xref: /openbmc/linux/include/drm/drm_module.h (revision 52506b09)
1 /* SPDX-License-Identifier: MIT */
2 
3 #ifndef DRM_MODULE_H
4 #define DRM_MODULE_H
5 
6 #include <linux/pci.h>
7 
8 #include <drm/drm_drv.h>
9 
10 /**
11  * DOC: overview
12  *
13  * This library provides helpers registering DRM drivers during module
14  * initialization and shutdown. The provided helpers act like bus-specific
15  * module helpers, such as module_pci_driver(), but respect additional
16  * parameters that control DRM driver registration.
17  *
18  * Below is an example of initializing a DRM driver for a device on the
19  * PCI bus.
20  *
21  * .. code-block:: c
22  *
23  *	struct pci_driver my_pci_drv = {
24  *	};
25  *
26  *	drm_module_pci_driver(my_pci_drv);
27  *
28  * The generated code will test if DRM drivers are enabled and register
29  * the PCI driver my_pci_drv. For more complex module initialization, you
30  * can still use module_init() and module_exit() in your driver.
31  */
32 
33 /*
34  * PCI drivers
35  */
36 
37 static inline int __init drm_pci_register_driver(struct pci_driver *pci_drv)
38 {
39 	if (drm_firmware_drivers_only())
40 		return -ENODEV;
41 
42 	return pci_register_driver(pci_drv);
43 }
44 
45 /**
46  * drm_module_pci_driver - Register a DRM driver for PCI-based devices
47  * @__pci_drv: the PCI driver structure
48  *
49  * Registers a DRM driver for devices on the PCI bus. The helper
50  * macro behaves like module_pci_driver() but tests the state of
51  * drm_firmware_drivers_only(). For more complex module initialization,
52  * use module_init() and module_exit() directly.
53  *
54  * Each module may only use this macro once. Calling it replaces
55  * module_init() and module_exit().
56  */
57 #define drm_module_pci_driver(__pci_drv) \
58 	module_driver(__pci_drv, drm_pci_register_driver, pci_unregister_driver)
59 
60 static inline int __init
61 drm_pci_register_driver_if_modeset(struct pci_driver *pci_drv, int modeset)
62 {
63 	if (drm_firmware_drivers_only() && modeset == -1)
64 		return -ENODEV;
65 	if (modeset == 0)
66 		return -ENODEV;
67 
68 	return pci_register_driver(pci_drv);
69 }
70 
71 static inline void __exit
72 drm_pci_unregister_driver_if_modeset(struct pci_driver *pci_drv, int modeset)
73 {
74 	pci_unregister_driver(pci_drv);
75 }
76 
77 /**
78  * drm_module_pci_driver_if_modeset - Register a DRM driver for PCI-based devices
79  * @__pci_drv: the PCI driver structure
80  * @__modeset: an additional parameter that disables the driver
81  *
82  * This macro is deprecated and only provided for existing drivers. For
83  * new drivers, use drm_module_pci_driver().
84  *
85  * Registers a DRM driver for devices on the PCI bus. The helper macro
86  * behaves like drm_module_pci_driver() with an additional driver-specific
87  * flag. If __modeset is 0, the driver has been disabled, if __modeset is
88  * -1 the driver state depends on the global DRM state. For all other
89  * values, the PCI driver has been enabled. The default should be -1.
90  */
91 #define drm_module_pci_driver_if_modeset(__pci_drv, __modeset) \
92 	module_driver(__pci_drv, drm_pci_register_driver_if_modeset, \
93 		      drm_pci_unregister_driver_if_modeset, __modeset)
94 
95 #endif
96