text: /*
   * ST Thermal Sensor Driver core routines
   * Author: Ajit Pal Singh <ajitpal.singh@st.com>
   *
   * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
   *
   * 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.
   *
   */
  
  #include <linux/clk.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  
  #include "st_thermal.h"
  
  /* The Thermal Framework expects millidegrees */
  #define mcelsius(temp)			((temp) * 1000)
  
  /*
   * Function to allocate regfields which are common
   * between syscfg and memory mapped based sensors
   */
  int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
  {
  	struct device *dev = sensor->dev;
  	struct regmap *regmap = sensor->regmap;
  	const struct reg_field *reg_fields = sensor->cdata->reg_fields;
  
  	sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
  						   reg_fields[DCORRECT]);
  
  	sensor->overflow = devm_regmap_field_alloc(dev, regmap,
  						   reg_fields[OVERFLOW]);
  
  	sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
  						    reg_fields[DATA]);
  
  	if (IS_ERR(sensor->dcorrect) ||
  	    IS_ERR(sensor->overflow) ||
  	    IS_ERR(sensor->temp_data)) {
  		dev_err(dev, "failed to allocate common regfields\n");
  		return -EINVAL;
  	}
  
  	return sensor->ops->alloc_regfields(sensor);
  }
  
  static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
  {
  	int ret;
  	struct device *dev = sensor->dev;
  
  	ret = clk_prepare_enable(sensor->clk);
  	if (ret) {
  		dev_err(dev, "failed to enable clk\n");
  		return ret;
  	}
  
  	ret = sensor->ops->power_ctrl(sensor, POWER_ON);
  	if (ret) {
  		dev_err(dev, "failed to power on sensor\n");
  		clk_disable_unprepare(sensor->clk);
  	}
  
  	return ret;
  }
  
  static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
  {
  	int ret;
  
  	ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
  	if (ret)
  		return ret;
  
  	clk_disable_unprepare(sensor->clk);
  
  	return 0;
  }
  
  static int st_thermal_calibration(struct st_thermal_sensor *sensor)
  {
  	int ret;
  	unsigned int val;
  	struct device *dev = sensor->dev;
  
  	/* Check if sensor calibration data is already written */
  	ret = regmap_field_read(sensor->dcorrect, &val);
  	if (ret) {
  		dev_err(dev, "failed to read calibration data\n");
  		return ret;
  	}
  
  	if (!val) {
  		/*
  		 * Sensor calibration value not set by bootloader,
  		 * default calibration data to be used
  		 */
  		ret = regmap_field_write(sensor->dcorrect,
  					 sensor->cdata->calibration_val);
  		if (ret)
  			dev_err(dev, "failed to set calibration data\n");
  	}
  
  	return ret;
  }
  
  /* Callback to get temperature from HW*/
  static int st_thermal_get_temp(struct thermal_zone_device *th,
  		unsigned long *temperature)
  {
  	struct st_thermal_sensor *sensor = th->devdata;
  	struct device *dev = sensor->dev;
  	unsigned int temp;
  	unsigned int overflow;
  	int ret;
  
  	ret = regmap_field_read(sensor->overflow, &overflow);
  	if (ret)
  		return ret;
  	if (overflow)
  		return -EIO;
  
  	ret = regmap_field_read(sensor->temp_data, &temp);
  	if (ret)
  		return ret;
  
  	temp += sensor->cdata->temp_adjust_val;
  	temp = mcelsius(temp);
  
  	dev_dbg(dev, "temperature: %d\n", temp);
  
  	*temperature = temp;
  
  	return 0;
  }
  
  static int st_thermal_get_trip_type(struct thermal_zone_device *th,
  				int trip, enum thermal_trip_type *type)
  {
  	struct st_thermal_sensor *sensor = th->devdata;
  	struct device *dev = sensor->dev;
  
  	switch (trip) {
  	case 0:
  		*type = THERMAL_TRIP_CRITICAL;
  		break;
  	default:
  		dev_err(dev, "invalid trip point\n");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
  				    int trip, unsigned long *temp)
  {
  	struct st_thermal_sensor *sensor = th->devdata;
  	struct device *dev = sensor->dev;
  
  	switch (trip) {
  	case 0:
  		*temp = mcelsius(sensor->cdata->crit_temp);
  		break;
  	default:
  		dev_err(dev, "Invalid trip point\n");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static struct thermal_zone_device_ops st_tz_ops = {
  	.get_temp	= st_thermal_get_temp,
  	.get_trip_type	= st_thermal_get_trip_type,
  	.get_trip_temp	= st_thermal_get_trip_temp,
  };
  
  int st_thermal_register(struct platform_device *pdev,
  			const struct of_device_id *st_thermal_of_match)
  {
  	struct st_thermal_sensor *sensor;
  	struct device *dev = &pdev->dev;
  	struct device_node *np = dev->of_node;
  	const struct of_device_id *match;
  
  	int polling_delay;
  	int ret;
  
  	if (!np) {
  		dev_err(dev, "device tree node not found\n");
  		return -EINVAL;
  	}
  
  	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
  	if (!sensor)
  		return -ENOMEM;
  
  	sensor->dev = dev;
  
  	match = of_match_device(st_thermal_of_match, dev);
  	if (!(match && match->data))
  		return -EINVAL;
  
  	sensor->cdata = match->data;
  	if (!sensor->cdata->ops)
  		return -EINVAL;
  
  	sensor->ops = sensor->cdata->ops;
  
  	ret = sensor->ops->regmap_init(sensor);
  	if (ret)
  		return ret;
  
  	ret = st_thermal_alloc_regfields(sensor);
  	if (ret)
  		return ret;
  
  	sensor->clk = devm_clk_get(dev, "thermal");
  	if (IS_ERR(sensor->clk)) {
  		dev_err(dev, "failed to fetch clock\n");
  		return PTR_ERR(sensor->clk);
  	}
  
  	if (sensor->ops->register_enable_irq) {
  		ret = sensor->ops->register_enable_irq(sensor);
  		if (ret)
  			return ret;
  	}
  
  	ret = st_thermal_sensor_on(sensor);
  	if (ret)
  		return ret;
  
  	ret = st_thermal_calibration(sensor);
  	if (ret)
  		goto sensor_off;
  
  	polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
  
  	sensor->thermal_dev =
  		thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
  					     &st_tz_ops, NULL, 0, polling_delay);
  	if (IS_ERR(sensor->thermal_dev)) {
  		dev_err(dev, "failed to register thermal zone device\n");
  		ret = PTR_ERR(sensor->thermal_dev);
  		goto sensor_off;
  	}
  
  	platform_set_drvdata(pdev, sensor);
  
  	return 0;
  
  sensor_off:
  	st_thermal_sensor_off(sensor);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(st_thermal_register);
  
  int st_thermal_unregister(struct platform_device *pdev)
  {
  	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
  
  	st_thermal_sensor_off(sensor);
  	thermal_zone_device_unregister(sensor->thermal_dev);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(st_thermal_unregister);
  
  #ifdef CONFIG_PM_SLEEP
  static int st_thermal_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
  
  	return st_thermal_sensor_off(sensor);
  }
  
  static int st_thermal_resume(struct device *dev)
  {
  	int ret;
  	struct platform_device *pdev = to_platform_device(dev);
  	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
  
  	ret = st_thermal_sensor_on(sensor);
  	if (ret)
  		return ret;
  
  	ret = st_thermal_calibration(sensor);
  	if (ret)
  		return ret;
  
  	if (sensor->ops->enable_irq) {
  		ret = sensor->ops->enable_irq(sensor);
  		if (ret)
  			return ret;
  	}
  
  	return 0;
  }
  #endif
  
  SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
  EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
  
  MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
  MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
  MODULE_LICENSE("GPL v2");
  