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1 /*
2  *  This program is free software; you can redistribute it and/or modify it
3  *  under the terms of the GNU General Public License version 2 as published
4  *  by the Free Software Foundation.
5  *
6  * Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com>
7  * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
8  */
9 #include <linux/io.h>
10 #include <linux/export.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/clk.h>
15 #include <linux/clkdev.h>
16 #include <linux/err.h>
17 #include <linux/list.h>
18 
19 #include <asm/time.h>
20 #include <asm/irq.h>
21 #include <asm/div64.h>
22 
23 #include <lantiq_soc.h>
24 
25 #include "clk.h"
26 #include "prom.h"
27 
28 /* lantiq socs have 3 static clocks */
29 static struct clk cpu_clk_generic[4];
30 
clkdev_add_static(unsigned long cpu,unsigned long fpi,unsigned long io,unsigned long ppe)31 void clkdev_add_static(unsigned long cpu, unsigned long fpi,
32 			unsigned long io, unsigned long ppe)
33 {
34 	cpu_clk_generic[0].rate = cpu;
35 	cpu_clk_generic[1].rate = fpi;
36 	cpu_clk_generic[2].rate = io;
37 	cpu_clk_generic[3].rate = ppe;
38 }
39 
clk_get_cpu(void)40 struct clk *clk_get_cpu(void)
41 {
42 	return &cpu_clk_generic[0];
43 }
44 
clk_get_fpi(void)45 struct clk *clk_get_fpi(void)
46 {
47 	return &cpu_clk_generic[1];
48 }
49 EXPORT_SYMBOL_GPL(clk_get_fpi);
50 
clk_get_io(void)51 struct clk *clk_get_io(void)
52 {
53 	return &cpu_clk_generic[2];
54 }
55 
clk_get_ppe(void)56 struct clk *clk_get_ppe(void)
57 {
58 	return &cpu_clk_generic[3];
59 }
60 EXPORT_SYMBOL_GPL(clk_get_ppe);
61 
clk_good(struct clk * clk)62 static inline int clk_good(struct clk *clk)
63 {
64 	return clk && !IS_ERR(clk);
65 }
66 
clk_get_rate(struct clk * clk)67 unsigned long clk_get_rate(struct clk *clk)
68 {
69 	if (unlikely(!clk_good(clk)))
70 		return 0;
71 
72 	if (clk->rate != 0)
73 		return clk->rate;
74 
75 	if (clk->get_rate != NULL)
76 		return clk->get_rate();
77 
78 	return 0;
79 }
80 EXPORT_SYMBOL(clk_get_rate);
81 
clk_set_rate(struct clk * clk,unsigned long rate)82 int clk_set_rate(struct clk *clk, unsigned long rate)
83 {
84 	if (unlikely(!clk_good(clk)))
85 		return 0;
86 	if (clk->rates && *clk->rates) {
87 		unsigned long *r = clk->rates;
88 
89 		while (*r && (*r != rate))
90 			r++;
91 		if (!*r) {
92 			pr_err("clk %s.%s: trying to set invalid rate %ld\n",
93 				clk->cl.dev_id, clk->cl.con_id, rate);
94 			return -1;
95 		}
96 	}
97 	clk->rate = rate;
98 	return 0;
99 }
100 EXPORT_SYMBOL(clk_set_rate);
101 
clk_round_rate(struct clk * clk,unsigned long rate)102 long clk_round_rate(struct clk *clk, unsigned long rate)
103 {
104 	if (unlikely(!clk_good(clk)))
105 		return 0;
106 	if (clk->rates && *clk->rates) {
107 		unsigned long *r = clk->rates;
108 
109 		while (*r && (*r != rate))
110 			r++;
111 		if (!*r) {
112 			return clk->rate;
113 		}
114 	}
115 	return rate;
116 }
117 EXPORT_SYMBOL(clk_round_rate);
118 
clk_enable(struct clk * clk)119 int clk_enable(struct clk *clk)
120 {
121 	if (unlikely(!clk_good(clk)))
122 		return -1;
123 
124 	if (clk->enable)
125 		return clk->enable(clk);
126 
127 	return -1;
128 }
129 EXPORT_SYMBOL(clk_enable);
130 
clk_disable(struct clk * clk)131 void clk_disable(struct clk *clk)
132 {
133 	if (unlikely(!clk_good(clk)))
134 		return;
135 
136 	if (clk->disable)
137 		clk->disable(clk);
138 }
139 EXPORT_SYMBOL(clk_disable);
140 
clk_activate(struct clk * clk)141 int clk_activate(struct clk *clk)
142 {
143 	if (unlikely(!clk_good(clk)))
144 		return -1;
145 
146 	if (clk->activate)
147 		return clk->activate(clk);
148 
149 	return -1;
150 }
151 EXPORT_SYMBOL(clk_activate);
152 
clk_deactivate(struct clk * clk)153 void clk_deactivate(struct clk *clk)
154 {
155 	if (unlikely(!clk_good(clk)))
156 		return;
157 
158 	if (clk->deactivate)
159 		clk->deactivate(clk);
160 }
161 EXPORT_SYMBOL(clk_deactivate);
162 
of_clk_get_from_provider(struct of_phandle_args * clkspec)163 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
164 {
165 	return NULL;
166 }
167 
clk_set_parent(struct clk * clk,struct clk * parent)168 int clk_set_parent(struct clk *clk, struct clk *parent)
169 {
170 	return 0;
171 }
172 EXPORT_SYMBOL(clk_set_parent);
173 
get_counter_resolution(void)174 static inline u32 get_counter_resolution(void)
175 {
176 	u32 res;
177 
178 	__asm__ __volatile__(
179 		".set	push\n"
180 		".set	mips32r2\n"
181 		"rdhwr	%0, $3\n"
182 		".set pop\n"
183 		: "=&r" (res)
184 		: /* no input */
185 		: "memory");
186 
187 	return res;
188 }
189 
plat_time_init(void)190 void __init plat_time_init(void)
191 {
192 	struct clk *clk;
193 
194 	ltq_soc_init();
195 
196 	clk = clk_get_cpu();
197 	mips_hpt_frequency = clk_get_rate(clk) / get_counter_resolution();
198 	write_c0_compare(read_c0_count());
199 	pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
200 	clk_put(clk);
201 }
202