[mirror_ubuntu-jammy-kernel.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 platform_device *icc_pdev;

	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");

	platform_device_unregister(bus->icc_pdev);

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

	platform_device_unregister(bus->icc_pdev);

	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;

	/* Create child platform device for the interconnect provider */
	if (of_get_property(dev->of_node, "#interconnect-cells", NULL)) {
		bus->icc_pdev = platform_device_register_data(
						dev, "exynos-generic-icc",
						PLATFORM_DEVID_AUTO, NULL, 0);

		if (IS_ERR(bus->icc_pdev)) {
			ret = PTR_ERR(bus->icc_pdev);
			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:
	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;
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
4294a779	36	struct opp_table *opp_table;
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;
0722249a CC	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);
8a31d9d9 VK	107
0722249a CC	108	/* Change voltage and frequency according to new OPP level */
0722249a CC	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);
404d59c5 SN	161
0722249a	162	dev_pm_opp_of_remove_table(dev);
403e0689	163	clk_disable_unprepare(bus->clk);
81456872 VK	164	dev_pm_opp_put_regulators(bus->opp_table);
81456872 VK	165	bus->opp_table = NULL;
403e0689 CC	166	}
	167
	168	static void exynos_bus_passive_exit(struct device *dev)
	169	{
	170	struct exynos_bus *bus = dev_get_drvdata(dev);
	171
404d59c5 SN	172	platform_device_unregister(bus->icc_pdev);
404d59c5 SN	173
403e0689 CC	174	dev_pm_opp_of_remove_table(dev);
	175	clk_disable_unprepare(bus->clk);
	176	}
	177
	178	static int exynos_bus_parent_parse_of(struct device_node *np,
	179	struct exynos_bus *bus)
	180	{
	181	struct device *dev = bus->dev;
4294a779 KK	182	struct opp_table *opp_table;
4294a779 KK	183	const char *vdd = "vdd";
403e0689	184	int i, ret, count, size;
0722249a	185
4294a779 KK	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);
403e0689	190	return ret;
0722249a CC	191	}
0722249a CC	192
4294a779 KK	193	bus->opp_table = opp_table;
4294a779 KK	194
0722249a CC	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	*/
02bdbf7d	199	count = devfreq_event_get_edev_count(dev, "devfreq-events");
0722249a CC	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++) {
02bdbf7d CC	215	bus->edev[i] = devfreq_event_get_edev_by_phandle(dev,
02bdbf7d CC	216	"devfreq-events", i);
0722249a CC	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
0722249a CC	236	return 0;
	237
	238	err_regulator:
4294a779 KK	239	dev_pm_opp_put_regulators(bus->opp_table);
4294a779 KK	240	bus->opp_table = NULL;
403e0689 CC	241
	242	return ret;
	243	}
	244
	245	static int exynos_bus_parse_of(struct device_node *np,
	246	struct exynos_bus *bus)
	247	{
	248	struct device *dev = bus->dev;
c8ce82b9	249	struct dev_pm_opp *opp;
403e0689 CC	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 */
403e0689 CC	267	ret = dev_pm_opp_of_add_table(dev);
	268	if (ret < 0) {
	269	dev_err(dev, "failed to get OPP table\n");
403e0689 CC	270	goto err_clk;
	271	}
	272
	273	rate = clk_get_rate(bus->clk);
c8ce82b9	274
c8ce82b9 VK	275	opp = devfreq_recommended_opp(dev, &rate, 0);
c8ce82b9 VK	276	if (IS_ERR(opp)) {
403e0689	277	dev_err(dev, "failed to find dev_pm_opp\n");
c8ce82b9	278	ret = PTR_ERR(opp);
403e0689 CC	279	goto err_opp;
403e0689 CC	280	}
c8ce82b9	281	bus->curr_freq = dev_pm_opp_get_freq(opp);
8a31d9d9	282	dev_pm_opp_put(opp);
403e0689 CC	283
	284	return 0;
	285
0722249a CC	286	err_opp:
	287	dev_pm_opp_of_remove_table(dev);
	288	err_clk:
	289	clk_disable_unprepare(bus->clk);
	290
	291	return ret;
	292	}
	293
a47a97ec AŚ	294	static int exynos_bus_profile_init(struct exynos_bus *bus,
a47a97ec AŚ	295	struct devfreq_dev_profile *profile)
0722249a	296	{
a47a97ec	297	struct device *dev = bus->dev;
0722249a	298	struct devfreq_simple_ondemand_data *ondemand_data;
a47a97ec	299	int ret;
403e0689	300
83cb0e4d	301	/* Initialize the struct profile and governor data for parent device */
0722249a CC	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);
a4408921 AŚ	308	if (!ondemand_data)
	309	return -ENOMEM;
	310
0722249a CC	311	ondemand_data->upthreshold = 40;
	312	ondemand_data->downdifferential = 5;
	313
	314	/* Add devfreq device to monitor and handle the exynos bus */
aa7c352f CC	315	bus->devfreq = devm_devfreq_add_device(dev, profile,
aa7c352f CC	316	DEVFREQ_GOV_SIMPLE_ONDEMAND,
0722249a CC	317	ondemand_data);
	318	if (IS_ERR(bus->devfreq)) {
	319	dev_err(dev, "failed to add devfreq device\n");
a4408921	320	return PTR_ERR(bus->devfreq);
0722249a CC	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");
a4408921	327	return ret;
0722249a CC	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");
a4408921	337	return ret;
0722249a CC	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");
6c315d8f	343	goto err_edev;
0722249a CC	344	}
0722249a CC	345
a4408921	346	return 0;
6c315d8f YL	347
	348	err_edev:
	349	if (exynos_bus_disable_edev(bus))
	350	dev_warn(dev, "failed to disable the devfreq-event devices\n");
	351
	352	return ret;
a47a97ec AŚ	353	}
a47a97ec AŚ	354
a05bb963 AŚ	355	static 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;
a05bb963 AŚ	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 */
86d90fd9	367	parent_devfreq = devfreq_get_devfreq_by_phandle(dev, "devfreq", 0);
a4408921 AŚ	368	if (IS_ERR(parent_devfreq))
a4408921 AŚ	369	return -EPROBE_DEFER;
a05bb963 AŚ	370
a05bb963 AŚ	371	passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
a4408921 AŚ	372	if (!passive_data)
	373	return -ENOMEM;
	374
a05bb963 AŚ	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");
a4408921	383	return PTR_ERR(bus->devfreq);
a05bb963 AŚ	384	}
a05bb963 AŚ	385
a4408921	386	return 0;
a05bb963 AŚ	387	}
a05bb963 AŚ	388
a47a97ec AŚ	389	static 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;
a47a97ec AŚ	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)
a4408921 AŚ	431	ret = exynos_bus_profile_init_passive(bus, profile);
	432	else
	433	ret = exynos_bus_profile_init(bus, profile);
a47a97ec	434
a05bb963	435	if (ret < 0)
403e0689	436	goto err;
403e0689	437
404d59c5 SN	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
403e0689 CC	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
0722249a	456	return 0;
403e0689 CC	457
	458	err:
	459	dev_pm_opp_of_remove_table(dev);
	460	clk_disable_unprepare(bus->clk);
2c2b20e0	461	err_reg:
81456872 VK	462	dev_pm_opp_put_regulators(bus->opp_table);
81456872 VK	463	bus->opp_table = NULL;
403e0689 CC	464
403e0689 CC	465	return ret;
0722249a CC	466	}
0722249a CC	467
fbb9c3c9 MS	468	static 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
0722249a CC	475	#ifdef CONFIG_PM_SLEEP
	476	static 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
	490	static 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
	505	static const struct dev_pm_ops exynos_bus_pm = {
	506	SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
	507	};
	508
	509	static const struct of_device_id exynos_bus_of_match[] = {
	510	{ .compatible = "samsung,exynos-bus", },
	511	{ /* sentinel */ },
	512	};
	513	MODULE_DEVICE_TABLE(of, exynos_bus_of_match);
	514
	515	static struct platform_driver exynos_bus_platdrv = {
	516	.probe = exynos_bus_probe,
fbb9c3c9	517	.shutdown = exynos_bus_shutdown,
0722249a CC	518	.driver = {
	519	.name = "exynos-bus",
	520	.pm = &exynos_bus_pm,
	521	.of_match_table = of_match_ptr(exynos_bus_of_match),
	522	},
	523	};
	524	module_platform_driver(exynos_bus_platdrv);
	525
	526	MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
	527	MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
	528	MODULE_LICENSE("GPL v2");