clock.c 2.7 KB

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  1. /*
  2. * linux/arch/arm/mach-sa1100/clock.c
  3. */
  4. #include <linux/module.h>
  5. #include <linux/kernel.h>
  6. #include <linux/list.h>
  7. #include <linux/errno.h>
  8. #include <linux/err.h>
  9. #include <linux/string.h>
  10. #include <linux/clk.h>
  11. #include <linux/spinlock.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/delay.h>
  14. #include <mach/pxa2xx-regs.h>
  15. #include <mach/pxa2xx-gpio.h>
  16. #include <mach/hardware.h>
  17. #include "devices.h"
  18. #include "generic.h"
  19. #include "clock.h"
  20. static LIST_HEAD(clocks);
  21. static DEFINE_MUTEX(clocks_mutex);
  22. static DEFINE_SPINLOCK(clocks_lock);
  23. static struct clk *clk_lookup(struct device *dev, const char *id)
  24. {
  25. struct clk *p;
  26. list_for_each_entry(p, &clocks, node)
  27. if (strcmp(id, p->name) == 0 && p->dev == dev)
  28. return p;
  29. return NULL;
  30. }
  31. struct clk *clk_get(struct device *dev, const char *id)
  32. {
  33. struct clk *p, *clk = ERR_PTR(-ENOENT);
  34. mutex_lock(&clocks_mutex);
  35. p = clk_lookup(dev, id);
  36. if (!p)
  37. p = clk_lookup(NULL, id);
  38. if (p)
  39. clk = p;
  40. mutex_unlock(&clocks_mutex);
  41. if (!IS_ERR(clk) && clk->ops == NULL)
  42. clk = clk->other;
  43. return clk;
  44. }
  45. EXPORT_SYMBOL(clk_get);
  46. void clk_put(struct clk *clk)
  47. {
  48. }
  49. EXPORT_SYMBOL(clk_put);
  50. int clk_enable(struct clk *clk)
  51. {
  52. unsigned long flags;
  53. spin_lock_irqsave(&clocks_lock, flags);
  54. if (clk->enabled++ == 0)
  55. clk->ops->enable(clk);
  56. spin_unlock_irqrestore(&clocks_lock, flags);
  57. if (clk->delay)
  58. udelay(clk->delay);
  59. return 0;
  60. }
  61. EXPORT_SYMBOL(clk_enable);
  62. void clk_disable(struct clk *clk)
  63. {
  64. unsigned long flags;
  65. WARN_ON(clk->enabled == 0);
  66. spin_lock_irqsave(&clocks_lock, flags);
  67. if (--clk->enabled == 0)
  68. clk->ops->disable(clk);
  69. spin_unlock_irqrestore(&clocks_lock, flags);
  70. }
  71. EXPORT_SYMBOL(clk_disable);
  72. unsigned long clk_get_rate(struct clk *clk)
  73. {
  74. unsigned long rate;
  75. rate = clk->rate;
  76. if (clk->ops->getrate)
  77. rate = clk->ops->getrate(clk);
  78. return rate;
  79. }
  80. EXPORT_SYMBOL(clk_get_rate);
  81. void clk_cken_enable(struct clk *clk)
  82. {
  83. CKEN |= 1 << clk->cken;
  84. }
  85. void clk_cken_disable(struct clk *clk)
  86. {
  87. CKEN &= ~(1 << clk->cken);
  88. }
  89. const struct clkops clk_cken_ops = {
  90. .enable = clk_cken_enable,
  91. .disable = clk_cken_disable,
  92. };
  93. void clks_register(struct clk *clks, size_t num)
  94. {
  95. int i;
  96. mutex_lock(&clocks_mutex);
  97. for (i = 0; i < num; i++)
  98. list_add(&clks[i].node, &clocks);
  99. mutex_unlock(&clocks_mutex);
  100. }
  101. int clk_add_alias(char *alias, struct device *alias_dev, char *id,
  102. struct device *dev)
  103. {
  104. struct clk *r = clk_lookup(dev, id);
  105. struct clk *new;
  106. if (!r)
  107. return -ENODEV;
  108. new = kzalloc(sizeof(struct clk), GFP_KERNEL);
  109. if (!new)
  110. return -ENOMEM;
  111. new->name = alias;
  112. new->dev = alias_dev;
  113. new->other = r;
  114. mutex_lock(&clocks_mutex);
  115. list_add(&new->node, &clocks);
  116. mutex_unlock(&clocks_mutex);
  117. return 0;
  118. }