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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 | 17 | #include <linux/string.h> |
fced80c7 | 18 | #include <linux/io.h> |
1d81eedb | 19 | #include <asm/div64.h> |
a09e64fb | 20 | #include <mach/hardware.h> |
1d81eedb LB |
21 | |
22 | struct clk { | |
23 | char *name; | |
24 | unsigned long rate; | |
25 | int users; | |
26 | u32 enable_reg; | |
27 | u32 enable_mask; | |
28 | }; | |
29 | ||
ed519ded RK |
30 | static struct clk clk_uart = { |
31 | .name = "UARTCLK", | |
32 | .rate = 14745600, | |
33 | }; | |
1d81eedb LB |
34 | static struct clk clk_pll1 = { |
35 | .name = "pll1", | |
36 | }; | |
37 | static struct clk clk_f = { | |
38 | .name = "fclk", | |
39 | }; | |
40 | static struct clk clk_h = { | |
41 | .name = "hclk", | |
42 | }; | |
43 | static struct clk clk_p = { | |
44 | .name = "pclk", | |
45 | }; | |
46 | static struct clk clk_pll2 = { | |
47 | .name = "pll2", | |
48 | }; | |
49 | static struct clk clk_usb_host = { | |
50 | .name = "usb_host", | |
51 | .enable_reg = EP93XX_SYSCON_CLOCK_CONTROL, | |
52 | .enable_mask = EP93XX_SYSCON_CLOCK_USH_EN, | |
53 | }; | |
54 | ||
55 | ||
56 | static struct clk *clocks[] = { | |
ed519ded | 57 | &clk_uart, |
1d81eedb LB |
58 | &clk_pll1, |
59 | &clk_f, | |
60 | &clk_h, | |
61 | &clk_p, | |
62 | &clk_pll2, | |
63 | &clk_usb_host, | |
64 | }; | |
65 | ||
66 | struct clk *clk_get(struct device *dev, const char *id) | |
67 | { | |
68 | int i; | |
69 | ||
70 | for (i = 0; i < ARRAY_SIZE(clocks); i++) { | |
71 | if (!strcmp(clocks[i]->name, id)) | |
72 | return clocks[i]; | |
73 | } | |
74 | ||
75 | return ERR_PTR(-ENOENT); | |
76 | } | |
0c5d5b70 | 77 | EXPORT_SYMBOL(clk_get); |
1d81eedb LB |
78 | |
79 | int clk_enable(struct clk *clk) | |
80 | { | |
81 | if (!clk->users++ && clk->enable_reg) { | |
82 | u32 value; | |
83 | ||
84 | value = __raw_readl(clk->enable_reg); | |
85 | __raw_writel(value | clk->enable_mask, clk->enable_reg); | |
86 | } | |
87 | ||
88 | return 0; | |
89 | } | |
0c5d5b70 | 90 | EXPORT_SYMBOL(clk_enable); |
1d81eedb LB |
91 | |
92 | void clk_disable(struct clk *clk) | |
93 | { | |
94 | if (!--clk->users && clk->enable_reg) { | |
95 | u32 value; | |
96 | ||
97 | value = __raw_readl(clk->enable_reg); | |
98 | __raw_writel(value & ~clk->enable_mask, clk->enable_reg); | |
99 | } | |
100 | } | |
0c5d5b70 | 101 | EXPORT_SYMBOL(clk_disable); |
1d81eedb LB |
102 | |
103 | unsigned long clk_get_rate(struct clk *clk) | |
104 | { | |
105 | return clk->rate; | |
106 | } | |
0c5d5b70 | 107 | EXPORT_SYMBOL(clk_get_rate); |
1d81eedb LB |
108 | |
109 | void clk_put(struct clk *clk) | |
110 | { | |
111 | } | |
0c5d5b70 | 112 | EXPORT_SYMBOL(clk_put); |
1d81eedb LB |
113 | |
114 | ||
115 | ||
116 | static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 }; | |
117 | static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 }; | |
118 | static char pclk_divisors[] = { 1, 2, 4, 8 }; | |
119 | ||
120 | /* | |
121 | * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS | |
122 | */ | |
123 | static unsigned long calc_pll_rate(u32 config_word) | |
124 | { | |
125 | unsigned long long rate; | |
126 | int i; | |
127 | ||
128 | rate = 14745600; | |
129 | rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */ | |
130 | rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */ | |
131 | do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */ | |
132 | for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */ | |
133 | rate >>= 1; | |
134 | ||
135 | return (unsigned long)rate; | |
136 | } | |
137 | ||
51dd249e | 138 | static int __init ep93xx_clock_init(void) |
1d81eedb LB |
139 | { |
140 | u32 value; | |
141 | ||
142 | value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1); | |
143 | if (!(value & 0x00800000)) { /* PLL1 bypassed? */ | |
144 | clk_pll1.rate = 14745600; | |
145 | } else { | |
146 | clk_pll1.rate = calc_pll_rate(value); | |
147 | } | |
148 | clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7]; | |
149 | clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7]; | |
150 | clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3]; | |
151 | ||
152 | value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2); | |
153 | if (!(value & 0x00080000)) { /* PLL2 bypassed? */ | |
154 | clk_pll2.rate = 14745600; | |
155 | } else if (value & 0x00040000) { /* PLL2 enabled? */ | |
156 | clk_pll2.rate = calc_pll_rate(value); | |
157 | } else { | |
158 | clk_pll2.rate = 0; | |
159 | } | |
160 | clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1); | |
161 | ||
162 | printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n", | |
163 | clk_pll1.rate / 1000000, clk_pll2.rate / 1000000); | |
164 | printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n", | |
165 | clk_f.rate / 1000000, clk_h.rate / 1000000, | |
166 | clk_p.rate / 1000000); | |
51dd249e LB |
167 | |
168 | return 0; | |
1d81eedb | 169 | } |
51dd249e | 170 | arch_initcall(ep93xx_clock_init); |