drivers/gpu/drm/udl/udl_drv.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Red Hat
 */

#include <linux/module.h>

#include <drm/drm_drv.h>
#include <drm/drm_fbdev_shmem.h>
#include <drm/drm_file.h>
#include <drm/drm_gem_shmem_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_modeset_helper.h>
#include <drm/drm_ioctl.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_print.h>

#include "udl_drv.h"

static int udl_usb_suspend(struct usb_interface *interface,
			   pm_message_t message)
{
	struct drm_device *dev = usb_get_intfdata(interface);
	int ret;

	ret = drm_mode_config_helper_suspend(dev);
	if (ret)
		return ret;

	udl_sync_pending_urbs(dev);
	return 0;
}

static int udl_usb_resume(struct usb_interface *interface)
{
	struct drm_device *dev = usb_get_intfdata(interface);

	return drm_mode_config_helper_resume(dev);
}

static int udl_usb_reset_resume(struct usb_interface *interface)
{
	struct drm_device *dev = usb_get_intfdata(interface);
	struct udl_device *udl = to_udl(dev);

	udl_select_std_channel(udl);

	return drm_mode_config_helper_resume(dev);
}

/*
 * FIXME: Dma-buf sharing requires DMA support by the importing device.
 *        This function is a workaround to make USB devices work as well.
 *        See todo.rst for how to fix the issue in the dma-buf framework.
 */
static struct drm_gem_object *udl_driver_gem_prime_import(struct drm_device *dev,
							  struct dma_buf *dma_buf)
{
	struct udl_device *udl = to_udl(dev);

	if (!udl->dmadev)
		return ERR_PTR(-ENODEV);

	return drm_gem_prime_import_dev(dev, dma_buf, udl->dmadev);
}

DEFINE_DRM_GEM_FOPS(udl_driver_fops);

static const struct drm_driver driver = {
	.driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,

	/* GEM hooks */
	.fops = &udl_driver_fops,
	DRM_GEM_SHMEM_DRIVER_OPS,
	.gem_prime_import = udl_driver_gem_prime_import,

	.name = DRIVER_NAME,
	.desc = DRIVER_DESC,
	.date = DRIVER_DATE,
	.major = DRIVER_MAJOR,
	.minor = DRIVER_MINOR,
	.patchlevel = DRIVER_PATCHLEVEL,
};

static struct udl_device *udl_driver_create(struct usb_interface *interface)
{
	struct udl_device *udl;
	int r;

	udl = devm_drm_dev_alloc(&interface->dev, &driver,
				 struct udl_device, drm);
	if (IS_ERR(udl))
		return udl;

	r = udl_init(udl);
	if (r)
		return ERR_PTR(r);

	usb_set_intfdata(interface, udl);

	return udl;
}

static int udl_usb_probe(struct usb_interface *interface,
			 const struct usb_device_id *id)
{
	int r;
	struct udl_device *udl;

	udl = udl_driver_create(interface);
	if (IS_ERR(udl))
		return PTR_ERR(udl);

	r = drm_dev_register(&udl->drm, 0);
	if (r)
		return r;

	DRM_INFO("Initialized udl on minor %d\n", udl->drm.primary->index);

	drm_fbdev_shmem_setup(&udl->drm, 0);

	return 0;
}

static void udl_usb_disconnect(struct usb_interface *interface)
{
	struct drm_device *dev = usb_get_intfdata(interface);

	drm_kms_helper_poll_fini(dev);
	udl_drop_usb(dev);
	drm_dev_unplug(dev);
}

/*
 * There are many DisplayLink-based graphics products, all with unique PIDs.
 * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
 * We also require a match on SubClass (0x00) and Protocol (0x00),
 * which is compatible with all known USB 2.0 era graphics chips and firmware,
 * but allows DisplayLink to increment those for any future incompatible chips
 */
static const struct usb_device_id id_table[] = {
	{.idVendor = 0x17e9, .bInterfaceClass = 0xff,
	 .bInterfaceSubClass = 0x00,
	 .bInterfaceProtocol = 0x00,
	 .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
			USB_DEVICE_ID_MATCH_INT_CLASS |
			USB_DEVICE_ID_MATCH_INT_SUBCLASS |
			USB_DEVICE_ID_MATCH_INT_PROTOCOL,},
	{},
};
MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_driver udl_driver = {
	.name = "udl",
	.probe = udl_usb_probe,
	.disconnect = udl_usb_disconnect,
	.suspend = udl_usb_suspend,
	.resume = udl_usb_resume,
	.reset_resume = udl_usb_reset_resume,
	.id_table = id_table,
};
module_usb_driver(udl_driver);
MODULE_DESCRIPTION("KMS driver for the USB displaylink video adapters");
MODULE_LICENSE("GPL");