diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_vga.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_vga.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c new file mode 100644 index 000000000000..2ff7293986d4 --- /dev/null +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -0,0 +1,160 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2019 Intel Corporation + */ + +#include <linux/pci.h> +#include <linux/vgaarb.h> + +#include <drm/i915_drm.h> + +#include "i915_drv.h" +#include "intel_vga.h" + +static i915_reg_t intel_vga_cntrl_reg(struct drm_i915_private *i915) +{ + if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) + return VLV_VGACNTRL; + else if (INTEL_GEN(i915) >= 5) + return CPU_VGACNTRL; + else + return VGACNTRL; +} + +/* Disable the VGA plane that we never use */ +void intel_vga_disable(struct drm_i915_private *dev_priv) +{ + struct pci_dev *pdev = dev_priv->drm.pdev; + i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); + u8 sr1; + + /* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ + vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); + outb(SR01, VGA_SR_INDEX); + sr1 = inb(VGA_SR_DATA); + outb(sr1 | 1 << 5, VGA_SR_DATA); + vga_put(pdev, VGA_RSRC_LEGACY_IO); + udelay(300); + + I915_WRITE(vga_reg, VGA_DISP_DISABLE); + POSTING_READ(vga_reg); +} + +void intel_vga_redisable_power_on(struct drm_i915_private *dev_priv) +{ + i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); + + if (!(I915_READ(vga_reg) & VGA_DISP_DISABLE)) { + DRM_DEBUG_KMS("Something enabled VGA plane, disabling it\n"); + intel_vga_disable(dev_priv); + } +} + +void intel_vga_redisable(struct drm_i915_private *i915) +{ + intel_wakeref_t wakeref; + + /* + * This function can be called both from intel_modeset_setup_hw_state or + * at a very early point in our resume sequence, where the power well + * structures are not yet restored. Since this function is at a very + * paranoid "someone might have enabled VGA while we were not looking" + * level, just check if the power well is enabled instead of trying to + * follow the "don't touch the power well if we don't need it" policy + * the rest of the driver uses. + */ + wakeref = intel_display_power_get_if_enabled(i915, POWER_DOMAIN_VGA); + if (!wakeref) + return; + + intel_vga_redisable_power_on(i915); + + intel_display_power_put(i915, POWER_DOMAIN_VGA, wakeref); +} + +void intel_vga_reset_io_mem(struct drm_i915_private *i915) +{ + struct pci_dev *pdev = i915->drm.pdev; + + /* + * After we re-enable the power well, if we touch VGA register 0x3d5 + * we'll get unclaimed register interrupts. This stops after we write + * anything to the VGA MSR register. The vgacon module uses this + * register all the time, so if we unbind our driver and, as a + * consequence, bind vgacon, we'll get stuck in an infinite loop at + * console_unlock(). So make here we touch the VGA MSR register, making + * sure vgacon can keep working normally without triggering interrupts + * and error messages. + */ + vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); + outb(inb(VGA_MSR_READ), VGA_MSR_WRITE); + vga_put(pdev, VGA_RSRC_LEGACY_IO); +} + +static int +intel_vga_set_state(struct drm_i915_private *i915, bool enable_decode) +{ + unsigned int reg = INTEL_GEN(i915) >= 6 ? SNB_GMCH_CTRL : INTEL_GMCH_CTRL; + u16 gmch_ctrl; + + if (pci_read_config_word(i915->bridge_dev, reg, &gmch_ctrl)) { + DRM_ERROR("failed to read control word\n"); + return -EIO; + } + + if (!!(gmch_ctrl & INTEL_GMCH_VGA_DISABLE) == !enable_decode) + return 0; + + if (enable_decode) + gmch_ctrl &= ~INTEL_GMCH_VGA_DISABLE; + else + gmch_ctrl |= INTEL_GMCH_VGA_DISABLE; + + if (pci_write_config_word(i915->bridge_dev, reg, gmch_ctrl)) { + DRM_ERROR("failed to write control word\n"); + return -EIO; + } + + return 0; +} + +static unsigned int +intel_vga_set_decode(void *cookie, bool enable_decode) +{ + struct drm_i915_private *i915 = cookie; + + intel_vga_set_state(i915, enable_decode); + + if (enable_decode) + return VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM | + VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; + else + return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; +} + +int intel_vga_register(struct drm_i915_private *i915) +{ + struct pci_dev *pdev = i915->drm.pdev; + int ret; + + /* + * If we have > 1 VGA cards, then we need to arbitrate access to the + * common VGA resources. + * + * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA), + * then we do not take part in VGA arbitration and the + * vga_client_register() fails with -ENODEV. + */ + ret = vga_client_register(pdev, i915, NULL, intel_vga_set_decode); + if (ret && ret != -ENODEV) + return ret; + + return 0; +} + +void intel_vga_unregister(struct drm_i915_private *i915) +{ + struct pci_dev *pdev = i915->drm.pdev; + + vga_client_register(pdev, NULL, NULL, NULL); +} |