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/opp.h>
  19 #include <linux/slab.h>
  20 #include <linux/suspend.h>
  21 #include <linux/opp.h>
  22 #include <linux/clk.h>
  23 #include <linux/delay.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/pm_qos.h>
  26 #include <linux/regulator/consumer.h>
  27 #include <linux/of_address.h>
  28 #include <linux/of_platform.h>
  29
  30 #include "exynos_ppmu.h"
  31
  32 #define MAX_SAFEVOLT                    1100000 /* 1.10V */
  33 /* Assume that the bus is saturated if the utilization is 25% */
  34 #define INT_BUS_SATURATION_RATIO        25
  35
  36 enum int_level_idx {
  37         LV_0,
  38         LV_1,
  39         LV_2,
  40         LV_3,
  41         LV_4,
  42         _LV_END
  43 };
  44
  45 enum exynos_ppmu_list {
  46         PPMU_RIGHT,
  47         PPMU_END,
  48 };
  49
  50 struct busfreq_data_int {
  51         struct device *dev;
  52         struct devfreq *devfreq;
  53         struct regulator *vdd_int;
  54         struct exynos_ppmu ppmu[PPMU_END];
  55         unsigned long curr_freq;
  56         bool disabled;
  57
  58         struct notifier_block pm_notifier;
  59         struct mutex lock;
  60         struct pm_qos_request int_req;
  61         struct clk *int_clk;
  62 };
  63
  64 struct int_bus_opp_table {
  65         unsigned int idx;
  66         unsigned long clk;
  67         unsigned long volt;
  68 };
  69
  70 static struct int_bus_opp_table exynos5_int_opp_table[] = {
  71         {LV_0, 266000, 1025000},
  72         {LV_1, 200000, 1025000},
  73         {LV_2, 160000, 1025000},
  74         {LV_3, 133000, 1025000},
  75         {LV_4, 100000, 1025000},
  76         {0, 0, 0},
  77 };
  78
  79 static void busfreq_mon_reset(struct busfreq_data_int *data)
  80 {
  81         unsigned int i;
  82
  83         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
  84                 void __iomem *ppmu_base = data->ppmu[i].hw_base;
  85
  86                 /* Reset the performance and cycle counters */
  87                 exynos_ppmu_reset(ppmu_base);
  88
  89                 /* Setup count registers to monitor read/write transactions */
  90                 data->ppmu[i].event[PPMU_PMNCNT3] = RDWR_DATA_COUNT;
  91                 exynos_ppmu_setevent(ppmu_base, PPMU_PMNCNT3,
  92                                         data->ppmu[i].event[PPMU_PMNCNT3]);
  93
  94                 exynos_ppmu_start(ppmu_base);
  95         }
  96 }
  97
  98 static void exynos5_read_ppmu(struct busfreq_data_int *data)
  99 {
 100         int i, j;
 101
 102         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
 103                 void __iomem *ppmu_base = data->ppmu[i].hw_base;
 104
 105                 exynos_ppmu_stop(ppmu_base);
 106
 107                 /* Update local data from PPMU */
 108                 data->ppmu[i].ccnt = __raw_readl(ppmu_base + PPMU_CCNT);
 109
 110                 for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
 111                         if (data->ppmu[i].event[j] == 0)
 112                                 data->ppmu[i].count[j] = 0;
 113                         else
 114                                 data->ppmu[i].count[j] =
 115                                         exynos_ppmu_read(ppmu_base, j);
 116                 }
 117         }
 118
 119         busfreq_mon_reset(data);
 120 }
 121
 122 static int exynos5_int_setvolt(struct busfreq_data_int *data,
 123                                 unsigned long volt)
 124 {
 125         return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT);
 126 }
 127
 128 static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq,
 129                               u32 flags)
 130 {
 131         int err = 0;
 132         struct platform_device *pdev = container_of(dev, struct platform_device,
 133                                                     dev);
 134         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 135         struct opp *opp;
 136         unsigned long old_freq, freq;
 137         unsigned long volt;
 138
 139         rcu_read_lock();
 140         opp = devfreq_recommended_opp(dev, _freq, flags);
 141         if (IS_ERR(opp)) {
 142                 rcu_read_unlock();
 143                 dev_err(dev, "%s: Invalid OPP.\n", __func__);
 144                 return PTR_ERR(opp);
 145         }
 146
 147         freq = opp_get_freq(opp);
 148         volt = opp_get_voltage(opp);
 149         rcu_read_unlock();
 150
 151         old_freq = data->curr_freq;
 152
 153         if (old_freq == freq)
 154                 return 0;
 155
 156         dev_dbg(dev, "targetting %lukHz %luuV\n", freq, volt);
 157
 158         mutex_lock(&data->lock);
 159
 160         if (data->disabled)
 161                 goto out;
 162
 163         if (freq > exynos5_int_opp_table[0].clk)
 164                 pm_qos_update_request(&data->int_req, freq * 16 / 1000);
 165         else
 166                 pm_qos_update_request(&data->int_req, -1);
 167
 168         if (old_freq < freq)
 169                 err = exynos5_int_setvolt(data, volt);
 170         if (err)
 171                 goto out;
 172
 173         err = clk_set_rate(data->int_clk, freq * 1000);
 174
 175         if (err)
 176                 goto out;
 177
 178         if (old_freq > freq)
 179                 err = exynos5_int_setvolt(data, volt);
 180         if (err)
 181                 goto out;
 182
 183         data->curr_freq = freq;
 184 out:
 185         mutex_unlock(&data->lock);
 186         return err;
 187 }
 188
 189 static int exynos5_get_busier_dmc(struct busfreq_data_int *data)
 190 {
 191         int i, j;
 192         int busy = 0;
 193         unsigned int temp = 0;
 194
 195         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
 196                 for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
 197                         if (data->ppmu[i].count[j] > temp) {
 198                                 temp = data->ppmu[i].count[j];
 199                                 busy = i;
 200                         }
 201                 }
 202         }
 203
 204         return busy;
 205 }
 206
 207 static int exynos5_int_get_dev_status(struct device *dev,
 208                                       struct devfreq_dev_status *stat)
 209 {
 210         struct platform_device *pdev = container_of(dev, struct platform_device,
 211                                                     dev);
 212         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 213         int busier_dmc;
 214
 215         exynos5_read_ppmu(data);
 216         busier_dmc = exynos5_get_busier_dmc(data);
 217
 218         stat->current_frequency = data->curr_freq;
 219
 220         /* Number of cycles spent on memory access */
 221         stat->busy_time = data->ppmu[busier_dmc].count[PPMU_PMNCNT3];
 222         stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO;
 223         stat->total_time = data->ppmu[busier_dmc].ccnt;
 224
 225         return 0;
 226 }
 227 static void exynos5_int_exit(struct device *dev)
 228 {
 229         struct platform_device *pdev = container_of(dev, struct platform_device,
 230                                                     dev);
 231         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 232
 233         devfreq_unregister_opp_notifier(dev, data->devfreq);
 234 }
 235
 236 static struct devfreq_dev_profile exynos5_devfreq_int_profile = {
 237         .initial_freq           = 160000,
 238         .polling_ms             = 100,
 239         .target                 = exynos5_busfreq_int_target,
 240         .get_dev_status         = exynos5_int_get_dev_status,
 241         .exit                   = exynos5_int_exit,
 242 };
 243
 244 static int exynos5250_init_int_tables(struct busfreq_data_int *data)
 245 {
 246         int i, err = 0;
 247
 248         for (i = LV_0; i < _LV_END; i++) {
 249                 err = opp_add(data->dev, exynos5_int_opp_table[i].clk,
 250                                 exynos5_int_opp_table[i].volt);
 251                 if (err) {
 252                         dev_err(data->dev, "Cannot add opp entries.\n");
 253                         return err;
 254                 }
 255         }
 256
 257         return 0;
 258 }
 259
 260 static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this,
 261                 unsigned long event, void *ptr)
 262 {
 263         struct busfreq_data_int *data = container_of(this,
 264                                         struct busfreq_data_int, pm_notifier);
 265         struct opp *opp;
 266         unsigned long maxfreq = ULONG_MAX;
 267         unsigned long freq;
 268         unsigned long volt;
 269         int err = 0;
 270
 271         switch (event) {
 272         case PM_SUSPEND_PREPARE:
 273                 /* Set Fastest and Deactivate DVFS */
 274                 mutex_lock(&data->lock);
 275
 276                 data->disabled = true;
 277
 278                 rcu_read_lock();
 279                 opp = opp_find_freq_floor(data->dev, &maxfreq);
 280                 if (IS_ERR(opp)) {
 281                         rcu_read_unlock();
 282                         err = PTR_ERR(opp);
 283                         goto unlock;
 284                 }
 285                 freq = opp_get_freq(opp);
 286                 volt = opp_get_voltage(opp);
 287                 rcu_read_unlock();
 288
 289                 err = exynos5_int_setvolt(data, volt);
 290                 if (err)
 291                         goto unlock;
 292
 293                 err = clk_set_rate(data->int_clk, freq * 1000);
 294
 295                 if (err)
 296                         goto unlock;
 297
 298                 data->curr_freq = freq;
 299 unlock:
 300                 mutex_unlock(&data->lock);
 301                 if (err)
 302                         return NOTIFY_BAD;
 303                 return NOTIFY_OK;
 304         case PM_POST_RESTORE:
 305         case PM_POST_SUSPEND:
 306                 /* Reactivate */
 307                 mutex_lock(&data->lock);
 308                 data->disabled = false;
 309                 mutex_unlock(&data->lock);
 310                 return NOTIFY_OK;
 311         }
 312
 313         return NOTIFY_DONE;
 314 }
 315
 316 static int exynos5_busfreq_int_probe(struct platform_device *pdev)
 317 {
 318         struct busfreq_data_int *data;
 319         struct opp *opp;
 320         struct device *dev = &pdev->dev;
 321         struct device_node *np;
 322         unsigned long initial_freq;
 323         unsigned long initial_volt;
 324         int err = 0;
 325         int i;
 326
 327         data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int),
 328                                 GFP_KERNEL);
 329         if (data == NULL) {
 330                 dev_err(dev, "Cannot allocate memory.\n");
 331                 return -ENOMEM;
 332         }
 333
 334         np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu");
 335         if (np == NULL) {
 336                 pr_err("Unable to find PPMU node\n");
 337                 return -ENOENT;
 338         }
 339
 340         for (i = PPMU_RIGHT; i < PPMU_END; i++) {
 341                 /* map PPMU memory region */
 342                 data->ppmu[i].hw_base = of_iomap(np, i);
 343                 if (data->ppmu[i].hw_base == NULL) {
 344                         dev_err(&pdev->dev, "failed to map memory region\n");
 345                         return -ENOMEM;
 346                 }
 347         }
 348         data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event;
 349         data->dev = dev;
 350         mutex_init(&data->lock);
 351
 352         err = exynos5250_init_int_tables(data);
 353         if (err)
 354                 goto err_regulator;
 355
 356         data->vdd_int = regulator_get(dev, "vdd_int");
 357         if (IS_ERR(data->vdd_int)) {
 358                 dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
 359                 err = PTR_ERR(data->vdd_int);
 360                 goto err_regulator;
 361         }
 362
 363         data->int_clk = clk_get(dev, "int_clk");
 364         if (IS_ERR(data->int_clk)) {
 365                 dev_err(dev, "Cannot get clock \"int_clk\"\n");
 366                 err = PTR_ERR(data->int_clk);
 367                 goto err_clock;
 368         }
 369
 370         rcu_read_lock();
 371         opp = opp_find_freq_floor(dev,
 372                         &exynos5_devfreq_int_profile.initial_freq);
 373         if (IS_ERR(opp)) {
 374                 rcu_read_unlock();
 375                 dev_err(dev, "Invalid initial frequency %lu kHz.\n",
 376                        exynos5_devfreq_int_profile.initial_freq);
 377                 err = PTR_ERR(opp);
 378                 goto err_opp_add;
 379         }
 380         initial_freq = opp_get_freq(opp);
 381         initial_volt = opp_get_voltage(opp);
 382         rcu_read_unlock();
 383         data->curr_freq = initial_freq;
 384
 385         err = clk_set_rate(data->int_clk, initial_freq * 1000);
 386         if (err) {
 387                 dev_err(dev, "Failed to set initial frequency\n");
 388                 goto err_opp_add;
 389         }
 390
 391         err = exynos5_int_setvolt(data, initial_volt);
 392         if (err)
 393                 goto err_opp_add;
 394
 395         platform_set_drvdata(pdev, data);
 396
 397         busfreq_mon_reset(data);
 398
 399         data->devfreq = devfreq_add_device(dev, &exynos5_devfreq_int_profile,
 400                                            "simple_ondemand", NULL);
 401
 402         if (IS_ERR(data->devfreq)) {
 403                 err = PTR_ERR(data->devfreq);
 404                 goto err_devfreq_add;
 405         }
 406
 407         devfreq_register_opp_notifier(dev, data->devfreq);
 408
 409         err = register_pm_notifier(&data->pm_notifier);
 410         if (err) {
 411                 dev_err(dev, "Failed to setup pm notifier\n");
 412                 goto err_devfreq_add;
 413         }
 414
 415         /* TODO: Add a new QOS class for int/mif bus */
 416         pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1);
 417
 418         return 0;
 419
 420 err_devfreq_add:
 421         devfreq_remove_device(data->devfreq);
 422         platform_set_drvdata(pdev, NULL);
 423 err_opp_add:
 424         clk_put(data->int_clk);
 425 err_clock:
 426         regulator_put(data->vdd_int);
 427 err_regulator:
 428         return err;
 429 }
 430
 431 static int exynos5_busfreq_int_remove(struct platform_device *pdev)
 432 {
 433         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 434
 435         pm_qos_remove_request(&data->int_req);
 436         unregister_pm_notifier(&data->pm_notifier);
 437         devfreq_remove_device(data->devfreq);
 438         regulator_put(data->vdd_int);
 439         clk_put(data->int_clk);
 440         platform_set_drvdata(pdev, NULL);
 441
 442         return 0;
 443 }
 444
 445 static int exynos5_busfreq_int_resume(struct device *dev)
 446 {
 447         struct platform_device *pdev = container_of(dev, struct platform_device,
 448                                                     dev);
 449         struct busfreq_data_int *data = platform_get_drvdata(pdev);
 450
 451         busfreq_mon_reset(data);
 452         return 0;
 453 }
 454
 455 static const struct dev_pm_ops exynos5_busfreq_int_pm = {
 456         .resume = exynos5_busfreq_int_resume,
 457 };
 458
 459 /* platform device pointer for exynos5 devfreq device. */
 460 static struct platform_device *exynos5_devfreq_pdev;
 461
 462 static struct platform_driver exynos5_busfreq_int_driver = {
 463         .probe          = exynos5_busfreq_int_probe,
 464         .remove         = exynos5_busfreq_int_remove,
 465         .driver         = {
 466                 .name           = "exynos5-bus-int",
 467                 .owner          = THIS_MODULE,
 468                 .pm             = &exynos5_busfreq_int_pm,
 469         },
 470 };
 471
 472 static int __init exynos5_busfreq_int_init(void)
 473 {
 474         int ret;
 475
 476         ret = platform_driver_register(&exynos5_busfreq_int_driver);
 477         if (ret < 0)
 478                 goto out;
 479
 480         exynos5_devfreq_pdev =
 481                 platform_device_register_simple("exynos5-bus-int", -1, NULL, 0);
 482         if (IS_ERR_OR_NULL(exynos5_devfreq_pdev)) {
 483                 ret = PTR_ERR(exynos5_devfreq_pdev);
 484                 goto out1;
 485         }
 486
 487         return 0;
 488 out1:
 489         platform_driver_unregister(&exynos5_busfreq_int_driver);
 490 out:
 491         return ret;
 492 }
 493 late_initcall(exynos5_busfreq_int_init);
 494
 495 static void __exit exynos5_busfreq_int_exit(void)
 496 {
 497         platform_device_unregister(exynos5_devfreq_pdev);
 498         platform_driver_unregister(&exynos5_busfreq_int_driver);
 499 }
 500 module_exit(exynos5_busfreq_int_exit);
 501
 502 MODULE_LICENSE("GPL");
 503 MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework");