// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Thermal device driver for DA9062 and DA9061
   * Copyright (C) 2017  Dialog Semiconductor

   */
  
  /* When over-temperature is reached, an interrupt from the device will be
   * triggered. Following this event the interrupt will be disabled and
   * periodic transmission of uevents (HOT trip point) should define the
   * first level of temperature supervision. It is expected that any final
   * implementation of the thermal driver will include a .notify() function
   * to implement these uevents to userspace.
   *
   * These uevents are intended to indicate non-invasive temperature control
   * of the system, where the necessary measures for cooling are the
   * responsibility of the host software. Once the temperature falls again,
   * the IRQ is re-enabled so the start of a new over-temperature event can
   * be detected without constant software monitoring.
   */
  
  #include <linux/errno.h>
  #include <linux/interrupt.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/platform_device.h>
  #include <linux/regmap.h>
  #include <linux/thermal.h>
  #include <linux/workqueue.h>
  
  #include <linux/mfd/da9062/core.h>
  #include <linux/mfd/da9062/registers.h>
  
  /* Minimum, maximum and default polling millisecond periods are provided
   * here as an example. It is expected that any final implementation to also
   * include a modification of these settings to match the required
   * application.
   */
  #define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
  #define DA9062_MAX_POLLING_MS_PERIOD		10000
  #define DA9062_MIN_POLLING_MS_PERIOD		1000
  
  #define DA9062_MILLI_CELSIUS(t)			((t) * 1000)
  
  struct da9062_thermal_config {
  	const char *name;
  };
  
  struct da9062_thermal {
  	struct da9062 *hw;
  	struct delayed_work work;
  	struct thermal_zone_device *zone;

  	struct mutex lock; /* protection for da9062_thermal temperature */
  	int temperature;
  	int irq;
  	const struct da9062_thermal_config *config;
  	struct device *dev;
  };
  
  static void da9062_thermal_poll_on(struct work_struct *work)
  {
  	struct da9062_thermal *thermal = container_of(work,
  						struct da9062_thermal,
  						work.work);
  	unsigned long delay;
  	unsigned int val;
  	int ret;
  
  	/* clear E_TEMP */
  	ret = regmap_write(thermal->hw->regmap,
  			   DA9062AA_EVENT_B,
  			   DA9062AA_E_TEMP_MASK);
  	if (ret < 0) {
  		dev_err(thermal->dev,
  			"Cannot clear the TJUNC temperature status
  ");
  		goto err_enable_irq;
  	}
  
  	/* Now read E_TEMP again: it is acting like a status bit.
  	 * If over-temperature, then this status will be true.
  	 * If not over-temperature, this status will be false.
  	 */
  	ret = regmap_read(thermal->hw->regmap,
  			  DA9062AA_EVENT_B,
  			  &val);
  	if (ret < 0) {
  		dev_err(thermal->dev,
  			"Cannot check the TJUNC temperature status
  ");
  		goto err_enable_irq;
  	}
  
  	if (val & DA9062AA_E_TEMP_MASK) {
  		mutex_lock(&thermal->lock);
  		thermal->temperature = DA9062_MILLI_CELSIUS(125);
  		mutex_unlock(&thermal->lock);
  		thermal_zone_device_update(thermal->zone,
  					   THERMAL_EVENT_UNSPECIFIED);

  		delay = thermal->zone->passive_delay_jiffies;

  		queue_delayed_work(system_freezable_wq, &thermal->work, delay);

  		return;
  	}
  
  	mutex_lock(&thermal->lock);
  	thermal->temperature = DA9062_MILLI_CELSIUS(0);
  	mutex_unlock(&thermal->lock);
  	thermal_zone_device_update(thermal->zone,
  				   THERMAL_EVENT_UNSPECIFIED);
  
  err_enable_irq:
  	enable_irq(thermal->irq);
  }
  
  static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
  {
  	struct da9062_thermal *thermal = data;
  
  	disable_irq_nosync(thermal->irq);

  	queue_delayed_work(system_freezable_wq, &thermal->work, 0);

  
  	return IRQ_HANDLED;
  }

  static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
  					int trip,
  					enum thermal_trip_type *type)
  {
  	struct da9062_thermal *thermal = z->devdata;
  
  	switch (trip) {
  	case 0:
  		*type = THERMAL_TRIP_HOT;
  		break;
  	default:
  		dev_err(thermal->dev,
  			"Driver does not support more than 1 trip-wire
  ");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
  					int trip,
  					int *temp)
  {
  	struct da9062_thermal *thermal = z->devdata;
  
  	switch (trip) {
  	case 0:
  		*temp = DA9062_MILLI_CELSIUS(125);
  		break;
  	default:
  		dev_err(thermal->dev,
  			"Driver does not support more than 1 trip-wire
  ");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int da9062_thermal_get_temp(struct thermal_zone_device *z,
  				   int *temp)
  {
  	struct da9062_thermal *thermal = z->devdata;
  
  	mutex_lock(&thermal->lock);
  	*temp = thermal->temperature;
  	mutex_unlock(&thermal->lock);
  
  	return 0;
  }
  
  static struct thermal_zone_device_ops da9062_thermal_ops = {
  	.get_temp	= da9062_thermal_get_temp,

  	.get_trip_type	= da9062_thermal_get_trip_type,
  	.get_trip_temp	= da9062_thermal_get_trip_temp,
  };
  
  static const struct da9062_thermal_config da9062_config = {
  	.name = "da9062-thermal",
  };
  
  static const struct of_device_id da9062_compatible_reg_id_table[] = {
  	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
  	{ },
  };
  
  MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
  
  static int da9062_thermal_probe(struct platform_device *pdev)
  {
  	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
  	struct da9062_thermal *thermal;
  	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
  	const struct of_device_id *match;
  	int ret = 0;
  
  	match = of_match_node(da9062_compatible_reg_id_table,
  			      pdev->dev.of_node);
  	if (!match)
  		return -ENXIO;
  
  	if (pdev->dev.of_node) {
  		if (!of_property_read_u32(pdev->dev.of_node,
  					  "polling-delay-passive",
  					  &pp_tmp)) {
  			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
  			    pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
  				dev_warn(&pdev->dev,
  					 "Out-of-range polling period %d ms
  ",
  					 pp_tmp);
  				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
  			}
  		}
  	}
  
  	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
  			       GFP_KERNEL);
  	if (!thermal) {
  		ret = -ENOMEM;
  		goto err;
  	}
  
  	thermal->config = match->data;
  	thermal->hw = chip;

  	thermal->dev = &pdev->dev;
  
  	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
  	mutex_init(&thermal->lock);
  
  	thermal->zone = thermal_zone_device_register(thermal->config->name,
  					1, 0, thermal,
  					&da9062_thermal_ops, NULL, pp_tmp,
  					0);
  	if (IS_ERR(thermal->zone)) {
  		dev_err(&pdev->dev, "Cannot register thermal zone device
  ");
  		ret = PTR_ERR(thermal->zone);
  		goto err;
  	}

  	ret = thermal_zone_device_enable(thermal->zone);
  	if (ret) {
  		dev_err(&pdev->dev, "Cannot enable thermal zone device
  ");
  		goto err_zone;
  	}

  
  	dev_dbg(&pdev->dev,
  		"TJUNC temperature polling period set at %d ms
  ",

  		jiffies_to_msecs(thermal->zone->passive_delay_jiffies));

  
  	ret = platform_get_irq_byname(pdev, "THERMAL");
  	if (ret < 0) {
  		dev_err(&pdev->dev, "Failed to get platform IRQ.
  ");
  		goto err_zone;
  	}
  	thermal->irq = ret;
  
  	ret = request_threaded_irq(thermal->irq, NULL,
  				   da9062_thermal_irq_handler,
  				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
  				   "THERMAL", thermal);
  	if (ret) {
  		dev_err(&pdev->dev,
  			"Failed to request thermal device IRQ.
  ");
  		goto err_zone;
  	}
  
  	platform_set_drvdata(pdev, thermal);
  	return 0;
  
  err_zone:
  	thermal_zone_device_unregister(thermal->zone);
  err:
  	return ret;
  }
  
  static int da9062_thermal_remove(struct platform_device *pdev)
  {
  	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
  
  	free_irq(thermal->irq, thermal);
  	cancel_delayed_work_sync(&thermal->work);
  	thermal_zone_device_unregister(thermal->zone);
  	return 0;
  }
  
  static struct platform_driver da9062_thermal_driver = {
  	.probe	= da9062_thermal_probe,
  	.remove	= da9062_thermal_remove,
  	.driver	= {
  		.name	= "da9062-thermal",
  		.of_match_table = da9062_compatible_reg_id_table,
  	},
  };
  
  module_platform_driver(da9062_thermal_driver);
  
  MODULE_AUTHOR("Steve Twiss");
  MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:da9062-thermal");