xref: /openbmc/linux/arch/arm/mach-sa1100/clock.c (revision 612a462a)
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 #include <mach/generic.h>
19 
20 struct clkops {
21 	void			(*enable)(struct clk *);
22 	void			(*disable)(struct clk *);
23 	unsigned long		(*get_rate)(struct clk *);
24 };
25 
26 struct clk {
27 	const struct clkops	*ops;
28 	unsigned int		enabled;
29 };
30 
31 #define DEFINE_CLK(_name, _ops)				\
32 struct clk clk_##_name = {				\
33 		.ops	= _ops,				\
34 	}
35 
36 static DEFINE_SPINLOCK(clocks_lock);
37 
38 /* Dummy clk routine to build generic kernel parts that may be using them */
39 long clk_round_rate(struct clk *clk, unsigned long rate)
40 {
41 	return clk_get_rate(clk);
42 }
43 EXPORT_SYMBOL(clk_round_rate);
44 
45 int clk_set_rate(struct clk *clk, unsigned long rate)
46 {
47 	return 0;
48 }
49 EXPORT_SYMBOL(clk_set_rate);
50 
51 int clk_set_parent(struct clk *clk, struct clk *parent)
52 {
53 	return 0;
54 }
55 EXPORT_SYMBOL(clk_set_parent);
56 
57 struct clk *clk_get_parent(struct clk *clk)
58 {
59 	return NULL;
60 }
61 EXPORT_SYMBOL(clk_get_parent);
62 
63 static void clk_gpio27_enable(struct clk *clk)
64 {
65 	/*
66 	 * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
67 	 * (SA-1110 Developer's Manual, section 9.1.2.1)
68 	 */
69 	GAFR |= GPIO_32_768kHz;
70 	GPDR |= GPIO_32_768kHz;
71 	TUCR = TUCR_3_6864MHz;
72 }
73 
74 static void clk_gpio27_disable(struct clk *clk)
75 {
76 	TUCR = 0;
77 	GPDR &= ~GPIO_32_768kHz;
78 	GAFR &= ~GPIO_32_768kHz;
79 }
80 
81 static void clk_cpu_enable(struct clk *clk)
82 {
83 }
84 
85 static void clk_cpu_disable(struct clk *clk)
86 {
87 }
88 
89 static unsigned long clk_cpu_get_rate(struct clk *clk)
90 {
91 	return sa11x0_getspeed(0) * 1000;
92 }
93 
94 int clk_enable(struct clk *clk)
95 {
96 	unsigned long flags;
97 
98 	if (clk) {
99 		spin_lock_irqsave(&clocks_lock, flags);
100 		if (clk->enabled++ == 0)
101 			clk->ops->enable(clk);
102 		spin_unlock_irqrestore(&clocks_lock, flags);
103 	}
104 
105 	return 0;
106 }
107 EXPORT_SYMBOL(clk_enable);
108 
109 void clk_disable(struct clk *clk)
110 {
111 	unsigned long flags;
112 
113 	if (clk) {
114 		WARN_ON(clk->enabled == 0);
115 		spin_lock_irqsave(&clocks_lock, flags);
116 		if (--clk->enabled == 0)
117 			clk->ops->disable(clk);
118 		spin_unlock_irqrestore(&clocks_lock, flags);
119 	}
120 }
121 EXPORT_SYMBOL(clk_disable);
122 
123 unsigned long clk_get_rate(struct clk *clk)
124 {
125 	if (clk && clk->ops && clk->ops->get_rate)
126 		return clk->ops->get_rate(clk);
127 
128 	return 0;
129 }
130 EXPORT_SYMBOL(clk_get_rate);
131 
132 const struct clkops clk_gpio27_ops = {
133 	.enable		= clk_gpio27_enable,
134 	.disable	= clk_gpio27_disable,
135 };
136 
137 const struct clkops clk_cpu_ops = {
138 	.enable		= clk_cpu_enable,
139 	.disable	= clk_cpu_disable,
140 	.get_rate	= clk_cpu_get_rate,
141 };
142 
143 static DEFINE_CLK(gpio27, &clk_gpio27_ops);
144 
145 static DEFINE_CLK(cpu, &clk_cpu_ops);
146 
147 static unsigned long clk_36864_get_rate(struct clk *clk)
148 {
149 	return 3686400;
150 }
151 
152 static struct clkops clk_36864_ops = {
153 	.enable		= clk_cpu_enable,
154 	.disable	= clk_cpu_disable,
155 	.get_rate	= clk_36864_get_rate,
156 };
157 
158 static DEFINE_CLK(36864, &clk_36864_ops);
159 
160 static struct clk_lookup sa11xx_clkregs[] = {
161 	CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
162 	CLKDEV_INIT("sa1100-rtc", NULL, NULL),
163 	CLKDEV_INIT("sa11x0-fb", NULL, &clk_cpu),
164 	CLKDEV_INIT("sa11x0-pcmcia", NULL, &clk_cpu),
165 	/* sa1111 names devices using internal offsets, PCMCIA is at 0x1800 */
166 	CLKDEV_INIT("1800", NULL, &clk_cpu),
167 	CLKDEV_INIT(NULL, "OSTIMER0", &clk_36864),
168 };
169 
170 int __init sa11xx_clk_init(void)
171 {
172 	clkdev_add_table(sa11xx_clkregs, ARRAY_SIZE(sa11xx_clkregs));
173 	return 0;
174 }
175