summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-s3c24xx/clock-s3c2440.c
blob: 1069b56808265b5efaf9877b9ed6a1b7dc5ea833 (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
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
211
212
213
214
/* linux/arch/arm/mach-s3c2440/clock.c
 *
 * Copyright (c) 2004-2005 Simtec Electronics
 *	http://armlinux.simtec.co.uk/
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C2440 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/interrupt.h>
#include <linux/ioport.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/serial_core.h>

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

#include <mach/regs-clock.h>

#include <plat/clock.h>
#include <plat/cpu.h>
#include <plat/regs-serial.h>

/* S3C2440 extended clock support */

static unsigned long s3c2440_camif_upll_round(struct clk *clk,
					      unsigned long rate)
{
	unsigned long parent_rate = clk_get_rate(clk->parent);
	int div;

	if (rate > parent_rate)
		return parent_rate;

	/* note, we remove the +/- 1 calculations for the divisor */

	div = (parent_rate / rate) / 2;

	if (div < 1)
		div = 1;
	else if (div > 16)
		div = 16;

	return parent_rate / (div * 2);
}

static int s3c2440_camif_upll_setrate(struct clk *clk, unsigned long rate)
{
	unsigned long parent_rate = clk_get_rate(clk->parent);
	unsigned long camdivn =  __raw_readl(S3C2440_CAMDIVN);

	rate = s3c2440_camif_upll_round(clk, rate);

	camdivn &= ~(S3C2440_CAMDIVN_CAMCLK_SEL | S3C2440_CAMDIVN_CAMCLK_MASK);

	if (rate != parent_rate) {
		camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
		camdivn |= (((parent_rate / rate) / 2) - 1);
	}

	__raw_writel(camdivn, S3C2440_CAMDIVN);

	return 0;
}

static unsigned long s3c2440_camif_upll_getrate(struct clk *clk)
{
	unsigned long parent_rate = clk_get_rate(clk->parent);
	unsigned long camdivn =  __raw_readl(S3C2440_CAMDIVN);

	if (!(camdivn & S3C2440_CAMDIVN_CAMCLK_SEL))
		return parent_rate;

	camdivn &= S3C2440_CAMDIVN_CAMCLK_MASK;

	return parent_rate / (camdivn + 1) / 2;
}

/* Extra S3C2440 clocks */

static struct clk s3c2440_clk_cam = {
	.name		= "camif",
	.enable		= s3c2410_clkcon_enable,
	.ctrlbit	= S3C2440_CLKCON_CAMERA,
};

static struct clk s3c2440_clk_cam_upll = {
	.name		= "camif-upll",
	.ops		= &(struct clk_ops) {
		.set_rate	= s3c2440_camif_upll_setrate,
		.get_rate	= s3c2440_camif_upll_getrate,
		.round_rate	= s3c2440_camif_upll_round,
	},
};

static struct clk s3c2440_clk_ac97 = {
	.name		= "ac97",
	.enable		= s3c2410_clkcon_enable,
	.ctrlbit	= S3C2440_CLKCON_AC97,
};

#define S3C24XX_VA_UART0      (S3C_VA_UART)
#define S3C24XX_VA_UART1      (S3C_VA_UART + 0x4000 )
#define S3C24XX_VA_UART2      (S3C_VA_UART + 0x8000 )
#define S3C24XX_VA_UART3      (S3C_VA_UART + 0xC000 )

static unsigned long  s3c2440_fclk_n_getrate(struct clk *clk)
{
	unsigned long ucon0, ucon1, ucon2, divisor;

	/* the fun of calculating the uart divisors on the s3c2440 */
	ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON);
	ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON);
	ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON);

	ucon0 &= S3C2440_UCON0_DIVMASK;
	ucon1 &= S3C2440_UCON1_DIVMASK;
	ucon2 &= S3C2440_UCON2_DIVMASK;

	if (ucon0 != 0)
		divisor = (ucon0 >> S3C2440_UCON_DIVSHIFT) + 6;
	else if (ucon1 != 0)
		divisor = (ucon1 >> S3C2440_UCON_DIVSHIFT) + 21;
	else if (ucon2 != 0)
		divisor = (ucon2 >> S3C2440_UCON_DIVSHIFT) + 36;
	else
		/* manual calims 44, seems to be 9 */
		divisor = 9;

	return clk_get_rate(clk->parent) / divisor;
}

static struct clk s3c2440_clk_fclk_n = {
	.name		= "fclk_n",
	.parent		= &clk_f,
	.ops		= &(struct clk_ops) {
		.get_rate	= s3c2440_fclk_n_getrate,
	},
};

static struct clk_lookup s3c2440_clk_lookup[] = {
	CLKDEV_INIT(NULL, "clk_uart_baud1", &s3c24xx_uclk),
	CLKDEV_INIT(NULL, "clk_uart_baud2", &clk_p),
	CLKDEV_INIT(NULL, "clk_uart_baud3", &s3c2440_clk_fclk_n),
	CLKDEV_INIT("s3c2440-camif", "camera", &s3c2440_clk_cam_upll),
};

static int __init_refok s3c2440_clk_add(struct device *dev, struct subsys_interface *sif)
{
	struct clk *clock_upll;
	struct clk *clock_h;
	struct clk *clock_p;

	clock_p = clk_get(NULL, "pclk");
	clock_h = clk_get(NULL, "hclk");
	clock_upll = clk_get(NULL, "upll");

	if (IS_ERR(clock_p) || IS_ERR(clock_h) || IS_ERR(clock_upll)) {
		printk(KERN_ERR "S3C2440: Failed to get parent clocks\n");
		return -EINVAL;
	}

	s3c2440_clk_cam.parent = clock_h;
	s3c2440_clk_ac97.parent = clock_p;
	s3c2440_clk_cam_upll.parent = clock_upll;
	s3c24xx_register_clock(&s3c2440_clk_fclk_n);

	s3c24xx_register_clock(&s3c2440_clk_ac97);
	s3c24xx_register_clock(&s3c2440_clk_cam);
	s3c24xx_register_clock(&s3c2440_clk_cam_upll);
	clkdev_add_table(s3c2440_clk_lookup, ARRAY_SIZE(s3c2440_clk_lookup));

	clk_disable(&s3c2440_clk_ac97);
	clk_disable(&s3c2440_clk_cam);

	return 0;
}

static struct subsys_interface s3c2440_clk_interface = {
	.name		= "s3c2440_clk",
	.subsys		= &s3c2440_subsys,
	.add_dev	= s3c2440_clk_add,
};

static __init int s3c24xx_clk_init(void)
{
	return subsys_interface_register(&s3c2440_clk_interface);
}

arch_initcall(s3c24xx_clk_init);