1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0+
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (c) Vaisala Oyj. All rights reserved.
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <linux/init.h>
7*4882a593Smuzhiyun #include <linux/module.h>
8*4882a593Smuzhiyun #include <linux/kernel.h>
9*4882a593Smuzhiyun #include <linux/of.h>
10*4882a593Smuzhiyun #include <linux/nvmem-consumer.h>
11*4882a593Smuzhiyun #include <linux/platform_device.h>
12*4882a593Smuzhiyun #include <linux/reboot-mode.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun struct nvmem_reboot_mode {
15*4882a593Smuzhiyun struct reboot_mode_driver reboot;
16*4882a593Smuzhiyun struct nvmem_cell *cell;
17*4882a593Smuzhiyun };
18*4882a593Smuzhiyun
nvmem_reboot_mode_write(struct reboot_mode_driver * reboot,unsigned int magic)19*4882a593Smuzhiyun static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
20*4882a593Smuzhiyun unsigned int magic)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun int ret;
23*4882a593Smuzhiyun struct nvmem_reboot_mode *nvmem_rbm;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
28*4882a593Smuzhiyun if (ret < 0)
29*4882a593Smuzhiyun dev_err(reboot->dev, "update reboot mode bits failed\n");
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun return ret;
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
nvmem_reboot_mode_probe(struct platform_device * pdev)34*4882a593Smuzhiyun static int nvmem_reboot_mode_probe(struct platform_device *pdev)
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun int ret;
37*4882a593Smuzhiyun struct nvmem_reboot_mode *nvmem_rbm;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun nvmem_rbm = devm_kzalloc(&pdev->dev, sizeof(*nvmem_rbm), GFP_KERNEL);
40*4882a593Smuzhiyun if (!nvmem_rbm)
41*4882a593Smuzhiyun return -ENOMEM;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun nvmem_rbm->reboot.dev = &pdev->dev;
44*4882a593Smuzhiyun nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun nvmem_rbm->cell = devm_nvmem_cell_get(&pdev->dev, "reboot-mode");
47*4882a593Smuzhiyun if (IS_ERR(nvmem_rbm->cell)) {
48*4882a593Smuzhiyun dev_err(&pdev->dev, "failed to get the nvmem cell reboot-mode\n");
49*4882a593Smuzhiyun return PTR_ERR(nvmem_rbm->cell);
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun ret = devm_reboot_mode_register(&pdev->dev, &nvmem_rbm->reboot);
53*4882a593Smuzhiyun if (ret)
54*4882a593Smuzhiyun dev_err(&pdev->dev, "can't register reboot mode\n");
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun return ret;
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun static const struct of_device_id nvmem_reboot_mode_of_match[] = {
60*4882a593Smuzhiyun { .compatible = "nvmem-reboot-mode" },
61*4882a593Smuzhiyun {}
62*4882a593Smuzhiyun };
63*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, nvmem_reboot_mode_of_match);
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun static struct platform_driver nvmem_reboot_mode_driver = {
66*4882a593Smuzhiyun .probe = nvmem_reboot_mode_probe,
67*4882a593Smuzhiyun .driver = {
68*4882a593Smuzhiyun .name = "nvmem-reboot-mode",
69*4882a593Smuzhiyun .of_match_table = nvmem_reboot_mode_of_match,
70*4882a593Smuzhiyun },
71*4882a593Smuzhiyun };
72*4882a593Smuzhiyun module_platform_driver(nvmem_reboot_mode_driver);
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun MODULE_AUTHOR("Nandor Han <nandor.han@vaisala.com>");
75*4882a593Smuzhiyun MODULE_DESCRIPTION("NVMEM reboot mode driver");
76*4882a593Smuzhiyun MODULE_LICENSE("GPL");
77