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 #include <linux/serial_core.h>
34
35 #include <asm/mach/map.h>
36
37 #include <asm/hardware.h>
38 #include <asm/io.h>
39
40 #include <asm/plat-s3c/regs-serial.h>
41 #include <asm/arch/regs-clock.h>
42 #include <asm/arch/regs-gpio.h>
43
44 #include <asm/plat-s3c24xx/s3c2410.h>
45 #include <asm/plat-s3c24xx/clock.h>
46 #include <asm/plat-s3c24xx/cpu.h>
47
48 int s3c2410_clkcon_enable(struct clk *clk, int enable)
49 {
50 unsigned int clocks = clk->ctrlbit;
51 unsigned long clkcon;
52
53 clkcon = __raw_readl(S3C2410_CLKCON);
54
55 if (enable)
56 clkcon |= clocks;
57 else
58 clkcon &= ~clocks;
59
60 /* ensure none of the special function bits set */
61 clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
62
63 __raw_writel(clkcon, S3C2410_CLKCON);
64
65 return 0;
66 }
67
68 static int s3c2410_upll_enable(struct clk *clk, int enable)
69 {
70 unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
71 unsigned long orig = clkslow;
72
73 if (enable)
74 clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
75 else
76 clkslow |= S3C2410_CLKSLOW_UCLK_OFF;
77
78 __raw_writel(clkslow, S3C2410_CLKSLOW);
79
80 /* if we started the UPLL, then allow to settle */
81
82 if (enable && (orig & S3C2410_CLKSLOW_UCLK_OFF))
83 udelay(200);
84
85 return 0;
86 }
87
88 /* standard clock definitions */
89
90 static struct clk init_clocks_disable[] = {
91 {
92 .name = "nand",
93 .id = -1,
94 .parent = &clk_h,
95 .enable = s3c2410_clkcon_enable,
96 .ctrlbit = S3C2410_CLKCON_NAND,
97 }, {
98 .name = "sdi",
99 .id = -1,
100 .parent = &clk_p,
101 .enable = s3c2410_clkcon_enable,
102 .ctrlbit = S3C2410_CLKCON_SDI,
103 }, {
104 .name = "adc",
105 .id = -1,
106 .parent = &clk_p,
107 .enable = s3c2410_clkcon_enable,
108 .ctrlbit = S3C2410_CLKCON_ADC,
109 }, {
110 .name = "i2c",
111 .id = -1,
112 .parent = &clk_p,
113 .enable = s3c2410_clkcon_enable,
114 .ctrlbit = S3C2410_CLKCON_IIC,
115 }, {
116 .name = "iis",
117 .id = -1,
118 .parent = &clk_p,
119 .enable = s3c2410_clkcon_enable,
120 .ctrlbit = S3C2410_CLKCON_IIS,
121 }, {
122 .name = "spi",
123 .id = -1,
124 .parent = &clk_p,
125 .enable = s3c2410_clkcon_enable,
126 .ctrlbit = S3C2410_CLKCON_SPI,
127 }
128 };
129
130 static struct clk init_clocks[] = {
131 {
132 .name = "lcd",
133 .id = -1,
134 .parent = &clk_h,
135 .enable = s3c2410_clkcon_enable,
136 .ctrlbit = S3C2410_CLKCON_LCDC,
137 }, {
138 .name = "gpio",
139 .id = -1,
140 .parent = &clk_p,
141 .enable = s3c2410_clkcon_enable,
142 .ctrlbit = S3C2410_CLKCON_GPIO,
143 }, {
144 .name = "usb-host",
145 .id = -1,
146 .parent = &clk_h,
147 .enable = s3c2410_clkcon_enable,
148 .ctrlbit = S3C2410_CLKCON_USBH,
149 }, {
150 .name = "usb-device",
151 .id = -1,
152 .parent = &clk_h,
153 .enable = s3c2410_clkcon_enable,
154 .ctrlbit = S3C2410_CLKCON_USBD,
155 }, {
156 .name = "timers",
157 .id = -1,
158 .parent = &clk_p,
159 .enable = s3c2410_clkcon_enable,
160 .ctrlbit = S3C2410_CLKCON_PWMT,
161 }, {
162 .name = "uart",
163 .id = 0,
164 .parent = &clk_p,
165 .enable = s3c2410_clkcon_enable,
166 .ctrlbit = S3C2410_CLKCON_UART0,
167 }, {
168 .name = "uart",
169 .id = 1,
170 .parent = &clk_p,
171 .enable = s3c2410_clkcon_enable,
172 .ctrlbit = S3C2410_CLKCON_UART1,
173 }, {
174 .name = "uart",
175 .id = 2,
176 .parent = &clk_p,
177 .enable = s3c2410_clkcon_enable,
178 .ctrlbit = S3C2410_CLKCON_UART2,
179 }, {
180 .name = "rtc",
181 .id = -1,
182 .parent = &clk_p,
183 .enable = s3c2410_clkcon_enable,
184 .ctrlbit = S3C2410_CLKCON_RTC,
185 }, {
186 .name = "watchdog",
187 .id = -1,
188 .parent = &clk_p,
189 .ctrlbit = 0,
190 }, {
191 .name = "usb-bus-host",
192 .id = -1,
193 .parent = &clk_usb_bus,
194 }, {
195 .name = "usb-bus-gadget",
196 .id = -1,
197 .parent = &clk_usb_bus,
198 },
199 };
200
201 /* s3c2410_baseclk_add()
202 *
203 * Add all the clocks used by the s3c2410 or compatible CPUs
204 * such as the S3C2440 and S3C2442.
205 *
206 * We cannot use a system device as we are needed before any
207 * of the init-calls that initialise the devices are actually
208 * done.
209 */
210
211 int __init s3c2410_baseclk_add(void)
212 {
213 unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
214 unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
215 struct clk *clkp;
216 struct clk *xtal;
217 int ret;
218 int ptr;
219
220 clk_upll.enable = s3c2410_upll_enable;
221
222 if (s3c24xx_register_clock(&clk_usb_bus) < 0)
223 printk(KERN_ERR "failed to register usb bus clock\n");
224
225 /* register clocks from clock array */
226
227 clkp = init_clocks;
228 for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
229 /* ensure that we note the clock state */
230
231 clkp->usage = clkcon & clkp->ctrlbit ? 1 : 0;
232
233 ret = s3c24xx_register_clock(clkp);
234 if (ret < 0) {
235 printk(KERN_ERR "Failed to register clock %s (%d)\n",
236 clkp->name, ret);
237 }
238 }
239
240 /* We must be careful disabling the clocks we are not intending to
241 * be using at boot time, as subsystems such as the LCD which do
242 * their own DMA requests to the bus can cause the system to lockup
243 * if they where in the middle of requesting bus access.
244 *
245 * Disabling the LCD clock if the LCD is active is very dangerous,
246 * and therefore the bootloader should be careful to not enable
247 * the LCD clock if it is not needed.
248 */
249
250 /* install (and disable) the clocks we do not need immediately */
251
252 clkp = init_clocks_disable;
253 for (ptr = 0; ptr < ARRAY_SIZE(init_clocks_disable); ptr++, clkp++) {
254
255 ret = s3c24xx_register_clock(clkp);
256 if (ret < 0) {
257 printk(KERN_ERR "Failed to register clock %s (%d)\n",
258 clkp->name, ret);
259 }
260
261 s3c2410_clkcon_enable(clkp, 0);
262 }
263
264 /* show the clock-slow value */
265
266 xtal = clk_get(NULL, "xtal");
267
268 printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
269 print_mhz(clk_get_rate(xtal) /
270 ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
271 (clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
272 (clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
273 (clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
274
275 return 0;
276 }
277
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