drm: Add panel orientation quirks, v6.

Some x86 clamshell design devices use portrait tablet screens and a display
engine which cannot rotate in hardware, so the firmware just leaves things
as is and we cannot figure out that the display is oriented non upright
from the hardware.

So at least on x86, we need a quirk table for this. This commit adds a DMI
based quirk table which is initially populated with 5 such devices: Asus
T100HA, GPD Pocket, GPD win, I.T.Works TW891 and the VIOS LTH17.

This quirk table will be used by the drm code to let userspace know that
the display is not mounted upright inside the devices case through a new
panel orientation drm-connector property, as well as to tell fbcon to
rotate the console so that it shows the right way up.

Changes in v5:
-Add a kernel-doc comment documenting drm_get_panel_orientation_quirk()
-Remove board_* matches from the dmi-matches for the VIOS LTH17 laptop,
 keeping only the (identical) sys_vendor and product_name matches.
 This is necessary because an older version of the bios has
 board_vendor set to VOIS instead of VIOS

Changes in v6:
-Add reference to added kernel-docs in Documentation/gpu/drm-kms-helpers.rst

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171125193553.23986-3-hdegoede@redhat.com

Documentation/gpu/drm-kms-helpers.rst

@@ -163,6 +163,9 @@ Panel Helper Reference
 .. kernel-doc:: drivers/gpu/drm/drm_panel.c
    :export:
 
+.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
+   :export:
+
 Display Port Helper Functions Reference
 =======================================
 

drivers/gpu/drm/Kconfig

@@ -26,6 +26,9 @@ config DRM_MIPI_DSI
 	bool
 	depends on DRM
 
+config DRM_PANEL_ORIENTATION_QUIRKS
+	tristate
+
 config DRM_DP_AUX_CHARDEV
 	bool "DRM DP AUX Interface"
 	depends on DRM

drivers/gpu/drm/Makefile

@@ -47,6 +47,7 @@ obj-$(CONFIG_DRM_DEBUG_MM_SELFTEST) += selftests/
 
 obj-$(CONFIG_DRM)	+= drm.o
 obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
+obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
 obj-$(CONFIG_DRM_ARM)	+= arm/
 obj-$(CONFIG_DRM_TTM)	+= ttm/
 obj-$(CONFIG_DRM_TDFX)	+= tdfx/

drivers/gpu/drm/drm_panel_orientation_quirks.c

@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * drm_panel_orientation_quirks.c -- Quirks for non-normal panel orientation
+ *
+ * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
+ *
+ * Note the quirks in this file are shared with fbdev/efifb and as such
+ * must not depend on other drm code.
+ */
+
+#include <linux/dmi.h>
+#include <drm/drm_connector.h>
+
+#ifdef CONFIG_DMI
+
+/*
+ * Some x86 clamshell design devices use portrait tablet screens and a display
+ * engine which cannot rotate in hardware, so we need to rotate the fbcon to
+ * compensate. Unfortunately these (cheap) devices also typically have quite
+ * generic DMI data, so we match on a combination of DMI data, screen resolution
+ * and a list of known BIOS dates to avoid false positives.
+ */
+
+struct drm_dmi_panel_orientation_data {
+	int width;
+	int height;
+	const char * const *bios_dates;
+	int orientation;
+};
+
+static const struct drm_dmi_panel_orientation_data asus_t100ha = {
+	.width = 800,
+	.height = 1280,
+	.orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP,
+};
+
+static const struct drm_dmi_panel_orientation_data gpd_pocket = {
+	.width = 1200,
+	.height = 1920,
+	.bios_dates = (const char * const []){ "05/26/2017", "06/28/2017",
+		"07/05/2017", "08/07/2017", NULL },
+	.orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
+};
+
+static const struct drm_dmi_panel_orientation_data gpd_win = {
+	.width = 720,
+	.height = 1280,
+	.bios_dates = (const char * const []){
+		"10/25/2016", "11/18/2016", "12/23/2016", "12/26/2016",
+		"02/21/2017", "03/20/2017", "05/25/2017", NULL },
+	.orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
+};
+
+static const struct drm_dmi_panel_orientation_data itworks_tw891 = {
+	.width = 800,
+	.height = 1280,
+	.bios_dates = (const char * const []){ "10/16/2015", NULL },
+	.orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
+};
+
+static const struct drm_dmi_panel_orientation_data vios_lth17 = {
+	.width = 800,
+	.height = 1280,
+	.orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
+};
+
+static const struct dmi_system_id orientation_data[] = {
+	{	/* Asus T100HA */
+		.matches = {
+		  DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100HAN"),
+		},
+		.driver_data = (void *)&asus_t100ha,
+	}, {	/*
+		 * GPD Pocket, note that the the DMI data is less generic then
+		 * it seems, devices with a board-vendor of "AMI Corporation"
+		 * are quite rare, as are devices which have both board- *and*
+		 * product-id set to "Default String"
+		 */
+		.matches = {
+		  DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
+		  DMI_EXACT_MATCH(DMI_BOARD_NAME, "Default string"),
+		  DMI_EXACT_MATCH(DMI_BOARD_SERIAL, "Default string"),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Default string"),
+		},
+		.driver_data = (void *)&gpd_pocket,
+	}, {	/* GPD Win (same note on DMI match as GPD Pocket) */
+		.matches = {
+		  DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
+		  DMI_EXACT_MATCH(DMI_BOARD_NAME, "Default string"),
+		  DMI_EXACT_MATCH(DMI_BOARD_SERIAL, "Default string"),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Default string"),
+		},
+		.driver_data = (void *)&gpd_win,
+	}, {	/* I.T.Works TW891 */
+		.matches = {
+		  DMI_EXACT_MATCH(DMI_SYS_VENDOR, "To be filled by O.E.M."),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "TW891"),
+		  DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "To be filled by O.E.M."),
+		  DMI_EXACT_MATCH(DMI_BOARD_NAME, "TW891"),
+		},
+		.driver_data = (void *)&itworks_tw891,
+	}, {	/* VIOS LTH17 */
+		.matches = {
+		  DMI_EXACT_MATCH(DMI_SYS_VENDOR, "VIOS"),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "LTH17"),
+		},
+		.driver_data = (void *)&vios_lth17,
+	},
+	{}
+};
+
+/**
+ * drm_get_panel_orientation_quirk - Check for panel orientation quirks
+ * @width: width in pixels of the panel
+ * @height: height in pixels of the panel
+ *
+ * This function checks for platform specific (e.g. DMI based) quirks
+ * providing info on panel_orientation for systems where this cannot be
+ * probed from the hard-/firm-ware. To avoid false-positive this function
+ * takes the panel resolution as argument and checks that against the
+ * resolution expected by the quirk-table entry.
+ *
+ * Note this function is also used outside of the drm-subsys, by for example
+ * the efifb code. Because of this this function gets compiled into its own
+ * kernel-module when built as a module.
+ *
+ * Returns:
+ * A DRM_MODE_PANEL_ORIENTATION_* value if there is a quirk for this system,
+ * or DRM_MODE_PANEL_ORIENTATION_UNKNOWN if there is no quirk.
+ */
+int drm_get_panel_orientation_quirk(int width, int height)
+{
+	const struct dmi_system_id *match;
+	const struct drm_dmi_panel_orientation_data *data;
+	const char *bios_date;
+	int i;
+
+	for (match = dmi_first_match(orientation_data);
+	     match;
+	     match = dmi_first_match(match + 1)) {
+		data = match->driver_data;
+
+		if (data->width != width ||
+		    data->height != height)
+			continue;
+
+		if (!data->bios_dates)
+			return data->orientation;
+
+		bios_date = dmi_get_system_info(DMI_BIOS_DATE);
+		if (!bios_date)
+			continue;
+
+		for (i = 0; data->bios_dates[i]; i++) {
+			if (!strcmp(data->bios_dates[i], bios_date))
+				return data->orientation;
+		}
+	}
+
+	return DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
+}
+EXPORT_SYMBOL(drm_get_panel_orientation_quirk);
+
+#else
+
+/* There are no quirks for non x86 devices yet */
+int drm_get_panel_orientation_quirk(int width, int height)
+{
+	return DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
+}
+EXPORT_SYMBOL(drm_get_panel_orientation_quirk);
+
+#endif

include/drm/drm_utils.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Function prototypes for misc. drm utility functions.
+ * Specifically this file is for function prototypes for functions which
+ * may also be used outside of drm code (e.g. in fbdev drivers).
+ *
+ * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#ifndef __DRM_UTILS_H__
+#define __DRM_UTILS_H__
+
+int drm_get_panel_orientation_quirk(int width, int height);
+
+#endif