[linux-block.git] / drivers / devfreq / exynos-bus.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic Exynos Bus frequency driver with DEVFREQ Framework
 *
 * Copyright (c) 2016 Samsung Electronics Co., Ltd.
 * Author : Chanwoo Choi <cw00.choi@samsung.com>
 *
 * This driver support Exynos Bus frequency feature by using
 * DEVFREQ framework and is based on drivers/devfreq/exynos/exynos4_bus.c.
 */

#include <linux/clk.h>
#include <linux/devfreq.h>
#include <linux/devfreq-event.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

#define DEFAULT_SATURATION_RATIO	40

struct exynos_bus {
	struct device *dev;

	struct devfreq *devfreq;
	struct devfreq_event_dev **edev;
	unsigned int edev_count;
	struct mutex lock;

	unsigned long curr_freq;

	struct opp_table *opp_table;
	struct clk *clk;
	unsigned int ratio;
};

/*
 * Control the devfreq-event device to get the current state of bus
 */
#define exynos_bus_ops_edev(ops)				\
static int exynos_bus_##ops(struct exynos_bus *bus)		\
{								\
	int i, ret;						\
								\
	for (i = 0; i < bus->edev_count; i++) {			\
		if (!bus->edev[i])				\
			continue;				\
		ret = devfreq_event_##ops(bus->edev[i]);	\
		if (ret < 0)					\
			return ret;				\
	}							\
								\
	return 0;						\
}
exynos_bus_ops_edev(enable_edev);
exynos_bus_ops_edev(disable_edev);
exynos_bus_ops_edev(set_event);

static int exynos_bus_get_event(struct exynos_bus *bus,
				struct devfreq_event_data *edata)
{
	struct devfreq_event_data event_data;
	unsigned long load_count = 0, total_count = 0;
	int i, ret = 0;

	for (i = 0; i < bus->edev_count; i++) {
		if (!bus->edev[i])
			continue;

		ret = devfreq_event_get_event(bus->edev[i], &event_data);
		if (ret < 0)
			return ret;

		if (i == 0 || event_data.load_count > load_count) {
			load_count = event_data.load_count;
			total_count = event_data.total_count;
		}
	}

	edata->load_count = load_count;
	edata->total_count = total_count;

	return ret;
}

/*
 * devfreq function for both simple-ondemand and passive governor
 */
static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
{
	struct exynos_bus *bus = dev_get_drvdata(dev);
	struct dev_pm_opp *new_opp;
	int ret = 0;

	/* Get correct frequency for bus. */
	new_opp = devfreq_recommended_opp(dev, freq, flags);
	if (IS_ERR(new_opp)) {
		dev_err(dev, "failed to get recommended opp instance\n");
		return PTR_ERR(new_opp);
	}

	dev_pm_opp_put(new_opp);

	/* Change voltage and frequency according to new OPP level */
	mutex_lock(&bus->lock);
	ret = dev_pm_opp_set_rate(dev, *freq);
	if (!ret)
		bus->curr_freq = *freq;

	mutex_unlock(&bus->lock);

	return ret;
}

static int exynos_bus_get_dev_status(struct device *dev,
				     struct devfreq_dev_status *stat)
{
	struct exynos_bus *bus = dev_get_drvdata(dev);
	struct devfreq_event_data edata;
	int ret;

	stat->current_frequency = bus->curr_freq;

	ret = exynos_bus_get_event(bus, &edata);
	if (ret < 0) {
		dev_err(dev, "failed to get event from devfreq-event devices\n");
		stat->total_time = stat->busy_time = 0;
		goto err;
	}

	stat->busy_time = (edata.load_count * 100) / bus->ratio;
	stat->total_time = edata.total_count;

	dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time,
							stat->total_time);

err:
	ret = exynos_bus_set_event(bus);
	if (ret < 0) {
		dev_err(dev, "failed to set event to devfreq-event devices\n");
		return ret;
	}

	return ret;
}

static void exynos_bus_exit(struct device *dev)
{
	struct exynos_bus *bus = dev_get_drvdata(dev);
	int ret;

	ret = exynos_bus_disable_edev(bus);
	if (ret < 0)
		dev_warn(dev, "failed to disable the devfreq-event devices\n");

	dev_pm_opp_of_remove_table(dev);
	clk_disable_unprepare(bus->clk);
	if (bus->opp_table) {
		dev_pm_opp_put_regulators(bus->opp_table);
		bus->opp_table = NULL;
	}
}

static void exynos_bus_passive_exit(struct device *dev)
{
	struct exynos_bus *bus = dev_get_drvdata(dev);

	dev_pm_opp_of_remove_table(dev);
	clk_disable_unprepare(bus->clk);
}

static int exynos_bus_parent_parse_of(struct device_node *np,
					struct exynos_bus *bus)
{
	struct device *dev = bus->dev;
	struct opp_table *opp_table;
	const char *vdd = "vdd";
	int i, ret, count, size;

	opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
	if (IS_ERR(opp_table)) {
		ret = PTR_ERR(opp_table);
		dev_err(dev, "failed to set regulators %d\n", ret);
		return ret;
	}

	bus->opp_table = opp_table;

	/*
	 * Get the devfreq-event devices to get the current utilization of
	 * buses. This raw data will be used in devfreq ondemand governor.
	 */
	count = devfreq_event_get_edev_count(dev, "devfreq-events");
	if (count < 0) {
		dev_err(dev, "failed to get the count of devfreq-event dev\n");
		ret = count;
		goto err_regulator;
	}
	bus->edev_count = count;

	size = sizeof(*bus->edev) * count;
	bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
	if (!bus->edev) {
		ret = -ENOMEM;
		goto err_regulator;
	}

	for (i = 0; i < count; i++) {
		bus->edev[i] = devfreq_event_get_edev_by_phandle(dev,
							"devfreq-events", i);
		if (IS_ERR(bus->edev[i])) {
			ret = -EPROBE_DEFER;
			goto err_regulator;
		}
	}

	/*
	 * Optionally, Get the saturation ratio according to Exynos SoC
	 * When measuring the utilization of each AXI bus with devfreq-event
	 * devices, the measured real cycle might be much lower than the
	 * total cycle of bus during sampling rate. In result, the devfreq
	 * simple-ondemand governor might not decide to change the current
	 * frequency due to too utilization (= real cycle/total cycle).
	 * So, this property is used to adjust the utilization when calculating
	 * the busy_time in exynos_bus_get_dev_status().
	 */
	if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
		bus->ratio = DEFAULT_SATURATION_RATIO;

	return 0;

err_regulator:
	dev_pm_opp_put_regulators(bus->opp_table);
	bus->opp_table = NULL;

	return ret;
}

static int exynos_bus_parse_of(struct device_node *np,
			      struct exynos_bus *bus)
{
	struct device *dev = bus->dev;
	struct dev_pm_opp *opp;
	unsigned long rate;
	int ret;

	/* Get the clock to provide each bus with source clock */
	bus->clk = devm_clk_get(dev, "bus");
	if (IS_ERR(bus->clk)) {
		dev_err(dev, "failed to get bus clock\n");
		return PTR_ERR(bus->clk);
	}

	ret = clk_prepare_enable(bus->clk);
	if (ret < 0) {
		dev_err(dev, "failed to get enable clock\n");
		return ret;
	}

	/* Get the freq and voltage from OPP table to scale the bus freq */
	ret = dev_pm_opp_of_add_table(dev);
	if (ret < 0) {
		dev_err(dev, "failed to get OPP table\n");
		goto err_clk;
	}

	rate = clk_get_rate(bus->clk);

	opp = devfreq_recommended_opp(dev, &rate, 0);
	if (IS_ERR(opp)) {
		dev_err(dev, "failed to find dev_pm_opp\n");
		ret = PTR_ERR(opp);
		goto err_opp;
	}
	bus->curr_freq = dev_pm_opp_get_freq(opp);
	dev_pm_opp_put(opp);

	return 0;

err_opp:
	dev_pm_opp_of_remove_table(dev);
err_clk:
	clk_disable_unprepare(bus->clk);

	return ret;
}

static int exynos_bus_profile_init(struct exynos_bus *bus,
				   struct devfreq_dev_profile *profile)
{
	struct device *dev = bus->dev;
	struct devfreq_simple_ondemand_data *ondemand_data;
	int ret;

	/* Initialize the struct profile and governor data for parent device */
	profile->polling_ms = 50;
	profile->target = exynos_bus_target;
	profile->get_dev_status = exynos_bus_get_dev_status;
	profile->exit = exynos_bus_exit;

	ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
	if (!ondemand_data)
		return -ENOMEM;

	ondemand_data->upthreshold = 40;
	ondemand_data->downdifferential = 5;

	/* Add devfreq device to monitor and handle the exynos bus */
	bus->devfreq = devm_devfreq_add_device(dev, profile,
						DEVFREQ_GOV_SIMPLE_ONDEMAND,
						ondemand_data);
	if (IS_ERR(bus->devfreq)) {
		dev_err(dev, "failed to add devfreq device\n");
		return PTR_ERR(bus->devfreq);
	}

	/* Register opp_notifier to catch the change of OPP  */
	ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
	if (ret < 0) {
		dev_err(dev, "failed to register opp notifier\n");
		return ret;
	}

	/*
	 * Enable devfreq-event to get raw data which is used to determine
	 * current bus load.
	 */
	ret = exynos_bus_enable_edev(bus);
	if (ret < 0) {
		dev_err(dev, "failed to enable devfreq-event devices\n");
		return ret;
	}

	ret = exynos_bus_set_event(bus);
	if (ret < 0) {
		dev_err(dev, "failed to set event to devfreq-event devices\n");
		goto err_edev;
	}

	return 0;

err_edev:
	if (exynos_bus_disable_edev(bus))
		dev_warn(dev, "failed to disable the devfreq-event devices\n");

	return ret;
}

static int exynos_bus_profile_init_passive(struct exynos_bus *bus,
					   struct devfreq_dev_profile *profile)
{
	struct device *dev = bus->dev;
	struct devfreq_passive_data *passive_data;
	struct devfreq *parent_devfreq;

	/* Initialize the struct profile and governor data for passive device */
	profile->target = exynos_bus_target;
	profile->exit = exynos_bus_passive_exit;

	/* Get the instance of parent devfreq device */
	parent_devfreq = devfreq_get_devfreq_by_phandle(dev, "devfreq", 0);
	if (IS_ERR(parent_devfreq))
		return -EPROBE_DEFER;

	passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
	if (!passive_data)
		return -ENOMEM;

	passive_data->parent = parent_devfreq;

	/* Add devfreq device for exynos bus with passive governor */
	bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE,
						passive_data);
	if (IS_ERR(bus->devfreq)) {
		dev_err(dev,
			"failed to add devfreq dev with passive governor\n");
		return PTR_ERR(bus->devfreq);
	}

	return 0;
}

static int exynos_bus_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node, *node;
	struct devfreq_dev_profile *profile;
	struct exynos_bus *bus;
	int ret, max_state;
	unsigned long min_freq, max_freq;
	bool passive = false;

	if (!np) {
		dev_err(dev, "failed to find devicetree node\n");
		return -EINVAL;
	}

	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
	if (!bus)
		return -ENOMEM;
	mutex_init(&bus->lock);
	bus->dev = &pdev->dev;
	platform_set_drvdata(pdev, bus);

	profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
	if (!profile)
		return -ENOMEM;

	node = of_parse_phandle(dev->of_node, "devfreq", 0);
	if (node) {
		of_node_put(node);
		passive = true;
	} else {
		ret = exynos_bus_parent_parse_of(np, bus);
		if (ret < 0)
			return ret;
	}

	/* Parse the device-tree to get the resource information */
	ret = exynos_bus_parse_of(np, bus);
	if (ret < 0)
		goto err_reg;

	if (passive)
		ret = exynos_bus_profile_init_passive(bus, profile);
	else
		ret = exynos_bus_profile_init(bus, profile);

	if (ret < 0)
		goto err;

	max_state = bus->devfreq->profile->max_state;
	min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
	max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
	pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
			dev_name(dev), min_freq, max_freq);

	return 0;

err:
	dev_pm_opp_of_remove_table(dev);
	clk_disable_unprepare(bus->clk);
err_reg:
	if (!passive) {
		dev_pm_opp_put_regulators(bus->opp_table);
		bus->opp_table = NULL;
	}

	return ret;
}

static void exynos_bus_shutdown(struct platform_device *pdev)
{
	struct exynos_bus *bus = dev_get_drvdata(&pdev->dev);

	devfreq_suspend_device(bus->devfreq);
}

#ifdef CONFIG_PM_SLEEP
static int exynos_bus_resume(struct device *dev)
{
	struct exynos_bus *bus = dev_get_drvdata(dev);
	int ret;

	ret = exynos_bus_enable_edev(bus);
	if (ret < 0) {
		dev_err(dev, "failed to enable the devfreq-event devices\n");
		return ret;
	}

	return 0;
}

static int exynos_bus_suspend(struct device *dev)
{
	struct exynos_bus *bus = dev_get_drvdata(dev);
	int ret;

	ret = exynos_bus_disable_edev(bus);
	if (ret < 0) {
		dev_err(dev, "failed to disable the devfreq-event devices\n");
		return ret;
	}

	return 0;
}
#endif

static const struct dev_pm_ops exynos_bus_pm = {
	SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
};

static const struct of_device_id exynos_bus_of_match[] = {
	{ .compatible = "samsung,exynos-bus", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, exynos_bus_of_match);

static struct platform_driver exynos_bus_platdrv = {
	.probe		= exynos_bus_probe,
	.shutdown	= exynos_bus_shutdown,
	.driver = {
		.name	= "exynos-bus",
		.pm	= &exynos_bus_pm,
		.of_match_table = of_match_ptr(exynos_bus_of_match),
	},
};
module_platform_driver(exynos_bus_platdrv);

MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
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
0722249a CC	23	#define DEFAULT_SATURATION_RATIO 40
0722249a CC	24
	25	struct exynos_bus {
	26	struct device *dev;
	27
	28	struct devfreq *devfreq;
	29	struct devfreq_event_dev **edev;
	30	unsigned int edev_count;
	31	struct mutex lock;
	32
c8ce82b9	33	unsigned long curr_freq;
0722249a	34
4294a779	35	struct opp_table *opp_table;
0722249a	36	struct clk *clk;
0722249a CC	37	unsigned int ratio;
	38	};
	39
	40	/*
	41	* Control the devfreq-event device to get the current state of bus
	42	*/
	43	#define exynos_bus_ops_edev(ops) \
	44	static int exynos_bus_##ops(struct exynos_bus *bus) \
	45	{ \
	46	int i, ret; \
	47	\
	48	for (i = 0; i < bus->edev_count; i++) { \
	49	if (!bus->edev[i]) \
	50	continue; \
	51	ret = devfreq_event_##ops(bus->edev[i]); \
	52	if (ret < 0) \
	53	return ret; \
	54	} \
	55	\
	56	return 0; \
	57	}
	58	exynos_bus_ops_edev(enable_edev);
	59	exynos_bus_ops_edev(disable_edev);
	60	exynos_bus_ops_edev(set_event);
	61
	62	static int exynos_bus_get_event(struct exynos_bus *bus,
	63	struct devfreq_event_data *edata)
	64	{
	65	struct devfreq_event_data event_data;
	66	unsigned long load_count = 0, total_count = 0;
	67	int i, ret = 0;
	68
	69	for (i = 0; i < bus->edev_count; i++) {
	70	if (!bus->edev[i])
	71	continue;
	72
	73	ret = devfreq_event_get_event(bus->edev[i], &event_data);
	74	if (ret < 0)
	75	return ret;
	76
	77	if (i == 0 \|\| event_data.load_count > load_count) {
	78	load_count = event_data.load_count;
	79	total_count = event_data.total_count;
	80	}
	81	}
	82
	83	edata->load_count = load_count;
	84	edata->total_count = total_count;
	85
	86	return ret;
	87	}
	88
	89	/*
4294a779	90	* devfreq function for both simple-ondemand and passive governor
0722249a CC	91	*/
	92	static int exynos_bus_target(struct device dev, unsigned long freq, u32 flags)
	93	{
	94	struct exynos_bus *bus = dev_get_drvdata(dev);
	95	struct dev_pm_opp *new_opp;
0722249a CC	96	int ret = 0;
0722249a CC	97
4294a779	98	/* Get correct frequency for bus. */
0722249a CC	99	new_opp = devfreq_recommended_opp(dev, freq, flags);
	100	if (IS_ERR(new_opp)) {
	101	dev_err(dev, "failed to get recommended opp instance\n");
0722249a CC	102	return PTR_ERR(new_opp);
	103	}
	104
8a31d9d9 VK	105	dev_pm_opp_put(new_opp);
8a31d9d9 VK	106
0722249a CC	107	/* Change voltage and frequency according to new OPP level */
0722249a CC	108	mutex_lock(&bus->lock);
4294a779 KK	109	ret = dev_pm_opp_set_rate(dev, *freq);
	110	if (!ret)
	111	bus->curr_freq = *freq;
0722249a	112
0722249a CC	113	mutex_unlock(&bus->lock);
	114
	115	return ret;
	116	}
	117
	118	static int exynos_bus_get_dev_status(struct device *dev,
	119	struct devfreq_dev_status *stat)
	120	{
	121	struct exynos_bus *bus = dev_get_drvdata(dev);
	122	struct devfreq_event_data edata;
	123	int ret;
	124
c8ce82b9	125	stat->current_frequency = bus->curr_freq;
0722249a CC	126
	127	ret = exynos_bus_get_event(bus, &edata);
	128	if (ret < 0) {
28135762	129	dev_err(dev, "failed to get event from devfreq-event devices\n");
0722249a CC	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
	140	err:
	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
	150	static 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
0722249a	159	dev_pm_opp_of_remove_table(dev);
403e0689	160	clk_disable_unprepare(bus->clk);
4294a779 KK	161	if (bus->opp_table) {
	162	dev_pm_opp_put_regulators(bus->opp_table);
	163	bus->opp_table = NULL;
0722249a	164	}
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
	171	dev_pm_opp_of_remove_table(dev);
	172	clk_disable_unprepare(bus->clk);
	173	}
	174
	175	static int exynos_bus_parent_parse_of(struct device_node *np,
	176	struct exynos_bus *bus)
	177	{
	178	struct device *dev = bus->dev;
4294a779 KK	179	struct opp_table *opp_table;
4294a779 KK	180	const char *vdd = "vdd";
403e0689	181	int i, ret, count, size;
0722249a	182
4294a779 KK	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);
403e0689	187	return ret;
0722249a CC	188	}
0722249a CC	189
4294a779 KK	190	bus->opp_table = opp_table;
4294a779 KK	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,
02bdbf7d CC	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:
4294a779 KK	236	dev_pm_opp_put_regulators(bus->opp_table);
4294a779 KK	237	bus->opp_table = NULL;
403e0689 CC	238
	239	return ret;
	240	}
	241
	242	static int exynos_bus_parse_of(struct device_node *np,
	243	struct exynos_bus *bus)
	244	{
	245	struct device *dev = bus->dev;
c8ce82b9	246	struct dev_pm_opp *opp;
403e0689 CC	247	unsigned long rate;
	248	int ret;
	249
	250	/* Get the clock to provide each bus with source clock */
	251	bus->clk = devm_clk_get(dev, "bus");
	252	if (IS_ERR(bus->clk)) {
	253	dev_err(dev, "failed to get bus clock\n");
	254	return PTR_ERR(bus->clk);
	255	}
	256
	257	ret = clk_prepare_enable(bus->clk);
	258	if (ret < 0) {
	259	dev_err(dev, "failed to get enable clock\n");
	260	return ret;
	261	}
	262
	263	/* Get the freq and voltage from OPP table to scale the bus freq */
403e0689 CC	264	ret = dev_pm_opp_of_add_table(dev);
	265	if (ret < 0) {
	266	dev_err(dev, "failed to get OPP table\n");
403e0689 CC	267	goto err_clk;
	268	}
	269
	270	rate = clk_get_rate(bus->clk);
c8ce82b9	271
c8ce82b9 VK	272	opp = devfreq_recommended_opp(dev, &rate, 0);
c8ce82b9 VK	273	if (IS_ERR(opp)) {
403e0689	274	dev_err(dev, "failed to find dev_pm_opp\n");
c8ce82b9	275	ret = PTR_ERR(opp);
403e0689 CC	276	goto err_opp;
403e0689 CC	277	}
c8ce82b9	278	bus->curr_freq = dev_pm_opp_get_freq(opp);
8a31d9d9	279	dev_pm_opp_put(opp);
403e0689 CC	280
	281	return 0;
	282
0722249a CC	283	err_opp:
	284	dev_pm_opp_of_remove_table(dev);
	285	err_clk:
	286	clk_disable_unprepare(bus->clk);
	287
	288	return ret;
	289	}
	290
a47a97ec AŚ	291	static int exynos_bus_profile_init(struct exynos_bus *bus,
a47a97ec AŚ	292	struct devfreq_dev_profile *profile)
0722249a	293	{
a47a97ec	294	struct device *dev = bus->dev;
0722249a	295	struct devfreq_simple_ondemand_data *ondemand_data;
a47a97ec	296	int ret;
403e0689	297
83cb0e4d	298	/* Initialize the struct profile and governor data for parent device */
0722249a CC	299	profile->polling_ms = 50;
	300	profile->target = exynos_bus_target;
	301	profile->get_dev_status = exynos_bus_get_dev_status;
	302	profile->exit = exynos_bus_exit;
	303
	304	ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
a4408921 AŚ	305	if (!ondemand_data)
	306	return -ENOMEM;
	307
0722249a CC	308	ondemand_data->upthreshold = 40;
	309	ondemand_data->downdifferential = 5;
	310
	311	/* Add devfreq device to monitor and handle the exynos bus */
aa7c352f CC	312	bus->devfreq = devm_devfreq_add_device(dev, profile,
aa7c352f CC	313	DEVFREQ_GOV_SIMPLE_ONDEMAND,
0722249a CC	314	ondemand_data);
	315	if (IS_ERR(bus->devfreq)) {
	316	dev_err(dev, "failed to add devfreq device\n");
a4408921	317	return PTR_ERR(bus->devfreq);
0722249a CC	318	}
	319
	320	/* Register opp_notifier to catch the change of OPP */
	321	ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
	322	if (ret < 0) {
	323	dev_err(dev, "failed to register opp notifier\n");
a4408921	324	return ret;
0722249a CC	325	}
	326
	327	/*
	328	* Enable devfreq-event to get raw data which is used to determine
	329	* current bus load.
	330	*/
	331	ret = exynos_bus_enable_edev(bus);
	332	if (ret < 0) {
	333	dev_err(dev, "failed to enable devfreq-event devices\n");
a4408921	334	return ret;
0722249a CC	335	}
	336
	337	ret = exynos_bus_set_event(bus);
	338	if (ret < 0) {
	339	dev_err(dev, "failed to set event to devfreq-event devices\n");
6c315d8f	340	goto err_edev;
0722249a CC	341	}
0722249a CC	342
a4408921	343	return 0;
6c315d8f YL	344
	345	err_edev:
	346	if (exynos_bus_disable_edev(bus))
	347	dev_warn(dev, "failed to disable the devfreq-event devices\n");
	348
	349	return ret;
a47a97ec AŚ	350	}
a47a97ec AŚ	351
a05bb963 AŚ	352	static int exynos_bus_profile_init_passive(struct exynos_bus *bus,
	353	struct devfreq_dev_profile *profile)
	354	{
	355	struct device *dev = bus->dev;
	356	struct devfreq_passive_data *passive_data;
	357	struct devfreq *parent_devfreq;
a05bb963 AŚ	358
	359	/* Initialize the struct profile and governor data for passive device */
	360	profile->target = exynos_bus_target;
	361	profile->exit = exynos_bus_passive_exit;
	362
	363	/* Get the instance of parent devfreq device */
86d90fd9	364	parent_devfreq = devfreq_get_devfreq_by_phandle(dev, "devfreq", 0);
a4408921 AŚ	365	if (IS_ERR(parent_devfreq))
a4408921 AŚ	366	return -EPROBE_DEFER;
a05bb963 AŚ	367
a05bb963 AŚ	368	passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
a4408921 AŚ	369	if (!passive_data)
	370	return -ENOMEM;
	371
a05bb963 AŚ	372	passive_data->parent = parent_devfreq;
	373
	374	/* Add devfreq device for exynos bus with passive governor */
	375	bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE,
	376	passive_data);
	377	if (IS_ERR(bus->devfreq)) {
	378	dev_err(dev,
	379	"failed to add devfreq dev with passive governor\n");
a4408921	380	return PTR_ERR(bus->devfreq);
a05bb963 AŚ	381	}
a05bb963 AŚ	382
a4408921	383	return 0;
a05bb963 AŚ	384	}
a05bb963 AŚ	385
a47a97ec AŚ	386	static int exynos_bus_probe(struct platform_device *pdev)
	387	{
	388	struct device *dev = &pdev->dev;
	389	struct device_node np = dev->of_node, node;
	390	struct devfreq_dev_profile *profile;
a47a97ec AŚ	391	struct exynos_bus *bus;
	392	int ret, max_state;
	393	unsigned long min_freq, max_freq;
	394	bool passive = false;
	395
	396	if (!np) {
	397	dev_err(dev, "failed to find devicetree node\n");
	398	return -EINVAL;
	399	}
	400
	401	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
	402	if (!bus)
	403	return -ENOMEM;
	404	mutex_init(&bus->lock);
	405	bus->dev = &pdev->dev;
	406	platform_set_drvdata(pdev, bus);
	407
	408	profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
	409	if (!profile)
	410	return -ENOMEM;
	411
	412	node = of_parse_phandle(dev->of_node, "devfreq", 0);
	413	if (node) {
	414	of_node_put(node);
	415	passive = true;
	416	} else {
	417	ret = exynos_bus_parent_parse_of(np, bus);
	418	if (ret < 0)
	419	return ret;
	420	}
	421
	422	/* Parse the device-tree to get the resource information */
	423	ret = exynos_bus_parse_of(np, bus);
	424	if (ret < 0)
	425	goto err_reg;
	426
	427	if (passive)
a4408921 AŚ	428	ret = exynos_bus_profile_init_passive(bus, profile);
	429	else
	430	ret = exynos_bus_profile_init(bus, profile);
a47a97ec	431
a05bb963	432	if (ret < 0)
403e0689	433	goto err;
403e0689	434
403e0689 CC	435	max_state = bus->devfreq->profile->max_state;
	436	min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
	437	max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
	438	pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
	439	dev_name(dev), min_freq, max_freq);
	440
0722249a	441	return 0;
403e0689 CC	442
	443	err:
	444	dev_pm_opp_of_remove_table(dev);
	445	clk_disable_unprepare(bus->clk);
2c2b20e0	446	err_reg:
4294a779 KK	447	if (!passive) {
	448	dev_pm_opp_put_regulators(bus->opp_table);
	449	bus->opp_table = NULL;
	450	}
403e0689 CC	451
403e0689 CC	452	return ret;
0722249a CC	453	}
0722249a CC	454
fbb9c3c9 MS	455	static void exynos_bus_shutdown(struct platform_device *pdev)
	456	{
	457	struct exynos_bus *bus = dev_get_drvdata(&pdev->dev);
	458
	459	devfreq_suspend_device(bus->devfreq);
	460	}
	461
0722249a CC	462	#ifdef CONFIG_PM_SLEEP
	463	static int exynos_bus_resume(struct device *dev)
	464	{
	465	struct exynos_bus *bus = dev_get_drvdata(dev);
	466	int ret;
	467
	468	ret = exynos_bus_enable_edev(bus);
	469	if (ret < 0) {
	470	dev_err(dev, "failed to enable the devfreq-event devices\n");
	471	return ret;
	472	}
	473
	474	return 0;
	475	}
	476
	477	static int exynos_bus_suspend(struct device *dev)
	478	{
	479	struct exynos_bus *bus = dev_get_drvdata(dev);
	480	int ret;
	481
	482	ret = exynos_bus_disable_edev(bus);
	483	if (ret < 0) {
	484	dev_err(dev, "failed to disable the devfreq-event devices\n");
	485	return ret;
	486	}
	487
	488	return 0;
	489	}
	490	#endif
	491
	492	static const struct dev_pm_ops exynos_bus_pm = {
	493	SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
	494	};
	495
	496	static const struct of_device_id exynos_bus_of_match[] = {
	497	{ .compatible = "samsung,exynos-bus", },
	498	{ /* sentinel */ },
	499	};
	500	MODULE_DEVICE_TABLE(of, exynos_bus_of_match);
	501
	502	static struct platform_driver exynos_bus_platdrv = {
	503	.probe = exynos_bus_probe,
fbb9c3c9	504	.shutdown = exynos_bus_shutdown,
0722249a CC	505	.driver = {
	506	.name = "exynos-bus",
	507	.pm = &exynos_bus_pm,
	508	.of_match_table = of_match_ptr(exynos_bus_of_match),
	509	},
	510	};
	511	module_platform_driver(exynos_bus_platdrv);
	512
	513	MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
	514	MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
	515	MODULE_LICENSE("GPL v2");