~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/arm/mach-davinci/cpufreq.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 #include <linux/export.h>
 28 
 29 #include <mach/hardware.h>
 30 #include <mach/cpufreq.h>
 31 #include <mach/common.h>
 32 
 33 #include "clock.h"
 34 
 35 struct davinci_cpufreq {
 36         struct device *dev;
 37         struct clk *armclk;
 38         struct clk *asyncclk;
 39         unsigned long asyncrate;
 40 };
 41 static struct davinci_cpufreq cpufreq;
 42 
 43 static int davinci_verify_speed(struct cpufreq_policy *policy)
 44 {
 45         struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
 46         struct cpufreq_frequency_table *freq_table = pdata->freq_table;
 47         struct clk *armclk = cpufreq.armclk;
 48 
 49         if (freq_table)
 50                 return cpufreq_frequency_table_verify(policy, freq_table);
 51 
 52         if (policy->cpu)
 53                 return -EINVAL;
 54 
 55         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 56                                      policy->cpuinfo.max_freq);
 57 
 58         policy->min = clk_round_rate(armclk, policy->min * 1000) / 1000;
 59         policy->max = clk_round_rate(armclk, policy->max * 1000) / 1000;
 60         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 61                                                 policy->cpuinfo.max_freq);
 62         return 0;
 63 }
 64 
 65 static unsigned int davinci_getspeed(unsigned int cpu)
 66 {
 67         if (cpu)
 68                 return 0;
 69 
 70         return clk_get_rate(cpufreq.armclk) / 1000;
 71 }
 72 
 73 static int davinci_target(struct cpufreq_policy *policy,
 74                                 unsigned int target_freq, unsigned int relation)
 75 {
 76         int ret = 0;
 77         unsigned int idx;
 78         struct cpufreq_freqs freqs;
 79         struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
 80         struct clk *armclk = cpufreq.armclk;
 81 
 82         /*
 83          * Ensure desired rate is within allowed range.  Some govenors
 84          * (ondemand) will just pass target_freq=0 to get the minimum.
 85          */
 86         if (target_freq < policy->cpuinfo.min_freq)
 87                 target_freq = policy->cpuinfo.min_freq;
 88         if (target_freq > policy->cpuinfo.max_freq)
 89                 target_freq = policy->cpuinfo.max_freq;
 90 
 91         freqs.old = davinci_getspeed(0);
 92         freqs.new = clk_round_rate(armclk, target_freq * 1000) / 1000;
 93         freqs.cpu = 0;
 94 
 95         if (freqs.old == freqs.new)
 96                 return ret;
 97 
 98         dev_dbg(cpufreq.dev, "transition: %u --> %u\n", freqs.old, freqs.new);
 99 
100         ret = cpufreq_frequency_table_target(policy, pdata->freq_table,
101                                                 freqs.new, relation, &idx);
102         if (ret)
103                 return -EINVAL;
104 
105         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
106 
107         /* if moving to higher frequency, up the voltage beforehand */
108         if (pdata->set_voltage && freqs.new > freqs.old) {
109                 ret = pdata->set_voltage(idx);
110                 if (ret)
111                         goto out;
112         }
113 
114         ret = clk_set_rate(armclk, idx);
115         if (ret)
116                 goto out;
117 
118         if (cpufreq.asyncclk) {
119                 ret = clk_set_rate(cpufreq.asyncclk, cpufreq.asyncrate);
120                 if (ret)
121                         goto out;
122         }
123 
124         /* if moving to lower freq, lower the voltage after lowering freq */
125         if (pdata->set_voltage && freqs.new < freqs.old)
126                 pdata->set_voltage(idx);
127 
128 out:
129         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
130 
131         return ret;
132 }
133 
134 static int davinci_cpu_init(struct cpufreq_policy *policy)
135 {
136         int result = 0;
137         struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
138         struct cpufreq_frequency_table *freq_table = pdata->freq_table;
139 
140         if (policy->cpu != 0)
141                 return -EINVAL;
142 
143         /* Finish platform specific initialization */
144         if (pdata->init) {
145                 result = pdata->init();
146                 if (result)
147                         return result;
148         }
149 
150         policy->cur = policy->min = policy->max = davinci_getspeed(0);
151 
152         if (freq_table) {
153                 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
154                 if (!result)
155                         cpufreq_frequency_table_get_attr(freq_table,
156                                                         policy->cpu);
157         } else {
158                 policy->cpuinfo.min_freq = policy->min;
159                 policy->cpuinfo.max_freq = policy->max;
160         }
161 
162         policy->min = policy->cpuinfo.min_freq;
163         policy->max = policy->cpuinfo.max_freq;
164         policy->cur = davinci_getspeed(0);
165 
166         /*
167          * Time measurement across the target() function yields ~1500-1800us
168          * time taken with no drivers on notification list.
169          * Setting the latency to 2000 us to accommodate addition of drivers
170          * to pre/post change notification list.
171          */
172         policy->cpuinfo.transition_latency = 2000 * 1000;
173         return 0;
174 }
175 
176 static int davinci_cpu_exit(struct cpufreq_policy *policy)
177 {
178         cpufreq_frequency_table_put_attr(policy->cpu);
179         return 0;
180 }
181 
182 static struct freq_attr *davinci_cpufreq_attr[] = {
183         &cpufreq_freq_attr_scaling_available_freqs,
184         NULL,
185 };
186 
187 static struct cpufreq_driver davinci_driver = {
188         .flags          = CPUFREQ_STICKY,
189         .verify         = davinci_verify_speed,
190         .target         = davinci_target,
191         .get            = davinci_getspeed,
192         .init           = davinci_cpu_init,
193         .exit           = davinci_cpu_exit,
194         .name           = "davinci",
195         .attr           = davinci_cpufreq_attr,
196 };
197 
198 static int __init davinci_cpufreq_probe(struct platform_device *pdev)
199 {
200         struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
201         struct clk *asyncclk;
202 
203         if (!pdata)
204                 return -EINVAL;
205         if (!pdata->freq_table)
206                 return -EINVAL;
207 
208         cpufreq.dev = &pdev->dev;
209 
210         cpufreq.armclk = clk_get(NULL, "arm");
211         if (IS_ERR(cpufreq.armclk)) {
212                 dev_err(cpufreq.dev, "Unable to get ARM clock\n");
213                 return PTR_ERR(cpufreq.armclk);
214         }
215 
216         asyncclk = clk_get(cpufreq.dev, "async");
217         if (!IS_ERR(asyncclk)) {
218                 cpufreq.asyncclk = asyncclk;
219                 cpufreq.asyncrate = clk_get_rate(asyncclk);
220         }
221 
222         return cpufreq_register_driver(&davinci_driver);
223 }
224 
225 static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
226 {
227         clk_put(cpufreq.armclk);
228 
229         if (cpufreq.asyncclk)
230                 clk_put(cpufreq.asyncclk);
231 
232         return cpufreq_unregister_driver(&davinci_driver);
233 }
234 
235 static struct platform_driver davinci_cpufreq_driver = {
236         .driver = {
237                 .name    = "cpufreq-davinci",
238                 .owner   = THIS_MODULE,
239         },
240         .remove = __exit_p(davinci_cpufreq_remove),
241 };
242 
243 int __init davinci_cpufreq_init(void)
244 {
245         return platform_driver_probe(&davinci_cpufreq_driver,
246                                                         davinci_cpufreq_probe);
247 }
248 
249 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp