drivers/regulator/vexpress-regulator.c

   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
  17 static 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
  25 static 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
  31 static const struct regulator_ops vexpress_regulator_ops_ro = {
  32         .get_voltage = vexpress_regulator_get_voltage,
  33 };
  34
  35 static const struct regulator_ops vexpress_regulator_ops = {
  36         .get_voltage = vexpress_regulator_get_voltage,
  37         .set_voltage = vexpress_regulator_set_voltage,
  38 };
  39
  40 static 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
  81 static const struct of_device_id vexpress_regulator_of_match[] = {
  82         { .compatible = "arm,vexpress-volt", },
  83         { }
  84 };
  85 MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);
  86
  87 static 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
  95 module_platform_driver(vexpress_regulator_driver);
  96
  97 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
  98 MODULE_DESCRIPTION("Versatile Express regulator");
  99 MODULE_LICENSE("GPL");
 100 MODULE_ALIAS("platform:vexpress-regulator");