1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright © 2019 Intel Corporation
4 */
5
6 #include <linux/delay.h>
7 #include <linux/vgaarb.h>
8
9 #include <video/vga.h>
10 #include "soc/intel_gmch.h"
11
12 #include "i915_drv.h"
13 #include "i915_reg.h"
14 #include "intel_de.h"
15 #include "intel_vga.h"
16
intel_vga_cntrl_reg(struct drm_i915_private * i915)17 static i915_reg_t intel_vga_cntrl_reg(struct drm_i915_private *i915)
18 {
19 if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
20 return VLV_VGACNTRL;
21 else if (DISPLAY_VER(i915) >= 5)
22 return CPU_VGACNTRL;
23 else
24 return VGACNTRL;
25 }
26
27 /* Disable the VGA plane that we never use */
intel_vga_disable(struct drm_i915_private * dev_priv)28 void intel_vga_disable(struct drm_i915_private *dev_priv)
29 {
30 struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
31 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);
32 u8 sr1;
33
34 if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)
35 return;
36
37 /* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */
38 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
39 outb(0x01, VGA_SEQ_I);
40 sr1 = inb(VGA_SEQ_D);
41 outb(sr1 | VGA_SR01_SCREEN_OFF, VGA_SEQ_D);
42 vga_put(pdev, VGA_RSRC_LEGACY_IO);
43 udelay(300);
44
45 intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE);
46 intel_de_posting_read(dev_priv, vga_reg);
47 }
48
intel_vga_redisable_power_on(struct drm_i915_private * dev_priv)49 void intel_vga_redisable_power_on(struct drm_i915_private *dev_priv)
50 {
51 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);
52
53 if (!(intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)) {
54 drm_dbg_kms(&dev_priv->drm,
55 "Something enabled VGA plane, disabling it\n");
56 intel_vga_disable(dev_priv);
57 }
58 }
59
intel_vga_redisable(struct drm_i915_private * i915)60 void intel_vga_redisable(struct drm_i915_private *i915)
61 {
62 intel_wakeref_t wakeref;
63
64 /*
65 * This function can be called both from intel_modeset_setup_hw_state or
66 * at a very early point in our resume sequence, where the power well
67 * structures are not yet restored. Since this function is at a very
68 * paranoid "someone might have enabled VGA while we were not looking"
69 * level, just check if the power well is enabled instead of trying to
70 * follow the "don't touch the power well if we don't need it" policy
71 * the rest of the driver uses.
72 */
73 wakeref = intel_display_power_get_if_enabled(i915, POWER_DOMAIN_VGA);
74 if (!wakeref)
75 return;
76
77 intel_vga_redisable_power_on(i915);
78
79 intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref);
80 }
81
intel_vga_reset_io_mem(struct drm_i915_private * i915)82 void intel_vga_reset_io_mem(struct drm_i915_private *i915)
83 {
84 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
85
86 /*
87 * After we re-enable the power well, if we touch VGA register 0x3d5
88 * we'll get unclaimed register interrupts. This stops after we write
89 * anything to the VGA MSR register. The vgacon module uses this
90 * register all the time, so if we unbind our driver and, as a
91 * consequence, bind vgacon, we'll get stuck in an infinite loop at
92 * console_unlock(). So make here we touch the VGA MSR register, making
93 * sure vgacon can keep working normally without triggering interrupts
94 * and error messages.
95 */
96 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
97 outb(inb(VGA_MIS_R), VGA_MIS_W);
98 vga_put(pdev, VGA_RSRC_LEGACY_IO);
99 }
100
intel_vga_register(struct drm_i915_private * i915)101 int intel_vga_register(struct drm_i915_private *i915)
102 {
103
104 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
105 int ret;
106
107 /*
108 * If we have > 1 VGA cards, then we need to arbitrate access to the
109 * common VGA resources.
110 *
111 * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA),
112 * then we do not take part in VGA arbitration and the
113 * vga_client_register() fails with -ENODEV.
114 */
115 ret = vga_client_register(pdev, intel_gmch_vga_set_decode);
116 if (ret && ret != -ENODEV)
117 return ret;
118
119 return 0;
120 }
121
intel_vga_unregister(struct drm_i915_private * i915)122 void intel_vga_unregister(struct drm_i915_private *i915)
123 {
124 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
125
126 vga_client_unregister(pdev);
127 }
128