[PATCH 2/2] input: gt801_2plus1 - Add initial support for Goodix GT801 2+1

From: Priit Laes
Date: Mon Dec 07 2015 - 02:26:32 EST

This patch adds Goodix GT801 2+1 touchscreen controller support.

GT801 2+1 is a 10-finger touch controller consisting of
ARM controller interfacing two GT801 5-finger controllers.

Signed-off-by: Priit Laes <plaes@xxxxxxxxx>
---
.../bindings/input/touchscreen/gt801_2plus1.txt | 23 ++
MAINTAINERS | 6 +
drivers/input/touchscreen/Kconfig | 19 +-
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/gt801_2plus1.c | 375 +++++++++++++++++++++
5 files changed, 421 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/gt801_2plus1.txt
create mode 100644 drivers/input/touchscreen/gt801_2plus1.c

diff --git a/Documentation/devicetree/bindings/input/touchscreen/gt801_2plus1.txt b/Documentation/devicetree/bindings/input/touchscreen/gt801_2plus1.txt
new file mode 100644
index 0000000..070ff5b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/gt801_2plus1.txt
@@ -0,0 +1,23 @@
+Device tree bindings for Goodix GT801 2+1 series touchscreen controller
+
+Required properties:
+
+ - compatible : Should be "goodix,gt801_2plus1"
+ - reg : I2C address of the chip. Should be 0x55
+ - interrupt-parent : Interrupt controller to which the chip is connected
+ - interrupts : Interrupt to which the chip is connected
+
+Example:
+
+ i2c@00000000 {
+ /* ... */
+
+ touchscreen@55 {
+ compatible = "goodix,gt801_2plus1";
+ reg = <0x55>;
+ interrupt-parent = <&gpio>;
+ interrupts = <0 0>;
+ };
+
+ /* ... */
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index cba790b..e292126 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4743,6 +4743,12 @@ L: linux-input@xxxxxxxxxxxxxxx
S: Maintained
F: drivers/input/touchscreen/goodix.c

+GOODIX GT801 2PLUS1 TOUCHSCREEN
+M: Priit Laes <plaes@xxxxxxxxx>
+L: linux-input@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/input/touchscreen/gt801_2plus1.c
+
GPIO SUBSYSTEM
M: Linus Walleij <linus.walleij@xxxxxxxxxx>
M: Alexandre Courbot <gnurou@xxxxxxxxx>
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index ae33da7..c7c3324 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -322,11 +322,11 @@ config TOUCHSCREEN_FUJITSU
module will be called fujitsu-ts.

config TOUCHSCREEN_GOODIX
- tristate "Goodix I2C touchscreen"
+ tristate "Goodix GT9xx I2C touchscreen"
depends on I2C
help
- Say Y here if you have the Goodix touchscreen (such as one
- installed in Onda v975w tablets) connected to your
+ Say Y here if you have one of the Goodix GT9xx touchscreens
+ (such as one installed in Onda v975w tablet) connected to your
system. It also supports 5-finger chip models, which can be
found on ARM tablets, like Wexler TAB7200 and MSI Primo73.

@@ -335,6 +335,19 @@ config TOUCHSCREEN_GOODIX
To compile this driver as a module, choose M here: the
module will be called goodix.

+config TOUCHSCREEN_GT801_2PLUS1
+ tristate "Goodix GT801 2+1 I2C touchscreen"
+ depends on I2C
+ help
+ Say Y here if you have the Goodix GT801 2+1 touchscreen.
+ This controller is found on some older ARM tablets like
+ (Gemei G9 and Zareason Zatab).
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called gt801_2plus1.
+
config TOUCHSCREEN_ILI210X
tristate "Ilitek ILI210X based touchscreen"
depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index cbaa6ab..ff25d1b4 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX) += egalax_ts.o
obj-$(CONFIG_TOUCHSCREEN_FT6236) += ft6236.o
obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix.o
+obj-$(CONFIG_TOUCHSCREEN_GT801_2PLUS1) += gt801_2plus1.o
obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
obj-$(CONFIG_TOUCHSCREEN_IMX6UL_TSC) += imx6ul_tsc.o
obj-$(CONFIG_TOUCHSCREEN_INEXIO) += inexio.o
diff --git a/drivers/input/touchscreen/gt801_2plus1.c b/drivers/input/touchscreen/gt801_2plus1.c
new file mode 100644
index 0000000..e2be479
--- /dev/null
+++ b/drivers/input/touchscreen/gt801_2plus1.c
@@ -0,0 +1,375 @@
+/*
+ * Driver for Goodix GT801 2+1 ARM touchscreen controllers
+ *
+ * Copyright (c) 2015 Priit Laes <plaes@xxxxxxxxx>.
+ *
+ * This code is based on goodix.c driver (c) 2014 Red Hat Inc,
+ * various Android codedumps (c) 2010 - 2012 Goodix Technology
+ * and cleanups done by Emilio LÃpez (turl) for linux-sunxi.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2 of the License.
+ */
+#include <asm/unaligned.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/input/mt.h>
+
+struct gt801x_ts_data {
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ int abs_x_max;
+ int abs_y_max;
+ unsigned int max_touch_num;
+ unsigned int int_trigger_type;
+};
+
+#define GOODIX_MAX_HEIGHT 4096
+#define GOODIX_MAX_WIDTH 4096
+#define GOODIX_INT_TRIGGER 1
+#define GOODIX_MAX_CONTACTS 10
+#define MAX_CONTACTS_LOC 5
+#define RESOLUTION_LOC 1
+#define TRIGGER_LOC 6
+
+/* Register defines */
+#define GT801X_COOR_ADDR 0x01
+#define GT801X_CONFIG_DATA 0x65
+#define GT801X_REG_ID 0xf0
+
+/* Device specific defines */
+#define GT801X_CONFIG_MAX_LENGTH 7
+#define GT801X_CONTACT_SIZE 5
+
+static const unsigned long goodix_irq_flags[] = {
+ IRQ_TYPE_EDGE_RISING,
+ IRQ_TYPE_EDGE_FALLING,
+ IRQ_TYPE_LEVEL_LOW,
+ IRQ_TYPE_LEVEL_HIGH,
+};
+
+/**
+ * gt801x_i2c_read - read data from a register of the i2c slave device.
+ *
+ * @client: i2c device.
+ * @reg: the register to read from.
+ * @buf: raw write data buffer.
+ * @len: length of the buffer to write
+ */
+static int gt801x_i2c_read(struct i2c_client *client,
+ u8 reg, u8 *buf, int len)
+{
+ struct i2c_msg msgs[2];
+ int ret;
+
+ msgs[0].flags = 0;
+ msgs[0].addr = client->addr;
+ msgs[0].len = 1;
+ msgs[0].buf = &reg;
+
+ msgs[1].flags = I2C_M_RD;
+ msgs[1].addr = client->addr;
+ msgs[1].len = len;
+ msgs[1].buf = buf;
+
+ ret = i2c_transfer(client->adapter, msgs, 2);
+ return ret < 0 ? ret : (ret != ARRAY_SIZE(msgs) ? -EIO : 0);
+}
+
+/**
+ * gt801x_process_events - Process incoming events
+ *
+ * @ts: our gt801x_ts_data pointer
+ *
+ * Called when the IRQ is triggered. Read the current device state, and push
+ * the input events to the user space.
+ */
+static void gt801x_process_events(struct gt801x_ts_data *ts)
+{
+ u8 point_data[3 + GT801X_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
+ u8 touch_map[GOODIX_MAX_CONTACTS] = {0};
+ int input_x, input_y, input_w;
+ u8 checksum = 0;
+ u16 touch_raw;
+ u8 touch_num;
+ int error;
+ int loc;
+ int i;
+
+ error = gt801x_i2c_read(ts->client, GT801X_COOR_ADDR,
+ point_data, sizeof(point_data));
+ if (error) {
+ dev_err(&ts->client->dev, "I2C transfer error: %d\n", error);
+ return;
+ }
+
+ /* Fetch touch mapping bits */
+ touch_raw = get_unaligned_le16(&point_data[0]);
+ if (!touch_raw)
+ return;
+
+ /* Build touch map */
+ touch_num = 0;
+ for (i = 0; (touch_raw != 0) && (i < ts->max_touch_num); i++) {
+ if (touch_raw & 1)
+ touch_map[touch_num++] = i;
+ touch_raw >>= 1;
+ }
+
+ /* Calculate checksum */
+ for (i = 0; i < (touch_num*GT801X_CONTACT_SIZE + 3); i++)
+ checksum += point_data[i];
+ if (checksum != 0)
+ return;
+
+ /* Report touches */
+ for (i = 0; i < touch_num; i++) {
+ loc = 2 + GT801X_CONTACT_SIZE * i;
+ input_x = get_unaligned_be16(&point_data[loc]);
+ input_y = get_unaligned_be16(&point_data[loc + 2]);
+ input_w = point_data[loc + 4];
+
+ input_mt_slot(ts->input_dev, i);
+ input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
+ input_report_abs(ts->input_dev, ABS_MT_POSITION_X, input_x);
+ input_report_abs(ts->input_dev, ABS_MT_POSITION_Y, input_y);
+ input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR, input_w);
+ input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
+ }
+
+ input_mt_sync_frame(ts->input_dev);
+ input_sync(ts->input_dev);
+}
+
+/**
+ * gt801x_ts_irq_handler - The IRQ handler
+ *
+ * @irq: interrupt number.
+ * @dev_id: private data pointer.
+ */
+static irqreturn_t gt801x_ts_irq_handler(int irq, void *dev_id)
+{
+ gt801x_process_events((struct gt801x_ts_data *)dev_id);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * gt801x_read_config - Read the embedded configuration of the panel
+ *
+ * @ts: our gt801x_ts_data pointer
+ *
+ * Must be called during probe
+ */
+static void gt801x_read_config(struct gt801x_ts_data *ts)
+{
+ u8 config[GT801X_CONFIG_MAX_LENGTH];
+ int error;
+
+ error = gt801x_i2c_read(ts->client, GT801X_CONFIG_DATA,
+ config,
+ GT801X_CONFIG_MAX_LENGTH);
+ if (error) {
+ dev_warn(&ts->client->dev,
+ "Error reading config (%d), using defaults\n",
+ error);
+ 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_be16(&config[RESOLUTION_LOC]);
+ ts->abs_y_max = get_unaligned_be16(&config[RESOLUTION_LOC + 2]);
+ ts->int_trigger_type = config[TRIGGER_LOC] & 0x03;
+ 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;
+ }
+}
+
+/**
+ * gt801x_read_version - Read GT801 2+1 touchscreen version
+ *
+ * @client: the i2c client
+ * @version: output buffer containing the version on success
+ * @id: output buffer containing the id on success
+ */
+static int gt801x_read_version(struct i2c_client *client, u16 *version, u16 *id)
+{
+ int error;
+ u8 buf[16];
+
+ error = gt801x_i2c_read(client, GT801X_REG_ID, buf, sizeof(buf));
+ if (error) {
+ dev_err(&client->dev, "read version failed: %d\n", error);
+ return error;
+ }
+ /* TODO: version info contains 'GT801NI_3R15_1AV' */
+ print_hex_dump_bytes("", DUMP_PREFIX_NONE, buf, ARRAY_SIZE(buf));
+ *id = 0x802;
+ *version = 0x15;
+ dev_info(&client->dev, "ID %d, version: %04x\n", *id, *version);
+ return 0;
+}
+
+/**
+ * gt801x_i2c_test - I2C test function to check if the device answers.
+ *
+ * @client: the i2c client
+ */
+static int gt801x_i2c_test(struct i2c_client *client)
+{
+ int retry = 0;
+ int error;
+ u8 test;
+
+ while (retry++ < 2) {
+ error = gt801x_i2c_read(client, GT801X_CONFIG_DATA,
+ &test, 1);
+ if (!error)
+ return 0;
+
+ dev_err(&client->dev, "i2c test failed attempt %d: %d\n",
+ retry, error);
+ msleep(20);
+ }
+
+ return error;
+}
+
+/**
+ * gt801x_request_input_dev - Allocate, populate and register the input device
+ *
+ * @ts: our gt801x_ts_data pointer
+ * @version: device firmware version
+ * @id: device ID
+ *
+ * Must be called during probe
+ */
+static int gt801x_request_input_dev(struct gt801x_ts_data *ts,
+ u16 version, u16 id)
+{
+ int error;
+
+ ts->input_dev = devm_input_allocate_device(&ts->client->dev);
+ if (!ts->input_dev) {
+ dev_err(&ts->client->dev, "Failed to allocate input device.");
+ return -ENOMEM;
+ }
+
+ input_set_abs_params(ts->input_dev, ABS_MT_POSITION_X,
+ 0, ts->abs_x_max, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_POSITION_Y,
+ 0, ts->abs_y_max, 0, 0);
+ 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, ts->max_touch_num,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+
+ ts->input_dev->name = "Goodix Capacitive TouchScreen (GT801 2+1)";
+ ts->input_dev->phys = "input/ts";
+ ts->input_dev->id.bustype = BUS_I2C;
+ ts->input_dev->id.vendor = 0x0416;
+ ts->input_dev->id.product = id;
+ ts->input_dev->id.version = version;
+
+ error = input_register_device(ts->input_dev);
+ if (error) {
+ dev_err(&ts->client->dev,
+ "Failed to register input device: %d", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int gt801x_ts_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct gt801x_ts_data *ts;
+ unsigned long irq_flags;
+ int error;
+ u16 version_info, id_info;
+
+ dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "I2C check functionality failed.\n");
+ return -ENXIO;
+ }
+
+ ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ ts->client = client;
+ i2c_set_clientdata(client, ts);
+
+ error = gt801x_i2c_test(client);
+ if (error) {
+ dev_err(&client->dev, "I2C communication failure: %d\n", error);
+ return error;
+ }
+
+ error = gt801x_read_version(client, &version_info, &id_info);
+ if (error) {
+ dev_err(&client->dev, "Read version failed.\n");
+ return error;
+ }
+
+ gt801x_read_config(ts);
+
+ error = gt801x_request_input_dev(ts, version_info, id_info);
+ if (error)
+ return error;
+
+ irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
+ error = devm_request_threaded_irq(&ts->client->dev, client->irq,
+ NULL, gt801x_ts_irq_handler,
+ irq_flags, client->name, ts);
+ if (error) {
+ dev_err(&client->dev, "request IRQ failed: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static const struct i2c_device_id gt801x_ts_id[] = {
+ { "GDIX1001:00", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, gt801x_ts_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id gt801x_of_match[] = {
+ { .compatible = "goodix,gt801_2plus1" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, gt801x_of_match);
+#endif
+
+static struct i2c_driver gt801x_ts_driver = {
+ .probe = gt801x_ts_probe,
+ .id_table = gt801x_ts_id,
+ .driver = {
+ .name = "Goodix-TS",
+ .of_match_table = of_match_ptr(gt801x_of_match),
+ },
+};
+module_i2c_driver(gt801x_ts_driver);
+
+MODULE_AUTHOR("Priit Laes <plaes@xxxxxxxxx>");
+MODULE_DESCRIPTION("Goodix GT801 2+1 touchscreen driver");
+MODULE_LICENSE("GPL v2");
--
2.6.3

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