| 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 busfreq_ppmu_data ppmu_data; |
| 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 int exynos5_int_setvolt(struct busfreq_data_int *data, |
| 79 | unsigned long volt) |
| 80 | { |
| 81 | return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT); |
| 82 | } |
| 83 | |
| 84 | static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq, |
| 85 | u32 flags) |
| 86 | { |
| 87 | int err = 0; |
| 88 | struct platform_device *pdev = container_of(dev, struct platform_device, |
| 89 | dev); |
| 90 | struct busfreq_data_int *data = platform_get_drvdata(pdev); |
| 91 | struct dev_pm_opp *opp; |
| 92 | unsigned long old_freq, freq; |
| 93 | unsigned long volt; |
| 94 | |
| 95 | rcu_read_lock(); |
| 96 | opp = devfreq_recommended_opp(dev, _freq, flags); |
| 97 | if (IS_ERR(opp)) { |
| 98 | rcu_read_unlock(); |
| 99 | dev_err(dev, "%s: Invalid OPP.\n", __func__); |
| 100 | return PTR_ERR(opp); |
| 101 | } |
| 102 | |
| 103 | freq = dev_pm_opp_get_freq(opp); |
| 104 | volt = dev_pm_opp_get_voltage(opp); |
| 105 | rcu_read_unlock(); |
| 106 | |
| 107 | old_freq = data->curr_freq; |
| 108 | |
| 109 | if (old_freq == freq) |
| 110 | return 0; |
| 111 | |
| 112 | dev_dbg(dev, "targeting %lukHz %luuV\n", freq, volt); |
| 113 | |
| 114 | mutex_lock(&data->lock); |
| 115 | |
| 116 | if (data->disabled) |
| 117 | goto out; |
| 118 | |
| 119 | if (freq > exynos5_int_opp_table[0].clk) |
| 120 | pm_qos_update_request(&data->int_req, freq * 16 / 1000); |
| 121 | else |
| 122 | pm_qos_update_request(&data->int_req, -1); |
| 123 | |
| 124 | if (old_freq < freq) |
| 125 | err = exynos5_int_setvolt(data, volt); |
| 126 | if (err) |
| 127 | goto out; |
| 128 | |
| 129 | err = clk_set_rate(data->int_clk, freq * 1000); |
| 130 | |
| 131 | if (err) |
| 132 | goto out; |
| 133 | |
| 134 | if (old_freq > freq) |
| 135 | err = exynos5_int_setvolt(data, volt); |
| 136 | if (err) |
| 137 | goto out; |
| 138 | |
| 139 | data->curr_freq = freq; |
| 140 | out: |
| 141 | mutex_unlock(&data->lock); |
| 142 | return err; |
| 143 | } |
| 144 | |
| 145 | static int exynos5_int_get_dev_status(struct device *dev, |
| 146 | struct devfreq_dev_status *stat) |
| 147 | { |
| 148 | struct platform_device *pdev = container_of(dev, struct platform_device, |
| 149 | dev); |
| 150 | struct busfreq_data_int *data = platform_get_drvdata(pdev); |
| 151 | struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data; |
| 152 | int busier_dmc; |
| 153 | |
| 154 | exynos_read_ppmu(ppmu_data); |
| 155 | busier_dmc = exynos_get_busier_ppmu(ppmu_data); |
| 156 | |
| 157 | stat->current_frequency = data->curr_freq; |
| 158 | |
| 159 | /* Number of cycles spent on memory access */ |
| 160 | stat->busy_time = ppmu_data->ppmu[busier_dmc].count[PPMU_PMNCNT3]; |
| 161 | stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO; |
| 162 | stat->total_time = ppmu_data->ppmu[busier_dmc].ccnt; |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static struct devfreq_dev_profile exynos5_devfreq_int_profile = { |
| 168 | .initial_freq = 160000, |
| 169 | .polling_ms = 100, |
| 170 | .target = exynos5_busfreq_int_target, |
| 171 | .get_dev_status = exynos5_int_get_dev_status, |
| 172 | }; |
| 173 | |
| 174 | static int exynos5250_init_int_tables(struct busfreq_data_int *data) |
| 175 | { |
| 176 | int i, err = 0; |
| 177 | |
| 178 | for (i = LV_0; i < _LV_END; i++) { |
| 179 | err = dev_pm_opp_add(data->dev, exynos5_int_opp_table[i].clk, |
| 180 | exynos5_int_opp_table[i].volt); |
| 181 | if (err) { |
| 182 | dev_err(data->dev, "Cannot add opp entries.\n"); |
| 183 | return err; |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this, |
| 191 | unsigned long event, void *ptr) |
| 192 | { |
| 193 | struct busfreq_data_int *data = container_of(this, |
| 194 | struct busfreq_data_int, pm_notifier); |
| 195 | struct dev_pm_opp *opp; |
| 196 | unsigned long maxfreq = ULONG_MAX; |
| 197 | unsigned long freq; |
| 198 | unsigned long volt; |
| 199 | int err = 0; |
| 200 | |
| 201 | switch (event) { |
| 202 | case PM_SUSPEND_PREPARE: |
| 203 | /* Set Fastest and Deactivate DVFS */ |
| 204 | mutex_lock(&data->lock); |
| 205 | |
| 206 | data->disabled = true; |
| 207 | |
| 208 | rcu_read_lock(); |
| 209 | opp = dev_pm_opp_find_freq_floor(data->dev, &maxfreq); |
| 210 | if (IS_ERR(opp)) { |
| 211 | rcu_read_unlock(); |
| 212 | err = PTR_ERR(opp); |
| 213 | goto unlock; |
| 214 | } |
| 215 | freq = dev_pm_opp_get_freq(opp); |
| 216 | volt = dev_pm_opp_get_voltage(opp); |
| 217 | rcu_read_unlock(); |
| 218 | |
| 219 | err = exynos5_int_setvolt(data, volt); |
| 220 | if (err) |
| 221 | goto unlock; |
| 222 | |
| 223 | err = clk_set_rate(data->int_clk, freq * 1000); |
| 224 | |
| 225 | if (err) |
| 226 | goto unlock; |
| 227 | |
| 228 | data->curr_freq = freq; |
| 229 | unlock: |
| 230 | mutex_unlock(&data->lock); |
| 231 | if (err) |
| 232 | return NOTIFY_BAD; |
| 233 | return NOTIFY_OK; |
| 234 | case PM_POST_RESTORE: |
| 235 | case PM_POST_SUSPEND: |
| 236 | /* Reactivate */ |
| 237 | mutex_lock(&data->lock); |
| 238 | data->disabled = false; |
| 239 | mutex_unlock(&data->lock); |
| 240 | return NOTIFY_OK; |
| 241 | } |
| 242 | |
| 243 | return NOTIFY_DONE; |
| 244 | } |
| 245 | |
| 246 | static int exynos5_busfreq_int_probe(struct platform_device *pdev) |
| 247 | { |
| 248 | struct busfreq_data_int *data; |
| 249 | struct busfreq_ppmu_data *ppmu_data; |
| 250 | struct dev_pm_opp *opp; |
| 251 | struct device *dev = &pdev->dev; |
| 252 | struct device_node *np; |
| 253 | unsigned long initial_freq; |
| 254 | unsigned long initial_volt; |
| 255 | int err = 0; |
| 256 | int i; |
| 257 | |
| 258 | data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int), |
| 259 | GFP_KERNEL); |
| 260 | if (data == NULL) { |
| 261 | dev_err(dev, "Cannot allocate memory.\n"); |
| 262 | return -ENOMEM; |
| 263 | } |
| 264 | |
| 265 | ppmu_data = &data->ppmu_data; |
| 266 | ppmu_data->ppmu_end = PPMU_END; |
| 267 | ppmu_data->ppmu = devm_kzalloc(dev, |
| 268 | sizeof(struct exynos_ppmu) * PPMU_END, |
| 269 | GFP_KERNEL); |
| 270 | if (!ppmu_data->ppmu) { |
| 271 | dev_err(dev, "Failed to allocate memory for exynos_ppmu\n"); |
| 272 | return -ENOMEM; |
| 273 | } |
| 274 | |
| 275 | np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu"); |
| 276 | if (np == NULL) { |
| 277 | pr_err("Unable to find PPMU node\n"); |
| 278 | return -ENOENT; |
| 279 | } |
| 280 | |
| 281 | for (i = 0; i < ppmu_data->ppmu_end; i++) { |
| 282 | /* map PPMU memory region */ |
| 283 | ppmu_data->ppmu[i].hw_base = of_iomap(np, i); |
| 284 | if (ppmu_data->ppmu[i].hw_base == NULL) { |
| 285 | dev_err(&pdev->dev, "failed to map memory region\n"); |
| 286 | return -ENOMEM; |
| 287 | } |
| 288 | } |
| 289 | data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event; |
| 290 | data->dev = dev; |
| 291 | mutex_init(&data->lock); |
| 292 | |
| 293 | err = exynos5250_init_int_tables(data); |
| 294 | if (err) |
| 295 | return err; |
| 296 | |
| 297 | data->vdd_int = devm_regulator_get(dev, "vdd_int"); |
| 298 | if (IS_ERR(data->vdd_int)) { |
| 299 | dev_err(dev, "Cannot get the regulator \"vdd_int\"\n"); |
| 300 | return PTR_ERR(data->vdd_int); |
| 301 | } |
| 302 | |
| 303 | data->int_clk = devm_clk_get(dev, "int_clk"); |
| 304 | if (IS_ERR(data->int_clk)) { |
| 305 | dev_err(dev, "Cannot get clock \"int_clk\"\n"); |
| 306 | return PTR_ERR(data->int_clk); |
| 307 | } |
| 308 | |
| 309 | rcu_read_lock(); |
| 310 | opp = dev_pm_opp_find_freq_floor(dev, |
| 311 | &exynos5_devfreq_int_profile.initial_freq); |
| 312 | if (IS_ERR(opp)) { |
| 313 | rcu_read_unlock(); |
| 314 | dev_err(dev, "Invalid initial frequency %lu kHz.\n", |
| 315 | exynos5_devfreq_int_profile.initial_freq); |
| 316 | return PTR_ERR(opp); |
| 317 | } |
| 318 | initial_freq = dev_pm_opp_get_freq(opp); |
| 319 | initial_volt = dev_pm_opp_get_voltage(opp); |
| 320 | rcu_read_unlock(); |
| 321 | data->curr_freq = initial_freq; |
| 322 | |
| 323 | err = clk_set_rate(data->int_clk, initial_freq * 1000); |
| 324 | if (err) { |
| 325 | dev_err(dev, "Failed to set initial frequency\n"); |
| 326 | return err; |
| 327 | } |
| 328 | |
| 329 | err = exynos5_int_setvolt(data, initial_volt); |
| 330 | if (err) |
| 331 | return err; |
| 332 | |
| 333 | platform_set_drvdata(pdev, data); |
| 334 | |
| 335 | busfreq_mon_reset(ppmu_data); |
| 336 | |
| 337 | data->devfreq = devm_devfreq_add_device(dev, &exynos5_devfreq_int_profile, |
| 338 | "simple_ondemand", NULL); |
| 339 | if (IS_ERR(data->devfreq)) |
| 340 | return PTR_ERR(data->devfreq); |
| 341 | |
| 342 | err = devm_devfreq_register_opp_notifier(dev, data->devfreq); |
| 343 | if (err < 0) { |
| 344 | dev_err(dev, "Failed to register opp notifier\n"); |
| 345 | return err; |
| 346 | } |
| 347 | |
| 348 | err = register_pm_notifier(&data->pm_notifier); |
| 349 | if (err) { |
| 350 | dev_err(dev, "Failed to setup pm notifier\n"); |
| 351 | return err; |
| 352 | } |
| 353 | |
| 354 | /* TODO: Add a new QOS class for int/mif bus */ |
| 355 | pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1); |
| 356 | |
| 357 | return 0; |
| 358 | } |
| 359 | |
| 360 | static int exynos5_busfreq_int_remove(struct platform_device *pdev) |
| 361 | { |
| 362 | struct busfreq_data_int *data = platform_get_drvdata(pdev); |
| 363 | |
| 364 | pm_qos_remove_request(&data->int_req); |
| 365 | unregister_pm_notifier(&data->pm_notifier); |
| 366 | |
| 367 | return 0; |
| 368 | } |
| 369 | |
| 370 | #ifdef CONFIG_PM_SLEEP |
| 371 | static int exynos5_busfreq_int_resume(struct device *dev) |
| 372 | { |
| 373 | struct platform_device *pdev = container_of(dev, struct platform_device, |
| 374 | dev); |
| 375 | struct busfreq_data_int *data = platform_get_drvdata(pdev); |
| 376 | struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data; |
| 377 | |
| 378 | busfreq_mon_reset(ppmu_data); |
| 379 | return 0; |
| 380 | } |
| 381 | static const struct dev_pm_ops exynos5_busfreq_int_pm = { |
| 382 | .resume = exynos5_busfreq_int_resume, |
| 383 | }; |
| 384 | #endif |
| 385 | static SIMPLE_DEV_PM_OPS(exynos5_busfreq_int_pm_ops, NULL, |
| 386 | exynos5_busfreq_int_resume); |
| 387 | |
| 388 | /* platform device pointer for exynos5 devfreq device. */ |
| 389 | static struct platform_device *exynos5_devfreq_pdev; |
| 390 | |
| 391 | static struct platform_driver exynos5_busfreq_int_driver = { |
| 392 | .probe = exynos5_busfreq_int_probe, |
| 393 | .remove = exynos5_busfreq_int_remove, |
| 394 | .driver = { |
| 395 | .name = "exynos5-bus-int", |
| 396 | .pm = &exynos5_busfreq_int_pm_ops, |
| 397 | }, |
| 398 | }; |
| 399 | |
| 400 | static int __init exynos5_busfreq_int_init(void) |
| 401 | { |
| 402 | int ret; |
| 403 | |
| 404 | ret = platform_driver_register(&exynos5_busfreq_int_driver); |
| 405 | if (ret < 0) |
| 406 | goto out; |
| 407 | |
| 408 | exynos5_devfreq_pdev = |
| 409 | platform_device_register_simple("exynos5-bus-int", -1, NULL, 0); |
| 410 | if (IS_ERR(exynos5_devfreq_pdev)) { |
| 411 | ret = PTR_ERR(exynos5_devfreq_pdev); |
| 412 | goto out1; |
| 413 | } |
| 414 | |
| 415 | return 0; |
| 416 | out1: |
| 417 | platform_driver_unregister(&exynos5_busfreq_int_driver); |
| 418 | out: |
| 419 | return ret; |
| 420 | } |
| 421 | late_initcall(exynos5_busfreq_int_init); |
| 422 | |
| 423 | static void __exit exynos5_busfreq_int_exit(void) |
| 424 | { |
| 425 | platform_device_unregister(exynos5_devfreq_pdev); |
| 426 | platform_driver_unregister(&exynos5_busfreq_int_driver); |
| 427 | } |
| 428 | module_exit(exynos5_busfreq_int_exit); |
| 429 | |
| 430 | MODULE_LICENSE("GPL"); |
| 431 | MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework"); |