// SPDX-License-Identifier: GPL-2.0
  //
  // Copyright (C) 2012 ARM Limited

  
  #define DRVNAME "vexpress-regulator"
  #define pr_fmt(fmt) DRVNAME ": " fmt
  
  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/module.h>
  #include <linux/of_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #include <linux/regulator/of_regulator.h>
  #include <linux/vexpress.h>

  static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
  {

  	unsigned int uV;
  	int err = regmap_read(regdev->regmap, 0, &uV);

  
  	return err ? err : uV;
  }
  
  static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
  		int min_uV, int max_uV, unsigned *selector)
  {

  	return regmap_write(regdev->regmap, 0, min_uV);

  }

  static const struct regulator_ops vexpress_regulator_ops_ro = {

  	.get_voltage = vexpress_regulator_get_voltage,
  };

  static const struct regulator_ops vexpress_regulator_ops = {

  	.get_voltage = vexpress_regulator_get_voltage,
  	.set_voltage = vexpress_regulator_set_voltage,
  };
  
  static int vexpress_regulator_probe(struct platform_device *pdev)
  {

  	struct regulator_desc *desc;

  	struct regulator_init_data *init_data;
  	struct regulator_config config = { };

  	struct regulator_dev *rdev;
  	struct regmap *regmap;

  	desc = devm_kzalloc(&pdev->dev, sizeof(*desc), GFP_KERNEL);
  	if (!desc)

  		return -ENOMEM;

  	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
  	if (IS_ERR(regmap))
  		return PTR_ERR(regmap);

  	desc->name = dev_name(&pdev->dev);
  	desc->type = REGULATOR_VOLTAGE;
  	desc->owner = THIS_MODULE;
  	desc->continuous_voltage_range = true;

  	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,

  					       desc);

  	if (!init_data)
  		return -EINVAL;

  
  	init_data->constraints.apply_uV = 0;
  	if (init_data->constraints.min_uV && init_data->constraints.max_uV)

  		desc->ops = &vexpress_regulator_ops;

  	else

  		desc->ops = &vexpress_regulator_ops_ro;

  	config.regmap = regmap;

  	config.dev = &pdev->dev;
  	config.init_data = init_data;

  	config.of_node = pdev->dev.of_node;

  	rdev = devm_regulator_register(&pdev->dev, desc, &config);

  	return PTR_ERR_OR_ZERO(rdev);

  }

  static const struct of_device_id vexpress_regulator_of_match[] = {

  	{ .compatible = "arm,vexpress-volt", },

  	{ }

  };

  MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);

  
  static struct platform_driver vexpress_regulator_driver = {
  	.probe = vexpress_regulator_probe,

  	.driver	= {
  		.name = DRVNAME,

  		.of_match_table = vexpress_regulator_of_match,
  	},
  };
  
  module_platform_driver(vexpress_regulator_driver);
  
  MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
  MODULE_DESCRIPTION("Versatile Express regulator");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:vexpress-regulator");