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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* Copyright (C) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/err.h>
#include <asm/io.h>
#include <mach/imx-regs.h>
/*
* Very simple approach: We can't disable clocks, so we do
* not need refcounting
*/
struct clk {
struct list_head node;
const char *name;
unsigned long (*get_rate)(void);
};
/*
* get the system pll clock in Hz
*
* mfi + mfn / (mfd +1)
* f = 2 * f_ref * --------------------
* pd + 1
*/
static unsigned long imx_decode_pll(unsigned int pll, u32 f_ref)
{
unsigned long long ll;
unsigned long quot;
u32 mfi = (pll >> 10) & 0xf;
u32 mfn = pll & 0x3ff;
u32 mfd = (pll >> 16) & 0x3ff;
u32 pd = (pll >> 26) & 0xf;
mfi = mfi <= 5 ? 5 : mfi;
ll = 2 * (unsigned long long)f_ref *
((mfi << 16) + (mfn << 16) / (mfd + 1));
quot = (pd + 1) * (1 << 16);
ll += quot / 2;
do_div(ll, quot);
return (unsigned long)ll;
}
static unsigned long imx_get_system_clk(void)
{
u32 f_ref = (CSCR & CSCR_SYSTEM_SEL) ? 16000000 : (CLK32 * 512);
return imx_decode_pll(SPCTL0, f_ref);
}
static unsigned long imx_get_mcu_clk(void)
{
return imx_decode_pll(MPCTL0, CLK32 * 512);
}
/*
* get peripheral clock 1 ( UART[12], Timer[12], PWM )
*/
static unsigned long imx_get_perclk1(void)
{
return imx_get_system_clk() / (((PCDR) & 0xf)+1);
}
/*
* get peripheral clock 2 ( LCD, SD, SPI[12] )
*/
static unsigned long imx_get_perclk2(void)
{
return imx_get_system_clk() / (((PCDR>>4) & 0xf)+1);
}
/*
* get peripheral clock 3 ( SSI )
*/
static unsigned long imx_get_perclk3(void)
{
return imx_get_system_clk() / (((PCDR>>16) & 0x7f)+1);
}
/*
* get hclk ( SDRAM, CSI, Memory Stick, I2C, DMA )
*/
static unsigned long imx_get_hclk(void)
{
return imx_get_system_clk() / (((CSCR>>10) & 0xf)+1);
}
static struct clk clk_system_clk = {
.name = "system_clk",
.get_rate = imx_get_system_clk,
};
static struct clk clk_hclk = {
.name = "hclk",
.get_rate = imx_get_hclk,
};
static struct clk clk_mcu_clk = {
.name = "mcu_clk",
.get_rate = imx_get_mcu_clk,
};
static struct clk clk_perclk1 = {
.name = "perclk1",
.get_rate = imx_get_perclk1,
};
static struct clk clk_uart_clk = {
.name = "uart_clk",
.get_rate = imx_get_perclk1,
};
static struct clk clk_perclk2 = {
.name = "perclk2",
.get_rate = imx_get_perclk2,
};
static struct clk clk_perclk3 = {
.name = "perclk3",
.get_rate = imx_get_perclk3,
};
static struct clk *clks[] = {
&clk_perclk1,
&clk_perclk2,
&clk_perclk3,
&clk_system_clk,
&clk_hclk,
&clk_mcu_clk,
&clk_uart_clk,
};
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
struct clk *clk_get(struct device *dev, const char *id)
{
struct clk *p, *clk = ERR_PTR(-ENOENT);
mutex_lock(&clocks_mutex);
list_for_each_entry(p, &clocks, node) {
if (!strcmp(p->name, id)) {
clk = p;
goto found;
}
}
found:
mutex_unlock(&clocks_mutex);
return clk;
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);
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->get_rate();
}
EXPORT_SYMBOL(clk_get_rate);
int imx_clocks_init(void)
{
int i;
mutex_lock(&clocks_mutex);
for (i = 0; i < ARRAY_SIZE(clks); i++)
list_add(&clks[i]->node, &clocks);
mutex_unlock(&clocks_mutex);
return 0;
}
|
