From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 drivers/gpu/drm/i915/display/intel_vga.c | 167 +++++++++++++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/display/intel_vga.c

(limited to 'drivers/gpu/drm/i915/display/intel_vga.c')

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 000000000..b5d058404
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_vga.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include <linux/pci.h>
+#include <linux/vgaarb.h>
+
+#include <drm/i915_drm.h>
+#include <video/vga.h>
+
+#include "i915_drv.h"
+#include "intel_de.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 (DISPLAY_VER(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 = to_pci_dev(dev_priv->drm.dev);
+	i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv);
+	u8 sr1;
+
+	if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)
+		return;
+
+	/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */
+	vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
+	outb(0x01, VGA_SEQ_I);
+	sr1 = inb(VGA_SEQ_D);
+	outb(sr1 | VGA_SR01_SCREEN_OFF, VGA_SEQ_D);
+	vga_put(pdev, VGA_RSRC_LEGACY_IO);
+	udelay(300);
+
+	intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE);
+	intel_de_posting_read(dev_priv, 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 (!(intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "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 = to_pci_dev(i915->drm.dev);
+
+	/*
+	 * 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_MIS_R), VGA_MIS_W);
+	vga_put(pdev, VGA_RSRC_LEGACY_IO);
+}
+
+static int
+intel_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->bridge_dev, 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->bridge_dev, reg, gmch_ctrl)) {
+		drm_err(&i915->drm, "failed to write control word\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static unsigned int
+intel_vga_set_decode(struct pci_dev *pdev, bool enable_decode)
+{
+	struct drm_i915_private *i915 = pdev_to_i915(pdev);
+
+	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 = to_pci_dev(i915->drm.dev);
+	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, 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 = to_pci_dev(i915->drm.dev);
+
+	vga_client_unregister(pdev);
+}
-- 
cgit v1.2.3