1 /* linux/arch/arm/mach-s3c2442/clock.c
3 * Copyright (c) 2004-2005 Simtec Electronics
4 * http://armlinux.simtec.co.uk/
5 * Ben Dooks <ben@simtec.co.uk>
7 * S3C2442 Clock support
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/list.h>
28 #include <linux/errno.h>
29 #include <linux/err.h>
30 #include <linux/device.h>
31 #include <linux/sysdev.h>
32 #include <linux/interrupt.h>
33 #include <linux/ioport.h>
34 #include <linux/mutex.h>
35 #include <linux/clk.h>
38 #include <mach/hardware.h>
39 #include <asm/atomic.h>
42 #include <mach/regs-clock.h>
44 #include <asm/plat-s3c24xx/clock.h>
45 #include <asm/plat-s3c24xx/cpu.h>
47 /* S3C2442 extended clock support */
49 static unsigned long s3c2442_camif_upll_round(struct clk *clk,
52 unsigned long parent_rate = clk_get_rate(clk->parent);
55 if (rate > parent_rate)
58 div = parent_rate / rate;
61 return parent_rate / 3;
63 /* note, we remove the +/- 1 calculations for the divisor */
72 return parent_rate / (div * 2);
75 static int s3c2442_camif_upll_setrate(struct clk *clk, unsigned long rate)
77 unsigned long parent_rate = clk_get_rate(clk->parent);
78 unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
80 rate = s3c2442_camif_upll_round(clk, rate);
82 camdivn &= ~S3C2442_CAMDIVN_CAMCLK_DIV3;
84 if (rate == parent_rate) {
85 camdivn &= ~S3C2440_CAMDIVN_CAMCLK_SEL;
86 } else if ((parent_rate / rate) == 3) {
87 camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
88 camdivn |= S3C2442_CAMDIVN_CAMCLK_DIV3;
90 camdivn &= ~S3C2440_CAMDIVN_CAMCLK_MASK;
91 camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
92 camdivn |= (((parent_rate / rate) / 2) - 1);
95 __raw_writel(camdivn, S3C2440_CAMDIVN);
100 /* Extra S3C2442 clocks */
102 static struct clk s3c2442_clk_cam = {
105 .enable = s3c2410_clkcon_enable,
106 .ctrlbit = S3C2440_CLKCON_CAMERA,
109 static struct clk s3c2442_clk_cam_upll = {
110 .name = "camif-upll",
112 .set_rate = s3c2442_camif_upll_setrate,
113 .round_rate = s3c2442_camif_upll_round,
116 static int s3c2442_clk_add(struct sys_device *sysdev)
118 struct clk *clock_upll;
122 clock_p = clk_get(NULL, "pclk");
123 clock_h = clk_get(NULL, "hclk");
124 clock_upll = clk_get(NULL, "upll");
126 if (IS_ERR(clock_p) || IS_ERR(clock_h) || IS_ERR(clock_upll)) {
127 printk(KERN_ERR "S3C2442: Failed to get parent clocks\n");
131 s3c2442_clk_cam.parent = clock_h;
132 s3c2442_clk_cam_upll.parent = clock_upll;
134 s3c24xx_register_clock(&s3c2442_clk_cam);
135 s3c24xx_register_clock(&s3c2442_clk_cam_upll);
137 clk_disable(&s3c2442_clk_cam);
142 static struct sysdev_driver s3c2442_clk_driver = {
143 .add = s3c2442_clk_add,
146 static __init int s3c2442_clk_init(void)
148 return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_clk_driver);
151 arch_initcall(s3c2442_clk_init);