[PATCH 1/1] drm/i915/display: Add quirk to force backlight type on some TUXEDO devices

[Werner Sembach <wse@tuxedocomputers.com>]

The display backlight on TUXEDO DX1708 and InsanityBook 15 v1 with panels
AUO 12701 and AUO 12701 must be forced to INTEL_DP_AUX_BACKLIGHT_ON to be
able to control the brightness.

This could already be archived via a module parameter, but this patch adds
a quirk to apply this by default on the mentioned device + panel
combinations.

Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Cc: stable@vger.kernel.org
---
 .../drm/i915/display/intel_dp_aux_backlight.c | 14 ++++++-
 drivers/gpu/drm/i915/display/intel_quirks.c   | 42 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_quirks.h   |  1 +
 3 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index c846ef4acf5b2..0cac04c98a3e3 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -34,12 +34,14 @@
  * for some reason.
  */
 
+#include <drm/drm_edid.h>
 #include "i915_utils.h"
 #include "intel_backlight.h"
 #include "intel_display_core.h"
 #include "intel_display_types.h"
 #include "intel_dp.h"
 #include "intel_dp_aux_backlight.h"
+#include "intel_quirks.h"
 
 /*
  * DP AUX registers for Intel's proprietary HDR backlight interface. We define
@@ -607,11 +609,21 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
 	struct drm_device *dev = connector->base.dev;
 	struct intel_panel *panel = &connector->panel;
 	bool try_intel_interface = false, try_vesa_interface = false;
+	int enable_dpcd_backlight;
+	u32 pnl_id;
 
 	/* Check the VBT and user's module parameters to figure out which
 	 * interfaces to probe
 	 */
-	switch (display->params.enable_dpcd_backlight) {
+	enable_dpcd_backlight = display->params.enable_dpcd_backlight;
+	if (enable_dpcd_backlight == INTEL_DP_AUX_BACKLIGHT_AUTO &&
+	    intel_has_quirk(display, QUIRK_AUO_12701_21229_ENABLE_DPCD_BACKLIGHT)) {
+		pnl_id = drm_edid_get_panel_id(panel->fixed_edid);
+		if (pnl_id == drm_edid_encode_panel_id('A', 'U', 'O', 0x319d) ||
+		    pnl_id == drm_edid_encode_panel_id('A', 'U', 'O', 0x52ed))
+			enable_dpcd_backlight = INTEL_DP_AUX_BACKLIGHT_ON;
+	}
+	switch (enable_dpcd_backlight) {
 	case INTEL_DP_AUX_BACKLIGHT_OFF:
 		return -ENODEV;
 	case INTEL_DP_AUX_BACKLIGHT_AUTO:
diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c b/drivers/gpu/drm/i915/display/intel_quirks.c
index 8b30e9fd936e7..6f724e5712664 100644
--- a/drivers/gpu/drm/i915/display/intel_quirks.c
+++ b/drivers/gpu/drm/i915/display/intel_quirks.c
@@ -78,6 +78,12 @@ static void quirk_fw_sync_len(struct intel_dp *intel_dp)
 	drm_info(display->drm, "Applying Fast Wake sync pulse count quirk\n");
 }
 
+static void quirk_auo_12701_21229_enable_dpcd_backlight(struct intel_display *display)
+{
+	intel_set_quirk(display, QUIRK_AUO_12701_21229_ENABLE_DPCD_BACKLIGHT);
+	drm_info(display->drm, "Applying Display AUO Model 12701 and 21229 Enable DPCD Backlight quirk\n");
+}
+
 struct intel_quirk {
 	int device;
 	int subsystem_vendor;
@@ -118,6 +124,12 @@ static int intel_dmi_no_pps_backlight(const struct dmi_system_id *id)
 	return 1;
 }
 
+static int intel_dmi_auo_12701_21229_enable_dpcd_backlight(const struct dmi_system_id *id)
+{
+	DRM_INFO("Display AUO model 12701 and 21229 DPCD backlight control on %s\n", id->ident);
+	return 1;
+}
+
 static const struct intel_dmi_quirk intel_dmi_quirks[] = {
 	{
 		.dmi_id_list = &(const struct dmi_system_id[]) {
@@ -164,6 +176,36 @@ static const struct intel_dmi_quirk intel_dmi_quirks[] = {
 		},
 		.hook = quirk_no_pps_backlight_power_hook,
 	},
+	{
+		.dmi_id_list = &(const struct dmi_system_id[]) {
+			{
+				.callback = intel_dmi_auo_12701_21229_enable_dpcd_backlight,
+				.ident = "TUXEDO DX1708",
+				.matches = {DMI_MATCH(DMI_BOARD_NAME, "N8xEJEK"),
+				},
+			},
+			{
+				.callback = intel_dmi_auo_12701_21229_enable_dpcd_backlight,
+				.ident = "TUXEDO InsanityBook 15 v1",
+				.matches = {DMI_MATCH(DMI_BOARD_NAME, "P95_HP"),
+				},
+			},
+			{
+				.callback = intel_dmi_auo_12701_21229_enable_dpcd_backlight,
+				.ident = "TUXEDO InsanityBook 15 v1",
+				.matches = {DMI_MATCH(DMI_BOARD_NAME, "P95_HR"),
+				},
+			},
+			{
+				.callback = intel_dmi_auo_12701_21229_enable_dpcd_backlight,
+				.ident = "TUXEDO InsanityBook 15 v1",
+				.matches = {DMI_MATCH(DMI_BOARD_NAME, "P95_HP,HR,HQ"),
+				},
+			},
+			{ }
+		},
+		.hook = quirk_auo_12701_21229_enable_dpcd_backlight,
+	},
 };
 
 static struct intel_quirk intel_quirks[] = {
diff --git a/drivers/gpu/drm/i915/display/intel_quirks.h b/drivers/gpu/drm/i915/display/intel_quirks.h
index cafdebda75354..38bdbd65d7efb 100644
--- a/drivers/gpu/drm/i915/display/intel_quirks.h
+++ b/drivers/gpu/drm/i915/display/intel_quirks.h
@@ -20,6 +20,7 @@ enum intel_quirk_id {
 	QUIRK_LVDS_SSC_DISABLE,
 	QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK,
 	QUIRK_FW_SYNC_LEN,
+	QUIRK_AUO_12701_21229_ENABLE_DPCD_BACKLIGHT,
 };
 
 void intel_init_quirks(struct intel_display *display);
-- 
2.43.0