summaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-s3c24xx/s3c244x-clock.c
blob: b998ee6244713cc4666d1d96d58cfb9ea523246a (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
/* linux/arch/arm/plat-s3c24xx/s3c24xx-clock.c
 *
 * Copyright (c) 2004-2005,2008 Simtec Electronics
 *	http://armlinux.simtec.co.uk/
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C2440/S3C2442 Common clock support
 *
 * 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/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/mutex.h>
#include <linux/clk.h>

#include <mach/hardware.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/io.h>

#include <mach/regs-clock.h>

#include <plat/clock.h>
#include <plat/cpu.h>

static int s3c2440_setparent_armclk(struct clk *clk, struct clk *parent)
{
	unsigned long camdivn;
	unsigned long dvs;

	if (parent == &clk_f)
		dvs = 0;
	else if (parent == &clk_h)
		dvs = S3C2440_CAMDIVN_DVSEN;
	else
		return -EINVAL;

	clk->parent = parent;

	camdivn  = __raw_readl(S3C2440_CAMDIVN);
	camdivn &= ~S3C2440_CAMDIVN_DVSEN;
	camdivn |= dvs;
	__raw_writel(camdivn, S3C2440_CAMDIVN);

	return 0;
}

static struct clk clk_arm = {
	.name		= "armclk",
	.id		= -1,
	.set_parent	= s3c2440_setparent_armclk,
};

static int s3c244x_clk_add(struct sys_device *sysdev)
{
	unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
	unsigned long clkdivn;
	struct clk *clock_upll;
	int ret;

	printk("S3C244X: Clock Support, DVS %s\n",
	       (camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off");

	clk_arm.parent = (camdivn & S3C2440_CAMDIVN_DVSEN) ? &clk_h : &clk_f;

	ret = s3c24xx_register_clock(&clk_arm);
	if (ret < 0) {
		printk(KERN_ERR "S3C24XX: Failed to add armclk (%d)\n", ret);
		return ret;
	}

	clock_upll = clk_get(NULL, "upll");
	if (IS_ERR(clock_upll)) {
		printk(KERN_ERR "S3C244X: Failed to get upll clock\n");
		return -ENOENT;
	}

	/* check rate of UPLL, and if it is near 96MHz, then change
	 * to using half the UPLL rate for the system */

	if (clk_get_rate(clock_upll) > (94 * MHZ)) {
		clk_usb_bus.rate = clk_get_rate(clock_upll) / 2;

		mutex_lock(&clocks_mutex);

		clkdivn = __raw_readl(S3C2410_CLKDIVN);
		clkdivn |= S3C2440_CLKDIVN_UCLK;
		__raw_writel(clkdivn, S3C2410_CLKDIVN);

		mutex_unlock(&clocks_mutex);
	}

	return 0;
}

static struct sysdev_driver s3c2440_clk_driver = {
	.add		= s3c244x_clk_add,
};

static int s3c2440_clk_init(void)
{
	return sysdev_driver_register(&s3c2440_sysclass, &s3c2440_clk_driver);
}

arch_initcall(s3c2440_clk_init);

static struct sysdev_driver s3c2442_clk_driver = {
	.add		= s3c244x_clk_add,
};

static int s3c2442_clk_init(void)
{
	return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_clk_driver);
}

arch_initcall(s3c2442_clk_init);