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 17 static i915_reg_t intel_vga_cntrl_reg(struct intel_display *display) 18 { 19 if (display->platform.valleyview || display->platform.cherryview) 20 return VLV_VGACNTRL; 21 else if (DISPLAY_VER(display) >= 5) 22 return CPU_VGACNTRL; 23 else 24 return VGACNTRL; 25 } 26 27 /* Disable the VGA plane that we never use */ 28 void intel_vga_disable(struct intel_display *display) 29 { 30 struct pci_dev *pdev = to_pci_dev(display->drm->dev); 31 i915_reg_t vga_reg = intel_vga_cntrl_reg(display); 32 u8 sr1; 33 34 if (intel_de_read(display, 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(display, vga_reg, VGA_DISP_DISABLE); 46 intel_de_posting_read(display, vga_reg); 47 } 48 49 void intel_vga_redisable_power_on(struct intel_display *display) 50 { 51 i915_reg_t vga_reg = intel_vga_cntrl_reg(display); 52 53 if (!(intel_de_read(display, vga_reg) & VGA_DISP_DISABLE)) { 54 drm_dbg_kms(display->drm, 55 "Something enabled VGA plane, disabling it\n"); 56 intel_vga_disable(display); 57 } 58 } 59 60 void intel_vga_redisable(struct intel_display *display) 61 { 62 struct drm_i915_private *i915 = to_i915(display->drm); 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(display); 79 80 intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref); 81 } 82 83 void intel_vga_reset_io_mem(struct intel_display *display) 84 { 85 struct pci_dev *pdev = to_pci_dev(display->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 int intel_vga_register(struct intel_display *display) 103 { 104 105 struct pci_dev *pdev = to_pci_dev(display->drm->dev); 106 int ret; 107 108 /* 109 * If we have > 1 VGA cards, then we need to arbitrate access to the 110 * common VGA resources. 111 * 112 * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA), 113 * then we do not take part in VGA arbitration and the 114 * vga_client_register() fails with -ENODEV. 115 */ 116 ret = vga_client_register(pdev, intel_gmch_vga_set_decode); 117 if (ret && ret != -ENODEV) 118 return ret; 119 120 return 0; 121 } 122 123 void intel_vga_unregister(struct intel_display *display) 124 { 125 struct pci_dev *pdev = to_pci_dev(display->drm->dev); 126 127 vga_client_unregister(pdev); 128 } 129