1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright © 2019 Intel Corporation
4 */
5
6 #include <linux/pci.h>
7 #include <linux/vgaarb.h>
8
9 #include <video/vga.h>
10
11 #include "soc/intel_gmch.h"
12
13 #include "i915_drv.h"
14 #include "i915_reg.h"
15 #include "intel_de.h"
16 #include "intel_vga.h"
17
intel_vga_cntrl_reg(struct drm_i915_private * i915)18 static i915_reg_t intel_vga_cntrl_reg(struct drm_i915_private *i915)
19 {
20 if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
21 return VLV_VGACNTRL;
22 else if (DISPLAY_VER(i915) >= 5)
23 return CPU_VGACNTRL;
24 else
25 return VGACNTRL;
26 }
27
28 /* Disable the VGA plane that we never use */
intel_vga_disable(struct drm_i915_private * dev_priv)29 void intel_vga_disable(struct drm_i915_private *dev_priv)
30 {
31 struct pci_dev *pdev = dev_priv->drm.pdev;
32 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);
33 u8 sr1;
34
35 if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)
36 return;
37
38 /* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */
39 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
40 #ifdef __linux__
41 outb(0x01, VGA_SEQ_I);
42 sr1 = inb(VGA_SEQ_D);
43 outb(sr1 | VGA_SR01_SCREEN_OFF, VGA_SEQ_D);
44 #else
45 outb(VGA_SEQ_I, 0x01);
46 sr1 = inb(VGA_SEQ_D);
47 outb(VGA_SEQ_D, sr1 | VGA_SR01_SCREEN_OFF);
48 #endif
49 vga_put(pdev, VGA_RSRC_LEGACY_IO);
50 udelay(300);
51
52 intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE);
53 intel_de_posting_read(dev_priv, vga_reg);
54 }
55
intel_vga_redisable_power_on(struct drm_i915_private * dev_priv)56 void intel_vga_redisable_power_on(struct drm_i915_private *dev_priv)
57 {
58 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);
59
60 if (!(intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)) {
61 drm_dbg_kms(&dev_priv->drm,
62 "Something enabled VGA plane, disabling it\n");
63 intel_vga_disable(dev_priv);
64 }
65 }
66
intel_vga_redisable(struct drm_i915_private * i915)67 void intel_vga_redisable(struct drm_i915_private *i915)
68 {
69 intel_wakeref_t wakeref;
70
71 /*
72 * This function can be called both from intel_modeset_setup_hw_state or
73 * at a very early point in our resume sequence, where the power well
74 * structures are not yet restored. Since this function is at a very
75 * paranoid "someone might have enabled VGA while we were not looking"
76 * level, just check if the power well is enabled instead of trying to
77 * follow the "don't touch the power well if we don't need it" policy
78 * the rest of the driver uses.
79 */
80 wakeref = intel_display_power_get_if_enabled(i915, POWER_DOMAIN_VGA);
81 if (!wakeref)
82 return;
83
84 intel_vga_redisable_power_on(i915);
85
86 intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref);
87 }
88
intel_vga_reset_io_mem(struct drm_i915_private * i915)89 void intel_vga_reset_io_mem(struct drm_i915_private *i915)
90 {
91 struct pci_dev *pdev = i915->drm.pdev;
92
93 /*
94 * After we re-enable the power well, if we touch VGA register 0x3d5
95 * we'll get unclaimed register interrupts. This stops after we write
96 * anything to the VGA MSR register. The vgacon module uses this
97 * register all the time, so if we unbind our driver and, as a
98 * consequence, bind vgacon, we'll get stuck in an infinite loop at
99 * console_unlock(). So make here we touch the VGA MSR register, making
100 * sure vgacon can keep working normally without triggering interrupts
101 * and error messages.
102 */
103 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
104 #ifdef __linux__
105 outb(inb(VGA_MIS_R), VGA_MIS_W);
106 #else
107 outb(VGA_MIS_W, inb(VGA_MIS_R));
108 #endif
109 vga_put(pdev, VGA_RSRC_LEGACY_IO);
110 }
111
112 static unsigned int
intel_vga_set_decode(struct pci_dev * pdev,bool enable_decode)113 intel_vga_set_decode(struct pci_dev *pdev, bool enable_decode)
114 {
115 STUB();
116 return 0;
117 #ifdef notyet
118 struct drm_i915_private *i915 = pdev_to_i915(pdev);
119
120 intel_gmch_vga_set_state(i915, enable_decode);
121
122 if (enable_decode)
123 return VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM |
124 VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
125 else
126 return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
127 #endif
128 }
129
intel_vga_register(struct drm_i915_private * i915)130 int intel_vga_register(struct drm_i915_private *i915)
131 {
132
133 struct pci_dev *pdev = i915->drm.pdev;
134 int ret;
135
136 /*
137 * If we have > 1 VGA cards, then we need to arbitrate access to the
138 * common VGA resources.
139 *
140 * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA),
141 * then we do not take part in VGA arbitration and the
142 * vga_client_register() fails with -ENODEV.
143 */
144 ret = vga_client_register(pdev, intel_vga_set_decode);
145 if (ret && ret != -ENODEV)
146 return ret;
147
148 return 0;
149 }
150
intel_vga_unregister(struct drm_i915_private * i915)151 void intel_vga_unregister(struct drm_i915_private *i915)
152 {
153 struct pci_dev *pdev = i915->drm.pdev;
154
155 vga_client_unregister(pdev);
156 }
157