LXR linux/drivers/regulator/vexpress.c

   1/*
   2 * This program is free software; you can redistribute it and/or modify
   3 * it under the terms of the GNU General Public License version 2 as
   4 * published by the Free Software Foundation.
   5 *
   6 * This program is distributed in the hope that it will be useful,
   7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 * GNU General Public License for more details.
  10 *
  11 * Copyright (C) 2012 ARM Limited
  12 */
  13
  14#define DRVNAME "vexpress-regulator"
  15#define pr_fmt(fmt) DRVNAME ": " fmt
  16
  17#include <linux/device.h>
  18#include <linux/err.h>
  19#include <linux/module.h>
  20#include <linux/of_device.h>
  21#include <linux/regulator/driver.h>
  22#include <linux/regulator/machine.h>
  23#include <linux/regulator/of_regulator.h>
  24#include <linux/vexpress.h>
  25
  26struct vexpress_regulator {
  27        struct regulator_desc desc;
  28        struct regulator_dev *regdev;
  29        struct regmap *regmap;
  30};
  31
  32static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
  33{
  34        struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
  35        u32 uV;
  36        int err = regmap_read(reg->regmap, 0, &uV);
  37
  38        return err ? err : uV;
  39}
  40
  41static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
  42                int min_uV, int max_uV, unsigned *selector)
  43{
  44        struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
  45
  46        return regmap_write(reg->regmap, 0, min_uV);
  47}
  48
  49static struct regulator_ops vexpress_regulator_ops_ro = {
  50        .get_voltage = vexpress_regulator_get_voltage,
  51};
  52
  53static struct regulator_ops vexpress_regulator_ops = {
  54        .get_voltage = vexpress_regulator_get_voltage,
  55        .set_voltage = vexpress_regulator_set_voltage,
  56};
  57
  58static int vexpress_regulator_probe(struct platform_device *pdev)
  59{
  60        struct vexpress_regulator *reg;
  61        struct regulator_init_data *init_data;
  62        struct regulator_config config = { };
  63
  64        reg = devm_kzalloc(&pdev->dev, sizeof(*reg), GFP_KERNEL);
  65        if (!reg)
  66                return -ENOMEM;
  67
  68        reg->regmap = devm_regmap_init_vexpress_config(&pdev->dev);
  69        if (IS_ERR(reg->regmap))
  70                return PTR_ERR(reg->regmap);
  71
  72        reg->desc.name = dev_name(&pdev->dev);
  73        reg->desc.type = REGULATOR_VOLTAGE;
  74        reg->desc.owner = THIS_MODULE;
  75        reg->desc.continuous_voltage_range = true;
  76
  77        init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,
  78                                               &reg->desc);
  79        if (!init_data)
  80                return -EINVAL;
  81
  82        init_data->constraints.apply_uV = 0;
  83        if (init_data->constraints.min_uV && init_data->constraints.max_uV)
  84                reg->desc.ops = &vexpress_regulator_ops;
  85        else
  86                reg->desc.ops = &vexpress_regulator_ops_ro;
  87
  88        config.dev = &pdev->dev;
  89        config.init_data = init_data;
  90        config.driver_data = reg;
  91        config.of_node = pdev->dev.of_node;
  92
  93        reg->regdev = devm_regulator_register(&pdev->dev, &reg->desc, &config);
  94        if (IS_ERR(reg->regdev))
  95                return PTR_ERR(reg->regdev);
  96
  97        platform_set_drvdata(pdev, reg);
  98
  99        return 0;
 100}
 101
 102static const struct of_device_id vexpress_regulator_of_match[] = {
 103        { .compatible = "arm,vexpress-volt", },
 104        { }
 105};
 106MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);
 107
 108static struct platform_driver vexpress_regulator_driver = {
 109        .probe = vexpress_regulator_probe,
 110        .driver = {
 111                .name = DRVNAME,
 112                .of_match_table = vexpress_regulator_of_match,
 113        },
 114};
 115
 116module_platform_driver(vexpress_regulator_driver);
 117
 118MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 119MODULE_DESCRIPTION("Versatile Express regulator");
 120MODULE_LICENSE("GPL");
 121MODULE_ALIAS("platform:vexpress-regulator");
 122