meson-efuse.c 2.8 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120
  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Amlogic Meson GX eFuse Driver
  4. *
  5. * Copyright (c) 2016 Endless Computers, Inc.
  6. * Author: Carlo Caione <carlo@endlessm.com>
  7. */
  8. #include <linux/clk.h>
  9. #include <linux/module.h>
  10. #include <linux/nvmem-provider.h>
  11. #include <linux/of.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/firmware/meson/meson_sm.h>
  14. static int meson_efuse_read(void *context, unsigned int offset,
  15. void *val, size_t bytes)
  16. {
  17. struct meson_sm_firmware *fw = context;
  18. return meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
  19. bytes, 0, 0, 0);
  20. }
  21. static int meson_efuse_write(void *context, unsigned int offset,
  22. void *val, size_t bytes)
  23. {
  24. struct meson_sm_firmware *fw = context;
  25. return meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
  26. bytes, 0, 0, 0);
  27. }
  28. static const struct of_device_id meson_efuse_match[] = {
  29. { .compatible = "amlogic,meson-gxbb-efuse", },
  30. { /* sentinel */ },
  31. };
  32. MODULE_DEVICE_TABLE(of, meson_efuse_match);
  33. static int meson_efuse_probe(struct platform_device *pdev)
  34. {
  35. struct device *dev = &pdev->dev;
  36. struct meson_sm_firmware *fw;
  37. struct device_node *sm_np;
  38. struct nvmem_device *nvmem;
  39. struct nvmem_config *econfig;
  40. struct clk *clk;
  41. unsigned int size;
  42. int ret;
  43. sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
  44. if (!sm_np) {
  45. dev_err(&pdev->dev, "no secure-monitor node\n");
  46. return -ENODEV;
  47. }
  48. fw = meson_sm_get(sm_np);
  49. of_node_put(sm_np);
  50. if (!fw)
  51. return -EPROBE_DEFER;
  52. clk = devm_clk_get(dev, NULL);
  53. if (IS_ERR(clk)) {
  54. ret = PTR_ERR(clk);
  55. if (ret != -EPROBE_DEFER)
  56. dev_err(dev, "failed to get efuse gate");
  57. return ret;
  58. }
  59. ret = clk_prepare_enable(clk);
  60. if (ret) {
  61. dev_err(dev, "failed to enable gate");
  62. return ret;
  63. }
  64. ret = devm_add_action_or_reset(dev,
  65. (void(*)(void *))clk_disable_unprepare,
  66. clk);
  67. if (ret) {
  68. dev_err(dev, "failed to add disable callback");
  69. return ret;
  70. }
  71. if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
  72. dev_err(dev, "failed to get max user");
  73. return -EINVAL;
  74. }
  75. econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
  76. if (!econfig)
  77. return -ENOMEM;
  78. econfig->dev = dev;
  79. econfig->name = dev_name(dev);
  80. econfig->stride = 1;
  81. econfig->word_size = 1;
  82. econfig->reg_read = meson_efuse_read;
  83. econfig->reg_write = meson_efuse_write;
  84. econfig->size = size;
  85. econfig->priv = fw;
  86. nvmem = devm_nvmem_register(&pdev->dev, econfig);
  87. return PTR_ERR_OR_ZERO(nvmem);
  88. }
  89. static struct platform_driver meson_efuse_driver = {
  90. .probe = meson_efuse_probe,
  91. .driver = {
  92. .name = "meson-efuse",
  93. .of_match_table = meson_efuse_match,
  94. },
  95. };
  96. module_platform_driver(meson_efuse_driver);
  97. MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
  98. MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
  99. MODULE_LICENSE("GPL v2");