Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic Exynos Bus frequency driver with DEVFREQ Framework
4 *
5 * Copyright (c) 2016 Samsung Electronics Co., Ltd.
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.
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>
18#include <linux/of_device.h>
19#include <linux/pm_opp.h>
20#include <linux/platform_device.h>
21#include <linux/regulator/consumer.h>
22#include <linux/slab.h>
23
24#define DEFAULT_SATURATION_RATIO 40
25
26struct exynos_bus {
27 struct device *dev;
28
29 struct devfreq *devfreq;
30 struct devfreq_event_dev **edev;
31 unsigned int edev_count;
32 struct mutex lock;
33
34 unsigned long curr_freq;
35
36 struct opp_table *opp_table;
37 struct clk *clk;
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) \
45static 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}
59exynos_bus_ops_edev(enable_edev);
60exynos_bus_ops_edev(disable_edev);
61exynos_bus_ops_edev(set_event);
62
63static 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/*
91 * devfreq function for both simple-ondemand and passive governor
92 */
93static 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;
97 int ret = 0;
98
99 /* Get correct frequency for bus. */
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");
103 return PTR_ERR(new_opp);
104 }
105
106 dev_pm_opp_put(new_opp);
107
108 /* Change voltage and frequency according to new OPP level */
109 mutex_lock(&bus->lock);
110 ret = dev_pm_opp_set_rate(dev, *freq);
111 if (!ret)
112 bus->curr_freq = *freq;
113
114 mutex_unlock(&bus->lock);
115
116 return ret;
117}
118
119static 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
126 stat->current_frequency = bus->curr_freq;
127
128 ret = exynos_bus_get_event(bus, &edata);
129 if (ret < 0) {
130 stat->total_time = stat->busy_time = 0;
131 goto err;
132 }
133
134 stat->busy_time = (edata.load_count * 100) / bus->ratio;
135 stat->total_time = edata.total_count;
136
137 dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time,
138 stat->total_time);
139
140err:
141 ret = exynos_bus_set_event(bus);
142 if (ret < 0) {
143 dev_err(dev, "failed to set event to devfreq-event devices\n");
144 return ret;
145 }
146
147 return ret;
148}
149
150static void exynos_bus_exit(struct device *dev)
151{
152 struct exynos_bus *bus = dev_get_drvdata(dev);
153 int ret;
154
155 ret = exynos_bus_disable_edev(bus);
156 if (ret < 0)
157 dev_warn(dev, "failed to disable the devfreq-event devices\n");
158
159 dev_pm_opp_of_remove_table(dev);
160 clk_disable_unprepare(bus->clk);
161 if (bus->opp_table) {
162 dev_pm_opp_put_regulators(bus->opp_table);
163 bus->opp_table = NULL;
164 }
165}
166
167static void exynos_bus_passive_exit(struct device *dev)
168{
169 struct exynos_bus *bus = dev_get_drvdata(dev);
170
171 dev_pm_opp_of_remove_table(dev);
172 clk_disable_unprepare(bus->clk);
173}
174
175static int exynos_bus_parent_parse_of(struct device_node *np,
176 struct exynos_bus *bus)
177{
178 struct device *dev = bus->dev;
179 struct opp_table *opp_table;
180 const char *vdd = "vdd";
181 int i, ret, count, size;
182
183 opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
184 if (IS_ERR(opp_table)) {
185 ret = PTR_ERR(opp_table);
186 dev_err(dev, "failed to set regulators %d\n", ret);
187 return ret;
188 }
189
190 bus->opp_table = opp_table;
191
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 */
196 count = devfreq_event_get_edev_count(dev);
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++) {
212 bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
213 if (IS_ERR(bus->edev[i])) {
214 ret = -EPROBE_DEFER;
215 goto err_regulator;
216 }
217 }
218
219 /*
220 * Optionally, Get the saturation ratio according to Exynos SoC
221 * When measuring the utilization of each AXI bus with devfreq-event
222 * devices, the measured real cycle might be much lower than the
223 * total cycle of bus during sampling rate. In result, the devfreq
224 * simple-ondemand governor might not decide to change the current
225 * frequency due to too utilization (= real cycle/total cycle).
226 * So, this property is used to adjust the utilization when calculating
227 * the busy_time in exynos_bus_get_dev_status().
228 */
229 if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
230 bus->ratio = DEFAULT_SATURATION_RATIO;
231
232 return 0;
233
234err_regulator:
235 dev_pm_opp_put_regulators(bus->opp_table);
236 bus->opp_table = NULL;
237
238 return ret;
239}
240
241static int exynos_bus_parse_of(struct device_node *np,
242 struct exynos_bus *bus)
243{
244 struct device *dev = bus->dev;
245 struct dev_pm_opp *opp;
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 */
263 ret = dev_pm_opp_of_add_table(dev);
264 if (ret < 0) {
265 dev_err(dev, "failed to get OPP table\n");
266 goto err_clk;
267 }
268
269 rate = clk_get_rate(bus->clk);
270
271 opp = devfreq_recommended_opp(dev, &rate, 0);
272 if (IS_ERR(opp)) {
273 dev_err(dev, "failed to find dev_pm_opp\n");
274 ret = PTR_ERR(opp);
275 goto err_opp;
276 }
277 bus->curr_freq = dev_pm_opp_get_freq(opp);
278 dev_pm_opp_put(opp);
279
280 return 0;
281
282err_opp:
283 dev_pm_opp_of_remove_table(dev);
284err_clk:
285 clk_disable_unprepare(bus->clk);
286
287 return ret;
288}
289
290static int exynos_bus_probe(struct platform_device *pdev)
291{
292 struct device *dev = &pdev->dev;
293 struct device_node *np = dev->of_node, *node;
294 struct devfreq_dev_profile *profile;
295 struct devfreq_simple_ondemand_data *ondemand_data;
296 struct devfreq_passive_data *passive_data;
297 struct devfreq *parent_devfreq;
298 struct exynos_bus *bus;
299 int ret, max_state;
300 unsigned long min_freq, max_freq;
301 bool passive = false;
302
303 if (!np) {
304 dev_err(dev, "failed to find devicetree node\n");
305 return -EINVAL;
306 }
307
308 bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
309 if (!bus)
310 return -ENOMEM;
311 mutex_init(&bus->lock);
312 bus->dev = &pdev->dev;
313 platform_set_drvdata(pdev, bus);
314
315 profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
316 if (!profile)
317 return -ENOMEM;
318
319 node = of_parse_phandle(dev->of_node, "devfreq", 0);
320 if (node) {
321 of_node_put(node);
322 passive = true;
323 } else {
324 ret = exynos_bus_parent_parse_of(np, bus);
325 if (ret < 0)
326 return ret;
327 }
328
329 /* Parse the device-tree to get the resource information */
330 ret = exynos_bus_parse_of(np, bus);
331 if (ret < 0)
332 goto err_reg;
333
334 if (passive)
335 goto passive;
336
337 /* Initialize the struct profile and governor data for parent device */
338 profile->polling_ms = 50;
339 profile->target = exynos_bus_target;
340 profile->get_dev_status = exynos_bus_get_dev_status;
341 profile->exit = exynos_bus_exit;
342
343 ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
344 if (!ondemand_data) {
345 ret = -ENOMEM;
346 goto err;
347 }
348 ondemand_data->upthreshold = 40;
349 ondemand_data->downdifferential = 5;
350
351 /* Add devfreq device to monitor and handle the exynos bus */
352 bus->devfreq = devm_devfreq_add_device(dev, profile,
353 DEVFREQ_GOV_SIMPLE_ONDEMAND,
354 ondemand_data);
355 if (IS_ERR(bus->devfreq)) {
356 dev_err(dev, "failed to add devfreq device\n");
357 ret = PTR_ERR(bus->devfreq);
358 goto err;
359 }
360
361 /* Register opp_notifier to catch the change of OPP */
362 ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
363 if (ret < 0) {
364 dev_err(dev, "failed to register opp notifier\n");
365 goto err;
366 }
367
368 /*
369 * Enable devfreq-event to get raw data which is used to determine
370 * current bus load.
371 */
372 ret = exynos_bus_enable_edev(bus);
373 if (ret < 0) {
374 dev_err(dev, "failed to enable devfreq-event devices\n");
375 goto err;
376 }
377
378 ret = exynos_bus_set_event(bus);
379 if (ret < 0) {
380 dev_err(dev, "failed to set event to devfreq-event devices\n");
381 goto err;
382 }
383
384 goto out;
385passive:
386 /* Initialize the struct profile and governor data for passive device */
387 profile->target = exynos_bus_target;
388 profile->exit = exynos_bus_passive_exit;
389
390 /* Get the instance of parent devfreq device */
391 parent_devfreq = devfreq_get_devfreq_by_phandle(dev, 0);
392 if (IS_ERR(parent_devfreq)) {
393 ret = -EPROBE_DEFER;
394 goto err;
395 }
396
397 passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
398 if (!passive_data) {
399 ret = -ENOMEM;
400 goto err;
401 }
402 passive_data->parent = parent_devfreq;
403
404 /* Add devfreq device for exynos bus with passive governor */
405 bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE,
406 passive_data);
407 if (IS_ERR(bus->devfreq)) {
408 dev_err(dev,
409 "failed to add devfreq dev with passive governor\n");
410 ret = PTR_ERR(bus->devfreq);
411 goto err;
412 }
413
414out:
415 max_state = bus->devfreq->profile->max_state;
416 min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
417 max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
418 pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
419 dev_name(dev), min_freq, max_freq);
420
421 return 0;
422
423err:
424 dev_pm_opp_of_remove_table(dev);
425 clk_disable_unprepare(bus->clk);
426err_reg:
427 if (!passive) {
428 dev_pm_opp_put_regulators(bus->opp_table);
429 bus->opp_table = NULL;
430 }
431
432 return ret;
433}
434
435static void exynos_bus_shutdown(struct platform_device *pdev)
436{
437 struct exynos_bus *bus = dev_get_drvdata(&pdev->dev);
438
439 devfreq_suspend_device(bus->devfreq);
440}
441
442#ifdef CONFIG_PM_SLEEP
443static int exynos_bus_resume(struct device *dev)
444{
445 struct exynos_bus *bus = dev_get_drvdata(dev);
446 int ret;
447
448 ret = exynos_bus_enable_edev(bus);
449 if (ret < 0) {
450 dev_err(dev, "failed to enable the devfreq-event devices\n");
451 return ret;
452 }
453
454 return 0;
455}
456
457static int exynos_bus_suspend(struct device *dev)
458{
459 struct exynos_bus *bus = dev_get_drvdata(dev);
460 int ret;
461
462 ret = exynos_bus_disable_edev(bus);
463 if (ret < 0) {
464 dev_err(dev, "failed to disable the devfreq-event devices\n");
465 return ret;
466 }
467
468 return 0;
469}
470#endif
471
472static const struct dev_pm_ops exynos_bus_pm = {
473 SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
474};
475
476static const struct of_device_id exynos_bus_of_match[] = {
477 { .compatible = "samsung,exynos-bus", },
478 { /* sentinel */ },
479};
480MODULE_DEVICE_TABLE(of, exynos_bus_of_match);
481
482static struct platform_driver exynos_bus_platdrv = {
483 .probe = exynos_bus_probe,
484 .shutdown = exynos_bus_shutdown,
485 .driver = {
486 .name = "exynos-bus",
487 .pm = &exynos_bus_pm,
488 .of_match_table = of_match_ptr(exynos_bus_of_match),
489 },
490};
491module_platform_driver(exynos_bus_platdrv);
492
493MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
494MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
495MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic Exynos Bus frequency driver with DEVFREQ Framework
4 *
5 * Copyright (c) 2016 Samsung Electronics Co., Ltd.
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.
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>
18#include <linux/of.h>
19#include <linux/pm_opp.h>
20#include <linux/platform_device.h>
21#include <linux/regulator/consumer.h>
22
23#define DEFAULT_SATURATION_RATIO 40
24
25struct exynos_bus {
26 struct device *dev;
27 struct platform_device *icc_pdev;
28
29 struct devfreq *devfreq;
30 struct devfreq_event_dev **edev;
31 unsigned int edev_count;
32 struct mutex lock;
33
34 unsigned long curr_freq;
35
36 struct opp_table *opp_table;
37 struct clk *clk;
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) \
45static 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}
59exynos_bus_ops_edev(enable_edev);
60exynos_bus_ops_edev(disable_edev);
61exynos_bus_ops_edev(set_event);
62
63static 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/*
91 * devfreq function for both simple-ondemand and passive governor
92 */
93static 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;
97 int ret = 0;
98
99 /* Get correct frequency for bus. */
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");
103 return PTR_ERR(new_opp);
104 }
105
106 dev_pm_opp_put(new_opp);
107
108 /* Change voltage and frequency according to new OPP level */
109 mutex_lock(&bus->lock);
110 ret = dev_pm_opp_set_rate(dev, *freq);
111 if (!ret)
112 bus->curr_freq = *freq;
113
114 mutex_unlock(&bus->lock);
115
116 return ret;
117}
118
119static 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
126 stat->current_frequency = bus->curr_freq;
127
128 ret = exynos_bus_get_event(bus, &edata);
129 if (ret < 0) {
130 dev_err(dev, "failed to get event from devfreq-event devices\n");
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
141err:
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
151static 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
160 platform_device_unregister(bus->icc_pdev);
161
162 dev_pm_opp_of_remove_table(dev);
163 clk_disable_unprepare(bus->clk);
164 dev_pm_opp_put_regulators(bus->opp_table);
165 bus->opp_table = NULL;
166}
167
168static void exynos_bus_passive_exit(struct device *dev)
169{
170 struct exynos_bus *bus = dev_get_drvdata(dev);
171
172 platform_device_unregister(bus->icc_pdev);
173
174 dev_pm_opp_of_remove_table(dev);
175 clk_disable_unprepare(bus->clk);
176}
177
178static int exynos_bus_parent_parse_of(struct device_node *np,
179 struct exynos_bus *bus)
180{
181 struct device *dev = bus->dev;
182 struct opp_table *opp_table;
183 const char *vdd = "vdd";
184 int i, ret, count, size;
185
186 opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
187 if (IS_ERR(opp_table)) {
188 ret = PTR_ERR(opp_table);
189 dev_err(dev, "failed to set regulators %d\n", ret);
190 return ret;
191 }
192
193 bus->opp_table = opp_table;
194
195 /*
196 * Get the devfreq-event devices to get the current utilization of
197 * buses. This raw data will be used in devfreq ondemand governor.
198 */
199 count = devfreq_event_get_edev_count(dev, "devfreq-events");
200 if (count < 0) {
201 dev_err(dev, "failed to get the count of devfreq-event dev\n");
202 ret = count;
203 goto err_regulator;
204 }
205 bus->edev_count = count;
206
207 size = sizeof(*bus->edev) * count;
208 bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
209 if (!bus->edev) {
210 ret = -ENOMEM;
211 goto err_regulator;
212 }
213
214 for (i = 0; i < count; i++) {
215 bus->edev[i] = devfreq_event_get_edev_by_phandle(dev,
216 "devfreq-events", i);
217 if (IS_ERR(bus->edev[i])) {
218 ret = -EPROBE_DEFER;
219 goto err_regulator;
220 }
221 }
222
223 /*
224 * Optionally, Get the saturation ratio according to Exynos SoC
225 * When measuring the utilization of each AXI bus with devfreq-event
226 * devices, the measured real cycle might be much lower than the
227 * total cycle of bus during sampling rate. In result, the devfreq
228 * simple-ondemand governor might not decide to change the current
229 * frequency due to too utilization (= real cycle/total cycle).
230 * So, this property is used to adjust the utilization when calculating
231 * the busy_time in exynos_bus_get_dev_status().
232 */
233 if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
234 bus->ratio = DEFAULT_SATURATION_RATIO;
235
236 return 0;
237
238err_regulator:
239 dev_pm_opp_put_regulators(bus->opp_table);
240 bus->opp_table = NULL;
241
242 return ret;
243}
244
245static int exynos_bus_parse_of(struct device_node *np,
246 struct exynos_bus *bus)
247{
248 struct device *dev = bus->dev;
249 struct dev_pm_opp *opp;
250 unsigned long rate;
251 int ret;
252
253 /* Get the clock to provide each bus with source clock */
254 bus->clk = devm_clk_get(dev, "bus");
255 if (IS_ERR(bus->clk)) {
256 dev_err(dev, "failed to get bus clock\n");
257 return PTR_ERR(bus->clk);
258 }
259
260 ret = clk_prepare_enable(bus->clk);
261 if (ret < 0) {
262 dev_err(dev, "failed to get enable clock\n");
263 return ret;
264 }
265
266 /* Get the freq and voltage from OPP table to scale the bus freq */
267 ret = dev_pm_opp_of_add_table(dev);
268 if (ret < 0) {
269 dev_err(dev, "failed to get OPP table\n");
270 goto err_clk;
271 }
272
273 rate = clk_get_rate(bus->clk);
274
275 opp = devfreq_recommended_opp(dev, &rate, 0);
276 if (IS_ERR(opp)) {
277 dev_err(dev, "failed to find dev_pm_opp\n");
278 ret = PTR_ERR(opp);
279 goto err_opp;
280 }
281 bus->curr_freq = dev_pm_opp_get_freq(opp);
282 dev_pm_opp_put(opp);
283
284 return 0;
285
286err_opp:
287 dev_pm_opp_of_remove_table(dev);
288err_clk:
289 clk_disable_unprepare(bus->clk);
290
291 return ret;
292}
293
294static int exynos_bus_profile_init(struct exynos_bus *bus,
295 struct devfreq_dev_profile *profile)
296{
297 struct device *dev = bus->dev;
298 struct devfreq_simple_ondemand_data *ondemand_data;
299 int ret;
300
301 /* Initialize the struct profile and governor data for parent device */
302 profile->polling_ms = 50;
303 profile->target = exynos_bus_target;
304 profile->get_dev_status = exynos_bus_get_dev_status;
305 profile->exit = exynos_bus_exit;
306
307 ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
308 if (!ondemand_data)
309 return -ENOMEM;
310
311 ondemand_data->upthreshold = 40;
312 ondemand_data->downdifferential = 5;
313
314 /* Add devfreq device to monitor and handle the exynos bus */
315 bus->devfreq = devm_devfreq_add_device(dev, profile,
316 DEVFREQ_GOV_SIMPLE_ONDEMAND,
317 ondemand_data);
318 if (IS_ERR(bus->devfreq)) {
319 dev_err(dev, "failed to add devfreq device\n");
320 return PTR_ERR(bus->devfreq);
321 }
322
323 /* Register opp_notifier to catch the change of OPP */
324 ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
325 if (ret < 0) {
326 dev_err(dev, "failed to register opp notifier\n");
327 return ret;
328 }
329
330 /*
331 * Enable devfreq-event to get raw data which is used to determine
332 * current bus load.
333 */
334 ret = exynos_bus_enable_edev(bus);
335 if (ret < 0) {
336 dev_err(dev, "failed to enable devfreq-event devices\n");
337 return ret;
338 }
339
340 ret = exynos_bus_set_event(bus);
341 if (ret < 0) {
342 dev_err(dev, "failed to set event to devfreq-event devices\n");
343 goto err_edev;
344 }
345
346 return 0;
347
348err_edev:
349 if (exynos_bus_disable_edev(bus))
350 dev_warn(dev, "failed to disable the devfreq-event devices\n");
351
352 return ret;
353}
354
355static int exynos_bus_profile_init_passive(struct exynos_bus *bus,
356 struct devfreq_dev_profile *profile)
357{
358 struct device *dev = bus->dev;
359 struct devfreq_passive_data *passive_data;
360 struct devfreq *parent_devfreq;
361
362 /* Initialize the struct profile and governor data for passive device */
363 profile->target = exynos_bus_target;
364 profile->exit = exynos_bus_passive_exit;
365
366 /* Get the instance of parent devfreq device */
367 parent_devfreq = devfreq_get_devfreq_by_phandle(dev, "devfreq", 0);
368 if (IS_ERR(parent_devfreq))
369 return -EPROBE_DEFER;
370
371 passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
372 if (!passive_data)
373 return -ENOMEM;
374
375 passive_data->parent = parent_devfreq;
376
377 /* Add devfreq device for exynos bus with passive governor */
378 bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE,
379 passive_data);
380 if (IS_ERR(bus->devfreq)) {
381 dev_err(dev,
382 "failed to add devfreq dev with passive governor\n");
383 return PTR_ERR(bus->devfreq);
384 }
385
386 return 0;
387}
388
389static int exynos_bus_probe(struct platform_device *pdev)
390{
391 struct device *dev = &pdev->dev;
392 struct device_node *np = dev->of_node, *node;
393 struct devfreq_dev_profile *profile;
394 struct exynos_bus *bus;
395 int ret, max_state;
396 unsigned long min_freq, max_freq;
397 bool passive = false;
398
399 if (!np) {
400 dev_err(dev, "failed to find devicetree node\n");
401 return -EINVAL;
402 }
403
404 bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
405 if (!bus)
406 return -ENOMEM;
407 mutex_init(&bus->lock);
408 bus->dev = &pdev->dev;
409 platform_set_drvdata(pdev, bus);
410
411 profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
412 if (!profile)
413 return -ENOMEM;
414
415 node = of_parse_phandle(dev->of_node, "devfreq", 0);
416 if (node) {
417 of_node_put(node);
418 passive = true;
419 } else {
420 ret = exynos_bus_parent_parse_of(np, bus);
421 if (ret < 0)
422 return ret;
423 }
424
425 /* Parse the device-tree to get the resource information */
426 ret = exynos_bus_parse_of(np, bus);
427 if (ret < 0)
428 goto err_reg;
429
430 if (passive)
431 ret = exynos_bus_profile_init_passive(bus, profile);
432 else
433 ret = exynos_bus_profile_init(bus, profile);
434
435 if (ret < 0)
436 goto err;
437
438 /* Create child platform device for the interconnect provider */
439 if (of_get_property(dev->of_node, "#interconnect-cells", NULL)) {
440 bus->icc_pdev = platform_device_register_data(
441 dev, "exynos-generic-icc",
442 PLATFORM_DEVID_AUTO, NULL, 0);
443
444 if (IS_ERR(bus->icc_pdev)) {
445 ret = PTR_ERR(bus->icc_pdev);
446 goto err;
447 }
448 }
449
450 max_state = bus->devfreq->profile->max_state;
451 min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
452 max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
453 pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
454 dev_name(dev), min_freq, max_freq);
455
456 return 0;
457
458err:
459 dev_pm_opp_of_remove_table(dev);
460 clk_disable_unprepare(bus->clk);
461err_reg:
462 dev_pm_opp_put_regulators(bus->opp_table);
463 bus->opp_table = NULL;
464
465 return ret;
466}
467
468static void exynos_bus_shutdown(struct platform_device *pdev)
469{
470 struct exynos_bus *bus = dev_get_drvdata(&pdev->dev);
471
472 devfreq_suspend_device(bus->devfreq);
473}
474
475#ifdef CONFIG_PM_SLEEP
476static int exynos_bus_resume(struct device *dev)
477{
478 struct exynos_bus *bus = dev_get_drvdata(dev);
479 int ret;
480
481 ret = exynos_bus_enable_edev(bus);
482 if (ret < 0) {
483 dev_err(dev, "failed to enable the devfreq-event devices\n");
484 return ret;
485 }
486
487 return 0;
488}
489
490static int exynos_bus_suspend(struct device *dev)
491{
492 struct exynos_bus *bus = dev_get_drvdata(dev);
493 int ret;
494
495 ret = exynos_bus_disable_edev(bus);
496 if (ret < 0) {
497 dev_err(dev, "failed to disable the devfreq-event devices\n");
498 return ret;
499 }
500
501 return 0;
502}
503#endif
504
505static const struct dev_pm_ops exynos_bus_pm = {
506 SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
507};
508
509static const struct of_device_id exynos_bus_of_match[] = {
510 { .compatible = "samsung,exynos-bus", },
511 { /* sentinel */ },
512};
513MODULE_DEVICE_TABLE(of, exynos_bus_of_match);
514
515static struct platform_driver exynos_bus_platdrv = {
516 .probe = exynos_bus_probe,
517 .shutdown = exynos_bus_shutdown,
518 .driver = {
519 .name = "exynos-bus",
520 .pm = &exynos_bus_pm,
521 .of_match_table = of_match_ptr(exynos_bus_of_match),
522 },
523};
524module_platform_driver(exynos_bus_platdrv);
525
526MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
527MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
528MODULE_LICENSE("GPL v2");