nvmem-reboot-mode.c 1.9 KB

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