1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * device.h - generic, centralized driver model
4  *
5  * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
6  * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
7  * Copyright (c) 2008-2009 Novell Inc.
8  *
9  * See Documentation/driver-api/driver-model/ for more information.
10  */
11 
12 #ifndef _DEVICE_H_
13 #define _DEVICE_H_
14 
15 #include <linux/dev_printk.h>
16 #include <linux/energy_model.h>
17 #include <linux/ioport.h>
18 #include <linux/kobject.h>
19 #include <linux/klist.h>
20 #include <linux/list.h>
21 #include <linux/lockdep.h>
22 #include <linux/compiler.h>
23 #include <linux/types.h>
24 #include <linux/mutex.h>
25 #include <linux/pm.h>
26 #include <linux/atomic.h>
27 #include <linux/uidgid.h>
28 #include <linux/gfp.h>
29 #include <linux/overflow.h>
30 #include <linux/device/bus.h>
31 #include <linux/device/class.h>
32 #include <linux/device/driver.h>
33 #include <asm/device.h>
34 
35 struct device;
36 struct device_private;
37 struct device_driver;
38 struct driver_private;
39 struct module;
40 struct class;
41 struct subsys_private;
42 struct device_node;
43 struct fwnode_handle;
44 struct iommu_ops;
45 struct iommu_group;
46 struct dev_pin_info;
47 struct dev_iommu;
48 struct msi_device_data;
49 
50 /**
51  * struct subsys_interface - interfaces to device functions
52  * @name:       name of the device function
53  * @subsys:     subsystem of the devices to attach to
54  * @node:       the list of functions registered at the subsystem
55  * @add_dev:    device hookup to device function handler
56  * @remove_dev: device hookup to device function handler
57  *
58  * Simple interfaces attached to a subsystem. Multiple interfaces can
59  * attach to a subsystem and its devices. Unlike drivers, they do not
60  * exclusively claim or control devices. Interfaces usually represent
61  * a specific functionality of a subsystem/class of devices.
62  */
63 struct subsys_interface {
64 	const char *name;
65 	struct bus_type *subsys;
66 	struct list_head node;
67 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
68 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
69 };
70 
71 int subsys_interface_register(struct subsys_interface *sif);
72 void subsys_interface_unregister(struct subsys_interface *sif);
73 
74 int subsys_system_register(struct bus_type *subsys,
75 			   const struct attribute_group **groups);
76 int subsys_virtual_register(struct bus_type *subsys,
77 			    const struct attribute_group **groups);
78 
79 /*
80  * The type of device, "struct device" is embedded in. A class
81  * or bus can contain devices of different types
82  * like "partitions" and "disks", "mouse" and "event".
83  * This identifies the device type and carries type-specific
84  * information, equivalent to the kobj_type of a kobject.
85  * If "name" is specified, the uevent will contain it in
86  * the DEVTYPE variable.
87  */
88 struct device_type {
89 	const char *name;
90 	const struct attribute_group **groups;
91 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
92 	char *(*devnode)(struct device *dev, umode_t *mode,
93 			 kuid_t *uid, kgid_t *gid);
94 	void (*release)(struct device *dev);
95 
96 	const struct dev_pm_ops *pm;
97 };
98 
99 /* interface for exporting device attributes */
100 struct device_attribute {
101 	struct attribute	attr;
102 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
103 			char *buf);
104 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
105 			 const char *buf, size_t count);
106 };
107 
108 struct dev_ext_attribute {
109 	struct device_attribute attr;
110 	void *var;
111 };
112 
113 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
114 			  char *buf);
115 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
116 			   const char *buf, size_t count);
117 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
118 			char *buf);
119 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
120 			 const char *buf, size_t count);
121 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
122 			char *buf);
123 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
124 			 const char *buf, size_t count);
125 
126 #define DEVICE_ATTR(_name, _mode, _show, _store) \
127 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
128 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
129 	struct device_attribute dev_attr_##_name = \
130 		__ATTR_PREALLOC(_name, _mode, _show, _store)
131 #define DEVICE_ATTR_RW(_name) \
132 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
133 #define DEVICE_ATTR_ADMIN_RW(_name) \
134 	struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
135 #define DEVICE_ATTR_RO(_name) \
136 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
137 #define DEVICE_ATTR_ADMIN_RO(_name) \
138 	struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
139 #define DEVICE_ATTR_WO(_name) \
140 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
141 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
142 	struct dev_ext_attribute dev_attr_##_name = \
143 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
144 #define DEVICE_INT_ATTR(_name, _mode, _var) \
145 	struct dev_ext_attribute dev_attr_##_name = \
146 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
147 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
148 	struct dev_ext_attribute dev_attr_##_name = \
149 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
150 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
151 	struct device_attribute dev_attr_##_name =		\
152 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
153 
154 int device_create_file(struct device *device,
155 		       const struct device_attribute *entry);
156 void device_remove_file(struct device *dev,
157 			const struct device_attribute *attr);
158 bool device_remove_file_self(struct device *dev,
159 			     const struct device_attribute *attr);
160 int __must_check device_create_bin_file(struct device *dev,
161 					const struct bin_attribute *attr);
162 void device_remove_bin_file(struct device *dev,
163 			    const struct bin_attribute *attr);
164 
165 /* device resource management */
166 typedef void (*dr_release_t)(struct device *dev, void *res);
167 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
168 
169 void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
170 			  int nid, const char *name) __malloc;
171 #define devres_alloc(release, size, gfp) \
172 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
173 #define devres_alloc_node(release, size, gfp, nid) \
174 	__devres_alloc_node(release, size, gfp, nid, #release)
175 
176 void devres_for_each_res(struct device *dev, dr_release_t release,
177 			 dr_match_t match, void *match_data,
178 			 void (*fn)(struct device *, void *, void *),
179 			 void *data);
180 void devres_free(void *res);
181 void devres_add(struct device *dev, void *res);
182 void *devres_find(struct device *dev, dr_release_t release,
183 		  dr_match_t match, void *match_data);
184 void *devres_get(struct device *dev, void *new_res,
185 		 dr_match_t match, void *match_data);
186 void *devres_remove(struct device *dev, dr_release_t release,
187 		    dr_match_t match, void *match_data);
188 int devres_destroy(struct device *dev, dr_release_t release,
189 		   dr_match_t match, void *match_data);
190 int devres_release(struct device *dev, dr_release_t release,
191 		   dr_match_t match, void *match_data);
192 
193 /* devres group */
194 void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp);
195 void devres_close_group(struct device *dev, void *id);
196 void devres_remove_group(struct device *dev, void *id);
197 int devres_release_group(struct device *dev, void *id);
198 
199 /* managed devm_k.alloc/kfree for device drivers */
200 void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
201 void *devm_krealloc(struct device *dev, void *ptr, size_t size,
202 		    gfp_t gfp) __must_check;
203 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
204 				     const char *fmt, va_list ap) __malloc;
205 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
206 				    const char *fmt, ...) __malloc;
devm_kzalloc(struct device * dev,size_t size,gfp_t gfp)207 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
208 {
209 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
210 }
devm_kmalloc_array(struct device * dev,size_t n,size_t size,gfp_t flags)211 static inline void *devm_kmalloc_array(struct device *dev,
212 				       size_t n, size_t size, gfp_t flags)
213 {
214 	size_t bytes;
215 
216 	if (unlikely(check_mul_overflow(n, size, &bytes)))
217 		return NULL;
218 
219 	return devm_kmalloc(dev, bytes, flags);
220 }
devm_kcalloc(struct device * dev,size_t n,size_t size,gfp_t flags)221 static inline void *devm_kcalloc(struct device *dev,
222 				 size_t n, size_t size, gfp_t flags)
223 {
224 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
225 }
226 void devm_kfree(struct device *dev, const void *p);
227 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
228 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
229 void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
230 
231 unsigned long devm_get_free_pages(struct device *dev,
232 				  gfp_t gfp_mask, unsigned int order);
233 void devm_free_pages(struct device *dev, unsigned long addr);
234 
235 void __iomem *devm_ioremap_resource(struct device *dev,
236 				    const struct resource *res);
237 void __iomem *devm_ioremap_resource_wc(struct device *dev,
238 				       const struct resource *res);
239 
240 void __iomem *devm_of_iomap(struct device *dev,
241 			    struct device_node *node, int index,
242 			    resource_size_t *size);
243 
244 /* allows to add/remove a custom action to devres stack */
245 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
246 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
247 void devm_release_action(struct device *dev, void (*action)(void *), void *data);
248 
devm_add_action_or_reset(struct device * dev,void (* action)(void *),void * data)249 static inline int devm_add_action_or_reset(struct device *dev,
250 					   void (*action)(void *), void *data)
251 {
252 	int ret;
253 
254 	ret = devm_add_action(dev, action, data);
255 	if (ret)
256 		action(data);
257 
258 	return ret;
259 }
260 
261 /**
262  * devm_alloc_percpu - Resource-managed alloc_percpu
263  * @dev: Device to allocate per-cpu memory for
264  * @type: Type to allocate per-cpu memory for
265  *
266  * Managed alloc_percpu. Per-cpu memory allocated with this function is
267  * automatically freed on driver detach.
268  *
269  * RETURNS:
270  * Pointer to allocated memory on success, NULL on failure.
271  */
272 #define devm_alloc_percpu(dev, type)      \
273 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
274 						      __alignof__(type)))
275 
276 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
277 				   size_t align);
278 void devm_free_percpu(struct device *dev, void __percpu *pdata);
279 
280 struct device_dma_parameters {
281 	/*
282 	 * a low level driver may set these to teach IOMMU code about
283 	 * sg limitations.
284 	 */
285 	unsigned int max_segment_size;
286 	unsigned int min_align_mask;
287 	unsigned long segment_boundary_mask;
288 };
289 
290 /**
291  * enum device_link_state - Device link states.
292  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
293  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
294  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
295  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
296  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
297  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
298  */
299 enum device_link_state {
300 	DL_STATE_NONE = -1,
301 	DL_STATE_DORMANT = 0,
302 	DL_STATE_AVAILABLE,
303 	DL_STATE_CONSUMER_PROBE,
304 	DL_STATE_ACTIVE,
305 	DL_STATE_SUPPLIER_UNBIND,
306 };
307 
308 /*
309  * Device link flags.
310  *
311  * STATELESS: The core will not remove this link automatically.
312  * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
313  * PM_RUNTIME: If set, the runtime PM framework will use this link.
314  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
315  * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
316  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
317  * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
318  * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
319  * INFERRED: Inferred from data (eg: firmware) and not from driver actions.
320  */
321 #define DL_FLAG_STATELESS		BIT(0)
322 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
323 #define DL_FLAG_PM_RUNTIME		BIT(2)
324 #define DL_FLAG_RPM_ACTIVE		BIT(3)
325 #define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)
326 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
327 #define DL_FLAG_MANAGED			BIT(6)
328 #define DL_FLAG_SYNC_STATE_ONLY		BIT(7)
329 #define DL_FLAG_INFERRED		BIT(8)
330 
331 /**
332  * enum dl_dev_state - Device driver presence tracking information.
333  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
334  * @DL_DEV_PROBING: A driver is probing.
335  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
336  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
337  */
338 enum dl_dev_state {
339 	DL_DEV_NO_DRIVER = 0,
340 	DL_DEV_PROBING,
341 	DL_DEV_DRIVER_BOUND,
342 	DL_DEV_UNBINDING,
343 };
344 
345 /**
346  * enum device_removable - Whether the device is removable. The criteria for a
347  * device to be classified as removable is determined by its subsystem or bus.
348  * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this
349  *				    device (default).
350  * @DEVICE_REMOVABLE_UNKNOWN:  Device location is Unknown.
351  * @DEVICE_FIXED: Device is not removable by the user.
352  * @DEVICE_REMOVABLE: Device is removable by the user.
353  */
354 enum device_removable {
355 	DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */
356 	DEVICE_REMOVABLE_UNKNOWN,
357 	DEVICE_FIXED,
358 	DEVICE_REMOVABLE,
359 };
360 
361 /**
362  * struct dev_links_info - Device data related to device links.
363  * @suppliers: List of links to supplier devices.
364  * @consumers: List of links to consumer devices.
365  * @defer_sync: Hook to global list of devices that have deferred sync_state.
366  * @status: Driver status information.
367  */
368 struct dev_links_info {
369 	struct list_head suppliers;
370 	struct list_head consumers;
371 	struct list_head defer_sync;
372 	enum dl_dev_state status;
373 };
374 
375 /**
376  * struct dev_msi_info - Device data related to MSI
377  * @domain:	The MSI interrupt domain associated to the device
378  * @data:	Pointer to MSI device data
379  */
380 struct dev_msi_info {
381 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
382 	struct irq_domain	*domain;
383 #endif
384 #ifdef CONFIG_GENERIC_MSI_IRQ
385 	struct msi_device_data	*data;
386 #endif
387 };
388 
389 /**
390  * enum device_physical_location_panel - Describes which panel surface of the
391  * system's housing the device connection point resides on.
392  * @DEVICE_PANEL_TOP: Device connection point is on the top panel.
393  * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel.
394  * @DEVICE_PANEL_LEFT: Device connection point is on the left panel.
395  * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel.
396  * @DEVICE_PANEL_FRONT: Device connection point is on the front panel.
397  * @DEVICE_PANEL_BACK: Device connection point is on the back panel.
398  * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown.
399  */
400 enum device_physical_location_panel {
401 	DEVICE_PANEL_TOP,
402 	DEVICE_PANEL_BOTTOM,
403 	DEVICE_PANEL_LEFT,
404 	DEVICE_PANEL_RIGHT,
405 	DEVICE_PANEL_FRONT,
406 	DEVICE_PANEL_BACK,
407 	DEVICE_PANEL_UNKNOWN,
408 };
409 
410 /**
411  * enum device_physical_location_vertical_position - Describes vertical
412  * position of the device connection point on the panel surface.
413  * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel.
414  * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel.
415  * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel.
416  */
417 enum device_physical_location_vertical_position {
418 	DEVICE_VERT_POS_UPPER,
419 	DEVICE_VERT_POS_CENTER,
420 	DEVICE_VERT_POS_LOWER,
421 };
422 
423 /**
424  * enum device_physical_location_horizontal_position - Describes horizontal
425  * position of the device connection point on the panel surface.
426  * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel.
427  * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel.
428  * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel.
429  */
430 enum device_physical_location_horizontal_position {
431 	DEVICE_HORI_POS_LEFT,
432 	DEVICE_HORI_POS_CENTER,
433 	DEVICE_HORI_POS_RIGHT,
434 };
435 
436 /**
437  * struct device_physical_location - Device data related to physical location
438  * of the device connection point.
439  * @panel: Panel surface of the system's housing that the device connection
440  *         point resides on.
441  * @vertical_position: Vertical position of the device connection point within
442  *                     the panel.
443  * @horizontal_position: Horizontal position of the device connection point
444  *                       within the panel.
445  * @dock: Set if the device connection point resides in a docking station or
446  *        port replicator.
447  * @lid: Set if this device connection point resides on the lid of laptop
448  *       system.
449  */
450 struct device_physical_location {
451 	enum device_physical_location_panel panel;
452 	enum device_physical_location_vertical_position vertical_position;
453 	enum device_physical_location_horizontal_position horizontal_position;
454 	bool dock;
455 	bool lid;
456 };
457 
458 /**
459  * struct device - The basic device structure
460  * @parent:	The device's "parent" device, the device to which it is attached.
461  * 		In most cases, a parent device is some sort of bus or host
462  * 		controller. If parent is NULL, the device, is a top-level device,
463  * 		which is not usually what you want.
464  * @p:		Holds the private data of the driver core portions of the device.
465  * 		See the comment of the struct device_private for detail.
466  * @kobj:	A top-level, abstract class from which other classes are derived.
467  * @init_name:	Initial name of the device.
468  * @type:	The type of device.
469  * 		This identifies the device type and carries type-specific
470  * 		information.
471  * @mutex:	Mutex to synchronize calls to its driver.
472  * @bus:	Type of bus device is on.
473  * @driver:	Which driver has allocated this
474  * @platform_data: Platform data specific to the device.
475  * 		Example: For devices on custom boards, as typical of embedded
476  * 		and SOC based hardware, Linux often uses platform_data to point
477  * 		to board-specific structures describing devices and how they
478  * 		are wired.  That can include what ports are available, chip
479  * 		variants, which GPIO pins act in what additional roles, and so
480  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
481  * 		minimizes board-specific #ifdefs in drivers.
482  * @driver_data: Private pointer for driver specific info.
483  * @links:	Links to suppliers and consumers of this device.
484  * @power:	For device power management.
485  *		See Documentation/driver-api/pm/devices.rst for details.
486  * @pm_domain:	Provide callbacks that are executed during system suspend,
487  * 		hibernation, system resume and during runtime PM transitions
488  * 		along with subsystem-level and driver-level callbacks.
489  * @em_pd:	device's energy model performance domain
490  * @pins:	For device pin management.
491  *		See Documentation/driver-api/pin-control.rst for details.
492  * @msi:	MSI related data
493  * @numa_node:	NUMA node this device is close to.
494  * @dma_ops:    DMA mapping operations for this device.
495  * @dma_mask:	Dma mask (if dma'ble device).
496  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
497  * 		hardware supports 64-bit addresses for consistent allocations
498  * 		such descriptors.
499  * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
500  *		DMA limit than the device itself supports.
501  * @dma_range_map: map for DMA memory ranges relative to that of RAM
502  * @dma_parms:	A low level driver may set these to teach IOMMU code about
503  * 		segment limitations.
504  * @dma_pools:	Dma pools (if dma'ble device).
505  * @dma_mem:	Internal for coherent mem override.
506  * @cma_area:	Contiguous memory area for dma allocations
507  * @dma_io_tlb_mem: Pointer to the swiotlb pool used.  Not for driver use.
508  * @archdata:	For arch-specific additions.
509  * @of_node:	Associated device tree node.
510  * @fwnode:	Associated device node supplied by platform firmware.
511  * @devt:	For creating the sysfs "dev".
512  * @id:		device instance
513  * @devres_lock: Spinlock to protect the resource of the device.
514  * @devres_head: The resources list of the device.
515  * @knode_class: The node used to add the device to the class list.
516  * @class:	The class of the device.
517  * @groups:	Optional attribute groups.
518  * @release:	Callback to free the device after all references have
519  * 		gone away. This should be set by the allocator of the
520  * 		device (i.e. the bus driver that discovered the device).
521  * @iommu_group: IOMMU group the device belongs to.
522  * @iommu:	Per device generic IOMMU runtime data
523  * @physical_location: Describes physical location of the device connection
524  *		point in the system housing.
525  * @removable:  Whether the device can be removed from the system. This
526  *              should be set by the subsystem / bus driver that discovered
527  *              the device.
528  *
529  * @offline_disabled: If set, the device is permanently online.
530  * @offline:	Set after successful invocation of bus type's .offline().
531  * @of_node_reused: Set if the device-tree node is shared with an ancestor
532  *              device.
533  * @state_synced: The hardware state of this device has been synced to match
534  *		  the software state of this device by calling the driver/bus
535  *		  sync_state() callback.
536  * @can_match:	The device has matched with a driver at least once or it is in
537  *		a bus (like AMBA) which can't check for matching drivers until
538  *		other devices probe successfully.
539  * @dma_coherent: this particular device is dma coherent, even if the
540  *		architecture supports non-coherent devices.
541  * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
542  *		streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
543  *		and optionall (if the coherent mask is large enough) also
544  *		for dma allocations.  This flag is managed by the dma ops
545  *		instance from ->dma_supported.
546  *
547  * At the lowest level, every device in a Linux system is represented by an
548  * instance of struct device. The device structure contains the information
549  * that the device model core needs to model the system. Most subsystems,
550  * however, track additional information about the devices they host. As a
551  * result, it is rare for devices to be represented by bare device structures;
552  * instead, that structure, like kobject structures, is usually embedded within
553  * a higher-level representation of the device.
554  */
555 struct device {
556 	struct kobject kobj;
557 	struct device		*parent;
558 
559 	struct device_private	*p;
560 
561 	const char		*init_name; /* initial name of the device */
562 	const struct device_type *type;
563 
564 	struct bus_type	*bus;		/* type of bus device is on */
565 	struct device_driver *driver;	/* which driver has allocated this
566 					   device */
567 	void		*platform_data;	/* Platform specific data, device
568 					   core doesn't touch it */
569 	void		*driver_data;	/* Driver data, set and get with
570 					   dev_set_drvdata/dev_get_drvdata */
571 	struct mutex		mutex;	/* mutex to synchronize calls to
572 					 * its driver.
573 					 */
574 
575 	struct dev_links_info	links;
576 	struct dev_pm_info	power;
577 	struct dev_pm_domain	*pm_domain;
578 
579 #ifdef CONFIG_ENERGY_MODEL
580 	struct em_perf_domain	*em_pd;
581 #endif
582 
583 #ifdef CONFIG_PINCTRL
584 	struct dev_pin_info	*pins;
585 #endif
586 	struct dev_msi_info	msi;
587 #ifdef CONFIG_DMA_OPS
588 	const struct dma_map_ops *dma_ops;
589 #endif
590 	u64		*dma_mask;	/* dma mask (if dma'able device) */
591 	u64		coherent_dma_mask;/* Like dma_mask, but for
592 					     alloc_coherent mappings as
593 					     not all hardware supports
594 					     64 bit addresses for consistent
595 					     allocations such descriptors. */
596 	u64		bus_dma_limit;	/* upstream dma constraint */
597 	const struct bus_dma_region *dma_range_map;
598 
599 	struct device_dma_parameters *dma_parms;
600 
601 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
602 
603 #ifdef CONFIG_DMA_DECLARE_COHERENT
604 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
605 					     override */
606 #endif
607 #ifdef CONFIG_DMA_CMA
608 	struct cma *cma_area;		/* contiguous memory area for dma
609 					   allocations */
610 #endif
611 #ifdef CONFIG_SWIOTLB
612 	struct io_tlb_mem *dma_io_tlb_mem;
613 #endif
614 	/* arch specific additions */
615 	struct dev_archdata	archdata;
616 
617 	struct device_node	*of_node; /* associated device tree node */
618 	struct fwnode_handle	*fwnode; /* firmware device node */
619 
620 #ifdef CONFIG_NUMA
621 	int		numa_node;	/* NUMA node this device is close to */
622 #endif
623 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
624 	u32			id;	/* device instance */
625 
626 	spinlock_t		devres_lock;
627 	struct list_head	devres_head;
628 
629 	struct class		*class;
630 	const struct attribute_group **groups;	/* optional groups */
631 
632 	void	(*release)(struct device *dev);
633 	struct iommu_group	*iommu_group;
634 	struct dev_iommu	*iommu;
635 
636 	struct device_physical_location *physical_location;
637 
638 	enum device_removable	removable;
639 
640 	bool			offline_disabled:1;
641 	bool			offline:1;
642 	bool			of_node_reused:1;
643 	bool			state_synced:1;
644 	bool			can_match:1;
645 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
646     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
647     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
648 	bool			dma_coherent:1;
649 #endif
650 #ifdef CONFIG_DMA_OPS_BYPASS
651 	bool			dma_ops_bypass : 1;
652 #endif
653 };
654 
655 /**
656  * struct device_link - Device link representation.
657  * @supplier: The device on the supplier end of the link.
658  * @s_node: Hook to the supplier device's list of links to consumers.
659  * @consumer: The device on the consumer end of the link.
660  * @c_node: Hook to the consumer device's list of links to suppliers.
661  * @link_dev: device used to expose link details in sysfs
662  * @status: The state of the link (with respect to the presence of drivers).
663  * @flags: Link flags.
664  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
665  * @kref: Count repeated addition of the same link.
666  * @rm_work: Work structure used for removing the link.
667  * @supplier_preactivated: Supplier has been made active before consumer probe.
668  */
669 struct device_link {
670 	struct device *supplier;
671 	struct list_head s_node;
672 	struct device *consumer;
673 	struct list_head c_node;
674 	struct device link_dev;
675 	enum device_link_state status;
676 	u32 flags;
677 	refcount_t rpm_active;
678 	struct kref kref;
679 	struct work_struct rm_work;
680 	bool supplier_preactivated; /* Owned by consumer probe. */
681 };
682 
kobj_to_dev(struct kobject * kobj)683 static inline struct device *kobj_to_dev(struct kobject *kobj)
684 {
685 	return container_of(kobj, struct device, kobj);
686 }
687 
688 /**
689  * device_iommu_mapped - Returns true when the device DMA is translated
690  *			 by an IOMMU
691  * @dev: Device to perform the check on
692  */
device_iommu_mapped(struct device * dev)693 static inline bool device_iommu_mapped(struct device *dev)
694 {
695 	return (dev->iommu_group != NULL);
696 }
697 
698 /* Get the wakeup routines, which depend on struct device */
699 #include <linux/pm_wakeup.h>
700 
dev_name(const struct device * dev)701 static inline const char *dev_name(const struct device *dev)
702 {
703 	/* Use the init name until the kobject becomes available */
704 	if (dev->init_name)
705 		return dev->init_name;
706 
707 	return kobject_name(&dev->kobj);
708 }
709 
710 /**
711  * dev_bus_name - Return a device's bus/class name, if at all possible
712  * @dev: struct device to get the bus/class name of
713  *
714  * Will return the name of the bus/class the device is attached to.  If it is
715  * not attached to a bus/class, an empty string will be returned.
716  */
dev_bus_name(const struct device * dev)717 static inline const char *dev_bus_name(const struct device *dev)
718 {
719 	return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
720 }
721 
722 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
723 
724 #ifdef CONFIG_NUMA
dev_to_node(struct device * dev)725 static inline int dev_to_node(struct device *dev)
726 {
727 	return dev->numa_node;
728 }
set_dev_node(struct device * dev,int node)729 static inline void set_dev_node(struct device *dev, int node)
730 {
731 	dev->numa_node = node;
732 }
733 #else
dev_to_node(struct device * dev)734 static inline int dev_to_node(struct device *dev)
735 {
736 	return NUMA_NO_NODE;
737 }
set_dev_node(struct device * dev,int node)738 static inline void set_dev_node(struct device *dev, int node)
739 {
740 }
741 #endif
742 
dev_get_msi_domain(const struct device * dev)743 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
744 {
745 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
746 	return dev->msi.domain;
747 #else
748 	return NULL;
749 #endif
750 }
751 
dev_set_msi_domain(struct device * dev,struct irq_domain * d)752 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
753 {
754 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
755 	dev->msi.domain = d;
756 #endif
757 }
758 
dev_get_drvdata(const struct device * dev)759 static inline void *dev_get_drvdata(const struct device *dev)
760 {
761 	return dev->driver_data;
762 }
763 
dev_set_drvdata(struct device * dev,void * data)764 static inline void dev_set_drvdata(struct device *dev, void *data)
765 {
766 	dev->driver_data = data;
767 }
768 
dev_to_psd(struct device * dev)769 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
770 {
771 	return dev ? dev->power.subsys_data : NULL;
772 }
773 
dev_get_uevent_suppress(const struct device * dev)774 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
775 {
776 	return dev->kobj.uevent_suppress;
777 }
778 
dev_set_uevent_suppress(struct device * dev,int val)779 static inline void dev_set_uevent_suppress(struct device *dev, int val)
780 {
781 	dev->kobj.uevent_suppress = val;
782 }
783 
device_is_registered(struct device * dev)784 static inline int device_is_registered(struct device *dev)
785 {
786 	return dev->kobj.state_in_sysfs;
787 }
788 
device_enable_async_suspend(struct device * dev)789 static inline void device_enable_async_suspend(struct device *dev)
790 {
791 	if (!dev->power.is_prepared)
792 		dev->power.async_suspend = true;
793 }
794 
device_disable_async_suspend(struct device * dev)795 static inline void device_disable_async_suspend(struct device *dev)
796 {
797 	if (!dev->power.is_prepared)
798 		dev->power.async_suspend = false;
799 }
800 
device_async_suspend_enabled(struct device * dev)801 static inline bool device_async_suspend_enabled(struct device *dev)
802 {
803 	return !!dev->power.async_suspend;
804 }
805 
device_pm_not_required(struct device * dev)806 static inline bool device_pm_not_required(struct device *dev)
807 {
808 	return dev->power.no_pm;
809 }
810 
device_set_pm_not_required(struct device * dev)811 static inline void device_set_pm_not_required(struct device *dev)
812 {
813 	dev->power.no_pm = true;
814 }
815 
dev_pm_syscore_device(struct device * dev,bool val)816 static inline void dev_pm_syscore_device(struct device *dev, bool val)
817 {
818 #ifdef CONFIG_PM_SLEEP
819 	dev->power.syscore = val;
820 #endif
821 }
822 
dev_pm_set_driver_flags(struct device * dev,u32 flags)823 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
824 {
825 	dev->power.driver_flags = flags;
826 }
827 
dev_pm_test_driver_flags(struct device * dev,u32 flags)828 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
829 {
830 	return !!(dev->power.driver_flags & flags);
831 }
832 
device_lock(struct device * dev)833 static inline void device_lock(struct device *dev)
834 {
835 	mutex_lock(&dev->mutex);
836 }
837 
device_lock_interruptible(struct device * dev)838 static inline int device_lock_interruptible(struct device *dev)
839 {
840 	return mutex_lock_interruptible(&dev->mutex);
841 }
842 
device_trylock(struct device * dev)843 static inline int device_trylock(struct device *dev)
844 {
845 	return mutex_trylock(&dev->mutex);
846 }
847 
device_unlock(struct device * dev)848 static inline void device_unlock(struct device *dev)
849 {
850 	mutex_unlock(&dev->mutex);
851 }
852 
device_lock_assert(struct device * dev)853 static inline void device_lock_assert(struct device *dev)
854 {
855 	lockdep_assert_held(&dev->mutex);
856 }
857 
dev_of_node(struct device * dev)858 static inline struct device_node *dev_of_node(struct device *dev)
859 {
860 	if (!IS_ENABLED(CONFIG_OF) || !dev)
861 		return NULL;
862 	return dev->of_node;
863 }
864 
dev_has_sync_state(struct device * dev)865 static inline bool dev_has_sync_state(struct device *dev)
866 {
867 	if (!dev)
868 		return false;
869 	if (dev->driver && dev->driver->sync_state)
870 		return true;
871 	if (dev->bus && dev->bus->sync_state)
872 		return true;
873 	return false;
874 }
875 
dev_set_removable(struct device * dev,enum device_removable removable)876 static inline void dev_set_removable(struct device *dev,
877 				     enum device_removable removable)
878 {
879 	dev->removable = removable;
880 }
881 
dev_is_removable(struct device * dev)882 static inline bool dev_is_removable(struct device *dev)
883 {
884 	return dev->removable == DEVICE_REMOVABLE;
885 }
886 
dev_removable_is_valid(struct device * dev)887 static inline bool dev_removable_is_valid(struct device *dev)
888 {
889 	return dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED;
890 }
891 
892 /*
893  * High level routines for use by the bus drivers
894  */
895 int __must_check device_register(struct device *dev);
896 void device_unregister(struct device *dev);
897 void device_initialize(struct device *dev);
898 int __must_check device_add(struct device *dev);
899 void device_del(struct device *dev);
900 int device_for_each_child(struct device *dev, void *data,
901 			  int (*fn)(struct device *dev, void *data));
902 int device_for_each_child_reverse(struct device *dev, void *data,
903 				  int (*fn)(struct device *dev, void *data));
904 struct device *device_find_child(struct device *dev, void *data,
905 				 int (*match)(struct device *dev, void *data));
906 struct device *device_find_child_by_name(struct device *parent,
907 					 const char *name);
908 int device_rename(struct device *dev, const char *new_name);
909 int device_move(struct device *dev, struct device *new_parent,
910 		enum dpm_order dpm_order);
911 int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
912 const char *device_get_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
913 			       kgid_t *gid, const char **tmp);
914 int device_is_dependent(struct device *dev, void *target);
915 
device_supports_offline(struct device * dev)916 static inline bool device_supports_offline(struct device *dev)
917 {
918 	return dev->bus && dev->bus->offline && dev->bus->online;
919 }
920 
921 #define __device_lock_set_class(dev, name, key)                        \
922 do {                                                                   \
923 	struct device *__d2 __maybe_unused = dev;                      \
924 	lock_set_class(&__d2->mutex.dep_map, name, key, 0, _THIS_IP_); \
925 } while (0)
926 
927 /**
928  * device_lock_set_class - Specify a temporary lock class while a device
929  *			   is attached to a driver
930  * @dev: device to modify
931  * @key: lock class key data
932  *
933  * This must be called with the device_lock() already held, for example
934  * from driver ->probe(). Take care to only override the default
935  * lockdep_no_validate class.
936  */
937 #ifdef CONFIG_LOCKDEP
938 #define device_lock_set_class(dev, key)                                    \
939 do {                                                                       \
940 	struct device *__d = dev;                                          \
941 	dev_WARN_ONCE(__d, !lockdep_match_class(&__d->mutex,               \
942 						&__lockdep_no_validate__), \
943 		 "overriding existing custom lock class\n");               \
944 	__device_lock_set_class(__d, #key, key);                           \
945 } while (0)
946 #else
947 #define device_lock_set_class(dev, key) __device_lock_set_class(dev, #key, key)
948 #endif
949 
950 /**
951  * device_lock_reset_class - Return a device to the default lockdep novalidate state
952  * @dev: device to modify
953  *
954  * This must be called with the device_lock() already held, for example
955  * from driver ->remove().
956  */
957 #define device_lock_reset_class(dev) \
958 do { \
959 	struct device *__d __maybe_unused = dev;                       \
960 	lock_set_novalidate_class(&__d->mutex.dep_map, "&dev->mutex",  \
961 				  _THIS_IP_);                          \
962 } while (0)
963 
964 void lock_device_hotplug(void);
965 void unlock_device_hotplug(void);
966 int lock_device_hotplug_sysfs(void);
967 int device_offline(struct device *dev);
968 int device_online(struct device *dev);
969 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
970 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
971 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
972 void device_set_node(struct device *dev, struct fwnode_handle *fwnode);
973 
dev_num_vf(struct device * dev)974 static inline int dev_num_vf(struct device *dev)
975 {
976 	if (dev->bus && dev->bus->num_vf)
977 		return dev->bus->num_vf(dev);
978 	return 0;
979 }
980 
981 /*
982  * Root device objects for grouping under /sys/devices
983  */
984 struct device *__root_device_register(const char *name, struct module *owner);
985 
986 /* This is a macro to avoid include problems with THIS_MODULE */
987 #define root_device_register(name) \
988 	__root_device_register(name, THIS_MODULE)
989 
990 void root_device_unregister(struct device *root);
991 
dev_get_platdata(const struct device * dev)992 static inline void *dev_get_platdata(const struct device *dev)
993 {
994 	return dev->platform_data;
995 }
996 
997 /*
998  * Manual binding of a device to driver. See drivers/base/bus.c
999  * for information on use.
1000  */
1001 int __must_check device_driver_attach(struct device_driver *drv,
1002 				      struct device *dev);
1003 int __must_check device_bind_driver(struct device *dev);
1004 void device_release_driver(struct device *dev);
1005 int  __must_check device_attach(struct device *dev);
1006 int __must_check driver_attach(struct device_driver *drv);
1007 void device_initial_probe(struct device *dev);
1008 int __must_check device_reprobe(struct device *dev);
1009 
1010 bool device_is_bound(struct device *dev);
1011 
1012 /*
1013  * Easy functions for dynamically creating devices on the fly
1014  */
1015 __printf(5, 6) struct device *
1016 device_create(struct class *cls, struct device *parent, dev_t devt,
1017 	      void *drvdata, const char *fmt, ...);
1018 __printf(6, 7) struct device *
1019 device_create_with_groups(struct class *cls, struct device *parent, dev_t devt,
1020 			  void *drvdata, const struct attribute_group **groups,
1021 			  const char *fmt, ...);
1022 void device_destroy(struct class *cls, dev_t devt);
1023 
1024 int __must_check device_add_groups(struct device *dev,
1025 				   const struct attribute_group **groups);
1026 void device_remove_groups(struct device *dev,
1027 			  const struct attribute_group **groups);
1028 
device_add_group(struct device * dev,const struct attribute_group * grp)1029 static inline int __must_check device_add_group(struct device *dev,
1030 					const struct attribute_group *grp)
1031 {
1032 	const struct attribute_group *groups[] = { grp, NULL };
1033 
1034 	return device_add_groups(dev, groups);
1035 }
1036 
device_remove_group(struct device * dev,const struct attribute_group * grp)1037 static inline void device_remove_group(struct device *dev,
1038 				       const struct attribute_group *grp)
1039 {
1040 	const struct attribute_group *groups[] = { grp, NULL };
1041 
1042 	return device_remove_groups(dev, groups);
1043 }
1044 
1045 int __must_check devm_device_add_groups(struct device *dev,
1046 					const struct attribute_group **groups);
1047 void devm_device_remove_groups(struct device *dev,
1048 			       const struct attribute_group **groups);
1049 int __must_check devm_device_add_group(struct device *dev,
1050 				       const struct attribute_group *grp);
1051 void devm_device_remove_group(struct device *dev,
1052 			      const struct attribute_group *grp);
1053 
1054 /*
1055  * Platform "fixup" functions - allow the platform to have their say
1056  * about devices and actions that the general device layer doesn't
1057  * know about.
1058  */
1059 /* Notify platform of device discovery */
1060 extern int (*platform_notify)(struct device *dev);
1061 
1062 extern int (*platform_notify_remove)(struct device *dev);
1063 
1064 
1065 /*
1066  * get_device - atomically increment the reference count for the device.
1067  *
1068  */
1069 struct device *get_device(struct device *dev);
1070 void put_device(struct device *dev);
1071 bool kill_device(struct device *dev);
1072 
1073 #ifdef CONFIG_DEVTMPFS
1074 int devtmpfs_mount(void);
1075 #else
devtmpfs_mount(void)1076 static inline int devtmpfs_mount(void) { return 0; }
1077 #endif
1078 
1079 /* drivers/base/power/shutdown.c */
1080 void device_shutdown(void);
1081 
1082 /* debugging and troubleshooting/diagnostic helpers. */
1083 const char *dev_driver_string(const struct device *dev);
1084 
1085 /* Device links interface. */
1086 struct device_link *device_link_add(struct device *consumer,
1087 				    struct device *supplier, u32 flags);
1088 void device_link_del(struct device_link *link);
1089 void device_link_remove(void *consumer, struct device *supplier);
1090 void device_links_supplier_sync_state_pause(void);
1091 void device_links_supplier_sync_state_resume(void);
1092 
1093 extern __printf(3, 4)
1094 int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
1095 
1096 /* Create alias, so I can be autoloaded. */
1097 #define MODULE_ALIAS_CHARDEV(major,minor) \
1098 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1099 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1100 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
1101 
1102 #ifdef CONFIG_SYSFS_DEPRECATED
1103 extern long sysfs_deprecated;
1104 #else
1105 #define sysfs_deprecated 0
1106 #endif
1107 
1108 #endif /* _DEVICE_H_ */
1109