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