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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 */
Joe Perches1c5864e2016-04-05 13:28:25 -070016
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
Tony Lindgrenec6bced2005-07-10 19:58:20 +010019#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/sched.h>
22#include <linux/cpufreq.h>
23#include <linux/delay.h>
24#include <linux/init.h>
25#include <linux/err.h>
Russell Kingf8ce2542006-01-07 16:15:52 +000026#include <linux/clk.h>
Russell Kingfced80c2008-09-06 12:10:45 +010027#include <linux/io.h>
Nishanth Menone4db1c72013-09-19 16:03:52 -050028#include <linux/pm_opp.h>
Russell King46c12212011-09-21 16:53:00 -070029#include <linux/cpu.h>
Kevin Hilmanc1b547b2011-09-30 10:41:26 -070030#include <linux/module.h>
Nishanth Menon49ded522013-04-09 23:22:01 +000031#include <linux/platform_device.h>
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070032#include <linux/regulator/consumer.h>
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070033
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070034#include <asm/smp_plat.h>
Russell King46c12212011-09-21 16:53:00 -070035#include <asm/cpu.h>
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070036
Afzal Mohammed42daffd2012-02-23 19:19:24 +053037/* OPP tolerance in percentage */
38#define OPP_TOLERANCE 4
39
Kevin Hilmanaeec2992009-01-27 19:13:38 -070040static struct cpufreq_frequency_table *freq_table;
Nishanth Menon1c782172011-05-26 19:39:20 -070041static atomic_t freq_table_users = ATOMIC_INIT(0);
Nishanth Menona820ffa2011-05-25 16:38:47 -070042static struct device *mpu_dev;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070043static struct regulator *mpu_reg;
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +030044
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +053045static int omap_target(struct cpufreq_policy *policy, unsigned int index)
Tony Lindgrenec6bced2005-07-10 19:58:20 +010046{
viresh kumar696d0b2c2013-11-13 15:39:23 +053047 int r, ret;
Nishanth Menon47d43ba2013-09-19 16:03:51 -050048 struct dev_pm_opp *opp;
Afzal Mohammed42daffd2012-02-23 19:19:24 +053049 unsigned long freq, volt = 0, volt_old = 0, tol = 0;
Viresh Kumard4019f02013-08-14 19:38:24 +053050 unsigned int old_freq, new_freq;
Tony Lindgrenec6bced2005-07-10 19:58:20 +010051
Viresh Kumar652ed952014-01-09 20:38:43 +053052 old_freq = policy->cur;
Viresh Kumard4019f02013-08-14 19:38:24 +053053 new_freq = freq_table[index].frequency;
Kevin Hilmanaeec2992009-01-27 19:13:38 -070054
Viresh Kumard4019f02013-08-14 19:38:24 +053055 freq = new_freq * 1000;
Viresh Kumar652ed952014-01-09 20:38:43 +053056 ret = clk_round_rate(policy->clk, freq);
Arnd Bergmann287980e2016-05-27 23:23:25 +020057 if (ret < 0) {
Kevin Hilman8df0a662012-10-02 15:39:03 -070058 dev_warn(mpu_dev,
59 "CPUfreq: Cannot find matching frequency for %lu\n",
60 freq);
61 return ret;
62 }
63 freq = ret;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070064
65 if (mpu_reg) {
Nishanth Menonf44d1882013-01-18 19:52:32 +000066 rcu_read_lock();
Nishanth Menon5d4879c2013-09-19 16:03:50 -050067 opp = dev_pm_opp_find_freq_ceil(mpu_dev, &freq);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070068 if (IS_ERR(opp)) {
Nishanth Menonf44d1882013-01-18 19:52:32 +000069 rcu_read_unlock();
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070070 dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
Viresh Kumard4019f02013-08-14 19:38:24 +053071 __func__, new_freq);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070072 return -EINVAL;
73 }
Nishanth Menon5d4879c2013-09-19 16:03:50 -050074 volt = dev_pm_opp_get_voltage(opp);
Nishanth Menonf44d1882013-01-18 19:52:32 +000075 rcu_read_unlock();
Afzal Mohammed42daffd2012-02-23 19:19:24 +053076 tol = volt * OPP_TOLERANCE / 100;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070077 volt_old = regulator_get_voltage(mpu_reg);
78 }
79
80 dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
Viresh Kumard4019f02013-08-14 19:38:24 +053081 old_freq / 1000, volt_old ? volt_old / 1000 : -1,
82 new_freq / 1000, volt ? volt / 1000 : -1);
Viresh Kumar44a49a22013-06-19 11:18:20 +053083
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070084 /* scaling up? scale voltage before frequency */
Viresh Kumard4019f02013-08-14 19:38:24 +053085 if (mpu_reg && (new_freq > old_freq)) {
Afzal Mohammed42daffd2012-02-23 19:19:24 +053086 r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070087 if (r < 0) {
88 dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
89 __func__);
Viresh Kumard4019f02013-08-14 19:38:24 +053090 return r;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070091 }
92 }
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070093
Viresh Kumar652ed952014-01-09 20:38:43 +053094 ret = clk_set_rate(policy->clk, new_freq * 1000);
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -070095
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070096 /* scaling down? scale voltage after frequency */
Viresh Kumard4019f02013-08-14 19:38:24 +053097 if (mpu_reg && (new_freq < old_freq)) {
Afzal Mohammed42daffd2012-02-23 19:19:24 +053098 r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -070099 if (r < 0) {
100 dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
101 __func__);
Viresh Kumar652ed952014-01-09 20:38:43 +0530102 clk_set_rate(policy->clk, old_freq * 1000);
Viresh Kumard4019f02013-08-14 19:38:24 +0530103 return r;
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700104 }
105 }
106
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100107 return ret;
108}
109
Nishanth Menon1c782172011-05-26 19:39:20 -0700110static inline void freq_table_free(void)
111{
112 if (atomic_dec_and_test(&freq_table_users))
Nishanth Menon5d4879c2013-09-19 16:03:50 -0500113 dev_pm_opp_free_cpufreq_table(mpu_dev, &freq_table);
Nishanth Menon1c782172011-05-26 19:39:20 -0700114}
115
Paul Gortmaker27609842013-06-19 13:54:04 -0400116static int omap_cpu_init(struct cpufreq_policy *policy)
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100117{
Viresh Kumar982bce12013-10-03 20:29:18 +0530118 int result;
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700119
Viresh Kumar652ed952014-01-09 20:38:43 +0530120 policy->clk = clk_get(NULL, "cpufreq_ck");
121 if (IS_ERR(policy->clk))
122 return PTR_ERR(policy->clk);
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100123
Viresh Kumar982bce12013-10-03 20:29:18 +0530124 if (!freq_table) {
Nishanth Menon5d4879c2013-09-19 16:03:50 -0500125 result = dev_pm_opp_init_cpufreq_table(mpu_dev, &freq_table);
Viresh Kumar982bce12013-10-03 20:29:18 +0530126 if (result) {
127 dev_err(mpu_dev,
128 "%s: cpu%d: failed creating freq table[%d]\n",
Nishanth Menonbf2a3592011-05-26 19:39:17 -0700129 __func__, policy->cpu, result);
Viresh Kumar982bce12013-10-03 20:29:18 +0530130 goto fail;
131 }
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700132 }
133
Rajendra Nayak1b865212012-08-09 12:38:21 +0530134 atomic_inc_return(&freq_table_users);
135
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700136 /* FIXME: what's the actual transition time? */
Viresh Kumar982bce12013-10-03 20:29:18 +0530137 result = cpufreq_generic_init(policy, freq_table, 300 * 1000);
138 if (!result)
139 return 0;
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100140
Nishanth Menon1c782172011-05-26 19:39:20 -0700141 freq_table_free();
Viresh Kumar982bce12013-10-03 20:29:18 +0530142fail:
Viresh Kumar652ed952014-01-09 20:38:43 +0530143 clk_put(policy->clk);
Nishanth Menon11e04fd2011-05-26 19:39:19 -0700144 return result;
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100145}
146
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +0300147static int omap_cpu_exit(struct cpufreq_policy *policy)
148{
Nishanth Menon1c782172011-05-26 19:39:20 -0700149 freq_table_free();
Viresh Kumar652ed952014-01-09 20:38:43 +0530150 clk_put(policy->clk);
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +0300151 return 0;
152}
153
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100154static struct cpufreq_driver omap_driver = {
Viresh Kumarae6b4272013-12-03 11:20:45 +0530155 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
Viresh Kumard5ca1642013-10-03 20:28:13 +0530156 .verify = cpufreq_generic_frequency_table_verify,
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530157 .target_index = omap_target,
Viresh Kumar652ed952014-01-09 20:38:43 +0530158 .get = cpufreq_generic_get,
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100159 .init = omap_cpu_init,
Hiroshi DOYUb8488fb2007-08-30 12:46:39 +0300160 .exit = omap_cpu_exit,
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100161 .name = "omap",
Viresh Kumard5ca1642013-10-03 20:28:13 +0530162 .attr = cpufreq_generic_attr,
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100163};
164
Nishanth Menon49ded522013-04-09 23:22:01 +0000165static int omap_cpufreq_probe(struct platform_device *pdev)
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100166{
Kevin Hilman747a7f62012-09-06 14:22:44 -0700167 mpu_dev = get_cpu_device(0);
168 if (!mpu_dev) {
Joe Perches1c5864e2016-04-05 13:28:25 -0700169 pr_warn("%s: unable to get the MPU device\n", __func__);
Kevin Hilman747a7f62012-09-06 14:22:44 -0700170 return -EINVAL;
Nishanth Menona820ffa2011-05-25 16:38:47 -0700171 }
172
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700173 mpu_reg = regulator_get(mpu_dev, "vcc");
174 if (IS_ERR(mpu_reg)) {
Joe Perchesb49c22a2016-04-05 13:28:24 -0700175 pr_warn("%s: unable to get MPU regulator\n", __func__);
Kevin Hilman53dfe8a2011-07-15 15:05:04 -0700176 mpu_reg = NULL;
177 } else {
178 /*
179 * Ensure physical regulator is present.
180 * (e.g. could be dummy regulator.)
181 */
182 if (regulator_get_voltage(mpu_reg) < 0) {
183 pr_warn("%s: physical regulator not present for MPU\n",
184 __func__);
185 regulator_put(mpu_reg);
186 mpu_reg = NULL;
187 }
188 }
189
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100190 return cpufreq_register_driver(&omap_driver);
191}
192
Nishanth Menon49ded522013-04-09 23:22:01 +0000193static int omap_cpufreq_remove(struct platform_device *pdev)
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700194{
Nishanth Menon49ded522013-04-09 23:22:01 +0000195 return cpufreq_unregister_driver(&omap_driver);
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700196}
Kevin Hilmanaeec2992009-01-27 19:13:38 -0700197
Nishanth Menon49ded522013-04-09 23:22:01 +0000198static struct platform_driver omap_cpufreq_platdrv = {
199 .driver = {
200 .name = "omap-cpufreq",
Nishanth Menon49ded522013-04-09 23:22:01 +0000201 },
202 .probe = omap_cpufreq_probe,
203 .remove = omap_cpufreq_remove,
204};
205module_platform_driver(omap_cpufreq_platdrv);
206
Santosh Shilimkar731e0cc2010-08-11 17:02:43 -0700207MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
208MODULE_LICENSE("GPL");