powergate.c 2.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (c) 2014-2019, NVIDIA CORPORATION. All rights reserved.
  4. */
  5. #include <common.h>
  6. #include <errno.h>
  7. #include <linux/delay.h>
  8. #include <asm/io.h>
  9. #include <asm/types.h>
  10. #include <asm/arch/powergate.h>
  11. #include <asm/arch/tegra.h>
  12. #include <asm/arch-tegra/pmc.h>
  13. #define PWRGATE_TOGGLE 0x30
  14. #define PWRGATE_TOGGLE_START (1 << 8)
  15. #define REMOVE_CLAMPING 0x34
  16. #define PWRGATE_STATUS 0x38
  17. static int tegra_powergate_set(enum tegra_powergate id, bool state)
  18. {
  19. u32 value, mask = state ? (1 << id) : 0, old_mask;
  20. unsigned long start, timeout = 25;
  21. value = tegra_pmc_readl(PWRGATE_STATUS);
  22. old_mask = value & (1 << id);
  23. if (mask == old_mask)
  24. return 0;
  25. tegra_pmc_writel(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE);
  26. start = get_timer(0);
  27. while (get_timer(start) < timeout) {
  28. value = tegra_pmc_readl(PWRGATE_STATUS);
  29. if ((value & (1 << id)) == mask)
  30. return 0;
  31. }
  32. return -ETIMEDOUT;
  33. }
  34. int tegra_powergate_power_on(enum tegra_powergate id)
  35. {
  36. return tegra_powergate_set(id, true);
  37. }
  38. int tegra_powergate_power_off(enum tegra_powergate id)
  39. {
  40. return tegra_powergate_set(id, false);
  41. }
  42. static int tegra_powergate_remove_clamping(enum tegra_powergate id)
  43. {
  44. unsigned long value;
  45. /*
  46. * The REMOVE_CLAMPING register has the bits for the PCIE and VDEC
  47. * partitions reversed. This was originally introduced on Tegra20 but
  48. * has since been carried forward for backwards-compatibility.
  49. */
  50. if (id == TEGRA_POWERGATE_VDEC)
  51. value = 1 << TEGRA_POWERGATE_PCIE;
  52. else if (id == TEGRA_POWERGATE_PCIE)
  53. value = 1 << TEGRA_POWERGATE_VDEC;
  54. else
  55. value = 1 << id;
  56. tegra_pmc_writel(value, REMOVE_CLAMPING);
  57. return 0;
  58. }
  59. int tegra_powergate_sequence_power_up(enum tegra_powergate id,
  60. enum periph_id periph)
  61. {
  62. int err;
  63. reset_set_enable(periph, 1);
  64. err = tegra_powergate_power_on(id);
  65. if (err < 0)
  66. return err;
  67. clock_enable(periph);
  68. udelay(10);
  69. err = tegra_powergate_remove_clamping(id);
  70. if (err < 0)
  71. return err;
  72. udelay(10);
  73. reset_set_enable(periph, 0);
  74. return 0;
  75. }