platform/x86: silead_dmi: Add support for the Onda oBook 20 Plus tablet

Add touchscreen platform data for the Onda oBook 20 Plus tablet.

Firmware for this is available here:
https://github.com/onitake/gsl-firmware/blob/master/firmware/linux/silead/gsl3676-onda-obook-20-plus.fw

Signed-off-by: Nerijus Baliūnas <nerijus@users.sourceforge.net>
Acked-by: Hans de Goede <hdegoede@redhat.com>
[andy: massaged title and wrote commit message]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/silead_dmi.c

@@ -186,6 +186,23 @@ static const struct silead_ts_dmi_data digma_citi_e200_data = {
 	.properties	= digma_citi_e200_props,
 };
 
+static const struct property_entry onda_obook_20_plus_props[] = {
+	PROPERTY_ENTRY_U32("touchscreen-size-x", 1728),
+	PROPERTY_ENTRY_U32("touchscreen-size-y", 1148),
+	PROPERTY_ENTRY_BOOL("touchscreen-inverted-x"),
+	PROPERTY_ENTRY_BOOL("touchscreen-inverted-y"),
+	PROPERTY_ENTRY_BOOL("touchscreen-swapped-x-y"),
+	PROPERTY_ENTRY_STRING("firmware-name", "gsl3676-onda-obook-20-plus.fw"),
+	PROPERTY_ENTRY_U32("silead,max-fingers", 10),
+	PROPERTY_ENTRY_BOOL("silead,home-button"),
+	{ }
+};
+
+static const struct silead_ts_dmi_data onda_obook_20_plus_data = {
+	.acpi_name	= "MSSL1680:00",
+	.properties	= onda_obook_20_plus_props,
+};
+
 static const struct dmi_system_id silead_ts_dmi_table[] = {
 	{
 		/* CUBE iwork8 Air */
@@ -294,6 +311,14 @@ static const struct dmi_system_id silead_ts_dmi_table[] = {
 			DMI_MATCH(DMI_BOARD_NAME, "Cherry Trail CR"),
 		},
 	},
+	{
+		/* Onda oBook 20 Plus */
+		.driver_data = (void *)&onda_obook_20_plus_data,
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ONDA"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "OBOOK 20 PLUS"),
+		},
+	},
 	{ },
 };