[linux-2.6-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.h>
#include <linux/of_device.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	13	#include <linux/module.h>
53c5ae63 RH	14	#include <linux/of.h>
53c5ae63 RH	15	#include <linux/of_device.h>
89d463ea GU	16	#include <linux/of_platform.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/pm_runtime.h>
	19
c4583930 LY	20	struct simple_pm_bus {
	21	struct clk_bulk_data *clks;
	22	int num_clks;
	23	};
	24
89d463ea GU	25	static int simple_pm_bus_probe(struct platform_device *pdev)
89d463ea GU	26	{
98e96cf8 SK	27	const struct device *dev = &pdev->dev;
	28	const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
	29	struct device_node *np = dev->of_node;
	30	const struct of_device_id *match;
c4583930	31	struct simple_pm_bus *bus;
98e96cf8 SK	32
	33	/*
	34	* Allow user to use driver_override to bind this driver to a
	35	* transparent bus device which has a different compatible string
	36	* that's not listed in simple_pm_bus_of_match. We don't want to do any
	37	* of the simple-pm-bus tasks for these devices, so return early.
	38	*/
	39	if (pdev->driver_override)
	40	return 0;
	41
	42	match = of_match_device(dev->driver->of_match_table, dev);
	43	/*
	44	* These are transparent bus devices (not simple-pm-bus matches) that
	45	* have their child nodes populated automatically. So, don't need to
	46	* do anything more. We only match with the device if this driver is
	47	* the most specific match because we don't want to incorrectly bind to
	48	* a device that has a more specific driver.
	49	*/
	50	if (match && match->data) {
	51	if (of_property_match_string(np, "compatible", match->compatible) == 0)
	52	return 0;
	53	else
	54	return -ENODEV;
	55	}
89d463ea	56
c4583930 LY	57	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
	58	if (!bus)
	59	return -ENOMEM;
	60
	61	bus->num_clks = devm_clk_bulk_get_all(&pdev->dev, &bus->clks);
	62	if (bus->num_clks < 0)
	63	return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n");
	64
	65	dev_set_drvdata(&pdev->dev, bus);
	66
89d463ea GU	67	dev_dbg(&pdev->dev, "%s\n", __func__);
	68
	69	pm_runtime_enable(&pdev->dev);
	70
	71	if (np)
eda080ea	72	of_platform_populate(np, NULL, lookup, &pdev->dev);
89d463ea GU	73
	74	return 0;
	75	}
	76
	77	static int simple_pm_bus_remove(struct platform_device *pdev)
	78	{
98e96cf8 SK	79	const void *data = of_device_get_match_data(&pdev->dev);
	80
	81	if (pdev->driver_override \|\| data)
	82	return 0;
	83
89d463ea GU	84	dev_dbg(&pdev->dev, "%s\n", __func__);
	85
	86	pm_runtime_disable(&pdev->dev);
	87	return 0;
	88	}
	89
c4583930 LY	90	static int simple_pm_bus_runtime_suspend(struct device *dev)
	91	{
	92	struct simple_pm_bus *bus = dev_get_drvdata(dev);
	93
	94	clk_bulk_disable_unprepare(bus->num_clks, bus->clks);
	95
	96	return 0;
	97	}
	98
	99	static int simple_pm_bus_runtime_resume(struct device *dev)
	100	{
	101	struct simple_pm_bus *bus = dev_get_drvdata(dev);
	102	int ret;
	103
	104	ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);
	105	if (ret) {
	106	dev_err(dev, "failed to enable clocks: %d\n", ret);
	107	return ret;
	108	}
	109
	110	return 0;
	111	}
	112
	113	static const struct dev_pm_ops simple_pm_bus_pm_ops = {
	114	RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL)
	115	NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
	116	};
	117
98e96cf8 SK	118	#define ONLY_BUS ((void ) 1) / Match if the device is only a bus. */
98e96cf8 SK	119
89d463ea GU	120	static const struct of_device_id simple_pm_bus_of_match[] = {
89d463ea GU	121	{ .compatible = "simple-pm-bus", },
98e96cf8 SK	122	{ .compatible = "simple-bus", .data = ONLY_BUS },
	123	{ .compatible = "simple-mfd", .data = ONLY_BUS },
	124	{ .compatible = "isa", .data = ONLY_BUS },
	125	{ .compatible = "arm,amba-bus", .data = ONLY_BUS },
89d463ea GU	126	{ /* sentinel */ }
	127	};
	128	MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);
	129
	130	static struct platform_driver simple_pm_bus_driver = {
	131	.probe = simple_pm_bus_probe,
	132	.remove = simple_pm_bus_remove,
	133	.driver = {
	134	.name = "simple-pm-bus",
	135	.of_match_table = simple_pm_bus_of_match,
c4583930	136	.pm = pm_ptr(&simple_pm_bus_pm_ops),
89d463ea GU	137	},
	138	};
	139
	140	module_platform_driver(simple_pm_bus_driver);
	141
	142	MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");
	143	MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");