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Tony Lindgrenec6bced2005-07-10 19:58:20 +01001/*
Nishanth Menonffe4f0f2011-05-26 19:39:18 -07002 * CPU frequency scaling for OMAP using OPP information
Tony Lindgrenec6bced2005-07-10 19:58:20 +01003 *
4 * Copyright (C) 2005 Nokia Corporation
5 * Written by Tony Lindgren <tony@atomide.com>
6 *
7 * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
8 *
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -07009 * Copyright (C) 2007-2011 Texas Instruments, Inc.
10 * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
11 *
Tony Lindgrenec6bced2005-07-10 19:58:20 +010012 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/sched.h>
19#include <linux/cpufreq.h>
20#include <linux/delay.h>
21#include <linux/init.h>
22#include <linux/err.h>
Russell Kingf8ce2542006-01-07 16:15:52 +000023#include <linux/clk.h>
Russell Kingfced80c2008-09-06 12:10:45 +010024#include <linux/io.h>
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070025#include <linux/opp.h>
Russell King46c12212011-09-21 16:53:00 -070026#include <linux/cpu.h>
Kevin Hilmanc1b547b2011-09-30 10:41:26 -070027#include <linux/module.h>
Nishanth Menon49ded522013-04-09 23:22:01 +000028#include <linux/platform_device.h>
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070029#include <linux/regulator/consumer.h>
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070030
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070031#include <asm/smp_plat.h>
Russell King46c12212011-09-21 16:53:00 -070032#include <asm/cpu.h>
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070033
Afzal Mohammed42daffd2012-02-23 19:19:24 +053034/* OPP tolerance in percentage */
35#define OPP_TOLERANCE 4
36
Kevin Hilmanaeec2992009-01-27 19:13:38 -070037static struct cpufreq_frequency_table *freq_table;
Nishanth Menon1c782172011-05-26 19:39:20 -070038static atomic_t freq_table_users = ATOMIC_INIT(0);
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +030039static struct clk *mpu_clk;
Nishanth Menona820ffa2011-05-25 16:38:47 -070040static struct device *mpu_dev;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070041static struct regulator *mpu_reg;
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +030042
Manjunath Kondaiah Gb0a330d2010-10-08 10:00:19 -070043static int omap_verify_speed(struct cpufreq_policy *policy)
Tony Lindgrenec6bced2005-07-10 19:58:20 +010044{
Nishanth Menonbf2a3592011-05-26 19:39:17 -070045 if (!freq_table)
Tony Lindgrenec6bced2005-07-10 19:58:20 +010046 return -EINVAL;
Nishanth Menonbf2a3592011-05-26 19:39:17 -070047 return cpufreq_frequency_table_verify(policy, freq_table);
Tony Lindgrenec6bced2005-07-10 19:58:20 +010048}
49
Manjunath Kondaiah Gb0a330d2010-10-08 10:00:19 -070050static unsigned int omap_getspeed(unsigned int cpu)
Tony Lindgrenec6bced2005-07-10 19:58:20 +010051{
Tony Lindgrenec6bced2005-07-10 19:58:20 +010052 unsigned long rate;
53
Russell King46c12212011-09-21 16:53:00 -070054 if (cpu >= NR_CPUS)
Tony Lindgrenec6bced2005-07-10 19:58:20 +010055 return 0;
56
Tony Lindgrenec6bced2005-07-10 19:58:20 +010057 rate = clk_get_rate(mpu_clk) / 1000;
Tony Lindgrenec6bced2005-07-10 19:58:20 +010058 return rate;
59}
60
61static int omap_target(struct cpufreq_policy *policy,
62 unsigned int target_freq,
63 unsigned int relation)
64{
Nishanth Menonbf2a3592011-05-26 19:39:17 -070065 unsigned int i;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070066 int r, ret = 0;
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070067 struct cpufreq_freqs freqs;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070068 struct opp *opp;
Afzal Mohammed42daffd2012-02-23 19:19:24 +053069 unsigned long freq, volt = 0, volt_old = 0, tol = 0;
Tony Lindgrenec6bced2005-07-10 19:58:20 +010070
Nishanth Menonbf2a3592011-05-26 19:39:17 -070071 if (!freq_table) {
72 dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
73 policy->cpu);
74 return -EINVAL;
75 }
76
77 ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
78 relation, &i);
79 if (ret) {
80 dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
81 __func__, policy->cpu, target_freq, ret);
82 return ret;
83 }
84 freqs.new = freq_table[i].frequency;
85 if (!freqs.new) {
86 dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
87 policy->cpu, target_freq);
88 return -EINVAL;
89 }
Kevin Hilmanaeec2992009-01-27 19:13:38 -070090
Russell King46c12212011-09-21 16:53:00 -070091 freqs.old = omap_getspeed(policy->cpu);
Tony Lindgrenec6bced2005-07-10 19:58:20 +010092
Colin Cross022ac032011-06-06 21:05:29 -050093 if (freqs.old == freqs.new && policy->cur == freqs.new)
Kevin Hilmanaeec2992009-01-27 19:13:38 -070094 return ret;
95
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070096 freq = freqs.new * 1000;
Kevin Hilman8df0a662012-10-02 15:39:03 -070097 ret = clk_round_rate(mpu_clk, freq);
98 if (IS_ERR_VALUE(ret)) {
99 dev_warn(mpu_dev,
100 "CPUfreq: Cannot find matching frequency for %lu\n",
101 freq);
102 return ret;
103 }
104 freq = ret;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700105
106 if (mpu_reg) {
Nishanth Menonf44d1882013-01-18 19:52:32 +0000107 rcu_read_lock();
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700108 opp = opp_find_freq_ceil(mpu_dev, &freq);
109 if (IS_ERR(opp)) {
Nishanth Menonf44d1882013-01-18 19:52:32 +0000110 rcu_read_unlock();
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700111 dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
112 __func__, freqs.new);
113 return -EINVAL;
114 }
115 volt = opp_get_voltage(opp);
Nishanth Menonf44d1882013-01-18 19:52:32 +0000116 rcu_read_unlock();
Afzal Mohammed42daffd2012-02-23 19:19:24 +0530117 tol = volt * OPP_TOLERANCE / 100;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700118 volt_old = regulator_get_voltage(mpu_reg);
119 }
120
121 dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
122 freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
123 freqs.new / 1000, volt ? volt / 1000 : -1);
124
Viresh Kumar44a49a22013-06-19 11:18:20 +0530125 /* notifiers */
126 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
127
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700128 /* scaling up? scale voltage before frequency */
129 if (mpu_reg && (freqs.new > freqs.old)) {
Afzal Mohammed42daffd2012-02-23 19:19:24 +0530130 r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700131 if (r < 0) {
132 dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
133 __func__);
134 freqs.new = freqs.old;
135 goto done;
136 }
137 }
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700138
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700139 ret = clk_set_rate(mpu_clk, freqs.new * 1000);
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700140
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700141 /* scaling down? scale voltage after frequency */
142 if (mpu_reg && (freqs.new < freqs.old)) {
Afzal Mohammed42daffd2012-02-23 19:19:24 +0530143 r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700144 if (r < 0) {
145 dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
146 __func__);
147 ret = clk_set_rate(mpu_clk, freqs.old * 1000);
148 freqs.new = freqs.old;
149 goto done;
150 }
151 }
152
153 freqs.new = omap_getspeed(policy->cpu);
Russell King46c12212011-09-21 16:53:00 -0700154
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700155done:
Russell King46c12212011-09-21 16:53:00 -0700156 /* notifiers */
Viresh Kumarb43a7ff2013-03-24 11:56:43 +0530157 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100158
159 return ret;
160}
161
Nishanth Menon1c782172011-05-26 19:39:20 -0700162static inline void freq_table_free(void)
163{
164 if (atomic_dec_and_test(&freq_table_users))
165 opp_free_cpufreq_table(mpu_dev, &freq_table);
166}
167
Paul Gortmaker27609842013-06-19 13:54:04 -0400168static int omap_cpu_init(struct cpufreq_policy *policy)
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100169{
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700170 int result = 0;
171
Paul Walmsleye2ee1b42012-09-07 18:16:35 +0000172 mpu_clk = clk_get(NULL, "cpufreq_ck");
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100173 if (IS_ERR(mpu_clk))
174 return PTR_ERR(mpu_clk);
175
Nishanth Menon11e04fd2011-05-26 19:39:19 -0700176 if (policy->cpu >= NR_CPUS) {
177 result = -EINVAL;
178 goto fail_ck;
179 }
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700180
Viresh Kumareb2f50f2013-04-01 12:57:48 +0000181 policy->cur = omap_getspeed(policy->cpu);
Nishanth Menon1c782172011-05-26 19:39:20 -0700182
Rajendra Nayak1b865212012-08-09 12:38:21 +0530183 if (!freq_table)
Nishanth Menon1c782172011-05-26 19:39:20 -0700184 result = opp_init_cpufreq_table(mpu_dev, &freq_table);
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700185
Nishanth Menonbf2a3592011-05-26 19:39:17 -0700186 if (result) {
187 dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
188 __func__, policy->cpu, result);
Nishanth Menon11e04fd2011-05-26 19:39:19 -0700189 goto fail_ck;
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700190 }
191
Rajendra Nayak1b865212012-08-09 12:38:21 +0530192 atomic_inc_return(&freq_table_users);
193
Nishanth Menonbf2a3592011-05-26 19:39:17 -0700194 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
Nishanth Menon1c782172011-05-26 19:39:20 -0700195 if (result)
196 goto fail_table;
197
198 cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
Nishanth Menonbf2a3592011-05-26 19:39:17 -0700199
Russell King46c12212011-09-21 16:53:00 -0700200 policy->cur = omap_getspeed(policy->cpu);
201
202 /*
203 * On OMAP SMP configuartion, both processors share the voltage
204 * and clock. So both CPUs needs to be scaled together and hence
205 * needs software co-ordination. Use cpufreq affected_cpus
206 * interface to handle this scenario. Additional is_smp() check
207 * is to keep SMP_ON_UP build working.
208 */
Viresh Kumar62b36cc2013-02-01 06:40:02 +0000209 if (is_smp())
Todd Poynored8ce002011-06-07 13:57:52 -0700210 cpumask_setall(policy->cpus);
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700211
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700212 /* FIXME: what's the actual transition time? */
Mike Turquetteb0298392009-11-11 11:00:38 -0800213 policy->cpuinfo.transition_latency = 300 * 1000;
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100214
215 return 0;
Nishanth Menon11e04fd2011-05-26 19:39:19 -0700216
Nishanth Menon1c782172011-05-26 19:39:20 -0700217fail_table:
218 freq_table_free();
Nishanth Menon11e04fd2011-05-26 19:39:19 -0700219fail_ck:
220 clk_put(mpu_clk);
221 return result;
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100222}
223
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +0300224static int omap_cpu_exit(struct cpufreq_policy *policy)
225{
Nishanth Menon1c782172011-05-26 19:39:20 -0700226 freq_table_free();
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +0300227 clk_put(mpu_clk);
228 return 0;
229}
230
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700231static struct freq_attr *omap_cpufreq_attr[] = {
232 &cpufreq_freq_attr_scaling_available_freqs,
233 NULL,
234};
235
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100236static struct cpufreq_driver omap_driver = {
237 .flags = CPUFREQ_STICKY,
238 .verify = omap_verify_speed,
239 .target = omap_target,
240 .get = omap_getspeed,
241 .init = omap_cpu_init,
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +0300242 .exit = omap_cpu_exit,
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100243 .name = "omap",
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700244 .attr = omap_cpufreq_attr,
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100245};
246
Nishanth Menon49ded522013-04-09 23:22:01 +0000247static int omap_cpufreq_probe(struct platform_device *pdev)
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100248{
Kevin Hilman747a7f62012-09-06 14:22:44 -0700249 mpu_dev = get_cpu_device(0);
250 if (!mpu_dev) {
Nishanth Menona820ffa2011-05-25 16:38:47 -0700251 pr_warning("%s: unable to get the mpu device\n", __func__);
Kevin Hilman747a7f62012-09-06 14:22:44 -0700252 return -EINVAL;
Nishanth Menona820ffa2011-05-25 16:38:47 -0700253 }
254
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700255 mpu_reg = regulator_get(mpu_dev, "vcc");
256 if (IS_ERR(mpu_reg)) {
257 pr_warning("%s: unable to get MPU regulator\n", __func__);
258 mpu_reg = NULL;
259 } else {
260 /*
261 * Ensure physical regulator is present.
262 * (e.g. could be dummy regulator.)
263 */
264 if (regulator_get_voltage(mpu_reg) < 0) {
265 pr_warn("%s: physical regulator not present for MPU\n",
266 __func__);
267 regulator_put(mpu_reg);
268 mpu_reg = NULL;
269 }
270 }
271
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100272 return cpufreq_register_driver(&omap_driver);
273}
274
Nishanth Menon49ded522013-04-09 23:22:01 +0000275static int omap_cpufreq_remove(struct platform_device *pdev)
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700276{
Nishanth Menon49ded522013-04-09 23:22:01 +0000277 return cpufreq_unregister_driver(&omap_driver);
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700278}
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700279
Nishanth Menon49ded522013-04-09 23:22:01 +0000280static struct platform_driver omap_cpufreq_platdrv = {
281 .driver = {
282 .name = "omap-cpufreq",
283 .owner = THIS_MODULE,
284 },
285 .probe = omap_cpufreq_probe,
286 .remove = omap_cpufreq_remove,
287};
288module_platform_driver(omap_cpufreq_platdrv);
289
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700290MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
291MODULE_LICENSE("GPL");