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