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

From: Rob Herring
Date: Tue Dec 08 2015 - 10:18:13 EST

On Mon, Dec 07, 2015 at 09:26:01AM +0200, Priit Laes wrote:
> 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 ++

For the binding:

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> 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 López (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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