clock.c 2.5 KB

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  1. /*
  2. * linux/arch/arm/mach-integrator/clock.c
  3. *
  4. * Copyright (C) 2004 ARM Limited.
  5. * Written by Deep Blue Solutions Limited.
  6. *
  7. * This program is free software; you can redistribute it and/or modify
  8. * it under the terms of the GNU General Public License version 2 as
  9. * published by the Free Software Foundation.
  10. */
  11. #include <linux/module.h>
  12. #include <linux/kernel.h>
  13. #include <linux/list.h>
  14. #include <linux/errno.h>
  15. #include <linux/err.h>
  16. #include <linux/string.h>
  17. #include <linux/clk.h>
  18. #include <linux/mutex.h>
  19. #include <asm/hardware/icst525.h>
  20. #include "clock.h"
  21. static LIST_HEAD(clocks);
  22. static DEFINE_MUTEX(clocks_mutex);
  23. struct clk *clk_get(struct device *dev, const char *id)
  24. {
  25. struct clk *p, *clk = ERR_PTR(-ENOENT);
  26. mutex_lock(&clocks_mutex);
  27. list_for_each_entry(p, &clocks, node) {
  28. if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  29. clk = p;
  30. break;
  31. }
  32. }
  33. mutex_unlock(&clocks_mutex);
  34. return clk;
  35. }
  36. EXPORT_SYMBOL(clk_get);
  37. void clk_put(struct clk *clk)
  38. {
  39. module_put(clk->owner);
  40. }
  41. EXPORT_SYMBOL(clk_put);
  42. int clk_enable(struct clk *clk)
  43. {
  44. return 0;
  45. }
  46. EXPORT_SYMBOL(clk_enable);
  47. void clk_disable(struct clk *clk)
  48. {
  49. }
  50. EXPORT_SYMBOL(clk_disable);
  51. unsigned long clk_get_rate(struct clk *clk)
  52. {
  53. return clk->rate;
  54. }
  55. EXPORT_SYMBOL(clk_get_rate);
  56. long clk_round_rate(struct clk *clk, unsigned long rate)
  57. {
  58. struct icst525_vco vco;
  59. vco = icst525_khz_to_vco(clk->params, rate / 1000);
  60. return icst525_khz(clk->params, vco) * 1000;
  61. }
  62. EXPORT_SYMBOL(clk_round_rate);
  63. int clk_set_rate(struct clk *clk, unsigned long rate)
  64. {
  65. int ret = -EIO;
  66. if (clk->setvco) {
  67. struct icst525_vco vco;
  68. vco = icst525_khz_to_vco(clk->params, rate / 1000);
  69. clk->rate = icst525_khz(clk->params, vco) * 1000;
  70. printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n",
  71. clk->name, vco.s, vco.r, vco.v);
  72. clk->setvco(clk, vco);
  73. ret = 0;
  74. }
  75. return 0;
  76. }
  77. EXPORT_SYMBOL(clk_set_rate);
  78. /*
  79. * These are fixed clocks.
  80. */
  81. static struct clk kmi_clk = {
  82. .name = "KMIREFCLK",
  83. .rate = 24000000,
  84. };
  85. static struct clk uart_clk = {
  86. .name = "UARTCLK",
  87. .rate = 14745600,
  88. };
  89. int clk_register(struct clk *clk)
  90. {
  91. mutex_lock(&clocks_mutex);
  92. list_add(&clk->node, &clocks);
  93. mutex_unlock(&clocks_mutex);
  94. return 0;
  95. }
  96. EXPORT_SYMBOL(clk_register);
  97. void clk_unregister(struct clk *clk)
  98. {
  99. mutex_lock(&clocks_mutex);
  100. list_del(&clk->node);
  101. mutex_unlock(&clocks_mutex);
  102. }
  103. EXPORT_SYMBOL(clk_unregister);
  104. static int __init clk_init(void)
  105. {
  106. clk_register(&kmi_clk);
  107. clk_register(&uart_clk);
  108. return 0;
  109. }
  110. arch_initcall(clk_init);