/*
   * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x PMIC
   *                                hardware monitoring features.
   *
   * Copyright (C) 2009 Wolfson Microelectronics plc
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License v2 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.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/err.h>
  #include <linux/hwmon.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/slab.h>
  
  #include <linux/mfd/wm831x/core.h>
  #include <linux/mfd/wm831x/auxadc.h>
  
  struct wm831x_hwmon {
  	struct wm831x *wm831x;
  	struct device *classdev;
  };
  
  static ssize_t show_name(struct device *dev,
  			 struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "wm831x
  ");
  }
  
  static const char * const input_names[] = {
  	[WM831X_AUX_SYSVDD]    = "SYSVDD",
  	[WM831X_AUX_USB]       = "USB",
  	[WM831X_AUX_BKUP_BATT] = "Backup battery",
  	[WM831X_AUX_BATT]      = "Battery",
  	[WM831X_AUX_WALL]      = "WALL",
  	[WM831X_AUX_CHIP_TEMP] = "PMIC",
  	[WM831X_AUX_BATT_TEMP] = "Battery",
  };
  
  
  static ssize_t show_voltage(struct device *dev,
  			    struct device_attribute *attr, char *buf)
  {
  	struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
  	int channel = to_sensor_dev_attr(attr)->index;
  	int ret;
  
  	ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel);
  	if (ret < 0)
  		return ret;
  
  	return sprintf(buf, "%d
  ", DIV_ROUND_CLOSEST(ret, 1000));
  }
  
  static ssize_t show_chip_temp(struct device *dev,
  			      struct device_attribute *attr, char *buf)
  {
  	struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
  	int channel = to_sensor_dev_attr(attr)->index;
  	int ret;
  
  	ret = wm831x_auxadc_read(hwmon->wm831x, channel);
  	if (ret < 0)
  		return ret;
  
  	/* Degrees celsius = (512.18-ret) / 1.0983 */
  	ret = 512180 - (ret * 1000);
  	ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
  
  	return sprintf(buf, "%d
  ", ret);
  }
  
  static ssize_t show_label(struct device *dev,
  			  struct device_attribute *attr, char *buf)
  {
  	int channel = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%s
  ", input_names[channel]);
  }
  
  #define WM831X_VOLTAGE(id, name) \
  	static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
  				  NULL, name)
  
  #define WM831X_NAMED_VOLTAGE(id, name) \
  	WM831X_VOLTAGE(id, name); \
  	static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,	\
  				  NULL, name)
  
  static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
  
  WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
  WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
  WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
  WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
  
  WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
  WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
  WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
  WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
  WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
  
  static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
  			  WM831X_AUX_CHIP_TEMP);
  static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
  			  WM831X_AUX_CHIP_TEMP);
  /*
   * Report as a voltage since conversion depends on external components
   * and that's what the ABI wants.
   */
  static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
  			  WM831X_AUX_BATT_TEMP);
  static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
  			  WM831X_AUX_BATT_TEMP);
  
  static struct attribute *wm831x_attributes[] = {
  	&dev_attr_name.attr,
  
  	&sensor_dev_attr_in0_input.dev_attr.attr,
  	&sensor_dev_attr_in1_input.dev_attr.attr,
  	&sensor_dev_attr_in2_input.dev_attr.attr,
  	&sensor_dev_attr_in3_input.dev_attr.attr,
  
  	&sensor_dev_attr_in4_input.dev_attr.attr,
  	&sensor_dev_attr_in4_label.dev_attr.attr,
  	&sensor_dev_attr_in5_input.dev_attr.attr,
  	&sensor_dev_attr_in5_label.dev_attr.attr,
  	&sensor_dev_attr_in6_input.dev_attr.attr,
  	&sensor_dev_attr_in6_label.dev_attr.attr,
  	&sensor_dev_attr_in7_input.dev_attr.attr,
  	&sensor_dev_attr_in7_label.dev_attr.attr,
  	&sensor_dev_attr_in8_input.dev_attr.attr,
  	&sensor_dev_attr_in8_label.dev_attr.attr,
  
  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp1_label.dev_attr.attr,
  	&sensor_dev_attr_temp2_input.dev_attr.attr,
  	&sensor_dev_attr_temp2_label.dev_attr.attr,
  
  	NULL
  };
  
  static const struct attribute_group wm831x_attr_group = {
  	.attrs	= wm831x_attributes,
  };
  
  static int wm831x_hwmon_probe(struct platform_device *pdev)
  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
  	struct wm831x_hwmon *hwmon;
  	int ret;
  
  	hwmon = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_hwmon),
  			     GFP_KERNEL);
  	if (!hwmon)
  		return -ENOMEM;
  
  	hwmon->wm831x = wm831x;
  
  	ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group);
  	if (ret)
  		return ret;
  
  	hwmon->classdev = hwmon_device_register(&pdev->dev);
  	if (IS_ERR(hwmon->classdev)) {
  		ret = PTR_ERR(hwmon->classdev);
  		goto err_sysfs;
  	}
  
  	platform_set_drvdata(pdev, hwmon);
  
  	return 0;
  
  err_sysfs:
  	sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
  	return ret;
  }
  
  static int wm831x_hwmon_remove(struct platform_device *pdev)
  {
  	struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev);
  
  	hwmon_device_unregister(hwmon->classdev);
  	sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
  
  	return 0;
  }
  
  static struct platform_driver wm831x_hwmon_driver = {
  	.probe = wm831x_hwmon_probe,
  	.remove = wm831x_hwmon_remove,
  	.driver = {
  		.name = "wm831x-hwmon",
  		.owner = THIS_MODULE,
  	},
  };
  
  module_platform_driver(wm831x_hwmon_driver);
  
  MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
  MODULE_DESCRIPTION("WM831x Hardware Monitoring");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm831x-hwmon");