[PATCH v2] input: goodix: Add device tree support

[Aleksei Mamlin <mamlinav@gmail.com>]

This patch 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, like Wexler TAB7200 and MSI Primo73.

Changes since v1:
* Merge patches into single patch.
* Use max touch number from config instead of hardcoding.
* Update description in Kconfig.

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

Signed-off-by: Aleksei Mamlin <mamlinav@gmail.com>
---
 .../bindings/input/touchscreen/goodix.txt          | 29 ++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.txt        |  1 +
 drivers/input/touchscreen/Kconfig                  |  5 ++--
 drivers/input/touchscreen/goodix.c                 | 34 ++++++++++++++++++----
 4 files changed, 61 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/goodix.txt

diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
new file mode 100644
index 0000000..8ba98ee
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
@@ -0,0 +1,29 @@
+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>;
+		};
+
+		/* ... */
+	};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 389ca13..ab6852d 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -76,6 +76,7 @@ geniatech	Geniatech, Inc.
 giantplus	Giantplus Technology Co., Ltd.
 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
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 5891752..2adf724 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -297,11 +297,12 @@ config TOUCHSCREEN_FUJITSU
 
 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.
 
diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index ca19668..efba6a3 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -23,6 +23,8 @@
 #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 {
@@ -48,6 +50,7 @@ struct goodix_ts_data {
 #define GOODIX_REG_VERSION		0x8140
 
 #define RESOLUTION_LOC		1
+#define MAX_CONTACTS_LOC	5
 #define TRIGGER_LOC		6
 
 static const unsigned long goodix_irq_flags[] = {
@@ -99,7 +102,7 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 	}
 
 	touch_num = data[0] & 0x0f;
-	if (touch_num > GOODIX_MAX_CONTACTS)
+	if (touch_num > ts->max_touch_num)
 		return -EPROTO;
 
 	if (touch_num > 1) {
@@ -141,7 +144,7 @@ static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
  */
 static void goodix_process_events(struct goodix_ts_data *ts)
 {
-	u8  point_data[1 + GOODIX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
+	u8  point_data[1 + GOODIX_CONTACT_SIZE * ts->max_touch_num];
 	int touch_num;
 	int i;
 
@@ -202,21 +205,23 @@ static void goodix_read_config(struct goodix_ts_data *ts)
 		ts->abs_x_max = GOODIX_MAX_WIDTH;
 		ts->abs_y_max = GOODIX_MAX_HEIGHT;
 		ts->int_trigger_type = GOODIX_INT_TRIGGER;
+		ts->max_touch_num = GOODIX_MAX_CONTACTS;
 		return;
 	}
 
 	ts->abs_x_max = get_unaligned_le16(&config[RESOLUTION_LOC]);
 	ts->abs_y_max = get_unaligned_le16(&config[RESOLUTION_LOC + 2]);
 	ts->int_trigger_type = (config[TRIGGER_LOC]) & 0x03;
-	if (!ts->abs_x_max || !ts->abs_y_max) {
+	ts->max_touch_num = (config[MAX_CONTACTS_LOC]) & 0x0f;
+	if (!ts->abs_x_max || !ts->abs_y_max || !ts->max_touch_num) {
 		dev_err(&ts->client->dev,
 			"Invalid config, using defaults\n");
 		ts->abs_x_max = GOODIX_MAX_WIDTH;
 		ts->abs_y_max = GOODIX_MAX_HEIGHT;
+		ts->max_touch_num = GOODIX_MAX_CONTACTS;
 	}
 }
 
-
 /**
  * goodix_read_version - Read goodix touchscreen version
  *
@@ -295,7 +300,7 @@ static int goodix_request_input_dev(struct goodix_ts_data *ts)
 	input_set_abs_params(ts->input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
 	input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
 
-	input_mt_init_slots(ts->input_dev, GOODIX_MAX_CONTACTS,
+	input_mt_init_slots(ts->input_dev, ts->max_touch_num,
 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 
 	ts->input_dev->name = "Goodix Capacitive TouchScreen";
@@ -372,11 +377,27 @@ static const struct i2c_device_id goodix_ts_id[] = {
 	{ }
 };
 
+#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,
@@ -384,7 +405,8 @@ static struct i2c_driver goodix_ts_driver = {
 	.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);
-- 
2.0.5