1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  CPU frequency scaling for OMAP using OPP information
  4 *
  5 *  Copyright (C) 2005 Nokia Corporation
  6 *  Written by Tony Lindgren <tony@atomide.com>
  7 *
  8 *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
  9 *
 10 * Copyright (C) 2007-2011 Texas Instruments, Inc.
 11 * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
 
 
 
 
 12 */
 13
 14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 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>
 23#include <linux/clk.h>
 24#include <linux/io.h>
 25#include <linux/pm_opp.h>
 26#include <linux/cpu.h>
 27#include <linux/module.h>
 28#include <linux/platform_device.h>
 29#include <linux/regulator/consumer.h>
 30
 31#include <asm/smp_plat.h>
 32#include <asm/cpu.h>
 33
 34/* OPP tolerance in percentage */
 35#define	OPP_TOLERANCE	4
 36
 37static struct cpufreq_frequency_table *freq_table;
 38static atomic_t freq_table_users = ATOMIC_INIT(0);
 39static struct device *mpu_dev;
 40static struct regulator *mpu_reg;
 41
 42static int omap_target(struct cpufreq_policy *policy, unsigned int index)
 43{
 44	int r, ret;
 45	struct dev_pm_opp *opp;
 46	unsigned long freq, volt = 0, volt_old = 0, tol = 0;
 47	unsigned int old_freq, new_freq;
 48
 49	old_freq = policy->cur;
 50	new_freq = freq_table[index].frequency;
 51
 52	freq = new_freq * 1000;
 53	ret = clk_round_rate(policy->clk, freq);
 54	if (ret < 0) {
 55		dev_warn(mpu_dev,
 56			 "CPUfreq: Cannot find matching frequency for %lu\n",
 57			 freq);
 58		return ret;
 59	}
 60	freq = ret;
 61
 62	if (mpu_reg) {
 
 63		opp = dev_pm_opp_find_freq_ceil(mpu_dev, &freq);
 64		if (IS_ERR(opp)) {
 
 65			dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
 66				__func__, new_freq);
 67			return -EINVAL;
 68		}
 69		volt = dev_pm_opp_get_voltage(opp);
 70		dev_pm_opp_put(opp);
 71		tol = volt * OPP_TOLERANCE / 100;
 72		volt_old = regulator_get_voltage(mpu_reg);
 73	}
 74
 75	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n", 
 76		old_freq / 1000, volt_old ? volt_old / 1000 : -1,
 77		new_freq / 1000, volt ? volt / 1000 : -1);
 78
 79	/* scaling up?  scale voltage before frequency */
 80	if (mpu_reg && (new_freq > old_freq)) {
 81		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
 82		if (r < 0) {
 83			dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
 84				 __func__);
 85			return r;
 86		}
 87	}
 88
 89	ret = clk_set_rate(policy->clk, new_freq * 1000);
 90
 91	/* scaling down?  scale voltage after frequency */
 92	if (mpu_reg && (new_freq < old_freq)) {
 93		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
 94		if (r < 0) {
 95			dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
 96				 __func__);
 97			clk_set_rate(policy->clk, old_freq * 1000);
 98			return r;
 99		}
100	}
101
102	return ret;
103}
104
105static inline void freq_table_free(void)
106{
107	if (atomic_dec_and_test(&freq_table_users))
108		dev_pm_opp_free_cpufreq_table(mpu_dev, &freq_table);
109}
110
111static int omap_cpu_init(struct cpufreq_policy *policy)
112{
113	int result;
114
115	policy->clk = clk_get(NULL, "cpufreq_ck");
116	if (IS_ERR(policy->clk))
117		return PTR_ERR(policy->clk);
118
119	if (!freq_table) {
120		result = dev_pm_opp_init_cpufreq_table(mpu_dev, &freq_table);
121		if (result) {
122			dev_err(mpu_dev,
123				"%s: cpu%d: failed creating freq table[%d]\n",
124				__func__, policy->cpu, result);
125			clk_put(policy->clk);
126			return result;
127		}
128	}
129
130	atomic_inc_return(&freq_table_users);
131
132	/* FIXME: what's the actual transition time? */
133	cpufreq_generic_init(policy, freq_table, 300 * 1000);
 
 
134
135	return 0;
 
 
 
136}
137
138static int omap_cpu_exit(struct cpufreq_policy *policy)
139{
140	freq_table_free();
141	clk_put(policy->clk);
142	return 0;
143}
144
145static struct cpufreq_driver omap_driver = {
146	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
147	.verify		= cpufreq_generic_frequency_table_verify,
148	.target_index	= omap_target,
149	.get		= cpufreq_generic_get,
150	.init		= omap_cpu_init,
151	.exit		= omap_cpu_exit,
152	.register_em	= cpufreq_register_em_with_opp,
153	.name		= "omap",
154	.attr		= cpufreq_generic_attr,
155};
156
157static int omap_cpufreq_probe(struct platform_device *pdev)
158{
159	mpu_dev = get_cpu_device(0);
160	if (!mpu_dev) {
161		pr_warn("%s: unable to get the MPU device\n", __func__);
162		return -EINVAL;
163	}
164
165	mpu_reg = regulator_get(mpu_dev, "vcc");
166	if (IS_ERR(mpu_reg)) {
167		pr_warn("%s: unable to get MPU regulator\n", __func__);
168		mpu_reg = NULL;
169	} else {
170		/* 
171		 * Ensure physical regulator is present.
172		 * (e.g. could be dummy regulator.)
173		 */
174		if (regulator_get_voltage(mpu_reg) < 0) {
175			pr_warn("%s: physical regulator not present for MPU\n",
176				__func__);
177			regulator_put(mpu_reg);
178			mpu_reg = NULL;
179		}
180	}
181
182	return cpufreq_register_driver(&omap_driver);
183}
184
185static void omap_cpufreq_remove(struct platform_device *pdev)
186{
187	cpufreq_unregister_driver(&omap_driver);
188}
189
190static struct platform_driver omap_cpufreq_platdrv = {
191	.driver = {
192		.name	= "omap-cpufreq",
193	},
194	.probe		= omap_cpufreq_probe,
195	.remove_new	= omap_cpufreq_remove,
196};
197module_platform_driver(omap_cpufreq_platdrv);
198
199MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
200MODULE_LICENSE("GPL");

 
  1/*
  2 *  CPU frequency scaling for OMAP using OPP information
  3 *
  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 *
  9 * Copyright (C) 2007-2011 Texas Instruments, Inc.
 10 * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
 11 *
 12 * 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>
 23#include <linux/clk.h>
 24#include <linux/io.h>
 25#include <linux/pm_opp.h>
 26#include <linux/cpu.h>
 27#include <linux/module.h>
 28#include <linux/platform_device.h>
 29#include <linux/regulator/consumer.h>
 30
 31#include <asm/smp_plat.h>
 32#include <asm/cpu.h>
 33
 34/* OPP tolerance in percentage */
 35#define	OPP_TOLERANCE	4
 36
 37static struct cpufreq_frequency_table *freq_table;
 38static atomic_t freq_table_users = ATOMIC_INIT(0);
 39static struct device *mpu_dev;
 40static struct regulator *mpu_reg;
 41
 42static int omap_target(struct cpufreq_policy *policy, unsigned int index)
 43{
 44	int r, ret;
 45	struct dev_pm_opp *opp;
 46	unsigned long freq, volt = 0, volt_old = 0, tol = 0;
 47	unsigned int old_freq, new_freq;
 48
 49	old_freq = policy->cur;
 50	new_freq = freq_table[index].frequency;
 51
 52	freq = new_freq * 1000;
 53	ret = clk_round_rate(policy->clk, freq);
 54	if (IS_ERR_VALUE(ret)) {
 55		dev_warn(mpu_dev,
 56			 "CPUfreq: Cannot find matching frequency for %lu\n",
 57			 freq);
 58		return ret;
 59	}
 60	freq = ret;
 61
 62	if (mpu_reg) {
 63		rcu_read_lock();
 64		opp = dev_pm_opp_find_freq_ceil(mpu_dev, &freq);
 65		if (IS_ERR(opp)) {
 66			rcu_read_unlock();
 67			dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
 68				__func__, new_freq);
 69			return -EINVAL;
 70		}
 71		volt = dev_pm_opp_get_voltage(opp);
 72		rcu_read_unlock();
 73		tol = volt * OPP_TOLERANCE / 100;
 74		volt_old = regulator_get_voltage(mpu_reg);
 75	}
 76
 77	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n", 
 78		old_freq / 1000, volt_old ? volt_old / 1000 : -1,
 79		new_freq / 1000, volt ? volt / 1000 : -1);
 80
 81	/* scaling up?  scale voltage before frequency */
 82	if (mpu_reg && (new_freq > old_freq)) {
 83		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
 84		if (r < 0) {
 85			dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
 86				 __func__);
 87			return r;
 88		}
 89	}
 90
 91	ret = clk_set_rate(policy->clk, new_freq * 1000);
 92
 93	/* scaling down?  scale voltage after frequency */
 94	if (mpu_reg && (new_freq < old_freq)) {
 95		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
 96		if (r < 0) {
 97			dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
 98				 __func__);
 99			clk_set_rate(policy->clk, old_freq * 1000);
100			return r;
101		}
102	}
103
104	return ret;
105}
106
107static inline void freq_table_free(void)
108{
109	if (atomic_dec_and_test(&freq_table_users))
110		dev_pm_opp_free_cpufreq_table(mpu_dev, &freq_table);
111}
112
113static int omap_cpu_init(struct cpufreq_policy *policy)
114{
115	int result;
116
117	policy->clk = clk_get(NULL, "cpufreq_ck");
118	if (IS_ERR(policy->clk))
119		return PTR_ERR(policy->clk);
120
121	if (!freq_table) {
122		result = dev_pm_opp_init_cpufreq_table(mpu_dev, &freq_table);
123		if (result) {
124			dev_err(mpu_dev,
125				"%s: cpu%d: failed creating freq table[%d]\n",
126				__func__, policy->cpu, result);
127			goto fail;
 
128		}
129	}
130
131	atomic_inc_return(&freq_table_users);
132
133	/* FIXME: what's the actual transition time? */
134	result = cpufreq_generic_init(policy, freq_table, 300 * 1000);
135	if (!result)
136		return 0;
137
138	freq_table_free();
139fail:
140	clk_put(policy->clk);
141	return result;
142}
143
144static int omap_cpu_exit(struct cpufreq_policy *policy)
145{
146	freq_table_free();
147	clk_put(policy->clk);
148	return 0;
149}
150
151static struct cpufreq_driver omap_driver = {
152	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
153	.verify		= cpufreq_generic_frequency_table_verify,
154	.target_index	= omap_target,
155	.get		= cpufreq_generic_get,
156	.init		= omap_cpu_init,
157	.exit		= omap_cpu_exit,
 
158	.name		= "omap",
159	.attr		= cpufreq_generic_attr,
160};
161
162static int omap_cpufreq_probe(struct platform_device *pdev)
163{
164	mpu_dev = get_cpu_device(0);
165	if (!mpu_dev) {
166		pr_warning("%s: unable to get the mpu device\n", __func__);
167		return -EINVAL;
168	}
169
170	mpu_reg = regulator_get(mpu_dev, "vcc");
171	if (IS_ERR(mpu_reg)) {
172		pr_warning("%s: unable to get MPU regulator\n", __func__);
173		mpu_reg = NULL;
174	} else {
175		/* 
176		 * Ensure physical regulator is present.
177		 * (e.g. could be dummy regulator.)
178		 */
179		if (regulator_get_voltage(mpu_reg) < 0) {
180			pr_warn("%s: physical regulator not present for MPU\n",
181				__func__);
182			regulator_put(mpu_reg);
183			mpu_reg = NULL;
184		}
185	}
186
187	return cpufreq_register_driver(&omap_driver);
188}
189
190static int omap_cpufreq_remove(struct platform_device *pdev)
191{
192	return cpufreq_unregister_driver(&omap_driver);
193}
194
195static struct platform_driver omap_cpufreq_platdrv = {
196	.driver = {
197		.name	= "omap-cpufreq",
198	},
199	.probe		= omap_cpufreq_probe,
200	.remove		= omap_cpufreq_remove,
201};
202module_platform_driver(omap_cpufreq_platdrv);
203
204MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
205MODULE_LICENSE("GPL");