1 // SPDX-License-Identifier: GPL-2.0-only
3  * Generic Exynos Bus frequency driver with DEVFREQ Framework
8  * This driver support Exynos Bus frequency feature by using
14 #include <linux/devfreq-event.h>
42  * Control the devfreq-event device to get the current state of bus
45 static int exynos_bus_##ops(struct exynos_bus *bus)		\
49 	for (i = 0; i < bus->edev_count; i++) {			\
50 		if (!bus->edev[i])				\
52 		ret = devfreq_event_##ops(bus->edev[i]);	\
63 static int exynos_bus_get_event(struct exynos_bus *bus,  in exynos_bus_get_event()  argument
70 	for (i = 0; i < bus->edev_count; i++) {  in exynos_bus_get_event()
71 		if (!bus->edev[i])  in exynos_bus_get_event()
74 		ret = devfreq_event_get_event(bus->edev[i], &event_data);  in exynos_bus_get_event()
84 	edata->load_count = load_count;  in exynos_bus_get_event()
85 	edata->total_count = total_count;  in exynos_bus_get_event()
91  * devfreq function for both simple-ondemand and passive governor
95 	struct exynos_bus *bus = dev_get_drvdata(dev);  in exynos_bus_target()  local
99 	/* Get correct frequency for bus. */  in exynos_bus_target()
108 	/* Change voltage and frequency according to new OPP level */  in exynos_bus_target()
109 	mutex_lock(&bus->lock);  in exynos_bus_target()
112 		bus->curr_freq = *freq;  in exynos_bus_target()
114 	mutex_unlock(&bus->lock);  in exynos_bus_target()
122 	struct exynos_bus *bus = dev_get_drvdata(dev);  in exynos_bus_get_dev_status()  local
126 	stat->current_frequency = bus->curr_freq;  in exynos_bus_get_dev_status()
128 	ret = exynos_bus_get_event(bus, &edata);  in exynos_bus_get_dev_status()
130 		dev_err(dev, "failed to get event from devfreq-event devices\n");  in exynos_bus_get_dev_status()
131 		stat->total_time = stat->busy_time = 0;  in exynos_bus_get_dev_status()
135 	stat->busy_time = (edata.load_count * 100) / bus->ratio;  in exynos_bus_get_dev_status()
136 	stat->total_time = edata.total_count;  in exynos_bus_get_dev_status()
138 	dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time,  in exynos_bus_get_dev_status()
139 							stat->total_time);  in exynos_bus_get_dev_status()
142 	ret = exynos_bus_set_event(bus);  in exynos_bus_get_dev_status()
144 		dev_err(dev, "failed to set event to devfreq-event devices\n");  in exynos_bus_get_dev_status()
153 	struct exynos_bus *bus = dev_get_drvdata(dev);  in exynos_bus_exit()  local
156 	ret = exynos_bus_disable_edev(bus);  in exynos_bus_exit()
158 		dev_warn(dev, "failed to disable the devfreq-event devices\n");  in exynos_bus_exit()
160 	platform_device_unregister(bus->icc_pdev);  in exynos_bus_exit()
163 	clk_disable_unprepare(bus->clk);  in exynos_bus_exit()
164 	dev_pm_opp_put_regulators(bus->opp_table);  in exynos_bus_exit()
165 	bus->opp_table = NULL;  in exynos_bus_exit()
170 	struct exynos_bus *bus = dev_get_drvdata(dev);  in exynos_bus_passive_exit()  local
172 	platform_device_unregister(bus->icc_pdev);  in exynos_bus_passive_exit()
175 	clk_disable_unprepare(bus->clk);  in exynos_bus_passive_exit()
179 					struct exynos_bus *bus)  in exynos_bus_parent_parse_of()  argument
181 	struct device *dev = bus->dev;  in exynos_bus_parent_parse_of()
193 	bus->opp_table = opp_table;  in exynos_bus_parent_parse_of()
196 	 * Get the devfreq-event devices to get the current utilization of  in exynos_bus_parent_parse_of()
199 	count = devfreq_event_get_edev_count(dev, "devfreq-events");  in exynos_bus_parent_parse_of()
201 		dev_err(dev, "failed to get the count of devfreq-event dev\n");  in exynos_bus_parent_parse_of()
205 	bus->edev_count = count;  in exynos_bus_parent_parse_of()
207 	size = sizeof(*bus->edev) * count;  in exynos_bus_parent_parse_of()
208 	bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);  in exynos_bus_parent_parse_of()
209 	if (!bus->edev) {  in exynos_bus_parent_parse_of()
210 		ret = -ENOMEM;  in exynos_bus_parent_parse_of()
215 		bus->edev[i] = devfreq_event_get_edev_by_phandle(dev,  in exynos_bus_parent_parse_of()
216 							"devfreq-events", i);  in exynos_bus_parent_parse_of()
217 		if (IS_ERR(bus->edev[i])) {  in exynos_bus_parent_parse_of()
218 			ret = -EPROBE_DEFER;  in exynos_bus_parent_parse_of()
225 	 * When measuring the utilization of each AXI bus with devfreq-event  in exynos_bus_parent_parse_of()
227 	 * total cycle of bus during sampling rate. In result, the devfreq  in exynos_bus_parent_parse_of()
228 	 * simple-ondemand governor might not decide to change the current  in exynos_bus_parent_parse_of()
229 	 * frequency due to too utilization (= real cycle/total cycle).  in exynos_bus_parent_parse_of()
233 	if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))  in exynos_bus_parent_parse_of()
234 		bus->ratio = DEFAULT_SATURATION_RATIO;  in exynos_bus_parent_parse_of()
239 	dev_pm_opp_put_regulators(bus->opp_table);  in exynos_bus_parent_parse_of()
240 	bus->opp_table = NULL;  in exynos_bus_parent_parse_of()
246 			      struct exynos_bus *bus)  in exynos_bus_parse_of()  argument
248 	struct device *dev = bus->dev;  in exynos_bus_parse_of()
253 	/* Get the clock to provide each bus with source clock */  in exynos_bus_parse_of()
254 	bus->clk = devm_clk_get(dev, "bus");  in exynos_bus_parse_of()
255 	if (IS_ERR(bus->clk)) {  in exynos_bus_parse_of()
256 		dev_err(dev, "failed to get bus clock\n");  in exynos_bus_parse_of()
257 		return PTR_ERR(bus->clk);  in exynos_bus_parse_of()
260 	ret = clk_prepare_enable(bus->clk);  in exynos_bus_parse_of()
266 	/* Get the freq and voltage from OPP table to scale the bus freq */  in exynos_bus_parse_of()
273 	rate = clk_get_rate(bus->clk);  in exynos_bus_parse_of()
281 	bus->curr_freq = dev_pm_opp_get_freq(opp);  in exynos_bus_parse_of()
289 	clk_disable_unprepare(bus->clk);  in exynos_bus_parse_of()
294 static int exynos_bus_profile_init(struct exynos_bus *bus,  in exynos_bus_profile_init()  argument
297 	struct device *dev = bus->dev;  in exynos_bus_profile_init()
302 	profile->polling_ms = 50;  in exynos_bus_profile_init()
303 	profile->target = exynos_bus_target;  in exynos_bus_profile_init()
304 	profile->get_dev_status = exynos_bus_get_dev_status;  in exynos_bus_profile_init()
305 	profile->exit = exynos_bus_exit;  in exynos_bus_profile_init()
309 		return -ENOMEM;  in exynos_bus_profile_init()
311 	ondemand_data->upthreshold = 40;  in exynos_bus_profile_init()
312 	ondemand_data->downdifferential = 5;  in exynos_bus_profile_init()
314 	/* Add devfreq device to monitor and handle the exynos bus */  in exynos_bus_profile_init()
315 	bus->devfreq = devm_devfreq_add_device(dev, profile,  in exynos_bus_profile_init()
318 	if (IS_ERR(bus->devfreq)) {  in exynos_bus_profile_init()
320 		return PTR_ERR(bus->devfreq);  in exynos_bus_profile_init()
324 	ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);  in exynos_bus_profile_init()
331 	 * Enable devfreq-event to get raw data which is used to determine  in exynos_bus_profile_init()
332 	 * current bus load.  in exynos_bus_profile_init()
334 	ret = exynos_bus_enable_edev(bus);  in exynos_bus_profile_init()
336 		dev_err(dev, "failed to enable devfreq-event devices\n");  in exynos_bus_profile_init()
340 	ret = exynos_bus_set_event(bus);  in exynos_bus_profile_init()
342 		dev_err(dev, "failed to set event to devfreq-event devices\n");  in exynos_bus_profile_init()
349 	if (exynos_bus_disable_edev(bus))  in exynos_bus_profile_init()
350 		dev_warn(dev, "failed to disable the devfreq-event devices\n");  in exynos_bus_profile_init()
355 static int exynos_bus_profile_init_passive(struct exynos_bus *bus,  in exynos_bus_profile_init_passive()  argument
358 	struct device *dev = bus->dev;  in exynos_bus_profile_init_passive()
363 	profile->target = exynos_bus_target;  in exynos_bus_profile_init_passive()
364 	profile->exit = exynos_bus_passive_exit;  in exynos_bus_profile_init_passive()
369 		return -EPROBE_DEFER;  in exynos_bus_profile_init_passive()
373 		return -ENOMEM;  in exynos_bus_profile_init_passive()
375 	passive_data->parent = parent_devfreq;  in exynos_bus_profile_init_passive()
377 	/* Add devfreq device for exynos bus with passive governor */  in exynos_bus_profile_init_passive()
378 	bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE,  in exynos_bus_profile_init_passive()
380 	if (IS_ERR(bus->devfreq)) {  in exynos_bus_profile_init_passive()
383 		return PTR_ERR(bus->devfreq);  in exynos_bus_profile_init_passive()
391 	struct device *dev = &pdev->dev;  in exynos_bus_probe()
392 	struct device_node *np = dev->of_node, *node;  in exynos_bus_probe()
394 	struct exynos_bus *bus;  in exynos_bus_probe()  local
401 		return -EINVAL;  in exynos_bus_probe()
404 	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);  in exynos_bus_probe()
405 	if (!bus)  in exynos_bus_probe()
406 		return -ENOMEM;  in exynos_bus_probe()
407 	mutex_init(&bus->lock);  in exynos_bus_probe()
408 	bus->dev = &pdev->dev;  in exynos_bus_probe()
409 	platform_set_drvdata(pdev, bus);  in exynos_bus_probe()
413 		return -ENOMEM;  in exynos_bus_probe()
415 	node = of_parse_phandle(dev->of_node, "devfreq", 0);  in exynos_bus_probe()
420 		ret = exynos_bus_parent_parse_of(np, bus);  in exynos_bus_probe()
425 	/* Parse the device-tree to get the resource information */  in exynos_bus_probe()
426 	ret = exynos_bus_parse_of(np, bus);  in exynos_bus_probe()
431 		ret = exynos_bus_profile_init_passive(bus, profile);  in exynos_bus_probe()
433 		ret = exynos_bus_profile_init(bus, profile);  in exynos_bus_probe()
439 	if (of_get_property(dev->of_node, "#interconnect-cells", NULL)) {  in exynos_bus_probe()
440 		bus->icc_pdev = platform_device_register_data(  in exynos_bus_probe()
441 						dev, "exynos-generic-icc",  in exynos_bus_probe()
444 		if (IS_ERR(bus->icc_pdev)) {  in exynos_bus_probe()
445 			ret = PTR_ERR(bus->icc_pdev);  in exynos_bus_probe()
450 	max_state = bus->devfreq->profile->max_state;  in exynos_bus_probe()
451 	min_freq = (bus->devfreq->profile->freq_table[0] / 1000);  in exynos_bus_probe()
452 	max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);  in exynos_bus_probe()
453 	pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",  in exynos_bus_probe()
460 	clk_disable_unprepare(bus->clk);  in exynos_bus_probe()
462 	dev_pm_opp_put_regulators(bus->opp_table);  in exynos_bus_probe()
463 	bus->opp_table = NULL;  in exynos_bus_probe()
470 	struct exynos_bus *bus = dev_get_drvdata(&pdev->dev);  in exynos_bus_shutdown()  local
472 	devfreq_suspend_device(bus->devfreq);  in exynos_bus_shutdown()
478 	struct exynos_bus *bus = dev_get_drvdata(dev);  in exynos_bus_resume()  local
481 	ret = exynos_bus_enable_edev(bus);  in exynos_bus_resume()
483 		dev_err(dev, "failed to enable the devfreq-event devices\n");  in exynos_bus_resume()
492 	struct exynos_bus *bus = dev_get_drvdata(dev);  in exynos_bus_suspend()  local
495 	ret = exynos_bus_disable_edev(bus);  in exynos_bus_suspend()
497 		dev_err(dev, "failed to disable the devfreq-event devices\n");  in exynos_bus_suspend()
510 	{ .compatible = "samsung,exynos-bus", },
519 		.name	= "exynos-bus",
526 MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");