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/mod_devicetable.h>
 12#include <linux/platform_device.h>
 13#include <linux/regulator/driver.h>
 14#include <linux/regulator/machine.h>
 15#include <linux/regulator/of_regulator.h>
 16#include <linux/vexpress.h>
 17
 18static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
 19{
 20	unsigned int uV;
 21	int err = regmap_read(regdev->regmap, 0, &uV);
 22
 23	return err ? err : uV;
 24}
 25
 26static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
 27		int min_uV, int max_uV, unsigned *selector)
 28{
 29	return regmap_write(regdev->regmap, 0, min_uV);
 30}
 31
 32static const struct regulator_ops vexpress_regulator_ops_ro = {
 33	.get_voltage = vexpress_regulator_get_voltage,
 34};
 35
 36static const struct regulator_ops vexpress_regulator_ops = {
 37	.get_voltage = vexpress_regulator_get_voltage,
 38	.set_voltage = vexpress_regulator_set_voltage,
 39};
 40
 41static int vexpress_regulator_probe(struct platform_device *pdev)
 42{
 43	struct regulator_desc *desc;
 44	struct regulator_init_data *init_data;
 45	struct regulator_config config = { };
 46	struct regulator_dev *rdev;
 47	struct regmap *regmap;
 48
 49	desc = devm_kzalloc(&pdev->dev, sizeof(*desc), GFP_KERNEL);
 50	if (!desc)
 51		return -ENOMEM;
 52
 53	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
 54	if (IS_ERR(regmap))
 55		return PTR_ERR(regmap);
 56
 57	desc->name = dev_name(&pdev->dev);
 58	desc->type = REGULATOR_VOLTAGE;
 59	desc->owner = THIS_MODULE;
 60	desc->continuous_voltage_range = true;
 61
 62	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,
 63					       desc);
 64	if (!init_data)
 65		return -EINVAL;
 66
 67	init_data->constraints.apply_uV = 0;
 68	if (init_data->constraints.min_uV && init_data->constraints.max_uV)
 69		desc->ops = &vexpress_regulator_ops;
 70	else
 71		desc->ops = &vexpress_regulator_ops_ro;
 72
 73	config.regmap = regmap;
 74	config.dev = &pdev->dev;
 75	config.init_data = init_data;
 76	config.of_node = pdev->dev.of_node;
 77
 78	rdev = devm_regulator_register(&pdev->dev, desc, &config);
 79	return PTR_ERR_OR_ZERO(rdev);
 80}
 81
 82static const struct of_device_id vexpress_regulator_of_match[] = {
 83	{ .compatible = "arm,vexpress-volt", },
 84	{ }
 85};
 86MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);
 87
 88static struct platform_driver vexpress_regulator_driver = {
 89	.probe = vexpress_regulator_probe,
 90	.driver	= {
 91		.name = DRVNAME,
 92		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 93		.of_match_table = vexpress_regulator_of_match,
 94	},
 95};
 96
 97module_platform_driver(vexpress_regulator_driver);
 98
 99MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
100MODULE_DESCRIPTION("Versatile Express regulator");
101MODULE_LICENSE("GPL");
102MODULE_ALIAS("platform:vexpress-regulator");