drivers/regulator/vexpress-regulator.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
  26 struct vexpress_regulator {
  27         struct regulator_desc desc;
  28         struct regulator_dev *regdev;
  29         struct regmap *regmap;
  30 };
  31
  32 static 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
  41 static 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
  49 static struct regulator_ops vexpress_regulator_ops_ro = {
  50         .get_voltage = vexpress_regulator_get_voltage,
  51 };
  52
  53 static struct regulator_ops vexpress_regulator_ops = {
  54         .get_voltage = vexpress_regulator_get_voltage,
  55         .set_voltage = vexpress_regulator_set_voltage,
  56 };
  57
  58 static 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
 102 static const struct of_device_id vexpress_regulator_of_match[] = {
 103         { .compatible = "arm,vexpress-volt", },
 104         { }
 105 };
 106 MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);
 107
 108 static 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
 116 module_platform_driver(vexpress_regulator_driver);
 117
 118 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 119 MODULE_DESCRIPTION("Versatile Express regulator");
 120 MODULE_LICENSE("GPL");
 121 MODULE_ALIAS("platform:vexpress-regulator");