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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0722249a CC |
2 | /* |
3 | * Generic Exynos Bus frequency driver with DEVFREQ Framework | |
4 | * | |
403e0689 | 5 | * Copyright (c) 2016 Samsung Electronics Co., Ltd. |
0722249a CC |
6 | * Author : Chanwoo Choi <cw00.choi@samsung.com> |
7 | * | |
8 | * This driver support Exynos Bus frequency feature by using | |
9 | * DEVFREQ framework and is based on drivers/devfreq/exynos/exynos4_bus.c. | |
0722249a CC |
10 | */ |
11 | ||
12 | #include <linux/clk.h> | |
13 | #include <linux/devfreq.h> | |
14 | #include <linux/devfreq-event.h> | |
15 | #include <linux/device.h> | |
16 | #include <linux/export.h> | |
17 | #include <linux/module.h> | |
a4408921 | 18 | #include <linux/of.h> |
0722249a CC |
19 | #include <linux/pm_opp.h> |
20 | #include <linux/platform_device.h> | |
21 | #include <linux/regulator/consumer.h> | |
0722249a CC |
22 | |
23 | #define DEFAULT_SATURATION_RATIO 40 | |
0722249a CC |
24 | |
25 | struct exynos_bus { | |
26 | struct device *dev; | |
404d59c5 | 27 | struct platform_device *icc_pdev; |
0722249a CC |
28 | |
29 | struct devfreq *devfreq; | |
30 | struct devfreq_event_dev **edev; | |
31 | unsigned int edev_count; | |
32 | struct mutex lock; | |
33 | ||
c8ce82b9 | 34 | unsigned long curr_freq; |
0722249a | 35 | |
b0ec0942 | 36 | int opp_token; |
0722249a | 37 | struct clk *clk; |
0722249a CC |
38 | unsigned int ratio; |
39 | }; | |
40 | ||
41 | /* | |
42 | * Control the devfreq-event device to get the current state of bus | |
43 | */ | |
44 | #define exynos_bus_ops_edev(ops) \ | |
45 | static int exynos_bus_##ops(struct exynos_bus *bus) \ | |
46 | { \ | |
47 | int i, ret; \ | |
48 | \ | |
49 | for (i = 0; i < bus->edev_count; i++) { \ | |
50 | if (!bus->edev[i]) \ | |
51 | continue; \ | |
52 | ret = devfreq_event_##ops(bus->edev[i]); \ | |
53 | if (ret < 0) \ | |
54 | return ret; \ | |
55 | } \ | |
56 | \ | |
57 | return 0; \ | |
58 | } | |
59 | exynos_bus_ops_edev(enable_edev); | |
60 | exynos_bus_ops_edev(disable_edev); | |
61 | exynos_bus_ops_edev(set_event); | |
62 | ||
63 | static int exynos_bus_get_event(struct exynos_bus *bus, | |
64 | struct devfreq_event_data *edata) | |
65 | { | |
66 | struct devfreq_event_data event_data; | |
67 | unsigned long load_count = 0, total_count = 0; | |
68 | int i, ret = 0; | |
69 | ||
70 | for (i = 0; i < bus->edev_count; i++) { | |
71 | if (!bus->edev[i]) | |
72 | continue; | |
73 | ||
74 | ret = devfreq_event_get_event(bus->edev[i], &event_data); | |
75 | if (ret < 0) | |
76 | return ret; | |
77 | ||
78 | if (i == 0 || event_data.load_count > load_count) { | |
79 | load_count = event_data.load_count; | |
80 | total_count = event_data.total_count; | |
81 | } | |
82 | } | |
83 | ||
84 | edata->load_count = load_count; | |
85 | edata->total_count = total_count; | |
86 | ||
87 | return ret; | |
88 | } | |
89 | ||
90 | /* | |
4294a779 | 91 | * devfreq function for both simple-ondemand and passive governor |
0722249a CC |
92 | */ |
93 | static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags) | |
94 | { | |
95 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
96 | struct dev_pm_opp *new_opp; | |
0722249a CC |
97 | int ret = 0; |
98 | ||
4294a779 | 99 | /* Get correct frequency for bus. */ |
0722249a CC |
100 | new_opp = devfreq_recommended_opp(dev, freq, flags); |
101 | if (IS_ERR(new_opp)) { | |
102 | dev_err(dev, "failed to get recommended opp instance\n"); | |
0722249a CC |
103 | return PTR_ERR(new_opp); |
104 | } | |
105 | ||
8a31d9d9 VK |
106 | dev_pm_opp_put(new_opp); |
107 | ||
0722249a CC |
108 | /* Change voltage and frequency according to new OPP level */ |
109 | mutex_lock(&bus->lock); | |
4294a779 KK |
110 | ret = dev_pm_opp_set_rate(dev, *freq); |
111 | if (!ret) | |
112 | bus->curr_freq = *freq; | |
0722249a | 113 | |
0722249a CC |
114 | mutex_unlock(&bus->lock); |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
119 | static int exynos_bus_get_dev_status(struct device *dev, | |
120 | struct devfreq_dev_status *stat) | |
121 | { | |
122 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
123 | struct devfreq_event_data edata; | |
124 | int ret; | |
125 | ||
c8ce82b9 | 126 | stat->current_frequency = bus->curr_freq; |
0722249a CC |
127 | |
128 | ret = exynos_bus_get_event(bus, &edata); | |
129 | if (ret < 0) { | |
28135762 | 130 | dev_err(dev, "failed to get event from devfreq-event devices\n"); |
0722249a CC |
131 | stat->total_time = stat->busy_time = 0; |
132 | goto err; | |
133 | } | |
134 | ||
135 | stat->busy_time = (edata.load_count * 100) / bus->ratio; | |
136 | stat->total_time = edata.total_count; | |
137 | ||
138 | dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time, | |
139 | stat->total_time); | |
140 | ||
141 | err: | |
142 | ret = exynos_bus_set_event(bus); | |
143 | if (ret < 0) { | |
144 | dev_err(dev, "failed to set event to devfreq-event devices\n"); | |
145 | return ret; | |
146 | } | |
147 | ||
148 | return ret; | |
149 | } | |
150 | ||
151 | static void exynos_bus_exit(struct device *dev) | |
152 | { | |
153 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
154 | int ret; | |
155 | ||
156 | ret = exynos_bus_disable_edev(bus); | |
157 | if (ret < 0) | |
158 | dev_warn(dev, "failed to disable the devfreq-event devices\n"); | |
159 | ||
404d59c5 SN |
160 | platform_device_unregister(bus->icc_pdev); |
161 | ||
0722249a | 162 | dev_pm_opp_of_remove_table(dev); |
403e0689 | 163 | clk_disable_unprepare(bus->clk); |
b0ec0942 | 164 | dev_pm_opp_put_regulators(bus->opp_token); |
403e0689 CC |
165 | } |
166 | ||
167 | static void exynos_bus_passive_exit(struct device *dev) | |
168 | { | |
169 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
170 | ||
404d59c5 SN |
171 | platform_device_unregister(bus->icc_pdev); |
172 | ||
403e0689 CC |
173 | dev_pm_opp_of_remove_table(dev); |
174 | clk_disable_unprepare(bus->clk); | |
175 | } | |
176 | ||
177 | static int exynos_bus_parent_parse_of(struct device_node *np, | |
178 | struct exynos_bus *bus) | |
179 | { | |
180 | struct device *dev = bus->dev; | |
87686cc8 | 181 | const char *supplies[] = { "vdd", NULL }; |
403e0689 | 182 | int i, ret, count, size; |
0722249a | 183 | |
b0ec0942 VK |
184 | ret = dev_pm_opp_set_regulators(dev, supplies); |
185 | if (ret < 0) { | |
4294a779 | 186 | dev_err(dev, "failed to set regulators %d\n", ret); |
403e0689 | 187 | return ret; |
0722249a CC |
188 | } |
189 | ||
b0ec0942 | 190 | bus->opp_token = ret; |
4294a779 | 191 | |
0722249a CC |
192 | /* |
193 | * Get the devfreq-event devices to get the current utilization of | |
194 | * buses. This raw data will be used in devfreq ondemand governor. | |
195 | */ | |
02bdbf7d | 196 | count = devfreq_event_get_edev_count(dev, "devfreq-events"); |
0722249a CC |
197 | if (count < 0) { |
198 | dev_err(dev, "failed to get the count of devfreq-event dev\n"); | |
199 | ret = count; | |
200 | goto err_regulator; | |
201 | } | |
202 | bus->edev_count = count; | |
203 | ||
204 | size = sizeof(*bus->edev) * count; | |
205 | bus->edev = devm_kzalloc(dev, size, GFP_KERNEL); | |
206 | if (!bus->edev) { | |
207 | ret = -ENOMEM; | |
208 | goto err_regulator; | |
209 | } | |
210 | ||
211 | for (i = 0; i < count; i++) { | |
02bdbf7d CC |
212 | bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, |
213 | "devfreq-events", i); | |
0722249a CC |
214 | if (IS_ERR(bus->edev[i])) { |
215 | ret = -EPROBE_DEFER; | |
216 | goto err_regulator; | |
217 | } | |
218 | } | |
219 | ||
220 | /* | |
221 | * Optionally, Get the saturation ratio according to Exynos SoC | |
222 | * When measuring the utilization of each AXI bus with devfreq-event | |
223 | * devices, the measured real cycle might be much lower than the | |
224 | * total cycle of bus during sampling rate. In result, the devfreq | |
225 | * simple-ondemand governor might not decide to change the current | |
226 | * frequency due to too utilization (= real cycle/total cycle). | |
227 | * So, this property is used to adjust the utilization when calculating | |
228 | * the busy_time in exynos_bus_get_dev_status(). | |
229 | */ | |
230 | if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio)) | |
231 | bus->ratio = DEFAULT_SATURATION_RATIO; | |
232 | ||
0722249a CC |
233 | return 0; |
234 | ||
235 | err_regulator: | |
b0ec0942 | 236 | dev_pm_opp_put_regulators(bus->opp_token); |
403e0689 CC |
237 | |
238 | return ret; | |
239 | } | |
240 | ||
241 | static int exynos_bus_parse_of(struct device_node *np, | |
242 | struct exynos_bus *bus) | |
243 | { | |
244 | struct device *dev = bus->dev; | |
c8ce82b9 | 245 | struct dev_pm_opp *opp; |
403e0689 CC |
246 | unsigned long rate; |
247 | int ret; | |
248 | ||
249 | /* Get the clock to provide each bus with source clock */ | |
250 | bus->clk = devm_clk_get(dev, "bus"); | |
251 | if (IS_ERR(bus->clk)) { | |
252 | dev_err(dev, "failed to get bus clock\n"); | |
253 | return PTR_ERR(bus->clk); | |
254 | } | |
255 | ||
256 | ret = clk_prepare_enable(bus->clk); | |
257 | if (ret < 0) { | |
258 | dev_err(dev, "failed to get enable clock\n"); | |
259 | return ret; | |
260 | } | |
261 | ||
262 | /* Get the freq and voltage from OPP table to scale the bus freq */ | |
403e0689 CC |
263 | ret = dev_pm_opp_of_add_table(dev); |
264 | if (ret < 0) { | |
265 | dev_err(dev, "failed to get OPP table\n"); | |
403e0689 CC |
266 | goto err_clk; |
267 | } | |
268 | ||
269 | rate = clk_get_rate(bus->clk); | |
c8ce82b9 | 270 | |
c8ce82b9 VK |
271 | opp = devfreq_recommended_opp(dev, &rate, 0); |
272 | if (IS_ERR(opp)) { | |
403e0689 | 273 | dev_err(dev, "failed to find dev_pm_opp\n"); |
c8ce82b9 | 274 | ret = PTR_ERR(opp); |
403e0689 CC |
275 | goto err_opp; |
276 | } | |
c8ce82b9 | 277 | bus->curr_freq = dev_pm_opp_get_freq(opp); |
8a31d9d9 | 278 | dev_pm_opp_put(opp); |
403e0689 CC |
279 | |
280 | return 0; | |
281 | ||
0722249a CC |
282 | err_opp: |
283 | dev_pm_opp_of_remove_table(dev); | |
284 | err_clk: | |
285 | clk_disable_unprepare(bus->clk); | |
286 | ||
287 | return ret; | |
288 | } | |
289 | ||
a47a97ec AŚ |
290 | static int exynos_bus_profile_init(struct exynos_bus *bus, |
291 | struct devfreq_dev_profile *profile) | |
0722249a | 292 | { |
a47a97ec | 293 | struct device *dev = bus->dev; |
0722249a | 294 | struct devfreq_simple_ondemand_data *ondemand_data; |
a47a97ec | 295 | int ret; |
403e0689 | 296 | |
83cb0e4d | 297 | /* Initialize the struct profile and governor data for parent device */ |
0722249a CC |
298 | profile->polling_ms = 50; |
299 | profile->target = exynos_bus_target; | |
300 | profile->get_dev_status = exynos_bus_get_dev_status; | |
301 | profile->exit = exynos_bus_exit; | |
302 | ||
303 | ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL); | |
a4408921 AŚ |
304 | if (!ondemand_data) |
305 | return -ENOMEM; | |
306 | ||
0722249a CC |
307 | ondemand_data->upthreshold = 40; |
308 | ondemand_data->downdifferential = 5; | |
309 | ||
310 | /* Add devfreq device to monitor and handle the exynos bus */ | |
aa7c352f CC |
311 | bus->devfreq = devm_devfreq_add_device(dev, profile, |
312 | DEVFREQ_GOV_SIMPLE_ONDEMAND, | |
0722249a CC |
313 | ondemand_data); |
314 | if (IS_ERR(bus->devfreq)) { | |
315 | dev_err(dev, "failed to add devfreq device\n"); | |
a4408921 | 316 | return PTR_ERR(bus->devfreq); |
0722249a CC |
317 | } |
318 | ||
319 | /* Register opp_notifier to catch the change of OPP */ | |
320 | ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq); | |
321 | if (ret < 0) { | |
322 | dev_err(dev, "failed to register opp notifier\n"); | |
a4408921 | 323 | return ret; |
0722249a CC |
324 | } |
325 | ||
326 | /* | |
327 | * Enable devfreq-event to get raw data which is used to determine | |
328 | * current bus load. | |
329 | */ | |
330 | ret = exynos_bus_enable_edev(bus); | |
331 | if (ret < 0) { | |
332 | dev_err(dev, "failed to enable devfreq-event devices\n"); | |
a4408921 | 333 | return ret; |
0722249a CC |
334 | } |
335 | ||
336 | ret = exynos_bus_set_event(bus); | |
337 | if (ret < 0) { | |
338 | dev_err(dev, "failed to set event to devfreq-event devices\n"); | |
6c315d8f | 339 | goto err_edev; |
0722249a CC |
340 | } |
341 | ||
a4408921 | 342 | return 0; |
6c315d8f YL |
343 | |
344 | err_edev: | |
345 | if (exynos_bus_disable_edev(bus)) | |
346 | dev_warn(dev, "failed to disable the devfreq-event devices\n"); | |
347 | ||
348 | return ret; | |
a47a97ec AŚ |
349 | } |
350 | ||
a05bb963 AŚ |
351 | static int exynos_bus_profile_init_passive(struct exynos_bus *bus, |
352 | struct devfreq_dev_profile *profile) | |
353 | { | |
354 | struct device *dev = bus->dev; | |
355 | struct devfreq_passive_data *passive_data; | |
356 | struct devfreq *parent_devfreq; | |
a05bb963 AŚ |
357 | |
358 | /* Initialize the struct profile and governor data for passive device */ | |
359 | profile->target = exynos_bus_target; | |
360 | profile->exit = exynos_bus_passive_exit; | |
361 | ||
362 | /* Get the instance of parent devfreq device */ | |
86d90fd9 | 363 | parent_devfreq = devfreq_get_devfreq_by_phandle(dev, "devfreq", 0); |
a4408921 AŚ |
364 | if (IS_ERR(parent_devfreq)) |
365 | return -EPROBE_DEFER; | |
a05bb963 AŚ |
366 | |
367 | passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL); | |
a4408921 AŚ |
368 | if (!passive_data) |
369 | return -ENOMEM; | |
370 | ||
a05bb963 AŚ |
371 | passive_data->parent = parent_devfreq; |
372 | ||
373 | /* Add devfreq device for exynos bus with passive governor */ | |
374 | bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE, | |
375 | passive_data); | |
376 | if (IS_ERR(bus->devfreq)) { | |
377 | dev_err(dev, | |
378 | "failed to add devfreq dev with passive governor\n"); | |
a4408921 | 379 | return PTR_ERR(bus->devfreq); |
a05bb963 AŚ |
380 | } |
381 | ||
a4408921 | 382 | return 0; |
a05bb963 AŚ |
383 | } |
384 | ||
a47a97ec AŚ |
385 | static int exynos_bus_probe(struct platform_device *pdev) |
386 | { | |
387 | struct device *dev = &pdev->dev; | |
388 | struct device_node *np = dev->of_node, *node; | |
389 | struct devfreq_dev_profile *profile; | |
a47a97ec AŚ |
390 | struct exynos_bus *bus; |
391 | int ret, max_state; | |
392 | unsigned long min_freq, max_freq; | |
393 | bool passive = false; | |
394 | ||
395 | if (!np) { | |
396 | dev_err(dev, "failed to find devicetree node\n"); | |
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); | |
401 | if (!bus) | |
402 | return -ENOMEM; | |
403 | mutex_init(&bus->lock); | |
404 | bus->dev = &pdev->dev; | |
405 | platform_set_drvdata(pdev, bus); | |
406 | ||
407 | profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL); | |
408 | if (!profile) | |
409 | return -ENOMEM; | |
410 | ||
411 | node = of_parse_phandle(dev->of_node, "devfreq", 0); | |
412 | if (node) { | |
413 | of_node_put(node); | |
414 | passive = true; | |
415 | } else { | |
416 | ret = exynos_bus_parent_parse_of(np, bus); | |
417 | if (ret < 0) | |
418 | return ret; | |
419 | } | |
420 | ||
421 | /* Parse the device-tree to get the resource information */ | |
422 | ret = exynos_bus_parse_of(np, bus); | |
423 | if (ret < 0) | |
424 | goto err_reg; | |
425 | ||
426 | if (passive) | |
a4408921 AŚ |
427 | ret = exynos_bus_profile_init_passive(bus, profile); |
428 | else | |
429 | ret = exynos_bus_profile_init(bus, profile); | |
a47a97ec | 430 | |
a05bb963 | 431 | if (ret < 0) |
403e0689 | 432 | goto err; |
403e0689 | 433 | |
404d59c5 | 434 | /* Create child platform device for the interconnect provider */ |
b7405e3f | 435 | if (of_property_present(dev->of_node, "#interconnect-cells")) { |
404d59c5 SN |
436 | bus->icc_pdev = platform_device_register_data( |
437 | dev, "exynos-generic-icc", | |
438 | PLATFORM_DEVID_AUTO, NULL, 0); | |
439 | ||
440 | if (IS_ERR(bus->icc_pdev)) { | |
441 | ret = PTR_ERR(bus->icc_pdev); | |
442 | goto err; | |
443 | } | |
444 | } | |
445 | ||
c8934e4e CM |
446 | max_state = bus->devfreq->max_state; |
447 | min_freq = (bus->devfreq->freq_table[0] / 1000); | |
448 | max_freq = (bus->devfreq->freq_table[max_state - 1] / 1000); | |
403e0689 CC |
449 | pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n", |
450 | dev_name(dev), min_freq, max_freq); | |
451 | ||
0722249a | 452 | return 0; |
403e0689 CC |
453 | |
454 | err: | |
455 | dev_pm_opp_of_remove_table(dev); | |
456 | clk_disable_unprepare(bus->clk); | |
2c2b20e0 | 457 | err_reg: |
b0ec0942 | 458 | dev_pm_opp_put_regulators(bus->opp_token); |
403e0689 CC |
459 | |
460 | return ret; | |
0722249a CC |
461 | } |
462 | ||
fbb9c3c9 MS |
463 | static void exynos_bus_shutdown(struct platform_device *pdev) |
464 | { | |
465 | struct exynos_bus *bus = dev_get_drvdata(&pdev->dev); | |
466 | ||
467 | devfreq_suspend_device(bus->devfreq); | |
468 | } | |
469 | ||
0722249a CC |
470 | #ifdef CONFIG_PM_SLEEP |
471 | static int exynos_bus_resume(struct device *dev) | |
472 | { | |
473 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
474 | int ret; | |
475 | ||
476 | ret = exynos_bus_enable_edev(bus); | |
477 | if (ret < 0) { | |
478 | dev_err(dev, "failed to enable the devfreq-event devices\n"); | |
479 | return ret; | |
480 | } | |
481 | ||
482 | return 0; | |
483 | } | |
484 | ||
485 | static int exynos_bus_suspend(struct device *dev) | |
486 | { | |
487 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
488 | int ret; | |
489 | ||
490 | ret = exynos_bus_disable_edev(bus); | |
491 | if (ret < 0) { | |
492 | dev_err(dev, "failed to disable the devfreq-event devices\n"); | |
493 | return ret; | |
494 | } | |
495 | ||
496 | return 0; | |
497 | } | |
498 | #endif | |
499 | ||
500 | static const struct dev_pm_ops exynos_bus_pm = { | |
501 | SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume) | |
502 | }; | |
503 | ||
504 | static const struct of_device_id exynos_bus_of_match[] = { | |
505 | { .compatible = "samsung,exynos-bus", }, | |
506 | { /* sentinel */ }, | |
507 | }; | |
508 | MODULE_DEVICE_TABLE(of, exynos_bus_of_match); | |
509 | ||
510 | static struct platform_driver exynos_bus_platdrv = { | |
511 | .probe = exynos_bus_probe, | |
fbb9c3c9 | 512 | .shutdown = exynos_bus_shutdown, |
0722249a CC |
513 | .driver = { |
514 | .name = "exynos-bus", | |
515 | .pm = &exynos_bus_pm, | |
f9d0393a | 516 | .of_match_table = exynos_bus_of_match, |
0722249a CC |
517 | }, |
518 | }; | |
519 | module_platform_driver(exynos_bus_platdrv); | |
520 | ||
ccb69e22 | 521 | MODULE_SOFTDEP("pre: exynos_ppmu"); |
0722249a CC |
522 | MODULE_DESCRIPTION("Generic Exynos Bus frequency driver"); |
523 | MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>"); | |
524 | MODULE_LICENSE("GPL v2"); |