[linux-block.git] / drivers / bus / simple-pm-bus.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Simple Power-Managed Bus Driver
 *
 * Copyright (C) 2014-2015 Glider bvba
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>

struct simple_pm_bus {
	struct clk_bulk_data *clks;
	int num_clks;
};

static int simple_pm_bus_probe(struct platform_device *pdev)
{
	const struct device *dev = &pdev->dev;
	const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
	struct device_node *np = dev->of_node;
	const struct of_device_id *match;
	struct simple_pm_bus *bus;

	/*
	 * Allow user to use driver_override to bind this driver to a
	 * transparent bus device which has a different compatible string
	 * that's not listed in simple_pm_bus_of_match. We don't want to do any
	 * of the simple-pm-bus tasks for these devices, so return early.
	 */
	if (pdev->driver_override)
		return 0;

	match = of_match_device(dev->driver->of_match_table, dev);
	/*
	 * These are transparent bus devices (not simple-pm-bus matches) that
	 * have their child nodes populated automatically.  So, don't need to
	 * do anything more. We only match with the device if this driver is
	 * the most specific match because we don't want to incorrectly bind to
	 * a device that has a more specific driver.
	 */
	if (match && match->data) {
		if (of_property_match_string(np, "compatible", match->compatible) == 0)
			return 0;
		else
			return -ENODEV;
	}

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

	bus->num_clks = devm_clk_bulk_get_all(&pdev->dev, &bus->clks);
	if (bus->num_clks < 0)
		return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n");

	dev_set_drvdata(&pdev->dev, bus);

	dev_dbg(&pdev->dev, "%s\n", __func__);

	pm_runtime_enable(&pdev->dev);

	if (np)
		of_platform_populate(np, NULL, lookup, &pdev->dev);

	return 0;
}

static int simple_pm_bus_remove(struct platform_device *pdev)
{
	const void *data = of_device_get_match_data(&pdev->dev);

	if (pdev->driver_override || data)
		return 0;

	dev_dbg(&pdev->dev, "%s\n", __func__);

	pm_runtime_disable(&pdev->dev);
	return 0;
}

static int simple_pm_bus_runtime_suspend(struct device *dev)
{
	struct simple_pm_bus *bus = dev_get_drvdata(dev);

	clk_bulk_disable_unprepare(bus->num_clks, bus->clks);

	return 0;
}

static int simple_pm_bus_runtime_resume(struct device *dev)
{
	struct simple_pm_bus *bus = dev_get_drvdata(dev);
	int ret;

	ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);
	if (ret) {
		dev_err(dev, "failed to enable clocks: %d\n", ret);
		return ret;
	}

	return 0;
}

static const struct dev_pm_ops simple_pm_bus_pm_ops = {
	RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL)
	NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
};

#define ONLY_BUS	((void *) 1) /* Match if the device is only a bus. */

static const struct of_device_id simple_pm_bus_of_match[] = {
	{ .compatible = "simple-pm-bus", },
	{ .compatible = "simple-bus",	.data = ONLY_BUS },
	{ .compatible = "simple-mfd",	.data = ONLY_BUS },
	{ .compatible = "isa",		.data = ONLY_BUS },
	{ .compatible = "arm,amba-bus",	.data = ONLY_BUS },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);

static struct platform_driver simple_pm_bus_driver = {
	.probe = simple_pm_bus_probe,
	.remove = simple_pm_bus_remove,
	.driver = {
		.name = "simple-pm-bus",
		.of_match_table = simple_pm_bus_of_match,
		.pm = pm_ptr(&simple_pm_bus_pm_ops),
	},
};

module_platform_driver(simple_pm_bus_driver);

MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");
MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
Commit	Line	Data
92a72297	1	// SPDX-License-Identifier: GPL-2.0
89d463ea GU	2	/*
	3	* Simple Power-Managed Bus Driver
	4	*
	5	* Copyright (C) 2014-2015 Glider bvba
	6	*
	7	* This file is subject to the terms and conditions of the GNU General Public
	8	* License. See the file "COPYING" in the main directory of this archive
	9	* for more details.
	10	*/
	11
c4583930	12	#include <linux/clk.h>
89d463ea GU	13	#include <linux/module.h>
	14	#include <linux/of_platform.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/pm_runtime.h>
	17
c4583930 LY	18	struct simple_pm_bus {
	19	struct clk_bulk_data *clks;
	20	int num_clks;
	21	};
	22
89d463ea GU	23	static int simple_pm_bus_probe(struct platform_device *pdev)
89d463ea GU	24	{
98e96cf8 SK	25	const struct device *dev = &pdev->dev;
	26	const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
	27	struct device_node *np = dev->of_node;
	28	const struct of_device_id *match;
c4583930	29	struct simple_pm_bus *bus;
98e96cf8 SK	30
	31	/*
	32	* Allow user to use driver_override to bind this driver to a
	33	* transparent bus device which has a different compatible string
	34	* that's not listed in simple_pm_bus_of_match. We don't want to do any
	35	* of the simple-pm-bus tasks for these devices, so return early.
	36	*/
	37	if (pdev->driver_override)
	38	return 0;
	39
	40	match = of_match_device(dev->driver->of_match_table, dev);
	41	/*
	42	* These are transparent bus devices (not simple-pm-bus matches) that
	43	* have their child nodes populated automatically. So, don't need to
	44	* do anything more. We only match with the device if this driver is
	45	* the most specific match because we don't want to incorrectly bind to
	46	* a device that has a more specific driver.
	47	*/
	48	if (match && match->data) {
	49	if (of_property_match_string(np, "compatible", match->compatible) == 0)
	50	return 0;
	51	else
	52	return -ENODEV;
	53	}
89d463ea	54
c4583930 LY	55	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
	56	if (!bus)
	57	return -ENOMEM;
	58
	59	bus->num_clks = devm_clk_bulk_get_all(&pdev->dev, &bus->clks);
	60	if (bus->num_clks < 0)
	61	return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n");
	62
	63	dev_set_drvdata(&pdev->dev, bus);
	64
89d463ea GU	65	dev_dbg(&pdev->dev, "%s\n", __func__);
	66
	67	pm_runtime_enable(&pdev->dev);
	68
	69	if (np)
eda080ea	70	of_platform_populate(np, NULL, lookup, &pdev->dev);
89d463ea GU	71
	72	return 0;
	73	}
	74
	75	static int simple_pm_bus_remove(struct platform_device *pdev)
	76	{
98e96cf8 SK	77	const void *data = of_device_get_match_data(&pdev->dev);
	78
	79	if (pdev->driver_override \|\| data)
	80	return 0;
	81
89d463ea GU	82	dev_dbg(&pdev->dev, "%s\n", __func__);
	83
	84	pm_runtime_disable(&pdev->dev);
	85	return 0;
	86	}
	87
c4583930 LY	88	static int simple_pm_bus_runtime_suspend(struct device *dev)
	89	{
	90	struct simple_pm_bus *bus = dev_get_drvdata(dev);
	91
	92	clk_bulk_disable_unprepare(bus->num_clks, bus->clks);
	93
	94	return 0;
	95	}
	96
	97	static int simple_pm_bus_runtime_resume(struct device *dev)
	98	{
	99	struct simple_pm_bus *bus = dev_get_drvdata(dev);
	100	int ret;
	101
	102	ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);
	103	if (ret) {
	104	dev_err(dev, "failed to enable clocks: %d\n", ret);
	105	return ret;
	106	}
	107
	108	return 0;
	109	}
	110
	111	static const struct dev_pm_ops simple_pm_bus_pm_ops = {
	112	RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL)
	113	NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
	114	};
	115
98e96cf8 SK	116	#define ONLY_BUS ((void ) 1) / Match if the device is only a bus. */
98e96cf8 SK	117
89d463ea GU	118	static const struct of_device_id simple_pm_bus_of_match[] = {
89d463ea GU	119	{ .compatible = "simple-pm-bus", },
98e96cf8 SK	120	{ .compatible = "simple-bus", .data = ONLY_BUS },
	121	{ .compatible = "simple-mfd", .data = ONLY_BUS },
	122	{ .compatible = "isa", .data = ONLY_BUS },
	123	{ .compatible = "arm,amba-bus", .data = ONLY_BUS },
89d463ea GU	124	{ /* sentinel */ }
	125	};
	126	MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);
	127
	128	static struct platform_driver simple_pm_bus_driver = {
	129	.probe = simple_pm_bus_probe,
	130	.remove = simple_pm_bus_remove,
	131	.driver = {
	132	.name = "simple-pm-bus",
	133	.of_match_table = simple_pm_bus_of_match,
c4583930	134	.pm = pm_ptr(&simple_pm_bus_pm_ops),
89d463ea GU	135	},
	136	};
	137
	138	module_platform_driver(simple_pm_bus_driver);
	139
	140	MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");
	141	MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");