kmemleak: Initialise kmemleak after debug_objects_mem_init()
[linux-2.6.git] / arch / arm / mach-davinci / cpufreq.c
1 /*
2  * CPU frequency scaling for DaVinci
3  *
4  * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
5  *
6  * Based on linux/arch/arm/plat-omap/cpu-omap.c. Original Copyright follows:
7  *
8  *  Copyright (C) 2005 Nokia Corporation
9  *  Written by Tony Lindgren <tony@atomide.com>
10  *
11  *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
12  *
13  * Copyright (C) 2007-2008 Texas Instruments, Inc.
14  * Updated to support OMAP3
15  * Rajendra Nayak <rnayak@ti.com>
16  *
17  * This program is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License version 2 as
19  * published by the Free Software Foundation.
20  */
21 #include <linux/types.h>
22 #include <linux/cpufreq.h>
23 #include <linux/init.h>
24 #include <linux/err.h>
25 #include <linux/clk.h>
26 #include <linux/platform_device.h>
27
28 #include <mach/hardware.h>
29 #include <mach/cpufreq.h>
30 #include <mach/common.h>
31
32 #include "clock.h"
33
34 struct davinci_cpufreq {
35         struct device *dev;
36         struct clk *armclk;
37         struct clk *asyncclk;
38         unsigned long asyncrate;
39 };
40 static struct davinci_cpufreq cpufreq;
41
42 static int davinci_verify_speed(struct cpufreq_policy *policy)
43 {
44         struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
45         struct cpufreq_frequency_table *freq_table = pdata->freq_table;
46         struct clk *armclk = cpufreq.armclk;
47
48         if (freq_table)
49                 return cpufreq_frequency_table_verify(policy, freq_table);
50
51         if (policy->cpu)
52                 return -EINVAL;
53
54         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
55                                      policy->cpuinfo.max_freq);
56
57         policy->min = clk_round_rate(armclk, policy->min * 1000) / 1000;
58         policy->max = clk_round_rate(armclk, policy->max * 1000) / 1000;
59         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
60                                                 policy->cpuinfo.max_freq);
61         return 0;
62 }
63
64 static unsigned int davinci_getspeed(unsigned int cpu)
65 {
66         if (cpu)
67                 return 0;
68
69         return clk_get_rate(cpufreq.armclk) / 1000;
70 }
71
72 static int davinci_target(struct cpufreq_policy *policy,
73                                 unsigned int target_freq, unsigned int relation)
74 {
75         int ret = 0;
76         unsigned int idx;
77         struct cpufreq_freqs freqs;
78         struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
79         struct clk *armclk = cpufreq.armclk;
80
81         /*
82          * Ensure desired rate is within allowed range.  Some govenors
83          * (ondemand) will just pass target_freq=0 to get the minimum.
84          */
85         if (target_freq < policy->cpuinfo.min_freq)
86                 target_freq = policy->cpuinfo.min_freq;
87         if (target_freq > policy->cpuinfo.max_freq)
88                 target_freq = policy->cpuinfo.max_freq;
89
90         freqs.old = davinci_getspeed(0);
91         freqs.new = clk_round_rate(armclk, target_freq * 1000) / 1000;
92         freqs.cpu = 0;
93
94         if (freqs.old == freqs.new)
95                 return ret;
96
97         cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,
98                         dev_driver_string(cpufreq.dev),
99                         "transition: %u --> %u\n", freqs.old, freqs.new);
100
101         ret = cpufreq_frequency_table_target(policy, pdata->freq_table,
102                                                 freqs.new, relation, &idx);
103         if (ret)
104                 return -EINVAL;
105
106         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
107
108         /* if moving to higher frequency, up the voltage beforehand */
109         if (pdata->set_voltage && freqs.new > freqs.old) {
110                 ret = pdata->set_voltage(idx);
111                 if (ret)
112                         goto out;
113         }
114
115         ret = clk_set_rate(armclk, idx);
116         if (ret)
117                 goto out;
118
119         if (cpufreq.asyncclk) {
120                 ret = clk_set_rate(cpufreq.asyncclk, cpufreq.asyncrate);
121                 if (ret)
122                         goto out;
123         }
124
125         /* if moving to lower freq, lower the voltage after lowering freq */
126         if (pdata->set_voltage && freqs.new < freqs.old)
127                 pdata->set_voltage(idx);
128
129 out:
130         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
131
132         return ret;
133 }
134
135 static int davinci_cpu_init(struct cpufreq_policy *policy)
136 {
137         int result = 0;
138         struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
139         struct cpufreq_frequency_table *freq_table = pdata->freq_table;
140
141         if (policy->cpu != 0)
142                 return -EINVAL;
143
144         /* Finish platform specific initialization */
145         if (pdata->init) {
146                 result = pdata->init();
147                 if (result)
148                         return result;
149         }
150
151         policy->cur = policy->min = policy->max = davinci_getspeed(0);
152
153         if (freq_table) {
154                 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
155                 if (!result)
156                         cpufreq_frequency_table_get_attr(freq_table,
157                                                         policy->cpu);
158         } else {
159                 policy->cpuinfo.min_freq = policy->min;
160                 policy->cpuinfo.max_freq = policy->max;
161         }
162
163         policy->min = policy->cpuinfo.min_freq;
164         policy->max = policy->cpuinfo.max_freq;
165         policy->cur = davinci_getspeed(0);
166
167         /*
168          * Time measurement across the target() function yields ~1500-1800us
169          * time taken with no drivers on notification list.
170          * Setting the latency to 2000 us to accommodate addition of drivers
171          * to pre/post change notification list.
172          */
173         policy->cpuinfo.transition_latency = 2000 * 1000;
174         return 0;
175 }
176
177 static int davinci_cpu_exit(struct cpufreq_policy *policy)
178 {
179         cpufreq_frequency_table_put_attr(policy->cpu);
180         return 0;
181 }
182
183 static struct freq_attr *davinci_cpufreq_attr[] = {
184         &cpufreq_freq_attr_scaling_available_freqs,
185         NULL,
186 };
187
188 static struct cpufreq_driver davinci_driver = {
189         .flags          = CPUFREQ_STICKY,
190         .verify         = davinci_verify_speed,
191         .target         = davinci_target,
192         .get            = davinci_getspeed,
193         .init           = davinci_cpu_init,
194         .exit           = davinci_cpu_exit,
195         .name           = "davinci",
196         .attr           = davinci_cpufreq_attr,
197 };
198
199 static int __init davinci_cpufreq_probe(struct platform_device *pdev)
200 {
201         struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
202         struct clk *asyncclk;
203
204         if (!pdata)
205                 return -EINVAL;
206         if (!pdata->freq_table)
207                 return -EINVAL;
208
209         cpufreq.dev = &pdev->dev;
210
211         cpufreq.armclk = clk_get(NULL, "arm");
212         if (IS_ERR(cpufreq.armclk)) {
213                 dev_err(cpufreq.dev, "Unable to get ARM clock\n");
214                 return PTR_ERR(cpufreq.armclk);
215         }
216
217         asyncclk = clk_get(cpufreq.dev, "async");
218         if (!IS_ERR(asyncclk)) {
219                 cpufreq.asyncclk = asyncclk;
220                 cpufreq.asyncrate = clk_get_rate(asyncclk);
221         }
222
223         return cpufreq_register_driver(&davinci_driver);
224 }
225
226 static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
227 {
228         clk_put(cpufreq.armclk);
229
230         if (cpufreq.asyncclk)
231                 clk_put(cpufreq.asyncclk);
232
233         return cpufreq_unregister_driver(&davinci_driver);
234 }
235
236 static struct platform_driver davinci_cpufreq_driver = {
237         .driver = {
238                 .name    = "cpufreq-davinci",
239                 .owner   = THIS_MODULE,
240         },
241         .remove = __exit_p(davinci_cpufreq_remove),
242 };
243
244 static int __init davinci_cpufreq_init(void)
245 {
246         return platform_driver_probe(&davinci_cpufreq_driver,
247                                                         davinci_cpufreq_probe);
248 }
249 late_initcall(davinci_cpufreq_init);
250