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1 /* arch/arm/mach-msm/clock.c
2  *
3  * Copyright (C) 2007 Google, Inc.
4  * Copyright (c) 2007 QUALCOMM Incorporated
5  *
6  * This software is licensed under the terms of the GNU General Public
7  * License version 2, as published by the Free Software Foundation, and
8  * may be copied, distributed, and modified under those terms.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
13  * GNU General Public License for more details.
14  *
15  */
16 
17 #include <linux/version.h>
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/list.h>
22 #include <linux/err.h>
23 #include <linux/clk.h>
24 #include <linux/spinlock.h>
25 
26 #include "clock.h"
27 #include "proc_comm.h"
28 
29 static DEFINE_MUTEX(clocks_mutex);
30 static DEFINE_SPINLOCK(clocks_lock);
31 static LIST_HEAD(clocks);
32 
33 /*
34  * glue for the proc_comm interface
35  */
pc_clk_enable(unsigned id)36 static inline int pc_clk_enable(unsigned id)
37 {
38 	return msm_proc_comm(PCOM_CLKCTL_RPC_ENABLE, &id, NULL);
39 }
40 
pc_clk_disable(unsigned id)41 static inline void pc_clk_disable(unsigned id)
42 {
43 	msm_proc_comm(PCOM_CLKCTL_RPC_DISABLE, &id, NULL);
44 }
45 
pc_clk_set_rate(unsigned id,unsigned rate)46 static inline int pc_clk_set_rate(unsigned id, unsigned rate)
47 {
48 	return msm_proc_comm(PCOM_CLKCTL_RPC_SET_RATE, &id, &rate);
49 }
50 
pc_clk_set_min_rate(unsigned id,unsigned rate)51 static inline int pc_clk_set_min_rate(unsigned id, unsigned rate)
52 {
53 	return msm_proc_comm(PCOM_CLKCTL_RPC_MIN_RATE, &id, &rate);
54 }
55 
pc_clk_set_max_rate(unsigned id,unsigned rate)56 static inline int pc_clk_set_max_rate(unsigned id, unsigned rate)
57 {
58 	return msm_proc_comm(PCOM_CLKCTL_RPC_MAX_RATE, &id, &rate);
59 }
60 
pc_clk_set_flags(unsigned id,unsigned flags)61 static inline int pc_clk_set_flags(unsigned id, unsigned flags)
62 {
63 	return msm_proc_comm(PCOM_CLKCTL_RPC_SET_FLAGS, &id, &flags);
64 }
65 
pc_clk_get_rate(unsigned id)66 static inline unsigned pc_clk_get_rate(unsigned id)
67 {
68 	if (msm_proc_comm(PCOM_CLKCTL_RPC_RATE, &id, NULL))
69 		return 0;
70 	else
71 		return id;
72 }
73 
pc_clk_is_enabled(unsigned id)74 static inline unsigned pc_clk_is_enabled(unsigned id)
75 {
76 	if (msm_proc_comm(PCOM_CLKCTL_RPC_ENABLED, &id, NULL))
77 		return 0;
78 	else
79 		return id;
80 }
81 
pc_pll_request(unsigned id,unsigned on)82 static inline int pc_pll_request(unsigned id, unsigned on)
83 {
84 	on = !!on;
85 	return msm_proc_comm(PCOM_CLKCTL_RPC_PLL_REQUEST, &id, &on);
86 }
87 
88 /*
89  * Standard clock functions defined in include/linux/clk.h
90  */
clk_get(struct device * dev,const char * id)91 struct clk *clk_get(struct device *dev, const char *id)
92 {
93 	struct clk *clk;
94 
95 	mutex_lock(&clocks_mutex);
96 
97 	list_for_each_entry(clk, &clocks, list)
98 		if (!strcmp(id, clk->name) && clk->dev == dev)
99 			goto found_it;
100 
101 	list_for_each_entry(clk, &clocks, list)
102 		if (!strcmp(id, clk->name) && clk->dev == NULL)
103 			goto found_it;
104 
105 	clk = ERR_PTR(-ENOENT);
106 found_it:
107 	mutex_unlock(&clocks_mutex);
108 	return clk;
109 }
110 EXPORT_SYMBOL(clk_get);
111 
clk_put(struct clk * clk)112 void clk_put(struct clk *clk)
113 {
114 }
115 EXPORT_SYMBOL(clk_put);
116 
clk_enable(struct clk * clk)117 int clk_enable(struct clk *clk)
118 {
119 	unsigned long flags;
120 	spin_lock_irqsave(&clocks_lock, flags);
121 	clk->count++;
122 	if (clk->count == 1)
123 		pc_clk_enable(clk->id);
124 	spin_unlock_irqrestore(&clocks_lock, flags);
125 	return 0;
126 }
127 EXPORT_SYMBOL(clk_enable);
128 
clk_disable(struct clk * clk)129 void clk_disable(struct clk *clk)
130 {
131 	unsigned long flags;
132 	spin_lock_irqsave(&clocks_lock, flags);
133 	BUG_ON(clk->count == 0);
134 	clk->count--;
135 	if (clk->count == 0)
136 		pc_clk_disable(clk->id);
137 	spin_unlock_irqrestore(&clocks_lock, flags);
138 }
139 EXPORT_SYMBOL(clk_disable);
140 
clk_get_rate(struct clk * clk)141 unsigned long clk_get_rate(struct clk *clk)
142 {
143 	return pc_clk_get_rate(clk->id);
144 }
145 EXPORT_SYMBOL(clk_get_rate);
146 
clk_set_rate(struct clk * clk,unsigned long rate)147 int clk_set_rate(struct clk *clk, unsigned long rate)
148 {
149 	int ret;
150 	if (clk->flags & CLKFLAG_USE_MIN_MAX_TO_SET) {
151 		ret = pc_clk_set_max_rate(clk->id, rate);
152 		if (ret)
153 			return ret;
154 		return pc_clk_set_min_rate(clk->id, rate);
155 	}
156 	return pc_clk_set_rate(clk->id, rate);
157 }
158 EXPORT_SYMBOL(clk_set_rate);
159 
clk_set_parent(struct clk * clk,struct clk * parent)160 int clk_set_parent(struct clk *clk, struct clk *parent)
161 {
162 	return -ENOSYS;
163 }
164 EXPORT_SYMBOL(clk_set_parent);
165 
clk_get_parent(struct clk * clk)166 struct clk *clk_get_parent(struct clk *clk)
167 {
168 	return ERR_PTR(-ENOSYS);
169 }
170 EXPORT_SYMBOL(clk_get_parent);
171 
clk_set_flags(struct clk * clk,unsigned long flags)172 int clk_set_flags(struct clk *clk, unsigned long flags)
173 {
174 	if (clk == NULL || IS_ERR(clk))
175 		return -EINVAL;
176 	return pc_clk_set_flags(clk->id, flags);
177 }
178 EXPORT_SYMBOL(clk_set_flags);
179 
180 
msm_clock_init(void)181 void __init msm_clock_init(void)
182 {
183 	unsigned n;
184 
185 	spin_lock_init(&clocks_lock);
186 	mutex_lock(&clocks_mutex);
187 	for (n = 0; n < msm_num_clocks; n++)
188 		list_add_tail(&msm_clocks[n].list, &clocks);
189 	mutex_unlock(&clocks_mutex);
190 }
191 
192 /* The bootloader and/or AMSS may have left various clocks enabled.
193  * Disable any clocks that belong to us (CLKFLAG_AUTO_OFF) but have
194  * not been explicitly enabled by a clk_enable() call.
195  */
clock_late_init(void)196 static int __init clock_late_init(void)
197 {
198 	unsigned long flags;
199 	struct clk *clk;
200 	unsigned count = 0;
201 
202 	mutex_lock(&clocks_mutex);
203 	list_for_each_entry(clk, &clocks, list) {
204 		if (clk->flags & CLKFLAG_AUTO_OFF) {
205 			spin_lock_irqsave(&clocks_lock, flags);
206 			if (!clk->count) {
207 				count++;
208 				pc_clk_disable(clk->id);
209 			}
210 			spin_unlock_irqrestore(&clocks_lock, flags);
211 		}
212 	}
213 	mutex_unlock(&clocks_mutex);
214 	pr_info("clock_late_init() disabled %d unused clocks\n", count);
215 	return 0;
216 }
217 
218 late_initcall(clock_late_init);
219