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 = dev_priv->drm.pdev;
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 #ifdef __linux__
40 outb(0x01, VGA_SEQ_I);
41 sr1 = inb(VGA_SEQ_D);
42 outb(sr1 | VGA_SR01_SCREEN_OFF, VGA_SEQ_D);
43 #else
44 outb(VGA_SEQ_I, 0x01);
45 sr1 = inb(VGA_SEQ_D);
46 outb(VGA_SEQ_D, sr1 | VGA_SR01_SCREEN_OFF);
47 #endif
48 vga_put(pdev, VGA_RSRC_LEGACY_IO);
49 udelay(300);
50
51 intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE);
52 intel_de_posting_read(dev_priv, vga_reg);
53 }
54
intel_vga_redisable_power_on(struct drm_i915_private * dev_priv)55 void intel_vga_redisable_power_on(struct drm_i915_private *dev_priv)
56 {
57 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);
58
59 if (!(intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)) {
60 drm_dbg_kms(&dev_priv->drm,
61 "Something enabled VGA plane, disabling it\n");
62 intel_vga_disable(dev_priv);
63 }
64 }
65
intel_vga_redisable(struct drm_i915_private * i915)66 void intel_vga_redisable(struct drm_i915_private *i915)
67 {
68 intel_wakeref_t wakeref;
69
70 /*
71 * This function can be called both from intel_modeset_setup_hw_state or
72 * at a very early point in our resume sequence, where the power well
73 * structures are not yet restored. Since this function is at a very
74 * paranoid "someone might have enabled VGA while we were not looking"
75 * level, just check if the power well is enabled instead of trying to
76 * follow the "don't touch the power well if we don't need it" policy
77 * the rest of the driver uses.
78 */
79 wakeref = intel_display_power_get_if_enabled(i915, POWER_DOMAIN_VGA);
80 if (!wakeref)
81 return;
82
83 intel_vga_redisable_power_on(i915);
84
85 intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref);
86 }
87
intel_vga_reset_io_mem(struct drm_i915_private * i915)88 void intel_vga_reset_io_mem(struct drm_i915_private *i915)
89 {
90 struct pci_dev *pdev = i915->drm.pdev;
91
92 /*
93 * After we re-enable the power well, if we touch VGA register 0x3d5
94 * we'll get unclaimed register interrupts. This stops after we write
95 * anything to the VGA MSR register. The vgacon module uses this
96 * register all the time, so if we unbind our driver and, as a
97 * consequence, bind vgacon, we'll get stuck in an infinite loop at
98 * console_unlock(). So make here we touch the VGA MSR register, making
99 * sure vgacon can keep working normally without triggering interrupts
100 * and error messages.
101 */
102 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
103 #ifdef __linux__
104 outb(inb(VGA_MIS_R), VGA_MIS_W);
105 #else
106 outb(VGA_MIS_W, inb(VGA_MIS_R));
107 #endif
108 vga_put(pdev, VGA_RSRC_LEGACY_IO);
109 }
110
intel_vga_register(struct drm_i915_private * i915)111 int intel_vga_register(struct drm_i915_private *i915)
112 {
113
114 struct pci_dev *pdev = i915->drm.pdev;
115 int ret;
116
117 /*
118 * If we have > 1 VGA cards, then we need to arbitrate access to the
119 * common VGA resources.
120 *
121 * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA),
122 * then we do not take part in VGA arbitration and the
123 * vga_client_register() fails with -ENODEV.
124 */
125 ret = vga_client_register(pdev, intel_gmch_vga_set_decode);
126 if (ret && ret != -ENODEV)
127 return ret;
128
129 return 0;
130 }
131
intel_vga_unregister(struct drm_i915_private * i915)132 void intel_vga_unregister(struct drm_i915_private *i915)
133 {
134 struct pci_dev *pdev = i915->drm.pdev;
135
136 vga_client_unregister(pdev);
137 }
138