[PATCH v2 21/32] drm/via: Add via_pm.c

[Kevin Brace]

From: Kevin Brace <kevinbrace at bracecomputerlab.com>

Signed-off-by: Kevin Brace <kevinbrace at bracecomputerlab.com>
---
 drivers/gpu/drm/via/via_pm.c | 187 +++++++++++++++++++++++++++++++++++
 1 file changed, 187 insertions(+)
 create mode 100644 drivers/gpu/drm/via/via_pm.c

diff --git a/drivers/gpu/drm/via/via_pm.c b/drivers/gpu/drm/via/via_pm.c
new file mode 100644
index 000000000000..9b80886ab06a
--- /dev/null
+++ b/drivers/gpu/drm/via/via_pm.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright © 2017-2020 Kevin Brace.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) OR COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author(s):
+ * Kevin Brace <kevinbrace at bracecomputerlab.com>
+ */
+
+
+#include <linux/console.h>
+#include <linux/pci.h>
+
+#include "via_drv.h"
+
+
+int via_dev_pm_ops_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct via_drm_priv *dev_priv = to_via_drm_priv(drm_dev);
+	int ret = 0;
+
+	DRM_DEBUG_KMS("Entered %s.\n", __func__);
+
+	console_lock();
+
+	/*
+	 * Frame Buffer Size Control register (SR14) and GTI registers
+	 * (SR66 through SR6F) need to be saved and restored upon standby
+	 * resume or can lead to a display corruption issue. These registers
+	 * are only available on VX800, VX855, and VX900 chipsets. This bug
+	 * was observed on VIA Embedded EPIA-M830 mainboard.
+	 */
+	if ((pdev->device == PCI_DEVICE_ID_VIA_VT1122) ||
+		(pdev->device == PCI_DEVICE_ID_VIA_VX875) ||
+		(pdev->device == PCI_DEVICE_ID_VIA_VX900_VGA)) {
+		dev_priv->saved_sr14 = vga_rseq(VGABASE, 0x14);
+
+		dev_priv->saved_sr66 = vga_rseq(VGABASE, 0x66);
+		dev_priv->saved_sr67 = vga_rseq(VGABASE, 0x67);
+		dev_priv->saved_sr68 = vga_rseq(VGABASE, 0x68);
+		dev_priv->saved_sr69 = vga_rseq(VGABASE, 0x69);
+		dev_priv->saved_sr6a = vga_rseq(VGABASE, 0x6a);
+		dev_priv->saved_sr6b = vga_rseq(VGABASE, 0x6b);
+		dev_priv->saved_sr6c = vga_rseq(VGABASE, 0x6c);
+		dev_priv->saved_sr6d = vga_rseq(VGABASE, 0x6d);
+		dev_priv->saved_sr6e = vga_rseq(VGABASE, 0x6e);
+		dev_priv->saved_sr6f = vga_rseq(VGABASE, 0x6f);
+	}
+
+	/*
+	 * 3X5.3B through 3X5.3F are scratch pad registers.
+	 * They are important for FP detection.
+	 * Their values need to be saved because they get lost
+	 * when resuming from standby.
+	 */
+	dev_priv->saved_cr3b = vga_rcrt(VGABASE, 0x3b);
+	dev_priv->saved_cr3c = vga_rcrt(VGABASE, 0x3c);
+	dev_priv->saved_cr3d = vga_rcrt(VGABASE, 0x3d);
+	dev_priv->saved_cr3e = vga_rcrt(VGABASE, 0x3e);
+	dev_priv->saved_cr3f = vga_rcrt(VGABASE, 0x3f);
+
+	console_unlock();
+
+	ret = drm_mode_config_helper_suspend(drm_dev);
+	if (ret) {
+		DRM_ERROR("Failed to prepare for suspend.\n");
+		goto exit;
+	}
+
+	pci_save_state(pdev);
+	pci_disable_device(pdev);
+exit:
+	DRM_DEBUG_KMS("Exiting %s.\n", __func__);
+	return ret;
+}
+
+int via_dev_pm_ops_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct drm_device *drm_dev = pci_get_drvdata(pdev);
+	struct via_drm_priv *dev_priv = to_via_drm_priv(drm_dev);
+	void __iomem *regs = ioport_map(0x3c0, 100);
+	u8 val;
+	int ret = 0;
+
+	DRM_DEBUG_KMS("Entered %s.\n", __func__);
+
+	if (pci_enable_device(pdev)) {
+		DRM_ERROR("Failed to initialize a PCI "
+				"after resume.\n");
+		ret = -EIO;
+		goto exit;
+	}
+
+	console_lock();
+
+	val = ioread8(regs + 0x03);
+	iowrite8(val | 0x1, regs + 0x03);
+	val = ioread8(regs + 0x0C);
+	iowrite8(val | 0x1, regs + 0x02);
+
+	/*
+	 * Unlock Extended IO Space.
+	 */
+	iowrite8(0x10, regs + 0x04);
+	iowrite8(0x01, regs + 0x05);
+
+	/*
+	 * Unlock CRTC register protect.
+	 */
+	iowrite8(0x47, regs + 0x14);
+
+	/*
+	 * Enable MMIO.
+	 */
+	iowrite8(0x1a, regs + 0x04);
+	val = ioread8(regs + 0x05);
+	iowrite8(val | 0x38, regs + 0x05);
+
+	/*
+	 * Frame Buffer Size Control register (SR14) and GTI registers
+	 * (SR66 through SR6F) need to be saved and restored upon standby
+	 * resume or can lead to a display corruption issue. These registers
+	 * are only available on VX800, VX855, and VX900 chipsets. This bug
+	 * was observed on VIA Embedded EPIA-M830 mainboard.
+	 */
+	if ((pdev->device == PCI_DEVICE_ID_VIA_VT1122) ||
+		(pdev->device == PCI_DEVICE_ID_VIA_VX875) ||
+		(pdev->device == PCI_DEVICE_ID_VIA_VX900_VGA)) {
+		vga_wseq(VGABASE, 0x14, dev_priv->saved_sr14);
+
+		vga_wseq(VGABASE, 0x66, dev_priv->saved_sr66);
+		vga_wseq(VGABASE, 0x67, dev_priv->saved_sr67);
+		vga_wseq(VGABASE, 0x68, dev_priv->saved_sr68);
+		vga_wseq(VGABASE, 0x69, dev_priv->saved_sr69);
+		vga_wseq(VGABASE, 0x6a, dev_priv->saved_sr6a);
+		vga_wseq(VGABASE, 0x6b, dev_priv->saved_sr6b);
+		vga_wseq(VGABASE, 0x6c, dev_priv->saved_sr6c);
+		vga_wseq(VGABASE, 0x6d, dev_priv->saved_sr6d);
+		vga_wseq(VGABASE, 0x6e, dev_priv->saved_sr6e);
+		vga_wseq(VGABASE, 0x6f, dev_priv->saved_sr6f);
+	}
+
+	/*
+	 * 3X5.3B through 3X5.3F are scratch pad registers.
+	 * They are important for FP detection.
+	 * Their values need to be restored because they are undefined
+	 * after resuming from standby.
+	 */
+	vga_wcrt(VGABASE, 0x3b, dev_priv->saved_cr3b);
+	vga_wcrt(VGABASE, 0x3c, dev_priv->saved_cr3c);
+	vga_wcrt(VGABASE, 0x3d, dev_priv->saved_cr3d);
+	vga_wcrt(VGABASE, 0x3e, dev_priv->saved_cr3e);
+	vga_wcrt(VGABASE, 0x3f, dev_priv->saved_cr3f);
+
+	console_unlock();
+
+	ret = drm_mode_config_helper_resume(drm_dev);
+	if (ret) {
+		DRM_ERROR("Failed to perform a modeset "
+				"after resume.\n");
+		goto exit;
+	}
+
+exit:
+	DRM_DEBUG_KMS("Exiting %s.\n", __func__);
+	return ret;
+}
--
2.35.1