drivers/regulator/dummy.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * dummy.c
   4  *
   5  * Copyright 2010 Wolfson Microelectronics PLC.
   6  *
   7  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   8  *
   9  * This is useful for systems with mixed controllable and
  10  * non-controllable regulators, as well as for allowing testing on
  11  * systems with no controllable regulators.
  12  */
  13
  14 #include <linux/err.h>
  15 #include <linux/export.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regulator/driver.h>
  18 #include <linux/regulator/machine.h>
  19
  20 #include "dummy.h"
  21
  22 struct regulator_dev *dummy_regulator_rdev;
  23
  24 static const struct regulator_init_data dummy_initdata = {
  25         .constraints = {
  26                 .always_on = 1,
  27         },
  28 };
  29
  30 static const struct regulator_ops dummy_ops;
  31
  32 static const struct regulator_desc dummy_desc = {
  33         .name = "regulator-dummy",
  34         .id = -1,
  35         .type = REGULATOR_VOLTAGE,
  36         .owner = THIS_MODULE,
  37         .ops = &dummy_ops,
  38 };
  39
  40 static int dummy_regulator_probe(struct platform_device *pdev)
  41 {
  42         struct regulator_config config = { };
  43         int ret;
  44
  45         config.dev = &pdev->dev;
  46         config.init_data = &dummy_initdata;
  47
  48         dummy_regulator_rdev = devm_regulator_register(&pdev->dev, &dummy_desc,
  49                                                        &config);
  50         if (IS_ERR(dummy_regulator_rdev)) {
  51                 ret = PTR_ERR(dummy_regulator_rdev);
  52                 pr_err("Failed to register regulator: %d\n", ret);
  53                 return ret;
  54         }
  55
  56         return 0;
  57 }
  58
  59 static struct platform_driver dummy_regulator_driver = {
  60         .probe          = dummy_regulator_probe,
  61         .driver         = {
  62                 .name           = "reg-dummy",
  63                 .probe_type     = PROBE_PREFER_ASYNCHRONOUS,
  64         },
  65 };
  66
  67 static struct platform_device *dummy_pdev;
  68
  69 void __init regulator_dummy_init(void)
  70 {
  71         int ret;
  72
  73         dummy_pdev = platform_device_alloc("reg-dummy", -1);
  74         if (!dummy_pdev) {
  75                 pr_err("Failed to allocate dummy regulator device\n");
  76                 return;
  77         }
  78
  79         ret = platform_device_add(dummy_pdev);
  80         if (ret != 0) {
  81                 pr_err("Failed to register dummy regulator device: %d\n", ret);
  82                 platform_device_put(dummy_pdev);
  83                 return;
  84         }
  85
  86         ret = platform_driver_register(&dummy_regulator_driver);
  87         if (ret != 0) {
  88                 pr_err("Failed to register dummy regulator driver: %d\n", ret);
  89                 platform_device_unregister(dummy_pdev);
  90         }
  91 }