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1 | /* linux/arch/arm/plat-s3c24xx/s3c24xx-clock.c |
2 | * | |
3 | * Copyright (c) 2004-2005,2008 Simtec Electronics | |
4 | * http://armlinux.simtec.co.uk/ | |
5 | * Ben Dooks <ben@simtec.co.uk> | |
6 | * | |
7 | * S3C2440/S3C2442 Common clock support | |
8 | * | |
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. | |
13 | * | |
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. | |
18 | * | |
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 | |
22 | */ | |
23 | ||
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> | |
fced80c7 | 36 | #include <linux/io.h> |
3a38e4be | 37 | |
a09e64fb | 38 | #include <mach/hardware.h> |
3a38e4be BD |
39 | #include <asm/atomic.h> |
40 | #include <asm/irq.h> | |
3a38e4be | 41 | |
a09e64fb | 42 | #include <mach/regs-clock.h> |
3a38e4be BD |
43 | |
44 | #include <asm/plat-s3c24xx/clock.h> | |
45 | #include <asm/plat-s3c24xx/cpu.h> | |
46 | ||
06dbbd69 BD |
47 | static int s3c2440_setparent_armclk(struct clk *clk, struct clk *parent) |
48 | { | |
49 | unsigned long camdivn; | |
50 | unsigned long dvs; | |
51 | ||
52 | if (parent == &clk_f) | |
53 | dvs = 0; | |
54 | else if (parent == &clk_h) | |
55 | dvs = S3C2440_CAMDIVN_DVSEN; | |
56 | else | |
57 | return -EINVAL; | |
58 | ||
59 | clk->parent = parent; | |
60 | ||
61 | camdivn = __raw_readl(S3C2440_CAMDIVN); | |
62 | camdivn &= ~S3C2440_CAMDIVN_DVSEN; | |
63 | camdivn |= dvs; | |
64 | __raw_writel(camdivn, S3C2440_CAMDIVN); | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | static struct clk clk_arm = { | |
70 | .name = "armclk", | |
71 | .id = -1, | |
72 | .set_parent = s3c2440_setparent_armclk, | |
73 | }; | |
74 | ||
3a38e4be BD |
75 | static int s3c244x_clk_add(struct sys_device *sysdev) |
76 | { | |
77 | unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN); | |
78 | unsigned long clkdivn; | |
79 | struct clk *clock_upll; | |
06dbbd69 | 80 | int ret; |
3a38e4be BD |
81 | |
82 | printk("S3C244X: Clock Support, DVS %s\n", | |
83 | (camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off"); | |
84 | ||
06dbbd69 BD |
85 | clk_arm.parent = (camdivn & S3C2440_CAMDIVN_DVSEN) ? &clk_h : &clk_f; |
86 | ||
87 | ret = s3c24xx_register_clock(&clk_arm); | |
88 | if (ret < 0) { | |
89 | printk(KERN_ERR "S3C24XX: Failed to add armclk (%d)\n", ret); | |
90 | return ret; | |
91 | } | |
92 | ||
3a38e4be BD |
93 | clock_upll = clk_get(NULL, "upll"); |
94 | if (IS_ERR(clock_upll)) { | |
95 | printk(KERN_ERR "S3C244X: Failed to get upll clock\n"); | |
96 | return -ENOENT; | |
97 | } | |
98 | ||
99 | /* check rate of UPLL, and if it is near 96MHz, then change | |
100 | * to using half the UPLL rate for the system */ | |
101 | ||
102 | if (clk_get_rate(clock_upll) > (94 * MHZ)) { | |
103 | clk_usb_bus.rate = clk_get_rate(clock_upll) / 2; | |
104 | ||
105 | mutex_lock(&clocks_mutex); | |
106 | ||
107 | clkdivn = __raw_readl(S3C2410_CLKDIVN); | |
108 | clkdivn |= S3C2440_CLKDIVN_UCLK; | |
109 | __raw_writel(clkdivn, S3C2410_CLKDIVN); | |
110 | ||
111 | mutex_unlock(&clocks_mutex); | |
112 | } | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | static struct sysdev_driver s3c2440_clk_driver = { | |
118 | .add = s3c244x_clk_add, | |
119 | }; | |
120 | ||
121 | static int s3c2440_clk_init(void) | |
122 | { | |
123 | return sysdev_driver_register(&s3c2440_sysclass, &s3c2440_clk_driver); | |
124 | } | |
125 | ||
126 | arch_initcall(s3c2440_clk_init); | |
127 | ||
128 | static struct sysdev_driver s3c2442_clk_driver = { | |
129 | .add = s3c244x_clk_add, | |
130 | }; | |
131 | ||
132 | static int s3c2442_clk_init(void) | |
133 | { | |
134 | return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_clk_driver); | |
135 | } | |
136 | ||
137 | arch_initcall(s3c2442_clk_init); |