Linux Kernel  3.7.1
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clock.c
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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/device.h>
7 #include <linux/list.h>
8 #include <linux/errno.h>
9 #include <linux/err.h>
10 #include <linux/string.h>
11 #include <linux/clk.h>
12 #include <linux/spinlock.h>
13 #include <linux/mutex.h>
14 #include <linux/io.h>
15 #include <linux/clkdev.h>
16 
17 #include <mach/hardware.h>
18 
19 struct clkops {
20  void (*enable)(struct clk *);
21  void (*disable)(struct clk *);
22 };
23 
24 struct clk {
25  const struct clkops *ops;
26  unsigned int enabled;
27 };
28 
29 #define DEFINE_CLK(_name, _ops) \
30 struct clk clk_##_name = { \
31  .ops = _ops, \
32  }
33 
34 static DEFINE_SPINLOCK(clocks_lock);
35 
36 static void clk_gpio27_enable(struct clk *clk)
37 {
38  /*
39  * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
40  * (SA-1110 Developer's Manual, section 9.1.2.1)
41  */
45 }
46 
47 static void clk_gpio27_disable(struct clk *clk)
48 {
49  TUCR = 0;
50  GPDR &= ~GPIO_32_768kHz;
51  GAFR &= ~GPIO_32_768kHz;
52 }
53 
54 int clk_enable(struct clk *clk)
55 {
56  unsigned long flags;
57 
58  if (clk) {
60  if (clk->enabled++ == 0)
61  clk->ops->enable(clk);
62  spin_unlock_irqrestore(&clocks_lock, flags);
63  }
64 
65  return 0;
66 }
68 
69 void clk_disable(struct clk *clk)
70 {
71  unsigned long flags;
72 
73  if (clk) {
74  WARN_ON(clk->enabled == 0);
76  if (--clk->enabled == 0)
77  clk->ops->disable(clk);
78  spin_unlock_irqrestore(&clocks_lock, flags);
79  }
80 }
82 
83 const struct clkops clk_gpio27_ops = {
84  .enable = clk_gpio27_enable,
85  .disable = clk_gpio27_disable,
86 };
87 
88 static DEFINE_CLK(gpio27, &clk_gpio27_ops);
89 
90 static struct clk_lookup sa11xx_clkregs[] = {
91  CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
92  CLKDEV_INIT("sa1100-rtc", NULL, NULL),
93 };
94 
95 static int __init sa11xx_clk_init(void)
96 {
97  clkdev_add_table(sa11xx_clkregs, ARRAY_SIZE(sa11xx_clkregs));
98  return 0;
99 }
100 core_initcall(sa11xx_clk_init);