[PATCH AUTOSEL 6.19-5.10] platform/x86: touchscreen_dmi: Add quirk for y-inverted Goodix touchscreen on SUPI S10

[Sasha Levin]

From: Hans de Goede <johannes.goede@xxxxxxxxxxxxxxxx>

[ Upstream commit 7d87ed70fc95482c12edf9493c249b6413be485e ]

The touchscreen on the SUPI S10 tablet reports inverted Y coordinates,
causing touch input to be mirrored vertically relative to the display.

Add a quirk to set the "touchscreen-inverted-y" boolean device-property
on the touchscreen device, so that the goodix_ts driver will fixup
the coordinates.

Reported-by: Yajat Kumar <yajatapps3@xxxxxxxxx>
Closes: https://lore.kernel.org/linux-input/20251230221639.582406-1-yajatapps3@xxxxxxxxx/
Tested-by: Yajat Kumar <yajatapps3@xxxxxxxxx>
Signed-off-by: Hans de Goede <johannes.goede@xxxxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20260217132346.34535-1-johannes.goede@xxxxxxxxxxxxxxxx
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---

LLM Generated explanations, may be completely bogus:

## Analysis

### What the commit does
This adds a DMI-based touchscreen quirk for the SUPI S10 tablet. The
tablet's Goodix touchscreen (GDIX1001) reports inverted Y coordinates,
causing touch input to be vertically mirrored. The fix adds:

1. A new property entry array `gdix1001_y_inverted_props[]` with
   `touchscreen-inverted-y`
2. A corresponding `ts_dmi_data` struct pointing to ACPI name "GDIX1001"
3. A DMI table entry matching vendor "SUPI", product "S10"

### Stable kernel criteria assessment

**Fixes a real bug:** Yes. Without this quirk, touch input is vertically
mirrored on this tablet, making it essentially unusable for touch
interaction.

**Hardware quirk exception:** This is a textbook DMI-based hardware
quirk — exactly the type explicitly listed as appropriate for stable
backporting. The `touchscreen_dmi.c` file exists solely for these
entries; it has hundreds of similar quirks already.

**Small and contained:** Yes. ~18 lines added to a single file,
following the exact same pattern as every other entry in the file.

**Risk of regression:** Extremely low. The DMI matching
(`DMI_SYS_VENDOR: "SUPI"`, `DMI_PRODUCT_NAME: "S10"`) ensures this code
only activates on the specific affected tablet. No other hardware is
impacted.

**Tested and reviewed:** Yes. Has both `Tested-by: Yajat Kumar` (the
reporter/user) and `Reviewed-by: Ilpo Järvinen` (Intel maintainer). The
commit author Hans de Goede is the well-known x86 platform maintainer
who handles most touchscreen quirks.

**No new features:** Correct. This uses existing infrastructure
(`ts_dmi_data`, `property_entry`, `dmi_system_id` matching) to fix a
specific device.

**Dependencies:** None. The `touchscreen_dmi.c` framework and the Goodix
driver's handling of `touchscreen-inverted-y` have been present for many
kernel versions.

### Verification
- The commit follows the identical pattern used by all other entries in
  `touchscreen_dmi.c` — no novel code patterns
- The `gdix1001_y_inverted_props` is a subset of the existing
  `gdix1001_upside_down_props` (which sets both inverted-x and
  inverted-y), confirming this is a well-established mechanism
- Reporter and tester are the same person (Yajat Kumar), confirming the
  fix resolves the reported issue
- The author (Hans de Goede) is the primary maintainer for x86
  touchscreen quirks
- The `Closes:` link to lore.kernel.org confirms a real user report from
  December 2025

### Risk vs benefit
- **Benefit:** Makes touchscreen usable on SUPI S10 tablets — critical
  for those users
- **Risk:** Near zero — DMI-scoped to one specific device model, uses
  existing well-tested infrastructure

**YES**

 drivers/platform/x86/touchscreen_dmi.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/platform/x86/touchscreen_dmi.c b/drivers/platform/x86/touchscreen_dmi.c
index bdc19cd8d3edf..d83c387821ea1 100644
--- a/drivers/platform/x86/touchscreen_dmi.c
+++ b/drivers/platform/x86/touchscreen_dmi.c
@@ -410,6 +410,16 @@ static const struct ts_dmi_data gdix1002_upside_down_data = {
 	.properties	= gdix1001_upside_down_props,
 };
 
+static const struct property_entry gdix1001_y_inverted_props[] = {
+	PROPERTY_ENTRY_BOOL("touchscreen-inverted-y"),
+	{ }
+};
+
+static const struct ts_dmi_data gdix1001_y_inverted_data = {
+	.acpi_name	= "GDIX1001",
+	.properties	= gdix1001_y_inverted_props,
+};
+
 static const struct property_entry gp_electronic_t701_props[] = {
 	PROPERTY_ENTRY_U32("touchscreen-size-x", 960),
 	PROPERTY_ENTRY_U32("touchscreen-size-y", 640),
@@ -1658,6 +1668,14 @@ const struct dmi_system_id touchscreen_dmi_table[] = {
 			DMI_MATCH(DMI_PRODUCT_SKU, "PN20170413488"),
 		},
 	},
+	{
+		/* SUPI S10 */
+		.driver_data = (void *)&gdix1001_y_inverted_data,
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "SUPI"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "S10"),
+		},
+	},
 	{
 		/* Techbite Arc 11.6 */
 		.driver_data = (void *)&techbite_arc_11_6_data,
-- 
2.51.0