[mirror_ubuntu-jammy-kernel.git] / drivers / base / auxiliary.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2019-2020 Intel Corporation
 *
 * Please see Documentation/driver-api/auxiliary_bus.rst for more information.
 */

#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__

#include <linux/device.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/string.h>
#include <linux/auxiliary_bus.h>
#include "base.h"

static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
							    const struct auxiliary_device *auxdev)
{
	for (; id->name[0]; id++) {
		const char *p = strrchr(dev_name(&auxdev->dev), '.');
		int match_size;

		if (!p)
			continue;
		match_size = p - dev_name(&auxdev->dev);

		/* use dev_name(&auxdev->dev) prefix before last '.' char to match to */
		if (strlen(id->name) == match_size &&
		    !strncmp(dev_name(&auxdev->dev), id->name, match_size))
			return id;
	}
	return NULL;
}

static int auxiliary_match(struct device *dev, struct device_driver *drv)
{
	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
	struct auxiliary_driver *auxdrv = to_auxiliary_drv(drv);

	return !!auxiliary_match_id(auxdrv->id_table, auxdev);
}

static int auxiliary_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	const char *name, *p;

	name = dev_name(dev);
	p = strrchr(name, '.');

	return add_uevent_var(env, "MODALIAS=%s%.*s", AUXILIARY_MODULE_PREFIX,
			      (int)(p - name), name);
}

static const struct dev_pm_ops auxiliary_dev_pm_ops = {
	SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL)
	SET_SYSTEM_SLEEP_PM_OPS(pm_generic_suspend, pm_generic_resume)
};

static int auxiliary_bus_probe(struct device *dev)
{
	struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver);
	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
	int ret;

	ret = dev_pm_domain_attach(dev, true);
	if (ret) {
		dev_warn(dev, "Failed to attach to PM Domain : %d\n", ret);
		return ret;
	}

	ret = auxdrv->probe(auxdev, auxiliary_match_id(auxdrv->id_table, auxdev));
	if (ret)
		dev_pm_domain_detach(dev, true);

	return ret;
}

static int auxiliary_bus_remove(struct device *dev)
{
	struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver);
	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);

	if (auxdrv->remove)
		auxdrv->remove(auxdev);
	dev_pm_domain_detach(dev, true);

	return 0;
}

static void auxiliary_bus_shutdown(struct device *dev)
{
	struct auxiliary_driver *auxdrv = NULL;
	struct auxiliary_device *auxdev;

	if (dev->driver) {
		auxdrv = to_auxiliary_drv(dev->driver);
		auxdev = to_auxiliary_dev(dev);
	}

	if (auxdrv && auxdrv->shutdown)
		auxdrv->shutdown(auxdev);
}

static struct bus_type auxiliary_bus_type = {
	.name = "auxiliary",
	.probe = auxiliary_bus_probe,
	.remove = auxiliary_bus_remove,
	.shutdown = auxiliary_bus_shutdown,
	.match = auxiliary_match,
	.uevent = auxiliary_uevent,
	.pm = &auxiliary_dev_pm_ops,
};

/**
 * auxiliary_device_init - check auxiliary_device and initialize
 * @auxdev: auxiliary device struct
 *
 * This is the first step in the two-step process to register an
 * auxiliary_device.
 *
 * When this function returns an error code, then the device_initialize will
 * *not* have been performed, and the caller will be responsible to free any
 * memory allocated for the auxiliary_device in the error path directly.
 *
 * It returns 0 on success.  On success, the device_initialize has been
 * performed.  After this point any error unwinding will need to include a call
 * to auxiliary_device_uninit().  In this post-initialize error scenario, a call
 * to the device's .release callback will be triggered, and all memory clean-up
 * is expected to be handled there.
 */
int auxiliary_device_init(struct auxiliary_device *auxdev)
{
	struct device *dev = &auxdev->dev;

	if (!dev->parent) {
		pr_err("auxiliary_device has a NULL dev->parent\n");
		return -EINVAL;
	}

	if (!auxdev->name) {
		pr_err("auxiliary_device has a NULL name\n");
		return -EINVAL;
	}

	dev->bus = &auxiliary_bus_type;
	device_initialize(&auxdev->dev);
	return 0;
}
EXPORT_SYMBOL_GPL(auxiliary_device_init);

/**
 * __auxiliary_device_add - add an auxiliary bus device
 * @auxdev: auxiliary bus device to add to the bus
 * @modname: name of the parent device's driver module
 *
 * This is the second step in the two-step process to register an
 * auxiliary_device.
 *
 * This function must be called after a successful call to
 * auxiliary_device_init(), which will perform the device_initialize.  This
 * means that if this returns an error code, then a call to
 * auxiliary_device_uninit() must be performed so that the .release callback
 * will be triggered to free the memory associated with the auxiliary_device.
 *
 * The expectation is that users will call the "auxiliary_device_add" macro so
 * that the caller's KBUILD_MODNAME is automatically inserted for the modname
 * parameter.  Only if a user requires a custom name would this version be
 * called directly.
 */
int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname)
{
	struct device *dev = &auxdev->dev;
	int ret;

	if (!modname) {
		dev_err(dev, "auxiliary device modname is NULL\n");
		return -EINVAL;
	}

	ret = dev_set_name(dev, "%s.%s.%d", modname, auxdev->name, auxdev->id);
	if (ret) {
		dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret);
		return ret;
	}

	ret = device_add(dev);
	if (ret)
		dev_err(dev, "adding auxiliary device failed!: %d\n", ret);

	return ret;
}
EXPORT_SYMBOL_GPL(__auxiliary_device_add);

/**
 * auxiliary_find_device - auxiliary device iterator for locating a particular device.
 * @start: Device to begin with
 * @data: Data to pass to match function
 * @match: Callback function to check device
 *
 * This function returns a reference to a device that is 'found'
 * for later use, as determined by the @match callback.
 *
 * The callback should return 0 if the device doesn't match and non-zero
 * if it does.  If the callback returns non-zero, this function will
 * return to the caller and not iterate over any more devices.
 */
struct auxiliary_device *auxiliary_find_device(struct device *start,
					       const void *data,
					       int (*match)(struct device *dev, const void *data))
{
	struct device *dev;

	dev = bus_find_device(&auxiliary_bus_type, start, data, match);
	if (!dev)
		return NULL;

	return to_auxiliary_dev(dev);
}
EXPORT_SYMBOL_GPL(auxiliary_find_device);

/**
 * __auxiliary_driver_register - register a driver for auxiliary bus devices
 * @auxdrv: auxiliary_driver structure
 * @owner: owning module/driver
 * @modname: KBUILD_MODNAME for parent driver
 */
int __auxiliary_driver_register(struct auxiliary_driver *auxdrv,
				struct module *owner, const char *modname)
{
	if (WARN_ON(!auxdrv->probe) || WARN_ON(!auxdrv->id_table))
		return -EINVAL;

	if (auxdrv->name)
		auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s.%s", modname,
						auxdrv->name);
	else
		auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s", modname);
	if (!auxdrv->driver.name)
		return -ENOMEM;

	auxdrv->driver.owner = owner;
	auxdrv->driver.bus = &auxiliary_bus_type;
	auxdrv->driver.mod_name = modname;

	return driver_register(&auxdrv->driver);
}
EXPORT_SYMBOL_GPL(__auxiliary_driver_register);

/**
 * auxiliary_driver_unregister - unregister a driver
 * @auxdrv: auxiliary_driver structure
 */
void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv)
{
	driver_unregister(&auxdrv->driver);
	kfree(auxdrv->driver.name);
}
EXPORT_SYMBOL_GPL(auxiliary_driver_unregister);

void __init auxiliary_bus_init(void)
{
	WARN_ON(bus_register(&auxiliary_bus_type));
}

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Auxiliary Bus");
MODULE_AUTHOR("David Ertman <david.m.ertman@intel.com>");
MODULE_AUTHOR("Kiran Patil <kiran.patil@intel.com>");
Commit	Line	Data
7de3697e DE	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* Copyright (c) 2019-2020 Intel Corporation
	4	*
	5	* Please see Documentation/driver-api/auxiliary_bus.rst for more information.
	6	*/
	7
	8	#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
	9
	10	#include <linux/device.h>
	11	#include <linux/init.h>
7bbb79ff	12	#include <linux/slab.h>
7de3697e DE	13	#include <linux/module.h>
	14	#include <linux/pm_domain.h>
	15	#include <linux/pm_runtime.h>
	16	#include <linux/string.h>
	17	#include <linux/auxiliary_bus.h>
471b12c4	18	#include "base.h"
7de3697e DE	19
	20	static const struct auxiliary_device_id auxiliary_match_id(const struct auxiliary_device_id id,
	21	const struct auxiliary_device *auxdev)
	22	{
	23	for (; id->name[0]; id++) {
	24	const char *p = strrchr(dev_name(&auxdev->dev), '.');
	25	int match_size;
	26
	27	if (!p)
	28	continue;
	29	match_size = p - dev_name(&auxdev->dev);
	30
	31	/* use dev_name(&auxdev->dev) prefix before last '.' char to match to */
	32	if (strlen(id->name) == match_size &&
	33	!strncmp(dev_name(&auxdev->dev), id->name, match_size))
	34	return id;
	35	}
	36	return NULL;
	37	}
	38
	39	static int auxiliary_match(struct device dev, struct device_driver drv)
	40	{
	41	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
	42	struct auxiliary_driver *auxdrv = to_auxiliary_drv(drv);
	43
	44	return !!auxiliary_match_id(auxdrv->id_table, auxdev);
	45	}
	46
	47	static int auxiliary_uevent(struct device dev, struct kobj_uevent_env env)
	48	{
	49	const char name, p;
	50
	51	name = dev_name(dev);
	52	p = strrchr(name, '.');
	53
0d2bf11a GKH	54	return add_uevent_var(env, "MODALIAS=%s%.*s", AUXILIARY_MODULE_PREFIX,
0d2bf11a GKH	55	(int)(p - name), name);
7de3697e DE	56	}
	57
	58	static const struct dev_pm_ops auxiliary_dev_pm_ops = {
	59	SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL)
	60	SET_SYSTEM_SLEEP_PM_OPS(pm_generic_suspend, pm_generic_resume)
	61	};
	62
	63	static int auxiliary_bus_probe(struct device *dev)
	64	{
	65	struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver);
	66	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
	67	int ret;
	68
	69	ret = dev_pm_domain_attach(dev, true);
	70	if (ret) {
	71	dev_warn(dev, "Failed to attach to PM Domain : %d\n", ret);
	72	return ret;
	73	}
	74
	75	ret = auxdrv->probe(auxdev, auxiliary_match_id(auxdrv->id_table, auxdev));
	76	if (ret)
	77	dev_pm_domain_detach(dev, true);
	78
	79	return ret;
	80	}
	81
	82	static int auxiliary_bus_remove(struct device *dev)
	83	{
	84	struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver);
	85	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
7de3697e DE	86
7de3697e DE	87	if (auxdrv->remove)
8142a46c	88	auxdrv->remove(auxdev);
7de3697e DE	89	dev_pm_domain_detach(dev, true);
7de3697e DE	90
8142a46c	91	return 0;
7de3697e DE	92	}
	93
	94	static void auxiliary_bus_shutdown(struct device *dev)
	95	{
784b2c48 DJ	96	struct auxiliary_driver *auxdrv = NULL;
	97	struct auxiliary_device *auxdev;
	98
	99	if (dev->driver) {
	100	auxdrv = to_auxiliary_drv(dev->driver);
	101	auxdev = to_auxiliary_dev(dev);
	102	}
7de3697e	103
784b2c48	104	if (auxdrv && auxdrv->shutdown)
7de3697e DE	105	auxdrv->shutdown(auxdev);
	106	}
	107
	108	static struct bus_type auxiliary_bus_type = {
	109	.name = "auxiliary",
	110	.probe = auxiliary_bus_probe,
	111	.remove = auxiliary_bus_remove,
	112	.shutdown = auxiliary_bus_shutdown,
	113	.match = auxiliary_match,
	114	.uevent = auxiliary_uevent,
	115	.pm = &auxiliary_dev_pm_ops,
	116	};
	117
	118	/**
	119	* auxiliary_device_init - check auxiliary_device and initialize
	120	* @auxdev: auxiliary device struct
	121	*
0d2bf11a GKH	122	* This is the first step in the two-step process to register an
0d2bf11a GKH	123	* auxiliary_device.
7de3697e	124	*
0d2bf11a GKH	125	* When this function returns an error code, then the device_initialize will
	126	* not have been performed, and the caller will be responsible to free any
	127	* memory allocated for the auxiliary_device in the error path directly.
7de3697e	128	*
0d2bf11a GKH	129	* It returns 0 on success. On success, the device_initialize has been
	130	* performed. After this point any error unwinding will need to include a call
	131	* to auxiliary_device_uninit(). In this post-initialize error scenario, a call
	132	* to the device's .release callback will be triggered, and all memory clean-up
	133	* is expected to be handled there.
7de3697e DE	134	*/
	135	int auxiliary_device_init(struct auxiliary_device *auxdev)
	136	{
	137	struct device *dev = &auxdev->dev;
	138
	139	if (!dev->parent) {
	140	pr_err("auxiliary_device has a NULL dev->parent\n");
	141	return -EINVAL;
	142	}
	143
	144	if (!auxdev->name) {
	145	pr_err("auxiliary_device has a NULL name\n");
	146	return -EINVAL;
	147	}
	148
	149	dev->bus = &auxiliary_bus_type;
	150	device_initialize(&auxdev->dev);
	151	return 0;
	152	}
	153	EXPORT_SYMBOL_GPL(auxiliary_device_init);
	154
	155	/**
	156	* __auxiliary_device_add - add an auxiliary bus device
	157	* @auxdev: auxiliary bus device to add to the bus
	158	* @modname: name of the parent device's driver module
	159	*
0d2bf11a GKH	160	* This is the second step in the two-step process to register an
0d2bf11a GKH	161	* auxiliary_device.
7de3697e	162	*
0d2bf11a GKH	163	* This function must be called after a successful call to
	164	* auxiliary_device_init(), which will perform the device_initialize. This
	165	* means that if this returns an error code, then a call to
	166	* auxiliary_device_uninit() must be performed so that the .release callback
	167	* will be triggered to free the memory associated with the auxiliary_device.
7de3697e	168	*
0d2bf11a GKH	169	* The expectation is that users will call the "auxiliary_device_add" macro so
	170	* that the caller's KBUILD_MODNAME is automatically inserted for the modname
	171	* parameter. Only if a user requires a custom name would this version be
	172	* called directly.
7de3697e DE	173	*/
	174	int __auxiliary_device_add(struct auxiliary_device auxdev, const char modname)
	175	{
	176	struct device *dev = &auxdev->dev;
	177	int ret;
	178
	179	if (!modname) {
0d2bf11a	180	dev_err(dev, "auxiliary device modname is NULL\n");
7de3697e DE	181	return -EINVAL;
	182	}
	183
	184	ret = dev_set_name(dev, "%s.%s.%d", modname, auxdev->name, auxdev->id);
	185	if (ret) {
0d2bf11a	186	dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret);
7de3697e DE	187	return ret;
	188	}
	189
	190	ret = device_add(dev);
	191	if (ret)
	192	dev_err(dev, "adding auxiliary device failed!: %d\n", ret);
	193
	194	return ret;
	195	}
	196	EXPORT_SYMBOL_GPL(__auxiliary_device_add);
	197
	198	/**
	199	* auxiliary_find_device - auxiliary device iterator for locating a particular device.
	200	* @start: Device to begin with
	201	* @data: Data to pass to match function
	202	* @match: Callback function to check device
	203	*
	204	* This function returns a reference to a device that is 'found'
	205	* for later use, as determined by the @match callback.
	206	*
	207	* The callback should return 0 if the device doesn't match and non-zero
	208	* if it does. If the callback returns non-zero, this function will
	209	* return to the caller and not iterate over any more devices.
	210	*/
0d2bf11a GKH	211	struct auxiliary_device auxiliary_find_device(struct device start,
	212	const void *data,
	213	int (match)(struct device dev, const void *data))
7de3697e DE	214	{
	215	struct device *dev;
	216
	217	dev = bus_find_device(&auxiliary_bus_type, start, data, match);
	218	if (!dev)
	219	return NULL;
	220
	221	return to_auxiliary_dev(dev);
	222	}
	223	EXPORT_SYMBOL_GPL(auxiliary_find_device);
	224
	225	/**
	226	* __auxiliary_driver_register - register a driver for auxiliary bus devices
	227	* @auxdrv: auxiliary_driver structure
	228	* @owner: owning module/driver
	229	* @modname: KBUILD_MODNAME for parent driver
	230	*/
0d2bf11a GKH	231	int __auxiliary_driver_register(struct auxiliary_driver *auxdrv,
0d2bf11a GKH	232	struct module owner, const char modname)
7de3697e DE	233	{
	234	if (WARN_ON(!auxdrv->probe) \|\| WARN_ON(!auxdrv->id_table))
	235	return -EINVAL;
	236
	237	if (auxdrv->name)
0d2bf11a GKH	238	auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s.%s", modname,
0d2bf11a GKH	239	auxdrv->name);
7de3697e DE	240	else
	241	auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s", modname);
	242	if (!auxdrv->driver.name)
	243	return -ENOMEM;
	244
	245	auxdrv->driver.owner = owner;
	246	auxdrv->driver.bus = &auxiliary_bus_type;
	247	auxdrv->driver.mod_name = modname;
	248
	249	return driver_register(&auxdrv->driver);
	250	}
	251	EXPORT_SYMBOL_GPL(__auxiliary_driver_register);
	252
	253	/**
	254	* auxiliary_driver_unregister - unregister a driver
	255	* @auxdrv: auxiliary_driver structure
	256	*/
	257	void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv)
	258	{
	259	driver_unregister(&auxdrv->driver);
	260	kfree(auxdrv->driver.name);
	261	}
	262	EXPORT_SYMBOL_GPL(auxiliary_driver_unregister);
	263
471b12c4	264	void __init auxiliary_bus_init(void)
7de3697e	265	{
471b12c4	266	WARN_ON(bus_register(&auxiliary_bus_type));
7de3697e DE	267	}
7de3697e DE	268
7de3697e DE	269	MODULE_LICENSE("GPL v2");
	270	MODULE_DESCRIPTION("Auxiliary Bus");
	271	MODULE_AUTHOR("David Ertman <david.m.ertman@intel.com>");
	272	MODULE_AUTHOR("Kiran Patil <kiran.patil@intel.com>");