HID: multitouch: Add quirks for flipped axes

Certain touchscreen devices, such as the ELAN9034, are oriented
incorrectly and report touches on opposite points on the X and Y axes.
For example, a 100x200 screen touched at (10,20) would report (90, 180)
and vice versa.

This is fixed by adding device quirks to transform the touch points
into the correct spaces, from X -> MAX(X) - X, and Y -> MAX(Y) - Y.

Signed-off-by: Allen Ballway <ballway@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 46 insertions, 0 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c b/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c
index 8e0f67455c09..554a7dc28536 100644
--- a/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c
+++ b/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c
@@ -10,8 +10,10 @@
 #include <linux/types.h>
 #include <linux/dmi.h>
 #include <linux/mod_devicetable.h>
+#include <linux/hid.h>
 
 #include "i2c-hid.h"
+#include "../hid-ids.h"
 
 
 struct i2c_hid_desc_override {
@@ -416,6 +418,28 @@ static const struct dmi_system_id i2c_hid_dmi_desc_override_table[] = {
 	{ }	/* Terminate list */
 };
 
+static const struct hid_device_id i2c_hid_elan_flipped_quirks = {
+	HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8, USB_VENDOR_ID_ELAN, 0x2dcd),
+		HID_QUIRK_X_INVERT | HID_QUIRK_Y_INVERT
+};
+
+/*
+ * This list contains devices which have specific issues based on the system
+ * they're on and not just the device itself. The driver_data will have a
+ * specific hid device to match against.
+ */
+static const struct dmi_system_id i2c_hid_dmi_quirk_table[] = {
+	{
+		.ident = "DynaBook K50/FR",
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dynabook Inc."),
+			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "dynabook K50/FR"),
+		},
+		.driver_data = (void *)&i2c_hid_elan_flipped_quirks,
+	},
+	{ }	/* Terminate list */
+};
+
 
 struct i2c_hid_desc *i2c_hid_get_dmi_i2c_hid_desc_override(uint8_t *i2c_name)
 {
@@ -450,3 +474,22 @@ char *i2c_hid_get_dmi_hid_report_desc_override(uint8_t *i2c_name,
 	*size = override->hid_report_desc_size;
 	return override->hid_report_desc;
 }
+
+u32 i2c_hid_get_dmi_quirks(const u16 vendor, const u16 product)
+{
+	u32 quirks = 0;
+	const struct dmi_system_id *system_id =
+			dmi_first_match(i2c_hid_dmi_quirk_table);
+
+	if (system_id) {
+		const struct hid_device_id *device_id =
+				(struct hid_device_id *)(system_id->driver_data);
+
+		if (device_id && device_id->vendor == vendor &&
+		    device_id->product == product)
+			quirks = device_id->driver_data;
+	}
+
+	return quirks;
+}
+EXPORT_SYMBOL_GPL(i2c_hid_get_dmi_quirks);
diff --git a/drivers/hid/i2c-hid/i2c-hid.h b/drivers/hid/i2c-hid/i2c-hid.h
index 96c75510ad3f..2c7b66d5caa0 100644
--- a/drivers/hid/i2c-hid/i2c-hid.h
+++ b/drivers/hid/i2c-hid/i2c-hid.h
@@ -9,6 +9,7 @@
 struct i2c_hid_desc *i2c_hid_get_dmi_i2c_hid_desc_override(uint8_t *i2c_name);
 char *i2c_hid_get_dmi_hid_report_desc_override(uint8_t *i2c_name,
 					       unsigned int *size);
+u32 i2c_hid_get_dmi_quirks(const u16 vendor, const u16 product);
 #else
 static inline struct i2c_hid_desc
 		   *i2c_hid_get_dmi_i2c_hid_desc_override(uint8_t *i2c_name)
@@ -16,6 +17,8 @@ static inline struct i2c_hid_desc
 static inline char *i2c_hid_get_dmi_hid_report_desc_override(uint8_t *i2c_name,
 							     unsigned int *size)
 { return NULL; }
+static inline u32 i2c_hid_get_dmi_quirks(const u16 vendor, const u16 product)
+{ return 0; }
 #endif
 
 /**