/*
   * db8500_thermal.c - DB8500 Thermal Management Implementation
   *
   * Copyright (C) 2012 ST-Ericsson
   * Copyright (C) 2012 Linaro Ltd.
   *
   * Author: Hongbo Zhang <hongbo.zhang@linaro.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * 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.
   */
  
  #include <linux/cpu_cooling.h>
  #include <linux/interrupt.h>
  #include <linux/mfd/dbx500-prcmu.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/platform_data/db8500_thermal.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/thermal.h>
  
  #define PRCMU_DEFAULT_MEASURE_TIME	0xFFF
  #define PRCMU_DEFAULT_LOW_TEMP		0
  
  struct db8500_thermal_zone {
  	struct thermal_zone_device *therm_dev;
  	struct mutex th_lock;
  	struct work_struct therm_work;
  	struct db8500_thsens_platform_data *trip_tab;
  	enum thermal_device_mode mode;
  	enum thermal_trend trend;
  	unsigned long cur_temp_pseudo;
  	unsigned int cur_index;
  };
  
  /* Local function to check if thermal zone matches cooling devices */
  static int db8500_thermal_match_cdev(struct thermal_cooling_device *cdev,
  		struct db8500_trip_point *trip_point)
  {
  	int i;
  
  	if (!strlen(cdev->type))
  		return -EINVAL;
  
  	for (i = 0; i < COOLING_DEV_MAX; i++) {
  		if (!strcmp(trip_point->cdev_name[i], cdev->type))
  			return 0;
  	}
  
  	return -ENODEV;
  }
  
  /* Callback to bind cooling device to thermal zone */
  static int db8500_cdev_bind(struct thermal_zone_device *thermal,
  		struct thermal_cooling_device *cdev)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  	unsigned long max_state, upper, lower;
  	int i, ret = -EINVAL;
  
  	cdev->ops->get_max_state(cdev, &max_state);
  
  	for (i = 0; i < ptrips->num_trips; i++) {
  		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
  			continue;
  
  		upper = lower = i > max_state ? max_state : i;
  
  		ret = thermal_zone_bind_cooling_device(thermal, i, cdev,
  			upper, lower);
  
  		dev_info(&cdev->device, "%s bind to %d: %d-%s
  ", cdev->type,
  			i, ret, ret ? "fail" : "succeed");
  	}
  
  	return ret;
  }
  
  /* Callback to unbind cooling device from thermal zone */
  static int db8500_cdev_unbind(struct thermal_zone_device *thermal,
  		struct thermal_cooling_device *cdev)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  	int i, ret = -EINVAL;
  
  	for (i = 0; i < ptrips->num_trips; i++) {
  		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
  			continue;
  
  		ret = thermal_zone_unbind_cooling_device(thermal, i, cdev);
  
  		dev_info(&cdev->device, "%s unbind from %d: %s
  ", cdev->type,
  			i, ret ? "fail" : "succeed");
  	}
  
  	return ret;
  }
  
  /* Callback to get current temperature */
  static int db8500_sys_get_temp(struct thermal_zone_device *thermal,
  		unsigned long *temp)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  
  	/*
  	 * TODO: There is no PRCMU interface to get temperature data currently,
  	 * so a pseudo temperature is returned , it works for thermal framework
  	 * and this will be fixed when the PRCMU interface is available.
  	 */
  	*temp = pzone->cur_temp_pseudo;
  
  	return 0;
  }
  
  /* Callback to get temperature changing trend */
  static int db8500_sys_get_trend(struct thermal_zone_device *thermal,
  		int trip, enum thermal_trend *trend)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  
  	*trend = pzone->trend;
  
  	return 0;
  }
  
  /* Callback to get thermal zone mode */
  static int db8500_sys_get_mode(struct thermal_zone_device *thermal,
  		enum thermal_device_mode *mode)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  
  	mutex_lock(&pzone->th_lock);
  	*mode = pzone->mode;
  	mutex_unlock(&pzone->th_lock);
  
  	return 0;
  }
  
  /* Callback to set thermal zone mode */
  static int db8500_sys_set_mode(struct thermal_zone_device *thermal,
  		enum thermal_device_mode mode)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  
  	mutex_lock(&pzone->th_lock);
  
  	pzone->mode = mode;
  	if (mode == THERMAL_DEVICE_ENABLED)
  		schedule_work(&pzone->therm_work);
  
  	mutex_unlock(&pzone->th_lock);
  
  	return 0;
  }
  
  /* Callback to get trip point type */
  static int db8500_sys_get_trip_type(struct thermal_zone_device *thermal,
  		int trip, enum thermal_trip_type *type)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  
  	if (trip >= ptrips->num_trips)
  		return -EINVAL;
  
  	*type = ptrips->trip_points[trip].type;
  
  	return 0;
  }
  
  /* Callback to get trip point temperature */
  static int db8500_sys_get_trip_temp(struct thermal_zone_device *thermal,
  		int trip, unsigned long *temp)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  
  	if (trip >= ptrips->num_trips)
  		return -EINVAL;
  
  	*temp = ptrips->trip_points[trip].temp;
  
  	return 0;
  }
  
  /* Callback to get critical trip point temperature */
  static int db8500_sys_get_crit_temp(struct thermal_zone_device *thermal,
  		unsigned long *temp)
  {
  	struct db8500_thermal_zone *pzone = thermal->devdata;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  	int i;
  
  	for (i = ptrips->num_trips - 1; i > 0; i--) {
  		if (ptrips->trip_points[i].type == THERMAL_TRIP_CRITICAL) {
  			*temp = ptrips->trip_points[i].temp;
  			return 0;
  		}
  	}
  
  	return -EINVAL;
  }
  
  static struct thermal_zone_device_ops thdev_ops = {
  	.bind = db8500_cdev_bind,
  	.unbind = db8500_cdev_unbind,
  	.get_temp = db8500_sys_get_temp,
  	.get_trend = db8500_sys_get_trend,
  	.get_mode = db8500_sys_get_mode,
  	.set_mode = db8500_sys_set_mode,
  	.get_trip_type = db8500_sys_get_trip_type,
  	.get_trip_temp = db8500_sys_get_trip_temp,
  	.get_crit_temp = db8500_sys_get_crit_temp,
  };
  
  static void db8500_thermal_update_config(struct db8500_thermal_zone *pzone,
  		unsigned int idx, enum thermal_trend trend,
  		unsigned long next_low, unsigned long next_high)
  {
  	prcmu_stop_temp_sense();
  
  	pzone->cur_index = idx;
  	pzone->cur_temp_pseudo = (next_low + next_high)/2;
  	pzone->trend = trend;
  
  	prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
  	prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
  }
  
  static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
  {
  	struct db8500_thermal_zone *pzone = irq_data;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  	unsigned int idx = pzone->cur_index;
  	unsigned long next_low, next_high;
  
  	if (unlikely(idx == 0))
  		/* Meaningless for thermal management, ignoring it */
  		return IRQ_HANDLED;
  
  	if (idx == 1) {
  		next_high = ptrips->trip_points[0].temp;
  		next_low = PRCMU_DEFAULT_LOW_TEMP;
  	} else {
  		next_high = ptrips->trip_points[idx-1].temp;
  		next_low = ptrips->trip_points[idx-2].temp;
  	}
  	idx -= 1;
  
  	db8500_thermal_update_config(pzone, idx, THERMAL_TREND_DROPPING,
  		next_low, next_high);
  
  	dev_dbg(&pzone->therm_dev->device,
  		"PRCMU set max %ld, min %ld
  ", next_high, next_low);
  
  	schedule_work(&pzone->therm_work);
  
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
  {
  	struct db8500_thermal_zone *pzone = irq_data;
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  	unsigned int idx = pzone->cur_index;
  	unsigned long next_low, next_high;
  
  	if (idx < ptrips->num_trips - 1) {
  		next_high = ptrips->trip_points[idx+1].temp;
  		next_low = ptrips->trip_points[idx].temp;
  		idx += 1;
  
  		db8500_thermal_update_config(pzone, idx, THERMAL_TREND_RAISING,
  			next_low, next_high);
  
  		dev_dbg(&pzone->therm_dev->device,
  		"PRCMU set max %ld, min %ld
  ", next_high, next_low);
  	} else if (idx == ptrips->num_trips - 1)
  		pzone->cur_temp_pseudo = ptrips->trip_points[idx].temp + 1;
  
  	schedule_work(&pzone->therm_work);
  
  	return IRQ_HANDLED;
  }
  
  static void db8500_thermal_work(struct work_struct *work)
  {
  	enum thermal_device_mode cur_mode;
  	struct db8500_thermal_zone *pzone;
  
  	pzone = container_of(work, struct db8500_thermal_zone, therm_work);
  
  	mutex_lock(&pzone->th_lock);
  	cur_mode = pzone->mode;
  	mutex_unlock(&pzone->th_lock);
  
  	if (cur_mode == THERMAL_DEVICE_DISABLED)
  		return;
  
  	thermal_zone_device_update(pzone->therm_dev);
  	dev_dbg(&pzone->therm_dev->device, "thermal work finished.
  ");
  }
  
  #ifdef CONFIG_OF
  static struct db8500_thsens_platform_data*
  		db8500_thermal_parse_dt(struct platform_device *pdev)
  {
  	struct db8500_thsens_platform_data *ptrips;
  	struct device_node *np = pdev->dev.of_node;
  	char prop_name[32];
  	const char *tmp_str;
  	u32 tmp_data;
  	int i, j;
  
  	ptrips = devm_kzalloc(&pdev->dev, sizeof(*ptrips), GFP_KERNEL);
  	if (!ptrips)
  		return NULL;
  
  	if (of_property_read_u32(np, "num-trips", &tmp_data))
  		goto err_parse_dt;
  
  	if (tmp_data > THERMAL_MAX_TRIPS)
  		goto err_parse_dt;
  
  	ptrips->num_trips = tmp_data;
  
  	for (i = 0; i < ptrips->num_trips; i++) {
  		sprintf(prop_name, "trip%d-temp", i);
  		if (of_property_read_u32(np, prop_name, &tmp_data))
  			goto err_parse_dt;
  
  		ptrips->trip_points[i].temp = tmp_data;
  
  		sprintf(prop_name, "trip%d-type", i);
  		if (of_property_read_string(np, prop_name, &tmp_str))
  			goto err_parse_dt;
  
  		if (!strcmp(tmp_str, "active"))
  			ptrips->trip_points[i].type = THERMAL_TRIP_ACTIVE;
  		else if (!strcmp(tmp_str, "passive"))
  			ptrips->trip_points[i].type = THERMAL_TRIP_PASSIVE;
  		else if (!strcmp(tmp_str, "hot"))
  			ptrips->trip_points[i].type = THERMAL_TRIP_HOT;
  		else if (!strcmp(tmp_str, "critical"))
  			ptrips->trip_points[i].type = THERMAL_TRIP_CRITICAL;
  		else
  			goto err_parse_dt;
  
  		sprintf(prop_name, "trip%d-cdev-num", i);
  		if (of_property_read_u32(np, prop_name, &tmp_data))
  			goto err_parse_dt;
  
  		if (tmp_data > COOLING_DEV_MAX)
  			goto err_parse_dt;
  
  		for (j = 0; j < tmp_data; j++) {
  			sprintf(prop_name, "trip%d-cdev-name%d", i, j);
  			if (of_property_read_string(np, prop_name, &tmp_str))
  				goto err_parse_dt;
  
  			if (strlen(tmp_str) >= THERMAL_NAME_LENGTH)
  				goto err_parse_dt;
  
  			strcpy(ptrips->trip_points[i].cdev_name[j], tmp_str);
  		}
  	}
  	return ptrips;
  
  err_parse_dt:
  	dev_err(&pdev->dev, "Parsing device tree data error.
  ");
  	return NULL;
  }
  #else
  static inline struct db8500_thsens_platform_data*
  		db8500_thermal_parse_dt(struct platform_device *pdev)
  {
  	return NULL;
  }
  #endif
  
  static int db8500_thermal_probe(struct platform_device *pdev)
  {
  	struct db8500_thermal_zone *pzone = NULL;
  	struct db8500_thsens_platform_data *ptrips = NULL;
  	struct device_node *np = pdev->dev.of_node;
  	int low_irq, high_irq, ret = 0;
  	unsigned long dft_low, dft_high;
  
  	if (np)
  		ptrips = db8500_thermal_parse_dt(pdev);
  	else
  		ptrips = dev_get_platdata(&pdev->dev);
  
  	if (!ptrips)
  		return -EINVAL;
  
  	pzone = devm_kzalloc(&pdev->dev, sizeof(*pzone), GFP_KERNEL);
  	if (!pzone)
  		return -ENOMEM;
  
  	mutex_init(&pzone->th_lock);
  	mutex_lock(&pzone->th_lock);
  
  	pzone->mode = THERMAL_DEVICE_DISABLED;
  	pzone->trip_tab = ptrips;
  
  	INIT_WORK(&pzone->therm_work, db8500_thermal_work);
  
  	low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
  	if (low_irq < 0) {
  		dev_err(&pdev->dev, "Get IRQ_HOTMON_LOW failed.
  ");
  		ret = low_irq;
  		goto out_unlock;
  	}
  
  	ret = devm_request_threaded_irq(&pdev->dev, low_irq, NULL,
  		prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
  		"dbx500_temp_low", pzone);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "Failed to allocate temp low irq.
  ");
  		goto out_unlock;
  	}
  
  	high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
  	if (high_irq < 0) {
  		dev_err(&pdev->dev, "Get IRQ_HOTMON_HIGH failed.
  ");
  		ret = high_irq;
  		goto out_unlock;
  	}
  
  	ret = devm_request_threaded_irq(&pdev->dev, high_irq, NULL,
  		prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
  		"dbx500_temp_high", pzone);
  	if (ret < 0) {
  		dev_err(&pdev->dev, "Failed to allocate temp high irq.
  ");
  		goto out_unlock;
  	}
  
  	pzone->therm_dev = thermal_zone_device_register("db8500_thermal_zone",
  		ptrips->num_trips, 0, pzone, &thdev_ops, NULL, 0, 0);
  
  	if (IS_ERR(pzone->therm_dev)) {
  		dev_err(&pdev->dev, "Register thermal zone device failed.
  ");
  		ret = PTR_ERR(pzone->therm_dev);
  		goto out_unlock;
  	}
  	dev_info(&pdev->dev, "Thermal zone device registered.
  ");
  
  	dft_low = PRCMU_DEFAULT_LOW_TEMP;
  	dft_high = ptrips->trip_points[0].temp;
  
  	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
  		dft_low, dft_high);
  
  	platform_set_drvdata(pdev, pzone);
  	pzone->mode = THERMAL_DEVICE_ENABLED;
  
  out_unlock:
  	mutex_unlock(&pzone->th_lock);
  
  	return ret;
  }
  
  static int db8500_thermal_remove(struct platform_device *pdev)
  {
  	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
  
  	thermal_zone_device_unregister(pzone->therm_dev);
  	cancel_work_sync(&pzone->therm_work);
  	mutex_destroy(&pzone->th_lock);
  
  	return 0;
  }
  
  static int db8500_thermal_suspend(struct platform_device *pdev,
  		pm_message_t state)
  {
  	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
  
  	flush_work(&pzone->therm_work);
  	prcmu_stop_temp_sense();
  
  	return 0;
  }
  
  static int db8500_thermal_resume(struct platform_device *pdev)
  {
  	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
  	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
  	unsigned long dft_low, dft_high;
  
  	dft_low = PRCMU_DEFAULT_LOW_TEMP;
  	dft_high = ptrips->trip_points[0].temp;
  
  	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
  		dft_low, dft_high);
  
  	return 0;
  }
  
  #ifdef CONFIG_OF
  static const struct of_device_id db8500_thermal_match[] = {
  	{ .compatible = "stericsson,db8500-thermal" },
  	{},
  };
  #endif
  
  static struct platform_driver db8500_thermal_driver = {
  	.driver = {
  		.owner = THIS_MODULE,
  		.name = "db8500-thermal",
  		.of_match_table = of_match_ptr(db8500_thermal_match),
  	},
  	.probe = db8500_thermal_probe,
  	.suspend = db8500_thermal_suspend,
  	.resume = db8500_thermal_resume,
  	.remove = db8500_thermal_remove,
  };
  
  module_platform_driver(db8500_thermal_driver);
  
  MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
  MODULE_DESCRIPTION("DB8500 thermal driver");
  MODULE_LICENSE("GPL");