summaryrefslogtreecommitdiff
path: root/arch/mips/kernel/cpufreq/loongson2_clock.c
blob: d7ca256e33ef9615547686c6a1e9ab24ae057311 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/*
 * Copyright (C) 2006 - 2008 Lemote Inc. & Insititute of Computing Technology
 * Author: Yanhua, yanh@lemote.com
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/cpufreq.h>
#include <linux/platform_device.h>

#include <asm/clock.h>

#include <loongson.h>

static LIST_HEAD(clock_list);
static DEFINE_SPINLOCK(clock_lock);
static DEFINE_MUTEX(clock_list_sem);

/* Minimum CLK support */
enum {
	DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
	DC_87PT, DC_DISABLE, DC_RESV
};

struct cpufreq_frequency_table loongson2_clockmod_table[] = {
	{DC_RESV, CPUFREQ_ENTRY_INVALID},
	{DC_ZERO, CPUFREQ_ENTRY_INVALID},
	{DC_25PT, 0},
	{DC_37PT, 0},
	{DC_50PT, 0},
	{DC_62PT, 0},
	{DC_75PT, 0},
	{DC_87PT, 0},
	{DC_DISABLE, 0},
	{DC_RESV, CPUFREQ_TABLE_END},
};
EXPORT_SYMBOL_GPL(loongson2_clockmod_table);

static struct clk cpu_clk = {
	.name = "cpu_clk",
	.flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
	.rate = 800000000,
};

struct clk *clk_get(struct device *dev, const char *id)
{
	return &cpu_clk;
}
EXPORT_SYMBOL(clk_get);

static void propagate_rate(struct clk *clk)
{
	struct clk *clkp;

	list_for_each_entry(clkp, &clock_list, node) {
		if (likely(clkp->parent != clk))
			continue;
		if (likely(clkp->ops && clkp->ops->recalc))
			clkp->ops->recalc(clkp);
		if (unlikely(clkp->flags & CLK_RATE_PROPAGATES))
			propagate_rate(clkp);
	}
}

int clk_enable(struct clk *clk)
{
	return 0;
}
EXPORT_SYMBOL(clk_enable);

void clk_disable(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_disable);

unsigned long clk_get_rate(struct clk *clk)
{
	return (unsigned long)clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);

void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);

int clk_set_rate(struct clk *clk, unsigned long rate)
{
	return clk_set_rate_ex(clk, rate, 0);
}
EXPORT_SYMBOL_GPL(clk_set_rate);

int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
{
	int ret = 0;
	int regval;
	int i;

	if (likely(clk->ops && clk->ops->set_rate)) {
		unsigned long flags;

		spin_lock_irqsave(&clock_lock, flags);
		ret = clk->ops->set_rate(clk, rate, algo_id);
		spin_unlock_irqrestore(&clock_lock, flags);
	}

	if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
		propagate_rate(clk);

	for (i = 0; loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END;
	     i++) {
		if (loongson2_clockmod_table[i].frequency ==
		    CPUFREQ_ENTRY_INVALID)
			continue;
		if (rate == loongson2_clockmod_table[i].frequency)
			break;
	}
	if (rate != loongson2_clockmod_table[i].frequency)
		return -ENOTSUPP;

	clk->rate = rate;

	regval = LOONGSON_CHIPCFG0;
	regval = (regval & ~0x7) | (loongson2_clockmod_table[i].index - 1);
	LOONGSON_CHIPCFG0 = regval;

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate_ex);

long clk_round_rate(struct clk *clk, unsigned long rate)
{
	if (likely(clk->ops && clk->ops->round_rate)) {
		unsigned long flags, rounded;

		spin_lock_irqsave(&clock_lock, flags);
		rounded = clk->ops->round_rate(clk, rate);
		spin_unlock_irqrestore(&clock_lock, flags);

		return rounded;
	}

	return rate;
}
EXPORT_SYMBOL_GPL(clk_round_rate);

/*
 * This is the simple version of Loongson-2 wait, Maybe we need do this in
 * interrupt disabled content
 */

DEFINE_SPINLOCK(loongson2_wait_lock);
void loongson2_cpu_wait(void)
{
	u32 cpu_freq;
	unsigned long flags;

	spin_lock_irqsave(&loongson2_wait_lock, flags);
	cpu_freq = LOONGSON_CHIPCFG0;
	LOONGSON_CHIPCFG0 &= ~0x7;	/* Put CPU into wait mode */
	LOONGSON_CHIPCFG0 = cpu_freq;	/* Restore CPU state */
	spin_unlock_irqrestore(&loongson2_wait_lock, flags);
}
EXPORT_SYMBOL_GPL(loongson2_cpu_wait);