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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 return dev_err_probe(&pdev->dev, PTR_ERR(nvmem_rbm->cell),49 "failed to get the nvmem cell reboot-mode\n");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