1 /* linux/arch/arm/mach-s3c2410/clock.c
3 * Copyright (c) 2004-2005 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
6 * S3C2410 Clock control support
8 * Based on, and code from linux/arch/arm/mach-versatile/clock.c
10 ** Copyright (C) 2004 ARM Limited.
11 ** Written by Deep Blue Solutions Limited.
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 #include <linux/init.h>
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/list.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/platform_device.h>
36 #include <linux/sysdev.h>
38 #include <linux/interrupt.h>
39 #include <linux/ioport.h>
41 #include <asm/hardware.h>
42 #include <asm/atomic.h>
46 #include <asm/hardware/clock.h>
47 #include <asm/arch/regs-clock.h>
52 /* clock information */
54 static LIST_HEAD(clocks
);
55 static DECLARE_MUTEX(clocks_sem
);
59 void inline s3c24xx_clk_enable(unsigned int clocks
, unsigned int enable
)
64 local_irq_save(flags
);
66 clkcon
= __raw_readl(S3C2410_CLKCON
);
72 /* ensure none of the special function bits set */
73 clkcon
&= ~(S3C2410_CLKCON_IDLE
|S3C2410_CLKCON_POWER
);
75 __raw_writel(clkcon
, S3C2410_CLKCON
);
77 local_irq_restore(flags
);
80 /* enable and disable calls for use with the clk struct */
82 static int clk_null_enable(struct clk
*clk
, int enable
)
87 int s3c24xx_clkcon_enable(struct clk
*clk
, int enable
)
89 s3c24xx_clk_enable(clk
->ctrlbit
, enable
);
95 struct clk
*clk_get(struct device
*dev
, const char *id
)
98 struct clk
*clk
= ERR_PTR(-ENOENT
);
101 if (dev
== NULL
|| dev
->bus
!= &platform_bus_type
)
104 idno
= to_platform_device(dev
)->id
;
108 list_for_each_entry(p
, &clocks
, list
) {
110 strcmp(id
, p
->name
) == 0 &&
111 try_module_get(p
->owner
)) {
117 /* check for the case where a device was supplied, but the
118 * clock that was being searched for is not device specific */
121 list_for_each_entry(p
, &clocks
, list
) {
122 if (p
->id
== -1 && strcmp(id
, p
->name
) == 0 &&
123 try_module_get(p
->owner
)) {
134 void clk_put(struct clk
*clk
)
136 module_put(clk
->owner
);
139 int clk_enable(struct clk
*clk
)
144 return (clk
->enable
)(clk
, 1);
147 void clk_disable(struct clk
*clk
)
150 (clk
->enable
)(clk
, 0);
154 int clk_use(struct clk
*clk
)
156 atomic_inc(&clk
->used
);
161 void clk_unuse(struct clk
*clk
)
163 atomic_dec(&clk
->used
);
166 unsigned long clk_get_rate(struct clk
*clk
)
174 while (clk
->parent
!= NULL
&& clk
->rate
== 0)
180 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
185 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
190 struct clk
*clk_get_parent(struct clk
*clk
)
195 EXPORT_SYMBOL(clk_get
);
196 EXPORT_SYMBOL(clk_put
);
197 EXPORT_SYMBOL(clk_enable
);
198 EXPORT_SYMBOL(clk_disable
);
199 EXPORT_SYMBOL(clk_use
);
200 EXPORT_SYMBOL(clk_unuse
);
201 EXPORT_SYMBOL(clk_get_rate
);
202 EXPORT_SYMBOL(clk_round_rate
);
203 EXPORT_SYMBOL(clk_set_rate
);
204 EXPORT_SYMBOL(clk_get_parent
);
208 static struct clk clk_xtal
= {
216 static struct clk clk_f
= {
224 static struct clk clk_h
= {
232 static struct clk clk_p
= {
240 /* clocks that could be registered by external code */
242 struct clk s3c24xx_dclk0
= {
247 struct clk s3c24xx_dclk1
= {
252 struct clk s3c24xx_clkout0
= {
257 struct clk s3c24xx_clkout1
= {
262 struct clk s3c24xx_uclk
= {
268 /* clock definitions */
270 static struct clk init_clocks
[] = {
274 .enable
= s3c24xx_clkcon_enable
,
275 .ctrlbit
= S3C2410_CLKCON_NAND
280 .enable
= s3c24xx_clkcon_enable
,
281 .ctrlbit
= S3C2410_CLKCON_LCDC
283 { .name
= "usb-host",
286 .enable
= s3c24xx_clkcon_enable
,
287 .ctrlbit
= S3C2410_CLKCON_USBH
289 { .name
= "usb-device",
292 .enable
= s3c24xx_clkcon_enable
,
293 .ctrlbit
= S3C2410_CLKCON_USBD
298 .enable
= s3c24xx_clkcon_enable
,
299 .ctrlbit
= S3C2410_CLKCON_PWMT
304 .enable
= s3c24xx_clkcon_enable
,
305 .ctrlbit
= S3C2410_CLKCON_SDI
310 .enable
= s3c24xx_clkcon_enable
,
311 .ctrlbit
= S3C2410_CLKCON_UART0
316 .enable
= s3c24xx_clkcon_enable
,
317 .ctrlbit
= S3C2410_CLKCON_UART1
322 .enable
= s3c24xx_clkcon_enable
,
323 .ctrlbit
= S3C2410_CLKCON_UART2
328 .enable
= s3c24xx_clkcon_enable
,
329 .ctrlbit
= S3C2410_CLKCON_GPIO
334 .enable
= s3c24xx_clkcon_enable
,
335 .ctrlbit
= S3C2410_CLKCON_RTC
340 .enable
= s3c24xx_clkcon_enable
,
341 .ctrlbit
= S3C2410_CLKCON_ADC
346 .enable
= s3c24xx_clkcon_enable
,
347 .ctrlbit
= S3C2410_CLKCON_IIC
352 .enable
= s3c24xx_clkcon_enable
,
353 .ctrlbit
= S3C2410_CLKCON_IIS
358 .enable
= s3c24xx_clkcon_enable
,
359 .ctrlbit
= S3C2410_CLKCON_SPI
361 { .name
= "watchdog",
368 /* initialise the clock system */
370 int s3c24xx_register_clock(struct clk
*clk
)
372 clk
->owner
= THIS_MODULE
;
373 atomic_set(&clk
->used
, 0);
375 if (clk
->enable
== NULL
)
376 clk
->enable
= clk_null_enable
;
378 /* add to the list of available clocks */
381 list_add(&clk
->list
, &clocks
);
387 /* initalise all the clocks */
389 int __init
s3c24xx_setup_clocks(unsigned long xtal
,
394 unsigned long clkslow
= __raw_readl(S3C2410_CLKSLOW
);
395 struct clk
*clkp
= init_clocks
;
399 printk(KERN_INFO
"S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
401 /* initialise the main system clocks */
403 clk_xtal
.rate
= xtal
;
409 /* it looks like just setting the register here is not good
410 * enough, and causes the odd hang at initial boot time, so
411 * do all of them indivdually.
413 * I think disabling the LCD clock if the LCD is active is
414 * very dangerous, and therefore the bootloader should be
415 * careful to not enable the LCD clock if it is not needed.
417 * and of course, this looks neater
420 s3c24xx_clk_enable(S3C2410_CLKCON_NAND
, 0);
421 s3c24xx_clk_enable(S3C2410_CLKCON_USBH
, 0);
422 s3c24xx_clk_enable(S3C2410_CLKCON_USBD
, 0);
423 s3c24xx_clk_enable(S3C2410_CLKCON_ADC
, 0);
424 s3c24xx_clk_enable(S3C2410_CLKCON_IIC
, 0);
425 s3c24xx_clk_enable(S3C2410_CLKCON_SPI
, 0);
427 /* assume uart clocks are correctly setup */
429 /* register our clocks */
431 if (s3c24xx_register_clock(&clk_xtal
) < 0)
432 printk(KERN_ERR
"failed to register master xtal\n");
434 if (s3c24xx_register_clock(&clk_f
) < 0)
435 printk(KERN_ERR
"failed to register cpu fclk\n");
437 if (s3c24xx_register_clock(&clk_h
) < 0)
438 printk(KERN_ERR
"failed to register cpu hclk\n");
440 if (s3c24xx_register_clock(&clk_p
) < 0)
441 printk(KERN_ERR
"failed to register cpu pclk\n");
443 /* register clocks from clock array */
445 for (ptr
= 0; ptr
< ARRAY_SIZE(init_clocks
); ptr
++, clkp
++) {
446 ret
= s3c24xx_register_clock(clkp
);
448 printk(KERN_ERR
"Failed to register clock %s (%d)\n",
453 /* show the clock-slow value */
455 printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
456 print_mhz(xtal
/ ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow
))),
457 (clkslow
& S3C2410_CLKSLOW_SLOW
) ? "slow" : "fast",
458 (clkslow
& S3C2410_CLKSLOW_MPLL_OFF
) ? "off" : "on",
459 (clkslow
& S3C2410_CLKSLOW_UCLK_OFF
) ? "off" : "on");