1 /*
2 * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
3 * Author: Yanhua, yanh@lemote.com
4 *
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 */
9 #include <linux/clk.h>
10 #include <linux/cpufreq.h>
11 #include <linux/errno.h>
12 #include <linux/export.h>
13 #include <linux/list.h>
14 #include <linux/mutex.h>
15 #include <linux/spinlock.h>
16
17 #include <asm/clock.h>
18 #include <asm/mach-loongson64/loongson.h>
19
20 static LIST_HEAD(clock_list);
21 static DEFINE_SPINLOCK(clock_lock);
22 static DEFINE_MUTEX(clock_list_sem);
23
24 /* Minimum CLK support */
25 enum {
26 DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
27 DC_87PT, DC_DISABLE, DC_RESV
28 };
29
30 struct cpufreq_frequency_table loongson2_clockmod_table[] = {
31 {0, DC_RESV, CPUFREQ_ENTRY_INVALID},
32 {0, DC_ZERO, CPUFREQ_ENTRY_INVALID},
33 {0, DC_25PT, 0},
34 {0, DC_37PT, 0},
35 {0, DC_50PT, 0},
36 {0, DC_62PT, 0},
37 {0, DC_75PT, 0},
38 {0, DC_87PT, 0},
39 {0, DC_DISABLE, 0},
40 {0, DC_RESV, CPUFREQ_TABLE_END},
41 };
42 EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
43
44 static struct clk cpu_clk = {
45 .name = "cpu_clk",
46 .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
47 .rate = 800000000,
48 };
49
50 struct clk *clk_get(struct device *dev, const char *id)
51 {
52 return &cpu_clk;
53 }
54 EXPORT_SYMBOL(clk_get);
55
56 static void propagate_rate(struct clk *clk)
57 {
58 struct clk *clkp;
59
60 list_for_each_entry(clkp, &clock_list, node) {
61 if (likely(clkp->parent != clk))
62 continue;
63 if (likely(clkp->ops && clkp->ops->recalc))
64 clkp->ops->recalc(clkp);
65 if (unlikely(clkp->flags & CLK_RATE_PROPAGATES))
66 propagate_rate(clkp);
67 }
68 }
69
70 int clk_enable(struct clk *clk)
71 {
72 return 0;
73 }
74 EXPORT_SYMBOL(clk_enable);
75
76 void clk_disable(struct clk *clk)
77 {
78 }
79 EXPORT_SYMBOL(clk_disable);
80
81 unsigned long clk_get_rate(struct clk *clk)
82 {
83 return (unsigned long)clk->rate;
84 }
85 EXPORT_SYMBOL(clk_get_rate);
86
87 void clk_put(struct clk *clk)
88 {
89 }
90 EXPORT_SYMBOL(clk_put);
91
92 int clk_set_rate(struct clk *clk, unsigned long rate)
93 {
94 unsigned int rate_khz = rate / 1000;
95 struct cpufreq_frequency_table *pos;
96 int ret = 0;
97 int regval;
98
99 if (likely(clk->ops && clk->ops->set_rate)) {
100 unsigned long flags;
101
102 spin_lock_irqsave(&clock_lock, flags);
103 ret = clk->ops->set_rate(clk, rate, 0);
104 spin_unlock_irqrestore(&clock_lock, flags);
105 }
106
107 if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
108 propagate_rate(clk);
109
110 cpufreq_for_each_valid_entry(pos, loongson2_clockmod_table)
111 if (rate_khz == pos->frequency)
112 break;
113 if (rate_khz != pos->frequency)
114 return -ENOTSUPP;
115
116 clk->rate = rate;
117
118 regval = LOONGSON_CHIPCFG(0);
119 regval = (regval & ~0x7) | (pos->driver_data - 1);
120 LOONGSON_CHIPCFG(0) = regval;
121
122 return ret;
123 }
124 EXPORT_SYMBOL_GPL(clk_set_rate);
125
126 long clk_round_rate(struct clk *clk, unsigned long rate)
127 {
128 if (likely(clk->ops && clk->ops->round_rate)) {
129 unsigned long flags, rounded;
130
131 spin_lock_irqsave(&clock_lock, flags);
132 rounded = clk->ops->round_rate(clk, rate);
133 spin_unlock_irqrestore(&clock_lock, flags);
134
135 return rounded;
136 }
137
138 return rate;
139 }
140 EXPORT_SYMBOL_GPL(clk_round_rate);
141
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.