reset-sifive.c 2.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2020 Sifive, Inc.
  4. * Author: Sagar Kadam <sagar.kadam@sifive.com>
  5. */
  6. #include <common.h>
  7. #include <dm.h>
  8. #include <reset-uclass.h>
  9. #include <asm/io.h>
  10. #include <dm/device_compat.h>
  11. #include <dm/lists.h>
  12. #include <linux/bitops.h>
  13. #define PRCI_RESETREG_OFFSET 0x28
  14. struct sifive_reset_priv {
  15. void *base;
  16. /* number of reset signals */
  17. int nr_reset;
  18. };
  19. static int sifive_rst_trigger(struct reset_ctl *rst, bool level)
  20. {
  21. struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
  22. int id = rst->id;
  23. int regval = readl(priv->base + PRCI_RESETREG_OFFSET);
  24. /* Derive bitposition from rst id */
  25. if (level)
  26. /* Reset deassert */
  27. regval |= BIT(id);
  28. else
  29. /* Reset assert */
  30. regval &= ~BIT(id);
  31. writel(regval, priv->base + PRCI_RESETREG_OFFSET);
  32. return 0;
  33. }
  34. static int sifive_reset_assert(struct reset_ctl *rst)
  35. {
  36. return sifive_rst_trigger(rst, false);
  37. }
  38. static int sifive_reset_deassert(struct reset_ctl *rst)
  39. {
  40. return sifive_rst_trigger(rst, true);
  41. }
  42. static int sifive_reset_request(struct reset_ctl *rst)
  43. {
  44. struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
  45. debug("%s(rst=%p) (dev=%p, id=%lu) (nr_reset=%d)\n", __func__,
  46. rst, rst->dev, rst->id, priv->nr_reset);
  47. if (rst->id > priv->nr_reset)
  48. return -EINVAL;
  49. return 0;
  50. }
  51. static int sifive_reset_free(struct reset_ctl *rst)
  52. {
  53. struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
  54. debug("%s(rst=%p) (dev=%p, id=%lu) (nr_reset=%d)\n", __func__,
  55. rst, rst->dev, rst->id, priv->nr_reset);
  56. return 0;
  57. }
  58. static int sifive_reset_probe(struct udevice *dev)
  59. {
  60. struct sifive_reset_priv *priv = dev_get_priv(dev);
  61. priv->base = dev_remap_addr(dev);
  62. if (!priv->base)
  63. return -ENOMEM;
  64. return 0;
  65. }
  66. int sifive_reset_bind(struct udevice *dev, ulong count)
  67. {
  68. struct udevice *rst_dev;
  69. struct sifive_reset_priv *priv;
  70. int ret;
  71. ret = device_bind_driver_to_node(dev, "sifive-reset", "reset",
  72. dev_ofnode(dev), &rst_dev);
  73. if (ret) {
  74. dev_err(dev, "failed to bind sifive_reset driver (ret=%d)\n", ret);
  75. return ret;
  76. }
  77. priv = malloc(sizeof(struct sifive_reset_priv));
  78. priv->nr_reset = count;
  79. rst_dev->priv = priv;
  80. return 0;
  81. }
  82. const struct reset_ops sifive_reset_ops = {
  83. .request = sifive_reset_request,
  84. .rfree = sifive_reset_free,
  85. .rst_assert = sifive_reset_assert,
  86. .rst_deassert = sifive_reset_deassert,
  87. };
  88. U_BOOT_DRIVER(sifive_reset) = {
  89. .name = "sifive-reset",
  90. .id = UCLASS_RESET,
  91. .ops = &sifive_reset_ops,
  92. .probe = sifive_reset_probe,
  93. .priv_auto_alloc_size = sizeof(struct sifive_reset_priv),
  94. };