xref: /openbmc/linux/arch/m68k/coldfire/clk.c (revision dea54fba) 
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  */
30 void __clk_init_enabled(struct clk *clk)
31 {
32 	clk->enabled = 1;
33 	clk->clk_ops->enable(clk);
34 }
35 
36 void __clk_init_disabled(struct clk *clk)
37 {
38 	clk->enabled = 0;
39 	clk->clk_ops->disable(clk);
40 }
41 
42 static void __clk_enable0(struct clk *clk)
43 {
44 	__raw_writeb(clk->slot, MCFPM_PPMCR0);
45 }
46 
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
58 static void __clk_enable1(struct clk *clk)
59 {
60 	__raw_writeb(clk->slot, MCFPM_PPMCR1);
61 }
62 
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 
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 
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 
101 void clk_disable(struct clk *clk)
102 {
103 	unsigned long flags;
104 
105 	if (!clk)
106 		return;
107 
108 	spin_lock_irqsave(&clk_lock, flags);
109 	if ((--clk->enabled == 0) && clk->clk_ops)
110 		clk->clk_ops->disable(clk);
111 	spin_unlock_irqrestore(&clk_lock, flags);
112 }
113 EXPORT_SYMBOL(clk_disable);
114 
115 void clk_put(struct clk *clk)
116 {
117 	if (clk->enabled != 0)
118 		pr_warn("clk_put %s still enabled\n", clk->name);
119 }
120 EXPORT_SYMBOL(clk_put);
121 
122 unsigned long clk_get_rate(struct clk *clk)
123 {
124 	return clk->rate;
125 }
126 EXPORT_SYMBOL(clk_get_rate);
127 
128 /***************************************************************************/
129