1 // SPDX-License-Identifier: MIT
21  * graphics drivers, such as EFI-GOP or VESA, early during the boot process.
23  * hardware-specific driver. To take over the device, the dedicated driver
25  * ownership of framebuffer memory and hand-over between drivers.
32  * .. code-block:: c
36  *		struct resource *mem;
37  *		resource_size_t base, size;
40  *		mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
41  *		if (!mem)
42  *			return -ENODEV;
43  *		base = mem->start;
44  *		size = resource_size(mem);
46  *		ret = aperture_remove_conflicting_devices(base, size, "example");
61  * The given example reads the platform device's I/O-memory range from the
82  * .. code-block:: c
86  *		struct resource *mem;
87  *		resource_size_t base, size;
89  *		mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
90  *		if (!mem)
91  *			return -ENODEV;
92  *		base = mem->start;
93  *		size = resource_size(mem);
95  *		ret = devm_aperture_acquire_for_platform_device(pdev, base, size);
107  *		// Hot-unplug the device
135 	resource_size_t base;  member
153 	bool detached = !ap->dev;  in devm_aperture_acquire_release()
159 	list_del(&ap->lh);  in devm_aperture_acquire_release()
164 				 resource_size_t base, resource_size_t size,  in devm_aperture_acquire()  argument
167 	size_t end = base + size;  in devm_aperture_acquire()
175 		if (overlap(base, end, ap->base, ap->base + ap->size)) {  in devm_aperture_acquire()
177 			return -EBUSY;  in devm_aperture_acquire()
184 		return -ENOMEM;  in devm_aperture_acquire()
187 	ap->dev = dev;  in devm_aperture_acquire()
188 	ap->base = base;  in devm_aperture_acquire()
189 	ap->size = size;  in devm_aperture_acquire()
190 	ap->detach = detach;  in devm_aperture_acquire()
191 	INIT_LIST_HEAD(&ap->lh);  in devm_aperture_acquire()
193 	list_add(&ap->lh, &apertures);  in devm_aperture_acquire()
206 	 * to do for firmware-based fb drivers, such as EFI, VESA or VGA. After  in aperture_detach_platform_device()
210 	 * For non-platform devices, a new callback would be required.  in aperture_detach_platform_device()
220  * devm_aperture_acquire_for_platform_device - Acquires ownership of an aperture
223  * @base:	the aperture's byte offset in physical memory
240 					      resource_size_t base,  in devm_aperture_acquire_for_platform_device()  argument
243 	return devm_aperture_acquire(&pdev->dev, base, size, aperture_detach_platform_device);  in devm_aperture_acquire_for_platform_device()
247 static void aperture_detach_devices(resource_size_t base, resource_size_t size)  in aperture_detach_devices()  argument
249 	resource_size_t end = base + size;  in aperture_detach_devices()
256 		struct device *dev = ap->dev;  in aperture_detach_devices()
261 		if (!overlap(base, end, ap->base, ap->base + ap->size))  in aperture_detach_devices()
264 		ap->dev = NULL; /* detach from device */  in aperture_detach_devices()
265 		list_del(&ap->lh);  in aperture_detach_devices()
267 		ap->detach(dev);  in aperture_detach_devices()
274  * aperture_remove_conflicting_devices - remove devices in the given range
275  * @base: the aperture's base address in physical memory
279  * This function removes devices that own apertures within @base and @size.
284 int aperture_remove_conflicting_devices(resource_size_t base, resource_size_t size,  in aperture_remove_conflicting_devices()  argument
300 	aperture_detach_devices(base, size);  in aperture_remove_conflicting_devices()
307  * __aperture_remove_legacy_vga_devices - remove legacy VGA devices of a PCI devices
311  * framebuffer or a console. This is useful if you have a VGA-compatible
312  * PCI graphics device with framebuffers in non-BAR locations. Drivers
342  * aperture_remove_conflicting_pci_devices - remove existing framebuffers for PCI devices
356 	resource_size_t base, size;  in aperture_remove_conflicting_pci_devices()  local
371 		base = pci_resource_start(pdev, bar);  in aperture_remove_conflicting_pci_devices()
373 		aperture_detach_devices(base, size);  in aperture_remove_conflicting_pci_devices()