clk_vexpress_osc.c 2.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2018 Arm Ltd
  4. * Author: Liviu Dudau <liviu.dudau@foss.arm.com>
  5. *
  6. */
  7. #define DEBUG
  8. #include <common.h>
  9. #include <clk-uclass.h>
  10. #include <dm.h>
  11. #include <dm/device_compat.h>
  12. #include <dm/lists.h>
  13. #include <errno.h>
  14. #include <misc.h>
  15. #define CLK_FUNCTION BIT(20)
  16. struct vexpress_osc_clk_priv {
  17. u8 osc;
  18. ulong rate_min;
  19. ulong rate_max;
  20. };
  21. static ulong vexpress_osc_clk_get_rate(struct clk *clk)
  22. {
  23. int err;
  24. u32 data;
  25. struct udevice *vexpress_cfg = dev_get_parent(clk->dev);
  26. struct vexpress_osc_clk_priv *priv = dev_get_priv(clk->dev);
  27. data = CLK_FUNCTION | priv->osc;
  28. err = misc_read(vexpress_cfg, 0, &data, sizeof(data));
  29. if (err < 0)
  30. return err;
  31. return data;
  32. }
  33. #ifndef CONFIG_SPL_BUILD
  34. static ulong vexpress_osc_clk_set_rate(struct clk *clk, ulong rate)
  35. {
  36. int err;
  37. u32 buffer[2];
  38. struct udevice *vexpress_cfg = dev_get_parent(clk->dev);
  39. struct vexpress_osc_clk_priv *priv = dev_get_priv(clk->dev);
  40. if (rate < priv->rate_min || rate > priv->rate_max)
  41. return -EINVAL;
  42. /*
  43. * we are sending the parent the info about the oscillator
  44. * and the value we want to set
  45. */
  46. buffer[0] = CLK_FUNCTION | priv->osc;
  47. buffer[1] = rate;
  48. err = misc_write(vexpress_cfg, 0, buffer, 2 * sizeof(u32));
  49. if (err < 0)
  50. return err;
  51. return rate;
  52. }
  53. #endif
  54. static struct clk_ops vexpress_osc_clk_ops = {
  55. .get_rate = vexpress_osc_clk_get_rate,
  56. #ifndef CONFIG_SPL_BUILD
  57. .set_rate = vexpress_osc_clk_set_rate,
  58. #endif
  59. };
  60. static int vexpress_osc_clk_probe(struct udevice *dev)
  61. {
  62. struct vexpress_osc_clk_priv *priv = dev_get_priv(dev);
  63. u32 values[2];
  64. int err;
  65. err = dev_read_u32_array(dev, "freq-range", values, 2);
  66. if (err)
  67. return err;
  68. priv->rate_min = values[0];
  69. priv->rate_max = values[1];
  70. err = dev_read_u32_array(dev, "arm,vexpress-sysreg,func", values, 2);
  71. if (err)
  72. return err;
  73. if (values[0] != 1) {
  74. dev_err(dev, "Invalid VExpress function for clock, must be '1'");
  75. return -EINVAL;
  76. }
  77. priv->osc = values[1];
  78. debug("clk \"%s%d\", min freq %luHz, max freq %luHz\n", dev->name,
  79. priv->osc, priv->rate_min, priv->rate_max);
  80. return 0;
  81. }
  82. static const struct udevice_id vexpress_osc_clk_ids[] = {
  83. { .compatible = "arm,vexpress-osc", },
  84. {}
  85. };
  86. U_BOOT_DRIVER(vexpress_osc_clk) = {
  87. .name = "vexpress_osc_clk",
  88. .id = UCLASS_CLK,
  89. .of_match = vexpress_osc_clk_ids,
  90. .ops = &vexpress_osc_clk_ops,
  91. .priv_auto_alloc_size = sizeof(struct vexpress_osc_clk_priv),
  92. .probe = vexpress_osc_clk_probe,
  93. };