reset-syscon.c 1.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (C) 2020 Sean Anderson
  4. */
  5. #include <common.h>
  6. #include <dm.h>
  7. #include <regmap.h>
  8. #include <reset.h>
  9. #include <reset-uclass.h>
  10. #include <syscon.h>
  11. #include <linux/bitops.h>
  12. #include <linux/err.h>
  13. struct syscon_reset_priv {
  14. struct regmap *regmap;
  15. uint offset;
  16. uint mask;
  17. bool assert_high;
  18. };
  19. static int syscon_reset_request(struct reset_ctl *rst)
  20. {
  21. struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
  22. if (BIT(rst->id) & priv->mask)
  23. return 0;
  24. else
  25. return -EINVAL;
  26. }
  27. static int syscon_reset_assert(struct reset_ctl *rst)
  28. {
  29. struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
  30. return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
  31. priv->assert_high ? BIT(rst->id) : 0);
  32. }
  33. static int syscon_reset_deassert(struct reset_ctl *rst)
  34. {
  35. struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
  36. return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
  37. priv->assert_high ? 0 : BIT(rst->id));
  38. }
  39. static const struct reset_ops syscon_reset_ops = {
  40. .request = syscon_reset_request,
  41. .rst_assert = syscon_reset_assert,
  42. .rst_deassert = syscon_reset_deassert,
  43. };
  44. int syscon_reset_probe(struct udevice *dev)
  45. {
  46. struct syscon_reset_priv *priv = dev_get_priv(dev);
  47. priv->regmap = syscon_regmap_lookup_by_phandle(dev, "regmap");
  48. if (IS_ERR(priv->regmap))
  49. return -ENODEV;
  50. priv->offset = dev_read_u32_default(dev, "offset", 0);
  51. priv->mask = dev_read_u32_default(dev, "mask", 0);
  52. priv->assert_high = dev_read_u32_default(dev, "assert-high", true);
  53. return 0;
  54. }
  55. static const struct udevice_id syscon_reset_ids[] = {
  56. { .compatible = "syscon-reset" },
  57. { },
  58. };
  59. U_BOOT_DRIVER(syscon_reset) = {
  60. .name = "syscon_reset",
  61. .id = UCLASS_RESET,
  62. .of_match = syscon_reset_ids,
  63. .probe = syscon_reset_probe,
  64. .priv_auto_alloc_size = sizeof(struct syscon_reset_priv),
  65. .ops = &syscon_reset_ops,
  66. };