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 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 */ 29 void intel_vga_disable(struct drm_i915_private *dev_priv) 30 { 31 struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev); 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 outb(0x01, VGA_SEQ_I); 41 sr1 = inb(VGA_SEQ_D); 42 outb(sr1 | VGA_SR01_SCREEN_OFF, VGA_SEQ_D); 43 vga_put(pdev, VGA_RSRC_LEGACY_IO); 44 udelay(300); 45 46 intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE); 47 intel_de_posting_read(dev_priv, vga_reg); 48 } 49 50 void intel_vga_redisable_power_on(struct drm_i915_private *dev_priv) 51 { 52 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); 53 54 if (!(intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)) { 55 drm_dbg_kms(&dev_priv->drm, 56 "Something enabled VGA plane, disabling it\n"); 57 intel_vga_disable(dev_priv); 58 } 59 } 60 61 void intel_vga_redisable(struct drm_i915_private *i915) 62 { 63 intel_wakeref_t wakeref; 64 65 /* 66 * This function can be called both from intel_modeset_setup_hw_state or 67 * at a very early point in our resume sequence, where the power well 68 * structures are not yet restored. Since this function is at a very 69 * paranoid "someone might have enabled VGA while we were not looking" 70 * level, just check if the power well is enabled instead of trying to 71 * follow the "don't touch the power well if we don't need it" policy 72 * the rest of the driver uses. 73 */ 74 wakeref = intel_display_power_get_if_enabled(i915, POWER_DOMAIN_VGA); 75 if (!wakeref) 76 return; 77 78 intel_vga_redisable_power_on(i915); 79 80 intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref); 81 } 82 83 void intel_vga_reset_io_mem(struct drm_i915_private *i915) 84 { 85 struct pci_dev *pdev = to_pci_dev(i915->drm.dev); 86 87 /* 88 * After we re-enable the power well, if we touch VGA register 0x3d5 89 * we'll get unclaimed register interrupts. This stops after we write 90 * anything to the VGA MSR register. The vgacon module uses this 91 * register all the time, so if we unbind our driver and, as a 92 * consequence, bind vgacon, we'll get stuck in an infinite loop at 93 * console_unlock(). So make here we touch the VGA MSR register, making 94 * sure vgacon can keep working normally without triggering interrupts 95 * and error messages. 96 */ 97 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); 98 outb(inb(VGA_MIS_R), VGA_MIS_W); 99 vga_put(pdev, VGA_RSRC_LEGACY_IO); 100 } 101 102 static unsigned int 103 intel_vga_set_decode(struct pci_dev *pdev, bool enable_decode) 104 { 105 struct drm_i915_private *i915 = pdev_to_i915(pdev); 106 107 intel_gmch_vga_set_state(i915, enable_decode); 108 109 if (enable_decode) 110 return VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM | 111 VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; 112 else 113 return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; 114 } 115 116 int intel_vga_register(struct drm_i915_private *i915) 117 { 118 119 struct pci_dev *pdev = to_pci_dev(i915->drm.dev); 120 int ret; 121 122 /* 123 * If we have > 1 VGA cards, then we need to arbitrate access to the 124 * common VGA resources. 125 * 126 * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA), 127 * then we do not take part in VGA arbitration and the 128 * vga_client_register() fails with -ENODEV. 129 */ 130 ret = vga_client_register(pdev, intel_vga_set_decode); 131 if (ret && ret != -ENODEV) 132 return ret; 133 134 return 0; 135 } 136 137 void intel_vga_unregister(struct drm_i915_private *i915) 138 { 139 struct pci_dev *pdev = to_pci_dev(i915->drm.dev); 140 141 vga_client_unregister(pdev); 142 } 143