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Commit 92deea13 authored by Noralf Trønnes's avatar Noralf Trønnes Committed by Dmitry Torokhov
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Input: add support for FocalTech FT6236 touchscreen controller 



This adds support for the FT6x06 and the FT6x36 family of capacitive touch
panel controllers, in particular the FT6236.

Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent d6f0c3d3

Documentation/devicetree/bindings/input/touchscreen/focaltech-ft6236.txt

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* FocalTech FT6236 I2C touchscreen controller



Required properties:

 - compatible		  : "focaltech,ft6236"

 - reg			  : I2C slave address of the chip (0x38)

 - interrupt-parent	  : a phandle pointing to the interrupt controller

			    serving the interrupt for this chip

 - interrupts		  : interrupt specification for the touch controller

			    interrupt

 - reset-gpios		  : GPIO specification for the RSTN input

 - touchscreen-size-x	  : horizontal resolution of touchscreen (in pixels)

 - touchscreen-size-y	  : vertical resolution of touchscreen (in pixels)



Optional properties:

 - touchscreen-fuzz-x	  : horizontal noise value of the absolute input

			    device (in pixels)

 - touchscreen-fuzz-y	  : vertical noise value of the absolute input

			    device (in pixels)

 - touchscreen-inverted-x : X axis is inverted (boolean)

 - touchscreen-inverted-y : Y axis is inverted (boolean)

 - touchscreen-swapped-x-y: X and Y axis are swapped (boolean)

			    Swapping is done after inverting the axis



Example:



	ft6x06@38 {

		compatible = "focaltech,ft6236";

		reg = <0x38>;

		interrupt-parent = <&gpio>;

		interrupts = <23 2>;

		touchscreen-size-x = <320>;

		touchscreen-size-y = <480>;

		touchscreen-inverted-x;

		touchscreen-swapped-x-y;

	};

Documentation/devicetree/bindings/vendor-prefixes.txt

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@@ -82,6 +82,7 @@ everspin Everspin Technologies, Inc. 
excito	Excito

fcs	Fairchild Semiconductor

firefly	Firefly

focaltech	FocalTech Systems Co.,Ltd

fsl	Freescale Semiconductor

GEFanuc	GE Fanuc Intelligent Platforms Embedded Systems, Inc.

gef	GE Fanuc Intelligent Platforms Embedded Systems, Inc.

drivers/input/touchscreen/Kconfig

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@@ -295,6 +295,19 @@ config TOUCHSCREEN_EGALAX 
	  To compile this driver as a module, choose M here: the

	  module will be called egalax_ts.



config TOUCHSCREEN_FT6236

	tristate "FT6236 I2C touchscreen"

	depends on I2C

	depends on GPIOLIB || COMPILE_TEST

	help

	  Say Y here to enable support for the I2C connected FT6x06 and

	  FT6x36 family of capacitive touchscreen drivers.



	  If unsure, say N.



	  To compile this driver as a module, choose M here: the

	  module will be called ft6236.



config TOUCHSCREEN_FUJITSU

	tristate "Fujitsu serial touchscreen"

	select SERIO

drivers/input/touchscreen/Makefile

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@@ -35,6 +35,7 @@ obj-$(CONFIG_TOUCHSCREEN_EETI) += eeti_ts.o 
obj-$(CONFIG_TOUCHSCREEN_ELAN)		+= elants_i2c.o

obj-$(CONFIG_TOUCHSCREEN_ELO)		+= elo.o

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_ILI210X)	+= ili210x.o

drivers/input/touchscreen/ft6236.c

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/*

 * FocalTech FT6236 TouchScreen driver.

 *

 * Copyright (c) 2010  Focal tech Ltd.

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/delay.h>

#include <linux/gpio/consumer.h>

#include <linux/i2c.h>

#include <linux/input.h>

#include <linux/input/mt.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/property.h>



#define FT6236_MAX_TOUCH_POINTS		2



#define FT6236_REG_TH_GROUP		0x80

#define FT6236_REG_PERIODACTIVE		0x88

#define FT6236_REG_LIB_VER_H		0xa1

#define FT6236_REG_LIB_VER_L		0xa2

#define FT6236_REG_CIPHER		0xa3

#define FT6236_REG_FIRMID		0xa6

#define FT6236_REG_FOCALTECH_ID		0xa8

#define FT6236_REG_RELEASE_CODE_ID	0xaf



#define FT6236_EVENT_PRESS_DOWN		0

#define FT6236_EVENT_LIFT_UP		1

#define FT6236_EVENT_CONTACT		2

#define FT6236_EVENT_NO_EVENT		3



struct ft6236_data {

	struct i2c_client *client;

	struct input_dev *input;

	struct gpio_desc *reset_gpio;

	u32 max_x;

	u32 max_y;

	bool invert_x;

	bool invert_y;

	bool swap_xy;

};



/*

 * This struct is a touchpoint as stored in hardware.  Note that the id,

 * as well as the event, are stored in the upper nybble of the hi byte.

 */

struct ft6236_touchpoint {

	union {

		u8 xhi;

		u8 event;

	};

	u8 xlo;

	union {

		u8 yhi;

		u8 id;

	};

	u8 ylo;

	u8 weight;

	u8 misc;

} __packed;



/* This packet represents the register map as read from offset 0 */

struct ft6236_packet {

	u8 dev_mode;

	u8 gest_id;

	u8 touches;

	struct ft6236_touchpoint points[FT6236_MAX_TOUCH_POINTS];

} __packed;



static int ft6236_read(struct i2c_client *client, u8 reg, u8 len, void *data)

{

	int error;



	error = i2c_smbus_read_i2c_block_data(client, reg, len, data);

	if (error < 0)

		return error;



	if (error != len)

		return -EIO;



	return 0;

}



static irqreturn_t ft6236_interrupt(int irq, void *dev_id)

{

	struct ft6236_data *ft6236 = dev_id;

	struct device *dev = &ft6236->client->dev;

	struct input_dev *input = ft6236->input;

	struct ft6236_packet buf;

	u8 touches;

	int i, error;



	error = ft6236_read(ft6236->client, 0, sizeof(buf), &buf);

	if (error) {

		dev_err(dev, "read touchdata failed %d\n", error);

		return IRQ_HANDLED;

	}



	touches = buf.touches & 0xf;

	if (touches > FT6236_MAX_TOUCH_POINTS) {

		dev_dbg(dev,

			"%d touch points reported, only %d are supported\n",

			touches, FT6236_MAX_TOUCH_POINTS);

		touches = FT6236_MAX_TOUCH_POINTS;

	}



	for (i = 0; i < touches; i++) {

		struct ft6236_touchpoint *point = &buf.points[i];

		u16 x = ((point->xhi & 0xf) << 8) | buf.points[i].xlo;

		u16 y = ((point->yhi & 0xf) << 8) | buf.points[i].ylo;

		u8 event = point->event >> 6;

		u8 id = point->id >> 4;

		bool act = (event == FT6236_EVENT_PRESS_DOWN ||

			    event == FT6236_EVENT_CONTACT);



		input_mt_slot(input, id);

		input_mt_report_slot_state(input, MT_TOOL_FINGER, act);

		if (!act)

			continue;



		if (ft6236->invert_x)

			x = ft6236->max_x - x;



		if (ft6236->invert_y)

			y = ft6236->max_y - y;



		if (ft6236->swap_xy) {

			input_report_abs(input, ABS_MT_POSITION_X, y);

			input_report_abs(input, ABS_MT_POSITION_Y, x);

		} else {

			input_report_abs(input, ABS_MT_POSITION_X, x);

			input_report_abs(input, ABS_MT_POSITION_Y, y);

		}

	}



	input_mt_sync_frame(input);

	input_sync(input);



	return IRQ_HANDLED;

}



static u8 ft6236_debug_read_byte(struct ft6236_data *ft6236, u8 reg)

{

	struct i2c_client *client = ft6236->client;

	u8 val = 0;

	int error;



	error = ft6236_read(client, reg, 1, &val);

	if (error)

		dev_dbg(&client->dev,

			"error reading register 0x%02x: %d\n", reg, error);



	return val;

}



static void ft6236_debug_info(struct ft6236_data *ft6236)

{

	struct device *dev = &ft6236->client->dev;



	dev_dbg(dev, "Touch threshold is %d\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_TH_GROUP) * 4);

	dev_dbg(dev, "Report rate is %dHz\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_PERIODACTIVE) * 10);

	dev_dbg(dev, "Firmware library version 0x%02x%02x\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_LIB_VER_H),

		ft6236_debug_read_byte(ft6236, FT6236_REG_LIB_VER_L));

	dev_dbg(dev, "Firmware version 0x%02x\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_FIRMID));

	dev_dbg(dev, "Chip vendor ID 0x%02x\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_CIPHER));

	dev_dbg(dev, "CTPM vendor ID 0x%02x\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_FOCALTECH_ID));

	dev_dbg(dev, "Release code version 0x%02x\n",

		ft6236_debug_read_byte(ft6236, FT6236_REG_RELEASE_CODE_ID));

}



static void ft6236_reset(struct ft6236_data *ft6236)

{

	if (!ft6236->reset_gpio)

		return;



	gpiod_set_value_cansleep(ft6236->reset_gpio, 1);

	usleep_range(5000, 20000);

	gpiod_set_value_cansleep(ft6236->reset_gpio, 0);

	msleep(300);

}



static int ft6236_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct device *dev = &client->dev;

	struct ft6236_data *ft6236;

	struct input_dev *input;

	u32 fuzz_x = 0, fuzz_y = 0;

	u8 val;

	int error;



	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))

		return -ENXIO;



	if (!client->irq) {

		dev_err(dev, "irq is missing\n");

		return -EINVAL;

	}



	ft6236 = devm_kzalloc(dev, sizeof(*ft6236), GFP_KERNEL);

	if (!ft6236)

		return -ENOMEM;



	ft6236->client = client;

	ft6236->reset_gpio = devm_gpiod_get_optional(dev, "reset",

						     GPIOD_OUT_LOW);

	if (IS_ERR(ft6236->reset_gpio)) {

		error = PTR_ERR(ft6236->reset_gpio);

		if (error != -EPROBE_DEFER)

			dev_err(dev, "error getting reset gpio: %d\n", error);

		return error;

	}



	ft6236_reset(ft6236);



	/* verify that the controller is present */

	error = ft6236_read(client, 0x00, 1, &val);

	if (error) {

		dev_err(dev, "failed to read from controller: %d\n", error);

		return error;

	}



	ft6236_debug_info(ft6236);



	input = devm_input_allocate_device(dev);

	if (!input)

		return -ENOMEM;



	ft6236->input = input;

	input->name = client->name;

	input->id.bustype = BUS_I2C;



	if (device_property_read_u32(dev, "touchscreen-size-x",

				     &ft6236->max_x) ||

	    device_property_read_u32(dev, "touchscreen-size-y",

				     &ft6236->max_y)) {

		dev_err(dev, "touchscreen-size-x and/or -y missing\n");

		return -EINVAL;

	}



	device_property_read_u32(dev, "touchscreen-fuzz-x", &fuzz_x);

	device_property_read_u32(dev, "touchscreen-fuzz-y", &fuzz_y);

	ft6236->invert_x = device_property_read_bool(dev,

						     "touchscreen-inverted-x");

	ft6236->invert_y = device_property_read_bool(dev,

						     "touchscreen-inverted-y");

	ft6236->swap_xy = device_property_read_bool(dev,

						    "touchscreen-swapped-x-y");



	if (ft6236->swap_xy) {

		input_set_abs_params(input, ABS_MT_POSITION_X, 0,

				     ft6236->max_y, fuzz_y, 0);

		input_set_abs_params(input, ABS_MT_POSITION_Y, 0,

				     ft6236->max_x, fuzz_x, 0);

	} else {

		input_set_abs_params(input, ABS_MT_POSITION_X, 0,

				     ft6236->max_x, fuzz_x, 0);

		input_set_abs_params(input, ABS_MT_POSITION_Y, 0,

				     ft6236->max_y, fuzz_y, 0);

	}



	error = input_mt_init_slots(input, FT6236_MAX_TOUCH_POINTS,

				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);

	if (error)

		return error;



	error = devm_request_threaded_irq(dev, client->irq, NULL,

					  ft6236_interrupt, IRQF_ONESHOT,

					  client->name, ft6236);

	if (error) {

		dev_err(dev, "request irq %d failed: %d\n", client->irq, error);

		return error;

	}



	error = input_register_device(input);

	if (error) {

		dev_err(dev, "failed to register input device: %d\n", error);

		return error;

	}



	return 0;

}



#ifdef CONFIG_OF

static const struct of_device_id ft6236_of_match[] = {

	{ .compatible = "focaltech,ft6236", },

	{ }

};

MODULE_DEVICE_TABLE(of, ft6236_of_match);

#endif



static const struct i2c_device_id ft6236_id[] = {

	{ "ft6236", },

	{ }

};

MODULE_DEVICE_TABLE(i2c, ft6236_id);



static struct i2c_driver ft6236_driver = {

	.driver = {

		.name = "ft6236",

		.owner = THIS_MODULE,

		.of_match_table = of_match_ptr(ft6236_of_match),

	},

	.probe = ft6236_probe,

	.id_table = ft6236_id,

};

module_i2c_driver(ft6236_driver);



MODULE_AUTHOR("Sean Cross <xobs@kosagi.com>");

MODULE_AUTHOR("Noralf Trønnes <noralf@tronnes.org>");

MODULE_DESCRIPTION("FocalTech FT6236 TouchScreen driver");

MODULE_LICENSE("GPL");