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Diffstat (limited to 'arch/arm/mach-s3c2410/s3c2410-clock.c')
-rw-r--r--arch/arm/mach-s3c2410/s3c2410-clock.c263
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diff --git a/arch/arm/mach-s3c2410/s3c2410-clock.c b/arch/arm/mach-s3c2410/s3c2410-clock.c
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index 000000000000..fd17c60e1132
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+++ b/arch/arm/mach-s3c2410/s3c2410-clock.c
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1/* linux/arch/arm/mach-s3c2410/clock.c
2 *
3 * Copyright (c) 2006 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2410,S3C2440,S3C2442 Clock control support
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21*/
22
23#include <linux/init.h>
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/list.h>
27#include <linux/errno.h>
28#include <linux/err.h>
29#include <linux/sysdev.h>
30#include <linux/clk.h>
31#include <linux/mutex.h>
32#include <linux/delay.h>
33
34#include <asm/hardware.h>
35#include <asm/io.h>
36
37#include <asm/arch/regs-clock.h>
38#include <asm/arch/regs-gpio.h>
39
40#include "clock.h"
41#include "cpu.h"
42
43int s3c2410_clkcon_enable(struct clk *clk, int enable)
44{
45 unsigned int clocks = clk->ctrlbit;
46 unsigned long clkcon;
47
48 clkcon = __raw_readl(S3C2410_CLKCON);
49
50 if (enable)
51 clkcon |= clocks;
52 else
53 clkcon &= ~clocks;
54
55 /* ensure none of the special function bits set */
56 clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
57
58 __raw_writel(clkcon, S3C2410_CLKCON);
59
60 return 0;
61}
62
63static int s3c2410_upll_enable(struct clk *clk, int enable)
64{
65 unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
66 unsigned long orig = clkslow;
67
68 if (enable)
69 clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
70 else
71 clkslow |= S3C2410_CLKSLOW_UCLK_OFF;
72
73 __raw_writel(clkslow, S3C2410_CLKSLOW);
74
75 /* if we started the UPLL, then allow to settle */
76
77 if (enable && (orig & S3C2410_CLKSLOW_UCLK_OFF))
78 udelay(200);
79
80 return 0;
81}
82
83/* standard clock definitions */
84
85static struct clk init_clocks_disable[] = {
86 {
87 .name = "nand",
88 .id = -1,
89 .parent = &clk_h,
90 .enable = s3c2410_clkcon_enable,
91 .ctrlbit = S3C2410_CLKCON_NAND,
92 }, {
93 .name = "sdi",
94 .id = -1,
95 .parent = &clk_p,
96 .enable = s3c2410_clkcon_enable,
97 .ctrlbit = S3C2410_CLKCON_SDI,
98 }, {
99 .name = "adc",
100 .id = -1,
101 .parent = &clk_p,
102 .enable = s3c2410_clkcon_enable,
103 .ctrlbit = S3C2410_CLKCON_ADC,
104 }, {
105 .name = "i2c",
106 .id = -1,
107 .parent = &clk_p,
108 .enable = s3c2410_clkcon_enable,
109 .ctrlbit = S3C2410_CLKCON_IIC,
110 }, {
111 .name = "iis",
112 .id = -1,
113 .parent = &clk_p,
114 .enable = s3c2410_clkcon_enable,
115 .ctrlbit = S3C2410_CLKCON_IIS,
116 }, {
117 .name = "spi",
118 .id = -1,
119 .parent = &clk_p,
120 .enable = s3c2410_clkcon_enable,
121 .ctrlbit = S3C2410_CLKCON_SPI,
122 }
123};
124
125static struct clk init_clocks[] = {
126 {
127 .name = "lcd",
128 .id = -1,
129 .parent = &clk_h,
130 .enable = s3c2410_clkcon_enable,
131 .ctrlbit = S3C2410_CLKCON_LCDC,
132 }, {
133 .name = "gpio",
134 .id = -1,
135 .parent = &clk_p,
136 .enable = s3c2410_clkcon_enable,
137 .ctrlbit = S3C2410_CLKCON_GPIO,
138 }, {
139 .name = "usb-host",
140 .id = -1,
141 .parent = &clk_h,
142 .enable = s3c2410_clkcon_enable,
143 .ctrlbit = S3C2410_CLKCON_USBH,
144 }, {
145 .name = "usb-device",
146 .id = -1,
147 .parent = &clk_h,
148 .enable = s3c2410_clkcon_enable,
149 .ctrlbit = S3C2410_CLKCON_USBD,
150 }, {
151 .name = "timers",
152 .id = -1,
153 .parent = &clk_p,
154 .enable = s3c2410_clkcon_enable,
155 .ctrlbit = S3C2410_CLKCON_PWMT,
156 }, {
157 .name = "uart",
158 .id = 0,
159 .parent = &clk_p,
160 .enable = s3c2410_clkcon_enable,
161 .ctrlbit = S3C2410_CLKCON_UART0,
162 }, {
163 .name = "uart",
164 .id = 1,
165 .parent = &clk_p,
166 .enable = s3c2410_clkcon_enable,
167 .ctrlbit = S3C2410_CLKCON_UART1,
168 }, {
169 .name = "uart",
170 .id = 2,
171 .parent = &clk_p,
172 .enable = s3c2410_clkcon_enable,
173 .ctrlbit = S3C2410_CLKCON_UART2,
174 }, {
175 .name = "rtc",
176 .id = -1,
177 .parent = &clk_p,
178 .enable = s3c2410_clkcon_enable,
179 .ctrlbit = S3C2410_CLKCON_RTC,
180 }, {
181 .name = "watchdog",
182 .id = -1,
183 .parent = &clk_p,
184 .ctrlbit = 0,
185 }
186};
187
188/* s3c2410_baseclk_add()
189 *
190 * Add all the clocks used by the s3c2410 or compatible CPUs
191 * such as the S3C2440 and S3C2442.
192 *
193 * We cannot use a system device as we are needed before any
194 * of the init-calls that initialise the devices are actually
195 * done.
196*/
197
198int __init s3c2410_baseclk_add(void)
199{
200 unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
201 unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
202 struct clk *clkp;
203 struct clk *xtal;
204 int ret;
205 int ptr;
206
207 clk_upll.enable = s3c2410_upll_enable;
208
209 if (s3c24xx_register_clock(&clk_usb_bus) < 0)
210 printk(KERN_ERR "failed to register usb bus clock\n");
211
212 /* register clocks from clock array */
213
214 clkp = init_clocks;
215 for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
216 /* ensure that we note the clock state */
217
218 clkp->usage = clkcon & clkp->ctrlbit ? 1 : 0;
219
220 ret = s3c24xx_register_clock(clkp);
221 if (ret < 0) {
222 printk(KERN_ERR "Failed to register clock %s (%d)\n",
223 clkp->name, ret);
224 }
225 }
226
227 /* We must be careful disabling the clocks we are not intending to
228 * be using at boot time, as subsytems such as the LCD which do
229 * their own DMA requests to the bus can cause the system to lockup
230 * if they where in the middle of requesting bus access.
231 *
232 * Disabling the LCD clock if the LCD is active is very dangerous,
233 * and therefore the bootloader should be careful to not enable
234 * the LCD clock if it is not needed.
235 */
236
237 /* install (and disable) the clocks we do not need immediately */
238
239 clkp = init_clocks_disable;
240 for (ptr = 0; ptr < ARRAY_SIZE(init_clocks_disable); ptr++, clkp++) {
241
242 ret = s3c24xx_register_clock(clkp);
243 if (ret < 0) {
244 printk(KERN_ERR "Failed to register clock %s (%d)\n",
245 clkp->name, ret);
246 }
247
248 s3c2410_clkcon_enable(clkp, 0);
249 }
250
251 /* show the clock-slow value */
252
253 xtal = clk_get(NULL, "xtal");
254
255 printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
256 print_mhz(clk_get_rate(xtal) /
257 ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
258 (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
259 (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
260 (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
261
262 return 0;
263}