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1d81eedb LB |
1 | /* |
2 | * arch/arm/mach-ep93xx/clock.c | |
3 | * Clock control for Cirrus EP93xx chips. | |
4 | * | |
5 | * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or (at | |
10 | * your option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/clk.h> | |
15 | #include <linux/err.h> | |
51dd249e | 16 | #include <linux/module.h> |
1d81eedb LB |
17 | #include <linux/string.h> |
18 | #include <asm/div64.h> | |
19 | #include <asm/hardware.h> | |
20 | #include <asm/io.h> | |
21 | ||
22 | struct clk { | |
23 | char *name; | |
24 | unsigned long rate; | |
25 | int users; | |
26 | u32 enable_reg; | |
27 | u32 enable_mask; | |
28 | }; | |
29 | ||
30 | static struct clk clk_pll1 = { | |
31 | .name = "pll1", | |
32 | }; | |
33 | static struct clk clk_f = { | |
34 | .name = "fclk", | |
35 | }; | |
36 | static struct clk clk_h = { | |
37 | .name = "hclk", | |
38 | }; | |
39 | static struct clk clk_p = { | |
40 | .name = "pclk", | |
41 | }; | |
42 | static struct clk clk_pll2 = { | |
43 | .name = "pll2", | |
44 | }; | |
45 | static struct clk clk_usb_host = { | |
46 | .name = "usb_host", | |
47 | .enable_reg = EP93XX_SYSCON_CLOCK_CONTROL, | |
48 | .enable_mask = EP93XX_SYSCON_CLOCK_USH_EN, | |
49 | }; | |
50 | ||
51 | ||
52 | static struct clk *clocks[] = { | |
53 | &clk_pll1, | |
54 | &clk_f, | |
55 | &clk_h, | |
56 | &clk_p, | |
57 | &clk_pll2, | |
58 | &clk_usb_host, | |
59 | }; | |
60 | ||
61 | struct clk *clk_get(struct device *dev, const char *id) | |
62 | { | |
63 | int i; | |
64 | ||
65 | for (i = 0; i < ARRAY_SIZE(clocks); i++) { | |
66 | if (!strcmp(clocks[i]->name, id)) | |
67 | return clocks[i]; | |
68 | } | |
69 | ||
70 | return ERR_PTR(-ENOENT); | |
71 | } | |
72 | ||
73 | int clk_enable(struct clk *clk) | |
74 | { | |
75 | if (!clk->users++ && clk->enable_reg) { | |
76 | u32 value; | |
77 | ||
78 | value = __raw_readl(clk->enable_reg); | |
79 | __raw_writel(value | clk->enable_mask, clk->enable_reg); | |
80 | } | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | void clk_disable(struct clk *clk) | |
86 | { | |
87 | if (!--clk->users && clk->enable_reg) { | |
88 | u32 value; | |
89 | ||
90 | value = __raw_readl(clk->enable_reg); | |
91 | __raw_writel(value & ~clk->enable_mask, clk->enable_reg); | |
92 | } | |
93 | } | |
94 | ||
95 | unsigned long clk_get_rate(struct clk *clk) | |
96 | { | |
97 | return clk->rate; | |
98 | } | |
99 | ||
100 | void clk_put(struct clk *clk) | |
101 | { | |
102 | } | |
103 | ||
104 | ||
105 | ||
106 | static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 }; | |
107 | static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 }; | |
108 | static char pclk_divisors[] = { 1, 2, 4, 8 }; | |
109 | ||
110 | /* | |
111 | * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS | |
112 | */ | |
113 | static unsigned long calc_pll_rate(u32 config_word) | |
114 | { | |
115 | unsigned long long rate; | |
116 | int i; | |
117 | ||
118 | rate = 14745600; | |
119 | rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */ | |
120 | rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */ | |
121 | do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */ | |
122 | for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */ | |
123 | rate >>= 1; | |
124 | ||
125 | return (unsigned long)rate; | |
126 | } | |
127 | ||
51dd249e | 128 | static int __init ep93xx_clock_init(void) |
1d81eedb LB |
129 | { |
130 | u32 value; | |
131 | ||
132 | value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1); | |
133 | if (!(value & 0x00800000)) { /* PLL1 bypassed? */ | |
134 | clk_pll1.rate = 14745600; | |
135 | } else { | |
136 | clk_pll1.rate = calc_pll_rate(value); | |
137 | } | |
138 | clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7]; | |
139 | clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7]; | |
140 | clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3]; | |
141 | ||
142 | value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2); | |
143 | if (!(value & 0x00080000)) { /* PLL2 bypassed? */ | |
144 | clk_pll2.rate = 14745600; | |
145 | } else if (value & 0x00040000) { /* PLL2 enabled? */ | |
146 | clk_pll2.rate = calc_pll_rate(value); | |
147 | } else { | |
148 | clk_pll2.rate = 0; | |
149 | } | |
150 | clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1); | |
151 | ||
152 | printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n", | |
153 | clk_pll1.rate / 1000000, clk_pll2.rate / 1000000); | |
154 | printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n", | |
155 | clk_f.rate / 1000000, clk_h.rate / 1000000, | |
156 | clk_p.rate / 1000000); | |
51dd249e LB |
157 | |
158 | return 0; | |
1d81eedb | 159 | } |
51dd249e | 160 | arch_initcall(ep93xx_clock_init); |