aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/ath79/clock.c
blob: 680bde99a26c3bf8ad314549b8d7ee16cbcdbfe0 (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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/*
 *  Atheros AR71XX/AR724X/AR913X common routines
 *
 *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>

#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include "common.h"

#define AR71XX_BASE_FREQ	40000000
#define AR724X_BASE_FREQ	5000000
#define AR913X_BASE_FREQ	5000000

struct clk {
	unsigned long rate;
};

static struct clk ath79_ref_clk;
static struct clk ath79_cpu_clk;
static struct clk ath79_ddr_clk;
static struct clk ath79_ahb_clk;
static struct clk ath79_wdt_clk;
static struct clk ath79_uart_clk;

static void __init ar71xx_clocks_init(void)
{
	u32 pll;
	u32 freq;
	u32 div;

	ath79_ref_clk.rate = AR71XX_BASE_FREQ;

	pll = ath79_pll_rr(AR71XX_PLL_REG_CPU_CONFIG);

	div = ((pll >> AR71XX_PLL_DIV_SHIFT) & AR71XX_PLL_DIV_MASK) + 1;
	freq = div * ath79_ref_clk.rate;

	div = ((pll >> AR71XX_CPU_DIV_SHIFT) & AR71XX_CPU_DIV_MASK) + 1;
	ath79_cpu_clk.rate = freq / div;

	div = ((pll >> AR71XX_DDR_DIV_SHIFT) & AR71XX_DDR_DIV_MASK) + 1;
	ath79_ddr_clk.rate = freq / div;

	div = (((pll >> AR71XX_AHB_DIV_SHIFT) & AR71XX_AHB_DIV_MASK) + 1) * 2;
	ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;

	ath79_wdt_clk.rate = ath79_ahb_clk.rate;
	ath79_uart_clk.rate = ath79_ahb_clk.rate;
}

static void __init ar724x_clocks_init(void)
{
	u32 pll;
	u32 freq;
	u32 div;

	ath79_ref_clk.rate = AR724X_BASE_FREQ;
	pll = ath79_pll_rr(AR724X_PLL_REG_CPU_CONFIG);

	div = ((pll >> AR724X_PLL_DIV_SHIFT) & AR724X_PLL_DIV_MASK);
	freq = div * ath79_ref_clk.rate;

	div = ((pll >> AR724X_PLL_REF_DIV_SHIFT) & AR724X_PLL_REF_DIV_MASK);
	freq *= div;

	ath79_cpu_clk.rate = freq;

	div = ((pll >> AR724X_DDR_DIV_SHIFT) & AR724X_DDR_DIV_MASK) + 1;
	ath79_ddr_clk.rate = freq / div;

	div = (((pll >> AR724X_AHB_DIV_SHIFT) & AR724X_AHB_DIV_MASK) + 1) * 2;
	ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;

	ath79_wdt_clk.rate = ath79_ahb_clk.rate;
	ath79_uart_clk.rate = ath79_ahb_clk.rate;
}

static void __init ar913x_clocks_init(void)
{
	u32 pll;
	u32 freq;
	u32 div;

	ath79_ref_clk.rate = AR913X_BASE_FREQ;
	pll = ath79_pll_rr(AR913X_PLL_REG_CPU_CONFIG);

	div = ((pll >> AR913X_PLL_DIV_SHIFT) & AR913X_PLL_DIV_MASK);
	freq = div * ath79_ref_clk.rate;

	ath79_cpu_clk.rate = freq;

	div = ((pll >> AR913X_DDR_DIV_SHIFT) & AR913X_DDR_DIV_MASK) + 1;
	ath79_ddr_clk.rate = freq / div;

	div = (((pll >> AR913X_AHB_DIV_SHIFT) & AR913X_AHB_DIV_MASK) + 1) * 2;
	ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;

	ath79_wdt_clk.rate = ath79_ahb_clk.rate;
	ath79_uart_clk.rate = ath79_ahb_clk.rate;
}

void __init ath79_clocks_init(void)
{
	if (soc_is_ar71xx())
		ar71xx_clocks_init();
	else if (soc_is_ar724x())
		ar724x_clocks_init();
	else if (soc_is_ar913x())
		ar913x_clocks_init();
	else
		BUG();

	pr_info("Clocks: CPU:%lu.%03luMHz, DDR:%lu.%03luMHz, AHB:%lu.%03luMHz, "
		"Ref:%lu.%03luMHz",
		ath79_cpu_clk.rate / 1000000,
		(ath79_cpu_clk.rate / 1000) % 1000,
		ath79_ddr_clk.rate / 1000000,
		(ath79_ddr_clk.rate / 1000) % 1000,
		ath79_ahb_clk.rate / 1000000,
		(ath79_ahb_clk.rate / 1000) % 1000,
		ath79_ref_clk.rate / 1000000,
		(ath79_ref_clk.rate / 1000) % 1000);
}

/*
 * Linux clock API
 */
struct clk *clk_get(struct device *dev, const char *id)
{
	if (!strcmp(id, "ref"))
		return &ath79_ref_clk;

	if (!strcmp(id, "cpu"))
		return &ath79_cpu_clk;

	if (!strcmp(id, "ddr"))
		return &ath79_ddr_clk;

	if (!strcmp(id, "ahb"))
		return &ath79_ahb_clk;

	if (!strcmp(id, "wdt"))
		return &ath79_wdt_clk;

	if (!strcmp(id, "uart"))
		return &ath79_uart_clk;

	return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);

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 clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);

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