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0722249a CC |
1 | /* |
2 | * Generic Exynos Bus frequency driver with DEVFREQ Framework | |
3 | * | |
403e0689 | 4 | * Copyright (c) 2016 Samsung Electronics Co., Ltd. |
0722249a CC |
5 | * Author : Chanwoo Choi <cw00.choi@samsung.com> |
6 | * | |
7 | * This driver support Exynos Bus frequency feature by using | |
8 | * DEVFREQ framework and is based on drivers/devfreq/exynos/exynos4_bus.c. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/clk.h> | |
16 | #include <linux/devfreq.h> | |
17 | #include <linux/devfreq-event.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/export.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/of_device.h> | |
22 | #include <linux/pm_opp.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/regulator/consumer.h> | |
25 | #include <linux/slab.h> | |
26 | ||
27 | #define DEFAULT_SATURATION_RATIO 40 | |
28 | #define DEFAULT_VOLTAGE_TOLERANCE 2 | |
29 | ||
30 | struct exynos_bus { | |
31 | struct device *dev; | |
32 | ||
33 | struct devfreq *devfreq; | |
34 | struct devfreq_event_dev **edev; | |
35 | unsigned int edev_count; | |
36 | struct mutex lock; | |
37 | ||
c8ce82b9 | 38 | unsigned long curr_freq; |
0722249a CC |
39 | |
40 | struct regulator *regulator; | |
41 | struct clk *clk; | |
42 | unsigned int voltage_tolerance; | |
43 | unsigned int ratio; | |
44 | }; | |
45 | ||
46 | /* | |
47 | * Control the devfreq-event device to get the current state of bus | |
48 | */ | |
49 | #define exynos_bus_ops_edev(ops) \ | |
50 | static int exynos_bus_##ops(struct exynos_bus *bus) \ | |
51 | { \ | |
52 | int i, ret; \ | |
53 | \ | |
54 | for (i = 0; i < bus->edev_count; i++) { \ | |
55 | if (!bus->edev[i]) \ | |
56 | continue; \ | |
57 | ret = devfreq_event_##ops(bus->edev[i]); \ | |
58 | if (ret < 0) \ | |
59 | return ret; \ | |
60 | } \ | |
61 | \ | |
62 | return 0; \ | |
63 | } | |
64 | exynos_bus_ops_edev(enable_edev); | |
65 | exynos_bus_ops_edev(disable_edev); | |
66 | exynos_bus_ops_edev(set_event); | |
67 | ||
68 | static int exynos_bus_get_event(struct exynos_bus *bus, | |
69 | struct devfreq_event_data *edata) | |
70 | { | |
71 | struct devfreq_event_data event_data; | |
72 | unsigned long load_count = 0, total_count = 0; | |
73 | int i, ret = 0; | |
74 | ||
75 | for (i = 0; i < bus->edev_count; i++) { | |
76 | if (!bus->edev[i]) | |
77 | continue; | |
78 | ||
79 | ret = devfreq_event_get_event(bus->edev[i], &event_data); | |
80 | if (ret < 0) | |
81 | return ret; | |
82 | ||
83 | if (i == 0 || event_data.load_count > load_count) { | |
84 | load_count = event_data.load_count; | |
85 | total_count = event_data.total_count; | |
86 | } | |
87 | } | |
88 | ||
89 | edata->load_count = load_count; | |
90 | edata->total_count = total_count; | |
91 | ||
92 | return ret; | |
93 | } | |
94 | ||
95 | /* | |
403e0689 | 96 | * Must necessary function for devfreq simple-ondemand governor |
0722249a CC |
97 | */ |
98 | static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags) | |
99 | { | |
100 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
101 | struct dev_pm_opp *new_opp; | |
c8ce82b9 | 102 | unsigned long old_freq, new_freq, new_volt, tol; |
0722249a CC |
103 | int ret = 0; |
104 | ||
105 | /* Get new opp-bus instance according to new bus clock */ | |
106 | rcu_read_lock(); | |
107 | new_opp = devfreq_recommended_opp(dev, freq, flags); | |
108 | if (IS_ERR(new_opp)) { | |
109 | dev_err(dev, "failed to get recommended opp instance\n"); | |
110 | rcu_read_unlock(); | |
111 | return PTR_ERR(new_opp); | |
112 | } | |
113 | ||
114 | new_freq = dev_pm_opp_get_freq(new_opp); | |
115 | new_volt = dev_pm_opp_get_voltage(new_opp); | |
c8ce82b9 | 116 | old_freq = bus->curr_freq; |
0722249a CC |
117 | rcu_read_unlock(); |
118 | ||
119 | if (old_freq == new_freq) | |
120 | return 0; | |
121 | tol = new_volt * bus->voltage_tolerance / 100; | |
122 | ||
123 | /* Change voltage and frequency according to new OPP level */ | |
124 | mutex_lock(&bus->lock); | |
125 | ||
126 | if (old_freq < new_freq) { | |
127 | ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol); | |
128 | if (ret < 0) { | |
129 | dev_err(bus->dev, "failed to set voltage\n"); | |
130 | goto out; | |
131 | } | |
132 | } | |
133 | ||
134 | ret = clk_set_rate(bus->clk, new_freq); | |
135 | if (ret < 0) { | |
136 | dev_err(dev, "failed to change clock of bus\n"); | |
137 | clk_set_rate(bus->clk, old_freq); | |
138 | goto out; | |
139 | } | |
140 | ||
141 | if (old_freq > new_freq) { | |
142 | ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol); | |
143 | if (ret < 0) { | |
144 | dev_err(bus->dev, "failed to set voltage\n"); | |
145 | goto out; | |
146 | } | |
147 | } | |
c8ce82b9 | 148 | bus->curr_freq = new_freq; |
0722249a CC |
149 | |
150 | dev_dbg(dev, "Set the frequency of bus (%lukHz -> %lukHz)\n", | |
151 | old_freq/1000, new_freq/1000); | |
152 | out: | |
153 | mutex_unlock(&bus->lock); | |
154 | ||
155 | return ret; | |
156 | } | |
157 | ||
158 | static int exynos_bus_get_dev_status(struct device *dev, | |
159 | struct devfreq_dev_status *stat) | |
160 | { | |
161 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
162 | struct devfreq_event_data edata; | |
163 | int ret; | |
164 | ||
c8ce82b9 | 165 | stat->current_frequency = bus->curr_freq; |
0722249a CC |
166 | |
167 | ret = exynos_bus_get_event(bus, &edata); | |
168 | if (ret < 0) { | |
169 | stat->total_time = stat->busy_time = 0; | |
170 | goto err; | |
171 | } | |
172 | ||
173 | stat->busy_time = (edata.load_count * 100) / bus->ratio; | |
174 | stat->total_time = edata.total_count; | |
175 | ||
176 | dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time, | |
177 | stat->total_time); | |
178 | ||
179 | err: | |
180 | ret = exynos_bus_set_event(bus); | |
181 | if (ret < 0) { | |
182 | dev_err(dev, "failed to set event to devfreq-event devices\n"); | |
183 | return ret; | |
184 | } | |
185 | ||
186 | return ret; | |
187 | } | |
188 | ||
189 | static void exynos_bus_exit(struct device *dev) | |
190 | { | |
191 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
192 | int ret; | |
193 | ||
194 | ret = exynos_bus_disable_edev(bus); | |
195 | if (ret < 0) | |
196 | dev_warn(dev, "failed to disable the devfreq-event devices\n"); | |
197 | ||
198 | if (bus->regulator) | |
199 | regulator_disable(bus->regulator); | |
200 | ||
201 | dev_pm_opp_of_remove_table(dev); | |
403e0689 | 202 | clk_disable_unprepare(bus->clk); |
0722249a CC |
203 | } |
204 | ||
403e0689 CC |
205 | /* |
206 | * Must necessary function for devfreq passive governor | |
207 | */ | |
208 | static int exynos_bus_passive_target(struct device *dev, unsigned long *freq, | |
209 | u32 flags) | |
0722249a | 210 | { |
403e0689 CC |
211 | struct exynos_bus *bus = dev_get_drvdata(dev); |
212 | struct dev_pm_opp *new_opp; | |
213 | unsigned long old_freq, new_freq; | |
214 | int ret = 0; | |
0722249a | 215 | |
403e0689 CC |
216 | /* Get new opp-bus instance according to new bus clock */ |
217 | rcu_read_lock(); | |
218 | new_opp = devfreq_recommended_opp(dev, freq, flags); | |
219 | if (IS_ERR(new_opp)) { | |
220 | dev_err(dev, "failed to get recommended opp instance\n"); | |
221 | rcu_read_unlock(); | |
222 | return PTR_ERR(new_opp); | |
0722249a CC |
223 | } |
224 | ||
403e0689 | 225 | new_freq = dev_pm_opp_get_freq(new_opp); |
c8ce82b9 | 226 | old_freq = bus->curr_freq; |
403e0689 | 227 | rcu_read_unlock(); |
0722249a | 228 | |
403e0689 CC |
229 | if (old_freq == new_freq) |
230 | return 0; | |
231 | ||
232 | /* Change the frequency according to new OPP level */ | |
233 | mutex_lock(&bus->lock); | |
234 | ||
235 | ret = clk_set_rate(bus->clk, new_freq); | |
0722249a | 236 | if (ret < 0) { |
403e0689 CC |
237 | dev_err(dev, "failed to set the clock of bus\n"); |
238 | goto out; | |
0722249a CC |
239 | } |
240 | ||
403e0689 | 241 | *freq = new_freq; |
c8ce82b9 | 242 | bus->curr_freq = new_freq; |
403e0689 CC |
243 | |
244 | dev_dbg(dev, "Set the frequency of bus (%lukHz -> %lukHz)\n", | |
245 | old_freq/1000, new_freq/1000); | |
246 | out: | |
247 | mutex_unlock(&bus->lock); | |
248 | ||
249 | return ret; | |
250 | } | |
251 | ||
252 | static void exynos_bus_passive_exit(struct device *dev) | |
253 | { | |
254 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
255 | ||
256 | dev_pm_opp_of_remove_table(dev); | |
257 | clk_disable_unprepare(bus->clk); | |
258 | } | |
259 | ||
260 | static int exynos_bus_parent_parse_of(struct device_node *np, | |
261 | struct exynos_bus *bus) | |
262 | { | |
263 | struct device *dev = bus->dev; | |
264 | int i, ret, count, size; | |
0722249a CC |
265 | |
266 | /* Get the regulator to provide each bus with the power */ | |
267 | bus->regulator = devm_regulator_get(dev, "vdd"); | |
268 | if (IS_ERR(bus->regulator)) { | |
269 | dev_err(dev, "failed to get VDD regulator\n"); | |
403e0689 | 270 | return PTR_ERR(bus->regulator); |
0722249a CC |
271 | } |
272 | ||
273 | ret = regulator_enable(bus->regulator); | |
274 | if (ret < 0) { | |
275 | dev_err(dev, "failed to enable VDD regulator\n"); | |
403e0689 | 276 | return ret; |
0722249a CC |
277 | } |
278 | ||
279 | /* | |
280 | * Get the devfreq-event devices to get the current utilization of | |
281 | * buses. This raw data will be used in devfreq ondemand governor. | |
282 | */ | |
283 | count = devfreq_event_get_edev_count(dev); | |
284 | if (count < 0) { | |
285 | dev_err(dev, "failed to get the count of devfreq-event dev\n"); | |
286 | ret = count; | |
287 | goto err_regulator; | |
288 | } | |
289 | bus->edev_count = count; | |
290 | ||
291 | size = sizeof(*bus->edev) * count; | |
292 | bus->edev = devm_kzalloc(dev, size, GFP_KERNEL); | |
293 | if (!bus->edev) { | |
294 | ret = -ENOMEM; | |
295 | goto err_regulator; | |
296 | } | |
297 | ||
298 | for (i = 0; i < count; i++) { | |
299 | bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i); | |
300 | if (IS_ERR(bus->edev[i])) { | |
301 | ret = -EPROBE_DEFER; | |
302 | goto err_regulator; | |
303 | } | |
304 | } | |
305 | ||
306 | /* | |
307 | * Optionally, Get the saturation ratio according to Exynos SoC | |
308 | * When measuring the utilization of each AXI bus with devfreq-event | |
309 | * devices, the measured real cycle might be much lower than the | |
310 | * total cycle of bus during sampling rate. In result, the devfreq | |
311 | * simple-ondemand governor might not decide to change the current | |
312 | * frequency due to too utilization (= real cycle/total cycle). | |
313 | * So, this property is used to adjust the utilization when calculating | |
314 | * the busy_time in exynos_bus_get_dev_status(). | |
315 | */ | |
316 | if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio)) | |
317 | bus->ratio = DEFAULT_SATURATION_RATIO; | |
318 | ||
319 | if (of_property_read_u32(np, "exynos,voltage-tolerance", | |
320 | &bus->voltage_tolerance)) | |
321 | bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE; | |
322 | ||
323 | return 0; | |
324 | ||
325 | err_regulator: | |
326 | regulator_disable(bus->regulator); | |
403e0689 CC |
327 | |
328 | return ret; | |
329 | } | |
330 | ||
331 | static int exynos_bus_parse_of(struct device_node *np, | |
332 | struct exynos_bus *bus) | |
333 | { | |
334 | struct device *dev = bus->dev; | |
c8ce82b9 | 335 | struct dev_pm_opp *opp; |
403e0689 CC |
336 | unsigned long rate; |
337 | int ret; | |
338 | ||
339 | /* Get the clock to provide each bus with source clock */ | |
340 | bus->clk = devm_clk_get(dev, "bus"); | |
341 | if (IS_ERR(bus->clk)) { | |
342 | dev_err(dev, "failed to get bus clock\n"); | |
343 | return PTR_ERR(bus->clk); | |
344 | } | |
345 | ||
346 | ret = clk_prepare_enable(bus->clk); | |
347 | if (ret < 0) { | |
348 | dev_err(dev, "failed to get enable clock\n"); | |
349 | return ret; | |
350 | } | |
351 | ||
352 | /* Get the freq and voltage from OPP table to scale the bus freq */ | |
403e0689 CC |
353 | ret = dev_pm_opp_of_add_table(dev); |
354 | if (ret < 0) { | |
355 | dev_err(dev, "failed to get OPP table\n"); | |
403e0689 CC |
356 | goto err_clk; |
357 | } | |
358 | ||
359 | rate = clk_get_rate(bus->clk); | |
c8ce82b9 VK |
360 | |
361 | rcu_read_lock(); | |
362 | opp = devfreq_recommended_opp(dev, &rate, 0); | |
363 | if (IS_ERR(opp)) { | |
403e0689 CC |
364 | dev_err(dev, "failed to find dev_pm_opp\n"); |
365 | rcu_read_unlock(); | |
c8ce82b9 | 366 | ret = PTR_ERR(opp); |
403e0689 CC |
367 | goto err_opp; |
368 | } | |
c8ce82b9 | 369 | bus->curr_freq = dev_pm_opp_get_freq(opp); |
403e0689 CC |
370 | rcu_read_unlock(); |
371 | ||
372 | return 0; | |
373 | ||
0722249a CC |
374 | err_opp: |
375 | dev_pm_opp_of_remove_table(dev); | |
376 | err_clk: | |
377 | clk_disable_unprepare(bus->clk); | |
378 | ||
379 | return ret; | |
380 | } | |
381 | ||
382 | static int exynos_bus_probe(struct platform_device *pdev) | |
383 | { | |
384 | struct device *dev = &pdev->dev; | |
d8150d14 | 385 | struct device_node *np = dev->of_node, *node; |
0722249a CC |
386 | struct devfreq_dev_profile *profile; |
387 | struct devfreq_simple_ondemand_data *ondemand_data; | |
403e0689 CC |
388 | struct devfreq_passive_data *passive_data; |
389 | struct devfreq *parent_devfreq; | |
0722249a | 390 | struct exynos_bus *bus; |
403e0689 CC |
391 | int ret, max_state; |
392 | unsigned long min_freq, max_freq; | |
0722249a CC |
393 | |
394 | if (!np) { | |
395 | dev_err(dev, "failed to find devicetree node\n"); | |
396 | return -EINVAL; | |
397 | } | |
398 | ||
399 | bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); | |
400 | if (!bus) | |
401 | return -ENOMEM; | |
402 | mutex_init(&bus->lock); | |
403 | bus->dev = &pdev->dev; | |
404 | platform_set_drvdata(pdev, bus); | |
405 | ||
406 | /* Parse the device-tree to get the resource information */ | |
407 | ret = exynos_bus_parse_of(np, bus); | |
408 | if (ret < 0) | |
c07e074b | 409 | return ret; |
0722249a | 410 | |
0722249a | 411 | profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL); |
403e0689 CC |
412 | if (!profile) { |
413 | ret = -ENOMEM; | |
414 | goto err; | |
415 | } | |
416 | ||
d8150d14 PC |
417 | node = of_parse_phandle(dev->of_node, "devfreq", 0); |
418 | if (node) { | |
419 | of_node_put(node); | |
403e0689 | 420 | goto passive; |
d8150d14 | 421 | } else { |
403e0689 | 422 | ret = exynos_bus_parent_parse_of(np, bus); |
d8150d14 | 423 | } |
403e0689 CC |
424 | |
425 | if (ret < 0) | |
426 | goto err; | |
427 | ||
83cb0e4d | 428 | /* Initialize the struct profile and governor data for parent device */ |
0722249a CC |
429 | profile->polling_ms = 50; |
430 | profile->target = exynos_bus_target; | |
431 | profile->get_dev_status = exynos_bus_get_dev_status; | |
432 | profile->exit = exynos_bus_exit; | |
433 | ||
434 | ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL); | |
403e0689 CC |
435 | if (!ondemand_data) { |
436 | ret = -ENOMEM; | |
437 | goto err; | |
438 | } | |
0722249a CC |
439 | ondemand_data->upthreshold = 40; |
440 | ondemand_data->downdifferential = 5; | |
441 | ||
442 | /* Add devfreq device to monitor and handle the exynos bus */ | |
443 | bus->devfreq = devm_devfreq_add_device(dev, profile, "simple_ondemand", | |
444 | ondemand_data); | |
445 | if (IS_ERR(bus->devfreq)) { | |
446 | dev_err(dev, "failed to add devfreq device\n"); | |
403e0689 CC |
447 | ret = PTR_ERR(bus->devfreq); |
448 | goto err; | |
0722249a CC |
449 | } |
450 | ||
451 | /* Register opp_notifier to catch the change of OPP */ | |
452 | ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq); | |
453 | if (ret < 0) { | |
454 | dev_err(dev, "failed to register opp notifier\n"); | |
403e0689 | 455 | goto err; |
0722249a CC |
456 | } |
457 | ||
458 | /* | |
459 | * Enable devfreq-event to get raw data which is used to determine | |
460 | * current bus load. | |
461 | */ | |
462 | ret = exynos_bus_enable_edev(bus); | |
463 | if (ret < 0) { | |
464 | dev_err(dev, "failed to enable devfreq-event devices\n"); | |
403e0689 | 465 | goto err; |
0722249a CC |
466 | } |
467 | ||
468 | ret = exynos_bus_set_event(bus); | |
469 | if (ret < 0) { | |
470 | dev_err(dev, "failed to set event to devfreq-event devices\n"); | |
403e0689 | 471 | goto err; |
0722249a CC |
472 | } |
473 | ||
403e0689 CC |
474 | goto out; |
475 | passive: | |
83cb0e4d | 476 | /* Initialize the struct profile and governor data for passive device */ |
403e0689 CC |
477 | profile->target = exynos_bus_passive_target; |
478 | profile->exit = exynos_bus_passive_exit; | |
479 | ||
480 | /* Get the instance of parent devfreq device */ | |
481 | parent_devfreq = devfreq_get_devfreq_by_phandle(dev, 0); | |
482 | if (IS_ERR(parent_devfreq)) { | |
483 | ret = -EPROBE_DEFER; | |
484 | goto err; | |
485 | } | |
486 | ||
487 | passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL); | |
488 | if (!passive_data) { | |
489 | ret = -ENOMEM; | |
490 | goto err; | |
491 | } | |
492 | passive_data->parent = parent_devfreq; | |
493 | ||
494 | /* Add devfreq device for exynos bus with passive governor */ | |
495 | bus->devfreq = devm_devfreq_add_device(dev, profile, "passive", | |
496 | passive_data); | |
497 | if (IS_ERR(bus->devfreq)) { | |
498 | dev_err(dev, | |
499 | "failed to add devfreq dev with passive governor\n"); | |
32dd7731 | 500 | ret = PTR_ERR(bus->devfreq); |
403e0689 CC |
501 | goto err; |
502 | } | |
503 | ||
504 | out: | |
505 | max_state = bus->devfreq->profile->max_state; | |
506 | min_freq = (bus->devfreq->profile->freq_table[0] / 1000); | |
507 | max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000); | |
508 | pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n", | |
509 | dev_name(dev), min_freq, max_freq); | |
510 | ||
0722249a | 511 | return 0; |
403e0689 CC |
512 | |
513 | err: | |
514 | dev_pm_opp_of_remove_table(dev); | |
515 | clk_disable_unprepare(bus->clk); | |
516 | ||
517 | return ret; | |
0722249a CC |
518 | } |
519 | ||
520 | #ifdef CONFIG_PM_SLEEP | |
521 | static int exynos_bus_resume(struct device *dev) | |
522 | { | |
523 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
524 | int ret; | |
525 | ||
526 | ret = exynos_bus_enable_edev(bus); | |
527 | if (ret < 0) { | |
528 | dev_err(dev, "failed to enable the devfreq-event devices\n"); | |
529 | return ret; | |
530 | } | |
531 | ||
532 | return 0; | |
533 | } | |
534 | ||
535 | static int exynos_bus_suspend(struct device *dev) | |
536 | { | |
537 | struct exynos_bus *bus = dev_get_drvdata(dev); | |
538 | int ret; | |
539 | ||
540 | ret = exynos_bus_disable_edev(bus); | |
541 | if (ret < 0) { | |
542 | dev_err(dev, "failed to disable the devfreq-event devices\n"); | |
543 | return ret; | |
544 | } | |
545 | ||
546 | return 0; | |
547 | } | |
548 | #endif | |
549 | ||
550 | static const struct dev_pm_ops exynos_bus_pm = { | |
551 | SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume) | |
552 | }; | |
553 | ||
554 | static const struct of_device_id exynos_bus_of_match[] = { | |
555 | { .compatible = "samsung,exynos-bus", }, | |
556 | { /* sentinel */ }, | |
557 | }; | |
558 | MODULE_DEVICE_TABLE(of, exynos_bus_of_match); | |
559 | ||
560 | static struct platform_driver exynos_bus_platdrv = { | |
561 | .probe = exynos_bus_probe, | |
562 | .driver = { | |
563 | .name = "exynos-bus", | |
564 | .pm = &exynos_bus_pm, | |
565 | .of_match_table = of_match_ptr(exynos_bus_of_match), | |
566 | }, | |
567 | }; | |
568 | module_platform_driver(exynos_bus_platdrv); | |
569 | ||
570 | MODULE_DESCRIPTION("Generic Exynos Bus frequency driver"); | |
571 | MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>"); | |
572 | MODULE_LICENSE("GPL v2"); |