text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * ST Thermal Sensor Driver for memory mapped sensors.
   * Author: Ajit Pal Singh <ajitpal.singh@st.com>
   *
   * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
   */
  
  #include <linux/of.h>
  #include <linux/module.h>
  
  #include "st_thermal.h"
  
  #define STIH416_MPE_CONF			0x0
  #define STIH416_MPE_STATUS			0x4
  #define STIH416_MPE_INT_THRESH			0x8
  #define STIH416_MPE_INT_EN			0xC
  
  /* Power control bits for the memory mapped thermal sensor */
  #define THERMAL_PDN				BIT(4)
  #define THERMAL_SRSTN				BIT(10)
  
  static const struct reg_field st_mmap_thermal_regfields[MAX_REGFIELDS] = {
  	/*
  	 * According to the STIH416 MPE temp sensor data sheet -
  	 * the PDN (Power Down Bit) and SRSTN (Soft Reset Bit) need to be
  	 * written simultaneously for powering on and off the temperature
  	 * sensor. regmap_update_bits() will be used to update the register.
  	 */
  	[INT_THRESH_HI]	= REG_FIELD(STIH416_MPE_INT_THRESH, 	0,  7),
  	[DCORRECT]	= REG_FIELD(STIH416_MPE_CONF,		5,  9),
  	[OVERFLOW]	= REG_FIELD(STIH416_MPE_STATUS,		9,  9),
  	[DATA]		= REG_FIELD(STIH416_MPE_STATUS,		11, 18),
  	[INT_ENABLE]	= REG_FIELD(STIH416_MPE_INT_EN,		0,  0),
  };
  
  static irqreturn_t st_mmap_thermal_trip_handler(int irq, void *sdata)
  {
  	struct st_thermal_sensor *sensor = sdata;
  
  	thermal_zone_device_update(sensor->thermal_dev,
  				   THERMAL_EVENT_UNSPECIFIED);
  
  	return IRQ_HANDLED;
  }
  
  /* Private ops for the Memory Mapped based thermal sensors */
  static int st_mmap_power_ctrl(struct st_thermal_sensor *sensor,
  			      enum st_thermal_power_state power_state)
  {
  	const unsigned int mask = (THERMAL_PDN | THERMAL_SRSTN);
  	const unsigned int val = power_state ? mask : 0;
  
  	return regmap_update_bits(sensor->regmap, STIH416_MPE_CONF, mask, val);
  }
  
  static int st_mmap_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->int_thresh_hi = devm_regmap_field_alloc(dev, regmap,
  						reg_fields[INT_THRESH_HI]);
  	sensor->int_enable = devm_regmap_field_alloc(dev, regmap,
  						reg_fields[INT_ENABLE]);
  
  	if (IS_ERR(sensor->int_thresh_hi) || IS_ERR(sensor->int_enable)) {
  		dev_err(dev, "failed to alloc mmap regfields\n");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int st_mmap_enable_irq(struct st_thermal_sensor *sensor)
  {
  	int ret;
  
  	/* Set upper critical threshold */
  	ret = regmap_field_write(sensor->int_thresh_hi,
  				 sensor->cdata->crit_temp -
  				 sensor->cdata->temp_adjust_val);
  	if (ret)
  		return ret;
  
  	return regmap_field_write(sensor->int_enable, 1);
  }
  
  static int st_mmap_register_enable_irq(struct st_thermal_sensor *sensor)
  {
  	struct device *dev = sensor->dev;
  	struct platform_device *pdev = to_platform_device(dev);
  	int ret;
  
  	sensor->irq = platform_get_irq(pdev, 0);
  	if (sensor->irq < 0) {
  		dev_err(dev, "failed to register IRQ\n");
  		return sensor->irq;
  	}
  
  	ret = devm_request_threaded_irq(dev, sensor->irq,
  					NULL, st_mmap_thermal_trip_handler,
  					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  					dev->driver->name, sensor);
  	if (ret) {
  		dev_err(dev, "failed to register IRQ %d\n", sensor->irq);
  		return ret;
  	}
  
  	return st_mmap_enable_irq(sensor);
  }
  
  static const struct regmap_config st_416mpe_regmap_config = {
  	.reg_bits = 32,
  	.val_bits = 32,
  	.reg_stride = 4,
  };
  
  static int st_mmap_regmap_init(struct st_thermal_sensor *sensor)
  {
  	struct device *dev = sensor->dev;
  	struct platform_device *pdev = to_platform_device(dev);
  	struct resource *res;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_err(dev, "no memory resources defined\n");
  		return -ENODEV;
  	}
  
  	sensor->mmio_base = devm_ioremap_resource(dev, res);
  	if (IS_ERR(sensor->mmio_base)) {
  		dev_err(dev, "failed to remap IO\n");
  		return PTR_ERR(sensor->mmio_base);
  	}
  
  	sensor->regmap = devm_regmap_init_mmio(dev, sensor->mmio_base,
  				&st_416mpe_regmap_config);
  	if (IS_ERR(sensor->regmap)) {
  		dev_err(dev, "failed to initialise regmap\n");
  		return PTR_ERR(sensor->regmap);
  	}
  
  	return 0;
  }
  
  static const struct st_thermal_sensor_ops st_mmap_sensor_ops = {
  	.power_ctrl		= st_mmap_power_ctrl,
  	.alloc_regfields	= st_mmap_alloc_regfields,
  	.regmap_init		= st_mmap_regmap_init,
  	.register_enable_irq	= st_mmap_register_enable_irq,
  	.enable_irq		= st_mmap_enable_irq,
  };
  
  /* Compatible device data stih416 mpe thermal sensor */
  static const struct st_thermal_compat_data st_416mpe_cdata = {
  	.reg_fields		= st_mmap_thermal_regfields,
  	.ops			= &st_mmap_sensor_ops,
  	.calibration_val	= 14,
  	.temp_adjust_val	= -95,
  	.crit_temp		= 120,
  };
  
  /* Compatible device data stih407 thermal sensor */
  static const struct st_thermal_compat_data st_407_cdata = {
  	.reg_fields		= st_mmap_thermal_regfields,
  	.ops			= &st_mmap_sensor_ops,
  	.calibration_val	= 16,
  	.temp_adjust_val	= -95,
  	.crit_temp		= 120,
  };
  
  static const struct of_device_id st_mmap_thermal_of_match[] = {
  	{ .compatible = "st,stih416-mpe-thermal", .data = &st_416mpe_cdata },
  	{ .compatible = "st,stih407-thermal",     .data = &st_407_cdata },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, st_mmap_thermal_of_match);
  
  static int st_mmap_probe(struct platform_device *pdev)
  {
  	return st_thermal_register(pdev,  st_mmap_thermal_of_match);
  }
  
  static int st_mmap_remove(struct platform_device *pdev)
  {
  	return st_thermal_unregister(pdev);
  }
  
  static struct platform_driver st_mmap_thermal_driver = {
  	.driver = {
  		.name	= "st_thermal_mmap",
  		.pm     = &st_thermal_pm_ops,
  		.of_match_table = st_mmap_thermal_of_match,
  	},
  	.probe		= st_mmap_probe,
  	.remove		= st_mmap_remove,
  };
  
  module_platform_driver(st_mmap_thermal_driver);
  
  MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
  MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
  MODULE_LICENSE("GPL v2");
  