diff options
Diffstat (limited to 'arch/arm/plat-samsung/clock-clksrc.c')
-rw-r--r-- | arch/arm/plat-samsung/clock-clksrc.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/clock-clksrc.c b/arch/arm/plat-samsung/clock-clksrc.c new file mode 100644 index 000000000000..ae8b8507663f --- /dev/null +++ b/arch/arm/plat-samsung/clock-clksrc.c | |||
@@ -0,0 +1,212 @@ | |||
1 | /* linux/arch/arm/plat-samsung/clock-clksrc.c | ||
2 | * | ||
3 | * Copyright 2008 Simtec Electronics | ||
4 | * Ben Dooks <ben@simtec.co.uk> | ||
5 | * http://armlinux.simtec.co.uk/ | ||
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 version 2 as | ||
9 | * published by the Free Software Foundation. | ||
10 | */ | ||
11 | |||
12 | #include <linux/init.h> | ||
13 | #include <linux/module.h> | ||
14 | #include <linux/kernel.h> | ||
15 | #include <linux/list.h> | ||
16 | #include <linux/errno.h> | ||
17 | #include <linux/err.h> | ||
18 | #include <linux/clk.h> | ||
19 | #include <linux/sysdev.h> | ||
20 | #include <linux/io.h> | ||
21 | |||
22 | #include <plat/clock.h> | ||
23 | #include <plat/clock-clksrc.h> | ||
24 | #include <plat/cpu-freq.h> | ||
25 | |||
26 | static inline struct clksrc_clk *to_clksrc(struct clk *clk) | ||
27 | { | ||
28 | return container_of(clk, struct clksrc_clk, clk); | ||
29 | } | ||
30 | |||
31 | static inline u32 bit_mask(u32 shift, u32 nr_bits) | ||
32 | { | ||
33 | u32 mask = 0xffffffff >> (32 - nr_bits); | ||
34 | |||
35 | return mask << shift; | ||
36 | } | ||
37 | |||
38 | static unsigned long s3c_getrate_clksrc(struct clk *clk) | ||
39 | { | ||
40 | struct clksrc_clk *sclk = to_clksrc(clk); | ||
41 | unsigned long rate = clk_get_rate(clk->parent); | ||
42 | u32 clkdiv = __raw_readl(sclk->reg_div.reg); | ||
43 | u32 mask = bit_mask(sclk->reg_div.shift, sclk->reg_div.size); | ||
44 | |||
45 | clkdiv &= mask; | ||
46 | clkdiv >>= sclk->reg_div.shift; | ||
47 | clkdiv++; | ||
48 | |||
49 | rate /= clkdiv; | ||
50 | return rate; | ||
51 | } | ||
52 | |||
53 | static int s3c_setrate_clksrc(struct clk *clk, unsigned long rate) | ||
54 | { | ||
55 | struct clksrc_clk *sclk = to_clksrc(clk); | ||
56 | void __iomem *reg = sclk->reg_div.reg; | ||
57 | unsigned int div; | ||
58 | u32 mask = bit_mask(sclk->reg_div.shift, sclk->reg_div.size); | ||
59 | u32 val; | ||
60 | |||
61 | rate = clk_round_rate(clk, rate); | ||
62 | div = clk_get_rate(clk->parent) / rate; | ||
63 | if (div > (1 << sclk->reg_div.size)) | ||
64 | return -EINVAL; | ||
65 | |||
66 | val = __raw_readl(reg); | ||
67 | val &= ~mask; | ||
68 | val |= (div - 1) << sclk->reg_div.shift; | ||
69 | __raw_writel(val, reg); | ||
70 | |||
71 | return 0; | ||
72 | } | ||
73 | |||
74 | static int s3c_setparent_clksrc(struct clk *clk, struct clk *parent) | ||
75 | { | ||
76 | struct clksrc_clk *sclk = to_clksrc(clk); | ||
77 | struct clksrc_sources *srcs = sclk->sources; | ||
78 | u32 clksrc = __raw_readl(sclk->reg_src.reg); | ||
79 | u32 mask = bit_mask(sclk->reg_src.shift, sclk->reg_src.size); | ||
80 | int src_nr = -1; | ||
81 | int ptr; | ||
82 | |||
83 | for (ptr = 0; ptr < srcs->nr_sources; ptr++) | ||
84 | if (srcs->sources[ptr] == parent) { | ||
85 | src_nr = ptr; | ||
86 | break; | ||
87 | } | ||
88 | |||
89 | if (src_nr >= 0) { | ||
90 | clk->parent = parent; | ||
91 | |||
92 | clksrc &= ~mask; | ||
93 | clksrc |= src_nr << sclk->reg_src.shift; | ||
94 | |||
95 | __raw_writel(clksrc, sclk->reg_src.reg); | ||
96 | return 0; | ||
97 | } | ||
98 | |||
99 | return -EINVAL; | ||
100 | } | ||
101 | |||
102 | static unsigned long s3c_roundrate_clksrc(struct clk *clk, | ||
103 | unsigned long rate) | ||
104 | { | ||
105 | struct clksrc_clk *sclk = to_clksrc(clk); | ||
106 | unsigned long parent_rate = clk_get_rate(clk->parent); | ||
107 | int max_div = 1 << sclk->reg_div.size; | ||
108 | int div; | ||
109 | |||
110 | if (rate >= parent_rate) | ||
111 | rate = parent_rate; | ||
112 | else { | ||
113 | div = parent_rate / rate; | ||
114 | if (parent_rate % rate) | ||
115 | div++; | ||
116 | |||
117 | if (div == 0) | ||
118 | div = 1; | ||
119 | if (div > max_div) | ||
120 | div = max_div; | ||
121 | |||
122 | rate = parent_rate / div; | ||
123 | } | ||
124 | |||
125 | return rate; | ||
126 | } | ||
127 | |||
128 | /* Clock initialisation code */ | ||
129 | |||
130 | void __init_or_cpufreq s3c_set_clksrc(struct clksrc_clk *clk, bool announce) | ||
131 | { | ||
132 | struct clksrc_sources *srcs = clk->sources; | ||
133 | u32 mask = bit_mask(clk->reg_src.shift, clk->reg_src.size); | ||
134 | u32 clksrc; | ||
135 | |||
136 | if (!clk->reg_src.reg) { | ||
137 | if (!clk->clk.parent) | ||
138 | printk(KERN_ERR "%s: no parent clock specified\n", | ||
139 | clk->clk.name); | ||
140 | return; | ||
141 | } | ||
142 | |||
143 | clksrc = __raw_readl(clk->reg_src.reg); | ||
144 | clksrc &= mask; | ||
145 | clksrc >>= clk->reg_src.shift; | ||
146 | |||
147 | if (clksrc > srcs->nr_sources || !srcs->sources[clksrc]) { | ||
148 | printk(KERN_ERR "%s: bad source %d\n", | ||
149 | clk->clk.name, clksrc); | ||
150 | return; | ||
151 | } | ||
152 | |||
153 | clk->clk.parent = srcs->sources[clksrc]; | ||
154 | |||
155 | if (announce) | ||
156 | printk(KERN_INFO "%s: source is %s (%d), rate is %ld\n", | ||
157 | clk->clk.name, clk->clk.parent->name, clksrc, | ||
158 | clk_get_rate(&clk->clk)); | ||
159 | } | ||
160 | |||
161 | static struct clk_ops clksrc_ops = { | ||
162 | .set_parent = s3c_setparent_clksrc, | ||
163 | .get_rate = s3c_getrate_clksrc, | ||
164 | .set_rate = s3c_setrate_clksrc, | ||
165 | .round_rate = s3c_roundrate_clksrc, | ||
166 | }; | ||
167 | |||
168 | static struct clk_ops clksrc_ops_nodiv = { | ||
169 | .set_parent = s3c_setparent_clksrc, | ||
170 | }; | ||
171 | |||
172 | static struct clk_ops clksrc_ops_nosrc = { | ||
173 | .get_rate = s3c_getrate_clksrc, | ||
174 | .set_rate = s3c_setrate_clksrc, | ||
175 | .round_rate = s3c_roundrate_clksrc, | ||
176 | }; | ||
177 | |||
178 | void __init s3c_register_clksrc(struct clksrc_clk *clksrc, int size) | ||
179 | { | ||
180 | int ret; | ||
181 | |||
182 | for (; size > 0; size--, clksrc++) { | ||
183 | if (!clksrc->reg_div.reg && !clksrc->reg_src.reg) | ||
184 | printk(KERN_ERR "%s: clock %s has no registers set\n", | ||
185 | __func__, clksrc->clk.name); | ||
186 | |||
187 | /* fill in the default functions */ | ||
188 | |||
189 | if (!clksrc->clk.ops) { | ||
190 | if (!clksrc->reg_div.reg) | ||
191 | clksrc->clk.ops = &clksrc_ops_nodiv; | ||
192 | else if (!clksrc->reg_src.reg) | ||
193 | clksrc->clk.ops = &clksrc_ops_nosrc; | ||
194 | else | ||
195 | clksrc->clk.ops = &clksrc_ops; | ||
196 | } | ||
197 | |||
198 | /* setup the clocksource, but do not announce it | ||
199 | * as it may be re-set by the setup routines | ||
200 | * called after the rest of the clocks have been | ||
201 | * registered | ||
202 | */ | ||
203 | s3c_set_clksrc(clksrc, false); | ||
204 | |||
205 | ret = s3c24xx_register_clock(&clksrc->clk); | ||
206 | |||
207 | if (ret < 0) { | ||
208 | printk(KERN_ERR "%s: failed to register %s (%d)\n", | ||
209 | __func__, clksrc->clk.name, ret); | ||
210 | } | ||
211 | } | ||
212 | } | ||