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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/opp.h>
26#include <linux/cpu.h>
27#include <linux/module.h>
28#include <linux/regulator/consumer.h>
29
30#include <asm/smp_plat.h>
31#include <asm/cpu.h>
32
33#include <plat/clock.h>
34#include <plat/omap-pm.h>
35#include <plat/common.h>
36#include <plat/omap_device.h>
37
38#include <mach/hardware.h>
39
40/* OPP tolerance in percentage */
41#define OPP_TOLERANCE 4
42
43#ifdef CONFIG_SMP
44struct lpj_info {
45 unsigned long ref;
46 unsigned int freq;
47};
48
49static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
50static struct lpj_info global_lpj_ref;
51#endif
52
53static struct cpufreq_frequency_table *freq_table;
54static atomic_t freq_table_users = ATOMIC_INIT(0);
55static struct clk *mpu_clk;
56static char *mpu_clk_name;
57static struct device *mpu_dev;
58static struct regulator *mpu_reg;
59
60static int omap_verify_speed(struct cpufreq_policy *policy)
61{
62 if (!freq_table)
63 return -EINVAL;
64 return cpufreq_frequency_table_verify(policy, freq_table);
65}
66
67static unsigned int omap_getspeed(unsigned int cpu)
68{
69 unsigned long rate;
70
71 if (cpu >= NR_CPUS)
72 return 0;
73
74 rate = clk_get_rate(mpu_clk) / 1000;
75 return rate;
76}
77
78static int omap_target(struct cpufreq_policy *policy,
79 unsigned int target_freq,
80 unsigned int relation)
81{
82 unsigned int i;
83 int r, ret = 0;
84 struct cpufreq_freqs freqs;
85 struct opp *opp;
86 unsigned long freq, volt = 0, volt_old = 0, tol = 0;
87
88 if (!freq_table) {
89 dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
90 policy->cpu);
91 return -EINVAL;
92 }
93
94 ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
95 relation, &i);
96 if (ret) {
97 dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
98 __func__, policy->cpu, target_freq, ret);
99 return ret;
100 }
101 freqs.new = freq_table[i].frequency;
102 if (!freqs.new) {
103 dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
104 policy->cpu, target_freq);
105 return -EINVAL;
106 }
107
108 freqs.old = omap_getspeed(policy->cpu);
109 freqs.cpu = policy->cpu;
110
111 if (freqs.old == freqs.new && policy->cur == freqs.new)
112 return ret;
113
114 /* notifiers */
115 for_each_cpu(i, policy->cpus) {
116 freqs.cpu = i;
117 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
118 }
119
120 freq = freqs.new * 1000;
121
122 if (mpu_reg) {
123 opp = opp_find_freq_ceil(mpu_dev, &freq);
124 if (IS_ERR(opp)) {
125 dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
126 __func__, freqs.new);
127 return -EINVAL;
128 }
129 volt = opp_get_voltage(opp);
130 tol = volt * OPP_TOLERANCE / 100;
131 volt_old = regulator_get_voltage(mpu_reg);
132 }
133
134 dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
135 freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
136 freqs.new / 1000, volt ? volt / 1000 : -1);
137
138 /* scaling up? scale voltage before frequency */
139 if (mpu_reg && (freqs.new > freqs.old)) {
140 r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
141 if (r < 0) {
142 dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
143 __func__);
144 freqs.new = freqs.old;
145 goto done;
146 }
147 }
148
149 ret = clk_set_rate(mpu_clk, freqs.new * 1000);
150
151 /* scaling down? scale voltage after frequency */
152 if (mpu_reg && (freqs.new < freqs.old)) {
153 r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
154 if (r < 0) {
155 dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
156 __func__);
157 ret = clk_set_rate(mpu_clk, freqs.old * 1000);
158 freqs.new = freqs.old;
159 goto done;
160 }
161 }
162
163 freqs.new = omap_getspeed(policy->cpu);
164#ifdef CONFIG_SMP
165 /*
166 * Note that loops_per_jiffy is not updated on SMP systems in
167 * cpufreq driver. So, update the per-CPU loops_per_jiffy value
168 * on frequency transition. We need to update all dependent CPUs.
169 */
170 for_each_cpu(i, policy->cpus) {
171 struct lpj_info *lpj = &per_cpu(lpj_ref, i);
172 if (!lpj->freq) {
173 lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
174 lpj->freq = freqs.old;
175 }
176
177 per_cpu(cpu_data, i).loops_per_jiffy =
178 cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
179 }
180
181 /* And don't forget to adjust the global one */
182 if (!global_lpj_ref.freq) {
183 global_lpj_ref.ref = loops_per_jiffy;
184 global_lpj_ref.freq = freqs.old;
185 }
186 loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
187 freqs.new);
188#endif
189
190done:
191 /* notifiers */
192 for_each_cpu(i, policy->cpus) {
193 freqs.cpu = i;
194 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
195 }
196
197 return ret;
198}
199
200static inline void freq_table_free(void)
201{
202 if (atomic_dec_and_test(&freq_table_users))
203 opp_free_cpufreq_table(mpu_dev, &freq_table);
204}
205
206static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
207{
208 int result = 0;
209
210 mpu_clk = clk_get(NULL, mpu_clk_name);
211 if (IS_ERR(mpu_clk))
212 return PTR_ERR(mpu_clk);
213
214 if (policy->cpu >= NR_CPUS) {
215 result = -EINVAL;
216 goto fail_ck;
217 }
218
219 policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
220
221 if (atomic_inc_return(&freq_table_users) == 1)
222 result = opp_init_cpufreq_table(mpu_dev, &freq_table);
223
224 if (result) {
225 dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
226 __func__, policy->cpu, result);
227 goto fail_ck;
228 }
229
230 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
231 if (result)
232 goto fail_table;
233
234 cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
235
236 policy->min = policy->cpuinfo.min_freq;
237 policy->max = policy->cpuinfo.max_freq;
238 policy->cur = omap_getspeed(policy->cpu);
239
240 /*
241 * On OMAP SMP configuartion, both processors share the voltage
242 * and clock. So both CPUs needs to be scaled together and hence
243 * needs software co-ordination. Use cpufreq affected_cpus
244 * interface to handle this scenario. Additional is_smp() check
245 * is to keep SMP_ON_UP build working.
246 */
247 if (is_smp()) {
248 policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
249 cpumask_setall(policy->cpus);
250 }
251
252 /* FIXME: what's the actual transition time? */
253 policy->cpuinfo.transition_latency = 300 * 1000;
254
255 return 0;
256
257fail_table:
258 freq_table_free();
259fail_ck:
260 clk_put(mpu_clk);
261 return result;
262}
263
264static int omap_cpu_exit(struct cpufreq_policy *policy)
265{
266 freq_table_free();
267 clk_put(mpu_clk);
268 return 0;
269}
270
271static struct freq_attr *omap_cpufreq_attr[] = {
272 &cpufreq_freq_attr_scaling_available_freqs,
273 NULL,
274};
275
276static struct cpufreq_driver omap_driver = {
277 .flags = CPUFREQ_STICKY,
278 .verify = omap_verify_speed,
279 .target = omap_target,
280 .get = omap_getspeed,
281 .init = omap_cpu_init,
282 .exit = omap_cpu_exit,
283 .name = "omap",
284 .attr = omap_cpufreq_attr,
285};
286
287static int __init omap_cpufreq_init(void)
288{
289 if (cpu_is_omap24xx())
290 mpu_clk_name = "virt_prcm_set";
291 else if (cpu_is_omap34xx())
292 mpu_clk_name = "dpll1_ck";
293 else if (cpu_is_omap44xx())
294 mpu_clk_name = "dpll_mpu_ck";
295
296 if (!mpu_clk_name) {
297 pr_err("%s: unsupported Silicon?\n", __func__);
298 return -EINVAL;
299 }
300
301 mpu_dev = omap_device_get_by_hwmod_name("mpu");
302 if (!mpu_dev) {
303 pr_warning("%s: unable to get the mpu device\n", __func__);
304 return -EINVAL;
305 }
306
307 mpu_reg = regulator_get(mpu_dev, "vcc");
308 if (IS_ERR(mpu_reg)) {
309 pr_warning("%s: unable to get MPU regulator\n", __func__);
310 mpu_reg = NULL;
311 } else {
312 /*
313 * Ensure physical regulator is present.
314 * (e.g. could be dummy regulator.)
315 */
316 if (regulator_get_voltage(mpu_reg) < 0) {
317 pr_warn("%s: physical regulator not present for MPU\n",
318 __func__);
319 regulator_put(mpu_reg);
320 mpu_reg = NULL;
321 }
322 }
323
324 return cpufreq_register_driver(&omap_driver);
325}
326
327static void __exit omap_cpufreq_exit(void)
328{
329 cpufreq_unregister_driver(&omap_driver);
330}
331
332MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
333MODULE_LICENSE("GPL");
334module_init(omap_cpufreq_init);
335module_exit(omap_cpufreq_exit);