1// SPDX-License-Identifier: MIT
 2/*
 3 * Copyright © 2019 Intel Corporation
 4 */
 5
 6#include <linux/vga_switcheroo.h>
 7
 8#include "i915_drv.h"
 9#include "i915_switcheroo.h"
10
11static void i915_switcheroo_set_state(struct pci_dev *pdev,
12				      enum vga_switcheroo_state state)
13{
14	struct drm_i915_private *i915 = pdev_to_i915(pdev);
15	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
16
17	if (!i915) {
18		dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
19		return;
20	}
21
22	if (state == VGA_SWITCHEROO_ON) {
23		drm_info(&i915->drm, "switched on\n");
24		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
25		/* i915 resume handler doesn't set to D0 */
26		pci_set_power_state(pdev, PCI_D0);
27		i915_resume_switcheroo(i915);
28		i915->drm.switch_power_state = DRM_SWITCH_POWER_ON;
29	} else {
30		drm_info(&i915->drm, "switched off\n");
31		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
32		i915_suspend_switcheroo(i915, pmm);
33		i915->drm.switch_power_state = DRM_SWITCH_POWER_OFF;
34	}
35}
36
37static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
38{
39	struct drm_i915_private *i915 = pdev_to_i915(pdev);
40
41	/*
42	 * FIXME: open_count is protected by drm_global_mutex but that would lead to
43	 * locking inversion with the driver load path. And the access here is
44	 * completely racy anyway. So don't bother with locking for now.
45	 */
46	return i915 && atomic_read(&i915->drm.open_count) == 0;
47}
48
49static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
50	.set_gpu_state = i915_switcheroo_set_state,
51	.reprobe = NULL,
52	.can_switch = i915_switcheroo_can_switch,
53};
54
55int i915_switcheroo_register(struct drm_i915_private *i915)
56{
57	struct pci_dev *pdev = i915->drm.pdev;
58
59	return vga_switcheroo_register_client(pdev, &i915_switcheroo_ops, false);
60}
61
62void i915_switcheroo_unregister(struct drm_i915_private *i915)
63{
64	struct pci_dev *pdev = i915->drm.pdev;
65
66	vga_switcheroo_unregister_client(pdev);
67}