1 // SPDX-License-Identifier: MIT
20  * driver can be active at any given time. Many systems load a generic
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
42  *			return -ENODEV;
43  *		base = mem->start;
61  * The given example reads the platform device's I/O-memory range from the
65  * output on the framebuffer. If successful, the new driver can take over
70  * device drivers can also call aperture_remove_conflicting_pci_devices() and
72  * knowledge of the framebuffer's location can call
82  * .. code-block:: c
91  *			return -ENODEV;
92  *		base = mem->start;
107  *		// Hot-unplug the device
153 	bool detached = !ap->dev;  in devm_aperture_acquire_release()
159 	list_del(&ap->lh);  in devm_aperture_acquire_release()
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
243 	return devm_aperture_acquire(&pdev->dev, base, size, aperture_detach_platform_device);  in devm_aperture_acquire_for_platform_device()
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
289 	 * sysfb, then can be assumed that this is a driver for a display  in aperture_remove_conflicting_devices()
305  * __aperture_remove_legacy_vga_devices - remove legacy VGA devices of a PCI devices
309  * framebuffer or a console. This is useful if you have a VGA-compatible
310  * PCI graphics device with framebuffers in non-BAR locations. Drivers
336  * aperture_remove_conflicting_pci_devices - remove existing framebuffers for PCI devices
342  * drives a primary display and therefore kicks out vga16fb as well.
349 	bool primary = false;  in aperture_remove_conflicting_pci_devices()  local
354 		primary = true;  in aperture_remove_conflicting_pci_devices()
356 	if (primary)  in aperture_remove_conflicting_pci_devices()
369 	 * If this is the primary adapter, there could be a VGA device  in aperture_remove_conflicting_pci_devices()
373 	if (primary)  in aperture_remove_conflicting_pci_devices()