diff options
Diffstat (limited to 'drivers/gpu/drm/i915/soc/intel_gmch.c')
| -rw-r--r-- | drivers/gpu/drm/i915/soc/intel_gmch.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/soc/intel_gmch.c b/drivers/gpu/drm/i915/soc/intel_gmch.c index d5fbb7907725..6d0204942f7a 100644 --- a/drivers/gpu/drm/i915/soc/intel_gmch.c +++ b/drivers/gpu/drm/i915/soc/intel_gmch.c @@ -7,6 +7,7 @@ #include <linux/pnp.h> #include <drm/drm_managed.h> +#include <drm/i915_drm.h> #include "i915_drv.h" #include "intel_gmch.h" @@ -142,3 +143,29 @@ void intel_gmch_bar_teardown(struct drm_i915_private *i915) if (i915->gmch.mch_res.start) release_resource(&i915->gmch.mch_res); } + +int intel_gmch_vga_set_state(struct drm_i915_private *i915, bool enable_decode) +{ + unsigned int reg = DISPLAY_VER(i915) >= 6 ? SNB_GMCH_CTRL : INTEL_GMCH_CTRL; + u16 gmch_ctrl; + + if (pci_read_config_word(i915->gmch.pdev, reg, &gmch_ctrl)) { + drm_err(&i915->drm, "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->gmch.pdev, reg, gmch_ctrl)) { + drm_err(&i915->drm, "failed to write control word\n"); + return -EIO; + } + + return 0; +} |