1// SPDX-License-Identifier: GPL-2.0
  2//
  3// Copyright (C) 2012 ARM Limited
  4
  5#define DRVNAME "vexpress-regulator"
  6#define pr_fmt(fmt) DRVNAME ": " fmt
  7
  8#include <linux/device.h>
  9#include <linux/err.h>
 10#include <linux/module.h>
 11#include <linux/of_device.h>
 12#include <linux/regulator/driver.h>
 13#include <linux/regulator/machine.h>
 14#include <linux/regulator/of_regulator.h>
 15#include <linux/vexpress.h>
 16
 17static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
 18{
 19	unsigned int uV;
 20	int err = regmap_read(regdev->regmap, 0, &uV);
 21
 22	return err ? err : uV;
 23}
 24
 25static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
 26		int min_uV, int max_uV, unsigned *selector)
 27{
 28	return regmap_write(regdev->regmap, 0, min_uV);
 29}
 30
 31static const struct regulator_ops vexpress_regulator_ops_ro = {
 32	.get_voltage = vexpress_regulator_get_voltage,
 33};
 34
 35static const struct regulator_ops vexpress_regulator_ops = {
 36	.get_voltage = vexpress_regulator_get_voltage,
 37	.set_voltage = vexpress_regulator_set_voltage,
 38};
 39
 40static int vexpress_regulator_probe(struct platform_device *pdev)
 41{
 42	struct regulator_desc *desc;
 43	struct regulator_init_data *init_data;
 44	struct regulator_config config = { };
 45	struct regulator_dev *rdev;
 46	struct regmap *regmap;
 47
 48	desc = devm_kzalloc(&pdev->dev, sizeof(*desc), GFP_KERNEL);
 49	if (!desc)
 50		return -ENOMEM;
 51
 52	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
 53	if (IS_ERR(regmap))
 54		return PTR_ERR(regmap);
 55
 56	desc->name = dev_name(&pdev->dev);
 57	desc->type = REGULATOR_VOLTAGE;
 58	desc->owner = THIS_MODULE;
 59	desc->continuous_voltage_range = true;
 60
 61	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,
 62					       desc);
 63	if (!init_data)
 64		return -EINVAL;
 65
 66	init_data->constraints.apply_uV = 0;
 67	if (init_data->constraints.min_uV && init_data->constraints.max_uV)
 68		desc->ops = &vexpress_regulator_ops;
 69	else
 70		desc->ops = &vexpress_regulator_ops_ro;
 71
 72	config.regmap = regmap;
 73	config.dev = &pdev->dev;
 74	config.init_data = init_data;
 75	config.of_node = pdev->dev.of_node;
 76
 77	rdev = devm_regulator_register(&pdev->dev, desc, &config);
 78	return PTR_ERR_OR_ZERO(rdev);
 79}
 80
 81static const struct of_device_id vexpress_regulator_of_match[] = {
 82	{ .compatible = "arm,vexpress-volt", },
 83	{ }
 84};
 85MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);
 86
 87static struct platform_driver vexpress_regulator_driver = {
 88	.probe = vexpress_regulator_probe,
 89	.driver	= {
 90		.name = DRVNAME,
 91		.of_match_table = vexpress_regulator_of_match,
 92	},
 93};
 94
 95module_platform_driver(vexpress_regulator_driver);
 96
 97MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 98MODULE_DESCRIPTION("Versatile Express regulator");
 99MODULE_LICENSE("GPL");
100MODULE_ALIAS("platform:vexpress-regulator");