LXR linux/drivers/power/reset/nvmem-reboot-mode.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (c) Vaisala Oyj. All rights reserved.
   4 */
   5
   6#include <linux/init.h>
   7#include <linux/module.h>
   8#include <linux/kernel.h>
   9#include <linux/of.h>
  10#include <linux/nvmem-consumer.h>
  11#include <linux/platform_device.h>
  12#include <linux/reboot-mode.h>
  13
  14struct nvmem_reboot_mode {
  15        struct reboot_mode_driver reboot;
  16        struct nvmem_cell *cell;
  17};
  18
  19static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
  20                                    unsigned int magic)
  21{
  22        int ret;
  23        struct nvmem_reboot_mode *nvmem_rbm;
  24
  25        nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
  26
  27        ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
  28        if (ret < 0)
  29                dev_err(reboot->dev, "update reboot mode bits failed\n");
  30
  31        return ret;
  32}
  33
  34static int nvmem_reboot_mode_probe(struct platform_device *pdev)
  35{
  36        int ret;
  37        struct nvmem_reboot_mode *nvmem_rbm;
  38
  39        nvmem_rbm = devm_kzalloc(&pdev->dev, sizeof(*nvmem_rbm), GFP_KERNEL);
  40        if (!nvmem_rbm)
  41                return -ENOMEM;
  42
  43        nvmem_rbm->reboot.dev = &pdev->dev;
  44        nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
  45
  46        nvmem_rbm->cell = devm_nvmem_cell_get(&pdev->dev, "reboot-mode");
  47        if (IS_ERR(nvmem_rbm->cell)) {
  48                dev_err(&pdev->dev, "failed to get the nvmem cell reboot-mode\n");
  49                return PTR_ERR(nvmem_rbm->cell);
  50        }
  51
  52        ret = devm_reboot_mode_register(&pdev->dev, &nvmem_rbm->reboot);
  53        if (ret)
  54                dev_err(&pdev->dev, "can't register reboot mode\n");
  55
  56        return ret;
  57}
  58
  59static const struct of_device_id nvmem_reboot_mode_of_match[] = {
  60        { .compatible = "nvmem-reboot-mode" },
  61        {}
  62};
  63MODULE_DEVICE_TABLE(of, nvmem_reboot_mode_of_match);
  64
  65static struct platform_driver nvmem_reboot_mode_driver = {
  66        .probe = nvmem_reboot_mode_probe,
  67        .driver = {
  68                .name = "nvmem-reboot-mode",
  69                .of_match_table = nvmem_reboot_mode_of_match,
  70        },
  71};
  72module_platform_driver(nvmem_reboot_mode_driver);
  73
  74MODULE_AUTHOR("Nandor Han <nandor.han@vaisala.com>");
  75MODULE_DESCRIPTION("NVMEM reboot mode driver");
  76MODULE_LICENSE("GPL");
  77