reset.c 2.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <linux/slab.h>
  3. #include <linux/io.h>
  4. #include <linux/of.h>
  5. #include <linux/of_address.h>
  6. #include <linux/reset-controller.h>
  7. #include "reset.h"
  8. #define rcdev_to_unit(rcdev) container_of(rcdev, struct mmp_clk_reset_unit, rcdev)
  9. static int mmp_of_reset_xlate(struct reset_controller_dev *rcdev,
  10. const struct of_phandle_args *reset_spec)
  11. {
  12. struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  13. struct mmp_clk_reset_cell *cell;
  14. int i;
  15. if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
  16. return -EINVAL;
  17. for (i = 0; i < rcdev->nr_resets; i++) {
  18. cell = &unit->cells[i];
  19. if (cell->clk_id == reset_spec->args[0])
  20. break;
  21. }
  22. if (i == rcdev->nr_resets)
  23. return -EINVAL;
  24. return i;
  25. }
  26. static int mmp_clk_reset_assert(struct reset_controller_dev *rcdev,
  27. unsigned long id)
  28. {
  29. struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  30. struct mmp_clk_reset_cell *cell;
  31. unsigned long flags = 0;
  32. u32 val;
  33. cell = &unit->cells[id];
  34. if (cell->lock)
  35. spin_lock_irqsave(cell->lock, flags);
  36. val = readl(cell->reg);
  37. val |= cell->bits;
  38. writel(val, cell->reg);
  39. if (cell->lock)
  40. spin_unlock_irqrestore(cell->lock, flags);
  41. return 0;
  42. }
  43. static int mmp_clk_reset_deassert(struct reset_controller_dev *rcdev,
  44. unsigned long id)
  45. {
  46. struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  47. struct mmp_clk_reset_cell *cell;
  48. unsigned long flags = 0;
  49. u32 val;
  50. cell = &unit->cells[id];
  51. if (cell->lock)
  52. spin_lock_irqsave(cell->lock, flags);
  53. val = readl(cell->reg);
  54. val &= ~cell->bits;
  55. writel(val, cell->reg);
  56. if (cell->lock)
  57. spin_unlock_irqrestore(cell->lock, flags);
  58. return 0;
  59. }
  60. static const struct reset_control_ops mmp_clk_reset_ops = {
  61. .assert = mmp_clk_reset_assert,
  62. .deassert = mmp_clk_reset_deassert,
  63. };
  64. void mmp_clk_reset_register(struct device_node *np,
  65. struct mmp_clk_reset_cell *cells, int nr_resets)
  66. {
  67. struct mmp_clk_reset_unit *unit;
  68. unit = kzalloc(sizeof(*unit), GFP_KERNEL);
  69. if (!unit)
  70. return;
  71. unit->cells = cells;
  72. unit->rcdev.of_reset_n_cells = 1;
  73. unit->rcdev.nr_resets = nr_resets;
  74. unit->rcdev.ops = &mmp_clk_reset_ops;
  75. unit->rcdev.of_node = np;
  76. unit->rcdev.of_xlate = mmp_of_reset_xlate;
  77. reset_controller_register(&unit->rcdev);
  78. }