reset-oxnas.c 2.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * drivers/reset/reset-oxnas.c
  4. *
  5. * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
  6. * Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com>
  7. * Copyright (C) 2009 Oxford Semiconductor Ltd
  8. */
  9. #include <linux/err.h>
  10. #include <linux/init.h>
  11. #include <linux/of.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/reset-controller.h>
  14. #include <linux/slab.h>
  15. #include <linux/delay.h>
  16. #include <linux/types.h>
  17. #include <linux/regmap.h>
  18. #include <linux/mfd/syscon.h>
  19. /* Regmap offsets */
  20. #define RST_SET_REGOFFSET 0x34
  21. #define RST_CLR_REGOFFSET 0x38
  22. struct oxnas_reset {
  23. struct regmap *regmap;
  24. struct reset_controller_dev rcdev;
  25. };
  26. static int oxnas_reset_reset(struct reset_controller_dev *rcdev,
  27. unsigned long id)
  28. {
  29. struct oxnas_reset *data =
  30. container_of(rcdev, struct oxnas_reset, rcdev);
  31. regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
  32. msleep(50);
  33. regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
  34. return 0;
  35. }
  36. static int oxnas_reset_assert(struct reset_controller_dev *rcdev,
  37. unsigned long id)
  38. {
  39. struct oxnas_reset *data =
  40. container_of(rcdev, struct oxnas_reset, rcdev);
  41. regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
  42. return 0;
  43. }
  44. static int oxnas_reset_deassert(struct reset_controller_dev *rcdev,
  45. unsigned long id)
  46. {
  47. struct oxnas_reset *data =
  48. container_of(rcdev, struct oxnas_reset, rcdev);
  49. regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
  50. return 0;
  51. }
  52. static const struct reset_control_ops oxnas_reset_ops = {
  53. .reset = oxnas_reset_reset,
  54. .assert = oxnas_reset_assert,
  55. .deassert = oxnas_reset_deassert,
  56. };
  57. static const struct of_device_id oxnas_reset_dt_ids[] = {
  58. { .compatible = "oxsemi,ox810se-reset", },
  59. { .compatible = "oxsemi,ox820-reset", },
  60. { /* sentinel */ },
  61. };
  62. static int oxnas_reset_probe(struct platform_device *pdev)
  63. {
  64. struct oxnas_reset *data;
  65. struct device *parent;
  66. parent = pdev->dev.parent;
  67. if (!parent) {
  68. dev_err(&pdev->dev, "no parent\n");
  69. return -ENODEV;
  70. }
  71. data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
  72. if (!data)
  73. return -ENOMEM;
  74. data->regmap = syscon_node_to_regmap(parent->of_node);
  75. if (IS_ERR(data->regmap)) {
  76. dev_err(&pdev->dev, "failed to get parent regmap\n");
  77. return PTR_ERR(data->regmap);
  78. }
  79. platform_set_drvdata(pdev, data);
  80. data->rcdev.owner = THIS_MODULE;
  81. data->rcdev.nr_resets = 32;
  82. data->rcdev.ops = &oxnas_reset_ops;
  83. data->rcdev.of_node = pdev->dev.of_node;
  84. return devm_reset_controller_register(&pdev->dev, &data->rcdev);
  85. }
  86. static struct platform_driver oxnas_reset_driver = {
  87. .probe = oxnas_reset_probe,
  88. .driver = {
  89. .name = "oxnas-reset",
  90. .of_match_table = oxnas_reset_dt_ids,
  91. },
  92. };
  93. builtin_platform_driver(oxnas_reset_driver);