drivers/devfreq/exynos/exynos5_bus.c

   1 /*
   2  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com/
   4  *
   5  * EXYNOS5 INT clock frequency scaling support using DEVFREQ framework
   6  * Based on work done by Jonghwan Choi <jhbird.choi@samsung.com>
   7  * Support for only EXYNOS5250 is present.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/devfreq.h>
  17 #include <linux/io.h>
  18 #include <linux/pm_opp.h>
  19 #include <linux/slab.h>
  20 #include <linux/suspend.h>
  21 #include <linux/clk.h>
  22 #include <linux/delay.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/pm_qos.h>
  25 #include <linux/regulator/consumer.h>
  26 #include <linux/of_address.h>
  27 #include <linux/of_platform.h>
  28
  29 #include "exynos_ppmu.h"
  30
  31 #define MAX_SAFEVOLT                    1100000 /* 1.10V */
  32 /* Assume that the bus is saturated if the utilization is 25% */
  33 #define INT_BUS_SATURATION_RATIO        25
  34
  35 enum int_level_idx {
  36         LV_0,
  37         LV_1,
  38         LV_2,
  39         LV_3,
  40         LV_4,
  41         _LV_END
  42 };
  43
  44 enum exynos_ppmu_list {
  45         PPMU_RIGHT,
  46         PPMU_END,
  47 };
  48
  49 struct busfreq_data_int {
  50         struct device *dev;
  51         struct devfreq *devfreq;
  52         struct regulator *vdd_int;
  53         struct exynos_ppmu ppmu[PPMU_END];
  54         unsigned long curr_freq;
  55         bool disabled;
  56
  57         struct notifier_block pm_notifier;
  58         struct mutex lock;
  59         struct pm_qos_request int_req;
  60         struct clk *int_clk;
  61 };
  62
  63 struct int_bus_opp_table {
  64         unsigned int idx;
  65         unsigned long clk;
  66         unsigned long volt;
  67 };
  68
  69 static struct int_bus_opp_table exynos5_int_opp_table[] = {
  70         {LV_0, 266000, 1025000},
  71         {LV_1, 200000, 1025000},
  72         {LV_2, 160000, 1025000},
  73         {LV_3, 133000, 1025000},
  74         {LV_4, 100000, 1025000},
  75         {0, 0, 0},
  76 };
  77
  78 static void busfreq_mon_reset(struct busfreq_data_int *data)
  79 {
  80         unsigned int i;
  81
  82         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
  83                 void __iomem *ppmu_base = data->ppmu[i].hw_base;
  84
  85                 /* Reset the performance and cycle counters */
  86                 exynos_ppmu_reset(ppmu_base);
  87
  88                 /* Setup count registers to monitor read/write transactions */
  89                 data->ppmu[i].event[PPMU_PMNCNT3] = RDWR_DATA_COUNT;
  90                 exynos_ppmu_setevent(ppmu_base, PPMU_PMNCNT3,
  91                                         data->ppmu[i].event[PPMU_PMNCNT3]);
  92
  93                 exynos_ppmu_start(ppmu_base);
  94         }
  95 }
  96
  97 static void exynos5_read_ppmu(struct busfreq_data_int *data)
  98 {
  99         int i, j;
 100
 101         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
 102                 void __iomem *ppmu_base = data->ppmu[i].hw_base;
 103
 104                 exynos_ppmu_stop(ppmu_base);
 105
 106                 /* Update local data from PPMU */
 107                 data->ppmu[i].ccnt = __raw_readl(ppmu_base + PPMU_CCNT);
 108
 109                 for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
 110                         if (data->ppmu[i].event[j] == 0)
 111                                 data->ppmu[i].count[j] = 0;
 112                         else
 113                                 data->ppmu[i].count[j] =
 114                                         exynos_ppmu_read(ppmu_base, j);
 115                 }
 116         }
 117
 118         busfreq_mon_reset(data);
 119 }
 120
 121 static int exynos5_int_setvolt(struct busfreq_data_int *data,
 122                                 unsigned long volt)
 123 {
 124         return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT);
 125 }
 126
 127 static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq,
 128                               u32 flags)
 129 {
 130         int err = 0;
 131         struct platform_device *pdev = container_of(dev, struct platform_device,
 132                                                     dev);
 133         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 134         struct dev_pm_opp *opp;
 135         unsigned long old_freq, freq;
 136         unsigned long volt;
 137
 138         rcu_read_lock();
 139         opp = devfreq_recommended_opp(dev, _freq, flags);
 140         if (IS_ERR(opp)) {
 141                 rcu_read_unlock();
 142                 dev_err(dev, "%s: Invalid OPP.\n", __func__);
 143                 return PTR_ERR(opp);
 144         }
 145
 146         freq = dev_pm_opp_get_freq(opp);
 147         volt = dev_pm_opp_get_voltage(opp);
 148         rcu_read_unlock();
 149
 150         old_freq = data->curr_freq;
 151
 152         if (old_freq == freq)
 153                 return 0;
 154
 155         dev_dbg(dev, "targeting %lukHz %luuV\n", freq, volt);
 156
 157         mutex_lock(&data->lock);
 158
 159         if (data->disabled)
 160                 goto out;
 161
 162         if (freq > exynos5_int_opp_table[0].clk)
 163                 pm_qos_update_request(&data->int_req, freq * 16 / 1000);
 164         else
 165                 pm_qos_update_request(&data->int_req, -1);
 166
 167         if (old_freq < freq)
 168                 err = exynos5_int_setvolt(data, volt);
 169         if (err)
 170                 goto out;
 171
 172         err = clk_set_rate(data->int_clk, freq * 1000);
 173
 174         if (err)
 175                 goto out;
 176
 177         if (old_freq > freq)
 178                 err = exynos5_int_setvolt(data, volt);
 179         if (err)
 180                 goto out;
 181
 182         data->curr_freq = freq;
 183 out:
 184         mutex_unlock(&data->lock);
 185         return err;
 186 }
 187
 188 static int exynos5_get_busier_dmc(struct busfreq_data_int *data)
 189 {
 190         int i, j;
 191         int busy = 0;
 192         unsigned int temp = 0;
 193
 194         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
 195                 for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
 196                         if (data->ppmu[i].count[j] > temp) {
 197                                 temp = data->ppmu[i].count[j];
 198                                 busy = i;
 199                         }
 200                 }
 201         }
 202
 203         return busy;
 204 }
 205
 206 static int exynos5_int_get_dev_status(struct device *dev,
 207                                       struct devfreq_dev_status *stat)
 208 {
 209         struct platform_device *pdev = container_of(dev, struct platform_device,
 210                                                     dev);
 211         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 212         int busier_dmc;
 213
 214         exynos5_read_ppmu(data);
 215         busier_dmc = exynos5_get_busier_dmc(data);
 216
 217         stat->current_frequency = data->curr_freq;
 218
 219         /* Number of cycles spent on memory access */
 220         stat->busy_time = data->ppmu[busier_dmc].count[PPMU_PMNCNT3];
 221         stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO;
 222         stat->total_time = data->ppmu[busier_dmc].ccnt;
 223
 224         return 0;
 225 }
 226 static void exynos5_int_exit(struct device *dev)
 227 {
 228         struct platform_device *pdev = container_of(dev, struct platform_device,
 229                                                     dev);
 230         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 231
 232         devfreq_unregister_opp_notifier(dev, data->devfreq);
 233 }
 234
 235 static struct devfreq_dev_profile exynos5_devfreq_int_profile = {
 236         .initial_freq           = 160000,
 237         .polling_ms             = 100,
 238         .target                 = exynos5_busfreq_int_target,
 239         .get_dev_status         = exynos5_int_get_dev_status,
 240         .exit                   = exynos5_int_exit,
 241 };
 242
 243 static int exynos5250_init_int_tables(struct busfreq_data_int *data)
 244 {
 245         int i, err = 0;
 246
 247         for (i = LV_0; i < _LV_END; i++) {
 248                 err = dev_pm_opp_add(data->dev, exynos5_int_opp_table[i].clk,
 249                                 exynos5_int_opp_table[i].volt);
 250                 if (err) {
 251                         dev_err(data->dev, "Cannot add opp entries.\n");
 252                         return err;
 253                 }
 254         }
 255
 256         return 0;
 257 }
 258
 259 static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this,
 260                 unsigned long event, void *ptr)
 261 {
 262         struct busfreq_data_int *data = container_of(this,
 263                                         struct busfreq_data_int, pm_notifier);
 264         struct dev_pm_opp *opp;
 265         unsigned long maxfreq = ULONG_MAX;
 266         unsigned long freq;
 267         unsigned long volt;
 268         int err = 0;
 269
 270         switch (event) {
 271         case PM_SUSPEND_PREPARE:
 272                 /* Set Fastest and Deactivate DVFS */
 273                 mutex_lock(&data->lock);
 274
 275                 data->disabled = true;
 276
 277                 rcu_read_lock();
 278                 opp = dev_pm_opp_find_freq_floor(data->dev, &maxfreq);
 279                 if (IS_ERR(opp)) {
 280                         rcu_read_unlock();
 281                         err = PTR_ERR(opp);
 282                         goto unlock;
 283                 }
 284                 freq = dev_pm_opp_get_freq(opp);
 285                 volt = dev_pm_opp_get_voltage(opp);
 286                 rcu_read_unlock();
 287
 288                 err = exynos5_int_setvolt(data, volt);
 289                 if (err)
 290                         goto unlock;
 291
 292                 err = clk_set_rate(data->int_clk, freq * 1000);
 293
 294                 if (err)
 295                         goto unlock;
 296
 297                 data->curr_freq = freq;
 298 unlock:
 299                 mutex_unlock(&data->lock);
 300                 if (err)
 301                         return NOTIFY_BAD;
 302                 return NOTIFY_OK;
 303         case PM_POST_RESTORE:
 304         case PM_POST_SUSPEND:
 305                 /* Reactivate */
 306                 mutex_lock(&data->lock);
 307                 data->disabled = false;
 308                 mutex_unlock(&data->lock);
 309                 return NOTIFY_OK;
 310         }
 311
 312         return NOTIFY_DONE;
 313 }
 314
 315 static int exynos5_busfreq_int_probe(struct platform_device *pdev)
 316 {
 317         struct busfreq_data_int *data;
 318         struct dev_pm_opp *opp;
 319         struct device *dev = &pdev->dev;
 320         struct device_node *np;
 321         unsigned long initial_freq;
 322         unsigned long initial_volt;
 323         int err = 0;
 324         int i;
 325
 326         data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int),
 327                                 GFP_KERNEL);
 328         if (data == NULL) {
 329                 dev_err(dev, "Cannot allocate memory.\n");
 330                 return -ENOMEM;
 331         }
 332
 333         np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu");
 334         if (np == NULL) {
 335                 pr_err("Unable to find PPMU node\n");
 336                 return -ENOENT;
 337         }
 338
 339         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
 340                 /* map PPMU memory region */
 341                 data->ppmu[i].hw_base = of_iomap(np, i);
 342                 if (data->ppmu[i].hw_base == NULL) {
 343                         dev_err(&pdev->dev, "failed to map memory region\n");
 344                         return -ENOMEM;
 345                 }
 346         }
 347         data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event;
 348         data->dev = dev;
 349         mutex_init(&data->lock);
 350
 351         err = exynos5250_init_int_tables(data);
 352         if (err)
 353                 return err;
 354
 355         data->vdd_int = devm_regulator_get(dev, "vdd_int");
 356         if (IS_ERR(data->vdd_int)) {
 357                 dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
 358                 return PTR_ERR(data->vdd_int);
 359         }
 360
 361         data->int_clk = devm_clk_get(dev, "int_clk");
 362         if (IS_ERR(data->int_clk)) {
 363                 dev_err(dev, "Cannot get clock \"int_clk\"\n");
 364                 return PTR_ERR(data->int_clk);
 365         }
 366
 367         rcu_read_lock();
 368         opp = dev_pm_opp_find_freq_floor(dev,
 369                         &exynos5_devfreq_int_profile.initial_freq);
 370         if (IS_ERR(opp)) {
 371                 rcu_read_unlock();
 372                 dev_err(dev, "Invalid initial frequency %lu kHz.\n",
 373                        exynos5_devfreq_int_profile.initial_freq);
 374                 return PTR_ERR(opp);
 375         }
 376         initial_freq = dev_pm_opp_get_freq(opp);
 377         initial_volt = dev_pm_opp_get_voltage(opp);
 378         rcu_read_unlock();
 379         data->curr_freq = initial_freq;
 380
 381         err = clk_set_rate(data->int_clk, initial_freq * 1000);
 382         if (err) {
 383                 dev_err(dev, "Failed to set initial frequency\n");
 384                 return err;
 385         }
 386
 387         err = exynos5_int_setvolt(data, initial_volt);
 388         if (err)
 389                 return err;
 390
 391         platform_set_drvdata(pdev, data);
 392
 393         busfreq_mon_reset(data);
 394
 395         data->devfreq = devfreq_add_device(dev, &exynos5_devfreq_int_profile,
 396                                            "simple_ondemand", NULL);
 397
 398         if (IS_ERR(data->devfreq)) {
 399                 err = PTR_ERR(data->devfreq);
 400                 goto err_devfreq_add;
 401         }
 402
 403         devfreq_register_opp_notifier(dev, data->devfreq);
 404
 405         err = register_pm_notifier(&data->pm_notifier);
 406         if (err) {
 407                 dev_err(dev, "Failed to setup pm notifier\n");
 408                 goto err_devfreq_add;
 409         }
 410
 411         /* TODO: Add a new QOS class for int/mif bus */
 412         pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1);
 413
 414         return 0;
 415
 416 err_devfreq_add:
 417         devfreq_remove_device(data->devfreq);
 418         return err;
 419 }
 420
 421 static int exynos5_busfreq_int_remove(struct platform_device *pdev)
 422 {
 423         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 424
 425         pm_qos_remove_request(&data->int_req);
 426         unregister_pm_notifier(&data->pm_notifier);
 427         devfreq_remove_device(data->devfreq);
 428
 429         return 0;
 430 }
 431
 432 static int exynos5_busfreq_int_resume(struct device *dev)
 433 {
 434         struct platform_device *pdev = container_of(dev, struct platform_device,
 435                                                     dev);
 436         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 437
 438         busfreq_mon_reset(data);
 439         return 0;
 440 }
 441
 442 static const struct dev_pm_ops exynos5_busfreq_int_pm = {
 443         .resume = exynos5_busfreq_int_resume,
 444 };
 445
 446 /* platform device pointer for exynos5 devfreq device. */
 447 static struct platform_device *exynos5_devfreq_pdev;
 448
 449 static struct platform_driver exynos5_busfreq_int_driver = {
 450         .probe          = exynos5_busfreq_int_probe,
 451         .remove         = exynos5_busfreq_int_remove,
 452         .driver         = {
 453                 .name           = "exynos5-bus-int",
 454                 .owner          = THIS_MODULE,
 455                 .pm             = &exynos5_busfreq_int_pm,
 456         },
 457 };
 458
 459 static int __init exynos5_busfreq_int_init(void)
 460 {
 461         int ret;
 462
 463         ret = platform_driver_register(&exynos5_busfreq_int_driver);
 464         if (ret < 0)
 465                 goto out;
 466
 467         exynos5_devfreq_pdev =
 468                 platform_device_register_simple("exynos5-bus-int", -1, NULL, 0);
 469         if (IS_ERR(exynos5_devfreq_pdev)) {
 470                 ret = PTR_ERR(exynos5_devfreq_pdev);
 471                 goto out1;
 472         }
 473
 474         return 0;
 475 out1:
 476         platform_driver_unregister(&exynos5_busfreq_int_driver);
 477 out:
 478         return ret;
 479 }
 480 late_initcall(exynos5_busfreq_int_init);
 481
 482 static void __exit exynos5_busfreq_int_exit(void)
 483 {
 484         platform_device_unregister(exynos5_devfreq_pdev);
 485         platform_driver_unregister(&exynos5_busfreq_int_driver);
 486 }
 487 module_exit(exynos5_busfreq_int_exit);
 488
 489 MODULE_LICENSE("GPL");
 490 MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework");