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1// SPDX-License-Identifier: MIT2/*3 * Copyright © 2019 Intel Corporation4 */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 17static 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 else24 return VGACNTRL;25}26 27/* Disable the VGA plane that we never use */28void intel_vga_disable(struct drm_i915_private *dev_priv)29{30 struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);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 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(dev_priv, vga_reg, VGA_DISP_DISABLE);46 intel_de_posting_read(dev_priv, vga_reg);47}48 49void intel_vga_redisable_power_on(struct drm_i915_private *dev_priv)50{51 i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);52 53 if (!(intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)) {54 drm_dbg_kms(&dev_priv->drm,55 "Something enabled VGA plane, disabling it\n");56 intel_vga_disable(dev_priv);57 }58}59 60void intel_vga_redisable(struct drm_i915_private *i915)61{62 intel_wakeref_t wakeref;63 64 /*65 * This function can be called both from intel_modeset_setup_hw_state or66 * at a very early point in our resume sequence, where the power well67 * structures are not yet restored. Since this function is at a very68 * paranoid "someone might have enabled VGA while we were not looking"69 * level, just check if the power well is enabled instead of trying to70 * follow the "don't touch the power well if we don't need it" policy71 * the rest of the driver uses.72 */73 wakeref = intel_display_power_get_if_enabled(i915, POWER_DOMAIN_VGA);74 if (!wakeref)75 return;76 77 intel_vga_redisable_power_on(i915);78 79 intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref);80}81 82void intel_vga_reset_io_mem(struct drm_i915_private *i915)83{84 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);85 86 /*87 * After we re-enable the power well, if we touch VGA register 0x3d588 * we'll get unclaimed register interrupts. This stops after we write89 * anything to the VGA MSR register. The vgacon module uses this90 * register all the time, so if we unbind our driver and, as a91 * consequence, bind vgacon, we'll get stuck in an infinite loop at92 * console_unlock(). So make here we touch the VGA MSR register, making93 * sure vgacon can keep working normally without triggering interrupts94 * and error messages.95 */96 vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);97 outb(inb(VGA_MIS_R), VGA_MIS_W);98 vga_put(pdev, VGA_RSRC_LEGACY_IO);99}100 101int intel_vga_register(struct drm_i915_private *i915)102{103 104 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);105 int ret;106 107 /*108 * If we have > 1 VGA cards, then we need to arbitrate access to the109 * common VGA resources.110 *111 * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA),112 * then we do not take part in VGA arbitration and the113 * vga_client_register() fails with -ENODEV.114 */115 ret = vga_client_register(pdev, intel_gmch_vga_set_decode);116 if (ret && ret != -ENODEV)117 return ret;118 119 return 0;120}121 122void intel_vga_unregister(struct drm_i915_private *i915)123{124 struct pci_dev *pdev = to_pci_dev(i915->drm.dev);125 126 vga_client_unregister(pdev);127}128