULE,
  		.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");