Input: goodix - add device tree support

This change adds device tree support and binding information for Goodix
GT9xx series touchscreen controller. It also adds support for 5-finger
chips, like GT911 and GT912, which can be found on ARM tablets, such as
Wexler TAB7200 and MSI Primo73.

Datasheets can be found here:
https://drive.google.com/folderview?id=0BxCVOQS3ZymGfmJyY2RKbE5XbVlKNlktVTlwV0lxNEdxd2dzeWZER094cmJPVnMxN1F0Yzg&usp=sharing

Signed-off-by: Aleksei Mamlin <[e-mail]>
Reviewed-by: Bastien Nocera <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/devicetree/bindings/input/touchscreen/goodix.txt

···
+Device tree bindings for Goodix GT9xx series touchscreen controller
+
+Required properties:
+
+ - compatible		: Should be "goodix,gt911"
+				 or "goodix,gt9110"
+				 or "goodix,gt912"
+				 or "goodix,gt927"
+				 or "goodix,gt9271"
+				 or "goodix,gt928"
+				 or "goodix,gt967"
+ - reg			: I2C address of the chip. Should be 0x5d or 0x14
+ - interrupt-parent	: Interrupt controller to which the chip is connected
+ - interrupts		: Interrupt to which the chip is connected
+
+Example:
+
+	i2c@00000000 {
+		/* ... */
+
+		gt928@5d {
+			compatible = "goodix,gt928";
+			reg = <0x5d>;
+			interrupt-parent = <&gpio>;
+			interrupts = <0 0>;
+		};
+
+		/* ... */
+	};

Documentation/devicetree/bindings/vendor-prefixes.txt

···
 geniatech	Geniatech, Inc.
 globalscale	Globalscale Technologies, Inc.
 gmt	Global Mixed-mode Technology, Inc.
+goodix	Shenzhen Huiding Technology Co., Ltd.
 google	Google, Inc.
 gumstix	Gumstix, Inc.
 gw	Gateworks Corporation

drivers/input/touchscreen/Kconfig

···
 
 config TOUCHSCREEN_GOODIX
 	tristate "Goodix I2C touchscreen"
-	depends on I2C && ACPI
+	depends on I2C
 	help
 	  Say Y here if you have the Goodix touchscreen (such as one
 	  installed in Onda v975w tablets) connected to your
-	  system.
+	  system. It also supports 5-finger chip models, which can be
+	  found on ARM tablets, like Wexler TAB7200 and MSI Primo73.
 
 	  If unsure, say N.
 

drivers/input/touchscreen/goodix.c

···
 #include <linux/irq.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/of.h>
 #include <asm/unaligned.h>
 
 struct goodix_ts_data {
···
 	{ }
 };
 
+#ifdef CONFIG_ACPI
 static const struct acpi_device_id goodix_acpi_match[] = {
 	{ "GDIX1001", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(acpi, goodix_acpi_match);
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id goodix_of_match[] = {
+	{ .compatible = "goodix,gt911" },
+	{ .compatible = "goodix,gt9110" },
+	{ .compatible = "goodix,gt912" },
+	{ .compatible = "goodix,gt927" },
+	{ .compatible = "goodix,gt9271" },
+	{ .compatible = "goodix,gt928" },
+	{ .compatible = "goodix,gt967" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, goodix_of_match);
+#endif
 
 static struct i2c_driver goodix_ts_driver = {
 	.probe = goodix_ts_probe,
···
 	.driver = {
 		.name = "Goodix-TS",
 		.owner = THIS_MODULE,
-		.acpi_match_table = goodix_acpi_match,
+		.acpi_match_table = ACPI_PTR(goodix_acpi_match),
+		.of_match_table = of_match_ptr(goodix_of_match),
 	},
 };
 module_i2c_driver(goodix_ts_driver);