1 /***************************************************************************/
2
3 /*
4 * clk.c -- general ColdFire CPU kernel clk handling
5 *
6 * Copyright (C) 2009, Greg Ungerer (gerg@snapgear.com)
7 */
8
9 /***************************************************************************/
10
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/mutex.h>
15 #include <linux/clk.h>
16 #include <linux/io.h>
17 #include <linux/err.h>
18 #include <asm/coldfire.h>
19 #include <asm/mcfsim.h>
20 #include <asm/mcfclk.h>
21
22 static DEFINE_SPINLOCK(clk_lock);
23
24 #ifdef MCFPM_PPMCR0
25 /*
26 * For more advanced ColdFire parts that have clocks that can be enabled
27 * we supply enable/disable functions. These must properly define their
28 * clocks in their platform specific code.
29 */
__clk_init_enabled(struct clk * clk)30 void __clk_init_enabled(struct clk *clk)
31 {
32 clk->enabled = 1;
33 clk->clk_ops->enable(clk);
34 }
35
__clk_init_disabled(struct clk * clk)36 void __clk_init_disabled(struct clk *clk)
37 {
38 clk->enabled = 0;
39 clk->clk_ops->disable(clk);
40 }
41
__clk_enable0(struct clk * clk)42 static void __clk_enable0(struct clk *clk)
43 {
44 __raw_writeb(clk->slot, MCFPM_PPMCR0);
45 }
46
__clk_disable0(struct clk * clk)47 static void __clk_disable0(struct clk *clk)
48 {
49 __raw_writeb(clk->slot, MCFPM_PPMSR0);
50 }
51
52 struct clk_ops clk_ops0 = {
53 .enable = __clk_enable0,
54 .disable = __clk_disable0,
55 };
56
57 #ifdef MCFPM_PPMCR1
__clk_enable1(struct clk * clk)58 static void __clk_enable1(struct clk *clk)
59 {
60 __raw_writeb(clk->slot, MCFPM_PPMCR1);
61 }
62
__clk_disable1(struct clk * clk)63 static void __clk_disable1(struct clk *clk)
64 {
65 __raw_writeb(clk->slot, MCFPM_PPMSR1);
66 }
67
68 struct clk_ops clk_ops1 = {
69 .enable = __clk_enable1,
70 .disable = __clk_disable1,
71 };
72 #endif /* MCFPM_PPMCR1 */
73 #endif /* MCFPM_PPMCR0 */
74
clk_get(struct device * dev,const char * id)75 struct clk *clk_get(struct device *dev, const char *id)
76 {
77 const char *clk_name = dev ? dev_name(dev) : id ? id : NULL;
78 struct clk *clk;
79 unsigned i;
80
81 for (i = 0; (clk = mcf_clks[i]) != NULL; ++i)
82 if (!strcmp(clk->name, clk_name))
83 return clk;
84 pr_warn("clk_get: didn't find clock %s\n", clk_name);
85 return ERR_PTR(-ENOENT);
86 }
87 EXPORT_SYMBOL(clk_get);
88
clk_enable(struct clk * clk)89 int clk_enable(struct clk *clk)
90 {
91 unsigned long flags;
92 spin_lock_irqsave(&clk_lock, flags);
93 if ((clk->enabled++ == 0) && clk->clk_ops)
94 clk->clk_ops->enable(clk);
95 spin_unlock_irqrestore(&clk_lock, flags);
96
97 return 0;
98 }
99 EXPORT_SYMBOL(clk_enable);
100
clk_disable(struct clk * clk)101 void clk_disable(struct clk *clk)
102 {
103 unsigned long flags;
104 spin_lock_irqsave(&clk_lock, flags);
105 if ((--clk->enabled == 0) && clk->clk_ops)
106 clk->clk_ops->disable(clk);
107 spin_unlock_irqrestore(&clk_lock, flags);
108 }
109 EXPORT_SYMBOL(clk_disable);
110
clk_put(struct clk * clk)111 void clk_put(struct clk *clk)
112 {
113 if (clk->enabled != 0)
114 pr_warn("clk_put %s still enabled\n", clk->name);
115 }
116 EXPORT_SYMBOL(clk_put);
117
clk_get_rate(struct clk * clk)118 unsigned long clk_get_rate(struct clk *clk)
119 {
120 return clk->rate;
121 }
122 EXPORT_SYMBOL(clk_get_rate);
123
124 /***************************************************************************/
125