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Commit 5a966261 authored by Tatsunosuke Tobita's avatar Tatsunosuke Tobita Committed by Dmitry Torokhov
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Input: add support for Wacom Stylus device with I2C interface 



This adds support for Wacom Stylus device with I2C interface.

[Dan Carpenter <dan.carpenter@oracle.com>: fix NULL-pointer dereference
 in error handling path.]
Signed-off-by: default avatarTatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 271002ca

drivers/input/touchscreen/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -306,6 +306,18 @@ config TOUCHSCREEN_WACOM_W8001 
	  To compile this driver as a module, choose M here: the

	  module will be called wacom_w8001.



config TOUCHSCREEN_WACOM_I2C

	tristate "Wacom Tablet support (I2C)"

	depends on I2C

	help

	  Say Y here if you want to use the I2C version of the Wacom

	  Pen Tablet.



	  If unsure, say N.



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

	  will be called wacom_i2c.



config TOUCHSCREEN_LPC32XX

	tristate "LPC32XX touchscreen controller"

	depends on ARCH_LPC32XX

drivers/input/touchscreen/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ obj-$(CONFIG_TOUCHSCREEN_TSC2005) += tsc2005.o 
obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o

obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o

obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o

obj-$(CONFIG_TOUCHSCREEN_WACOM_I2C)	+= wacom_i2c.o

obj-$(CONFIG_TOUCHSCREEN_WM831X)	+= wm831x-ts.o

obj-$(CONFIG_TOUCHSCREEN_WM97XX)	+= wm97xx-ts.o

wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705)	+= wm9705.o

drivers/input/touchscreen/wacom_i2c.c

0 → 100644
+315 −0
Original line number Diff line number Diff line 
/*

 * Wacom Penabled Driver for I2C

 *

 * Copyright (c) 2011 Tatsunosuke Tobita, Wacom.

 * <tobita.tatsunosuke@wacom.co.jp>

 *

 * 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; either version of 2 of the License,

 * or (at your option) any later version.

 */



#include <linux/module.h>

#include <linux/input.h>

#include <linux/i2c.h>

#include <linux/slab.h>

#include <linux/irq.h>

#include <linux/interrupt.h>

#include <linux/gpio.h>

#include <asm/unaligned.h>



#define WACOM_CMD_QUERY0	0x04

#define WACOM_CMD_QUERY1	0x00

#define WACOM_CMD_QUERY2	0x33

#define WACOM_CMD_QUERY3	0x02

#define WACOM_CMD_THROW0	0x05

#define WACOM_CMD_THROW1	0x00

#define WACOM_QUERY_SIZE	19

#define WACOM_RETRY_CNT		100



struct wacom_features {

	int x_max;

	int y_max;

	int pressure_max;

	char fw_version;

};



struct wacom_i2c {

	struct i2c_client *client;

	struct input_dev *input;

	unsigned int gpio;

	u8 data[WACOM_QUERY_SIZE];

};



static int wacom_query_device(struct i2c_client *client,

			      struct wacom_features *features)

{

	int ret;

	u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,

			WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };

	u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };

	u8 data[WACOM_QUERY_SIZE];

	struct i2c_msg msgs[] = {

		{

			.addr = client->addr,

			.flags = 0,

			.len = sizeof(cmd1),

			.buf = cmd1,

		},

		{

			.addr = client->addr,

			.flags = 0,

			.len = sizeof(cmd2),

			.buf = cmd2,

		},

		{

			.addr = client->addr,

			.flags = I2C_M_RD,

			.len = sizeof(data),

			.buf = data,

		},

	};



	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));

	if (ret < 0)

		return ret;

	if (ret != ARRAY_SIZE(msgs))

		return -EIO;



	features->x_max = get_unaligned_le16(&data[3]);

	features->y_max = get_unaligned_le16(&data[5]);

	features->pressure_max = get_unaligned_le16(&data[11]);

	features->fw_version = get_unaligned_le16(&data[13]);



	dev_dbg(&client->dev,

		"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",

		features->x_max, features->y_max,

		features->pressure_max, features->fw_version);



	return 0;

}



static int wacom_i2c_fetch_data(struct wacom_i2c *wac_i2c)

{

	int retries = 0;

	int ret;



	do {

		ret = i2c_master_recv(wac_i2c->client,

				      wac_i2c->data, sizeof(wac_i2c->data));

	} while (gpio_get_value(wac_i2c->gpio) == 0 &&

		 retries++ < WACOM_RETRY_CNT);



	if (retries >= WACOM_RETRY_CNT)

		ret = -EIO;



	return ret < 0 ? ret : 0;

}



static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)

{

	struct wacom_i2c *wac_i2c = dev_id;

	struct input_dev *input = wac_i2c->input;

	u8 *data = wac_i2c->data;

	unsigned int x, y, pressure;

	unsigned char tsw, f1, f2, ers;

	int error;



	error = wacom_i2c_fetch_data(wac_i2c);

	if (error)

		goto out;



	tsw = data[3] & 0x01;

	ers = data[3] & 0x04;

	f1 = data[3] & 0x02;

	f2 = data[3] & 0x10;

	x = le16_to_cpup((__le16 *)&data[4]);

	y = le16_to_cpup((__le16 *)&data[6]);

	pressure = le16_to_cpup((__le16 *)&data[8]);



	input_report_key(input, BTN_TOUCH, tsw || ers);

	input_report_key(input, BTN_TOOL_PEN, tsw);

	input_report_key(input, BTN_TOOL_RUBBER, ers);

	input_report_key(input, BTN_STYLUS, f1);

	input_report_key(input, BTN_STYLUS2, f2);

	input_report_abs(input, ABS_X, x);

	input_report_abs(input, ABS_Y, y);

	input_report_abs(input, ABS_PRESSURE, pressure);

	input_sync(input);



out:

	return IRQ_HANDLED;

}



static int wacom_i2c_open(struct input_dev *dev)

{

	struct wacom_i2c *wac_i2c = input_get_drvdata(dev);

	struct i2c_client *client = wac_i2c->client;

	int error;



	/* Clear the device buffer */

	error = wacom_i2c_fetch_data(wac_i2c);

	if (error)

		return error;



	enable_irq(client->irq);



	return 0;

}



static void wacom_i2c_close(struct input_dev *dev)

{

	struct wacom_i2c *wac_i2c = input_get_drvdata(dev);

	struct i2c_client *client = wac_i2c->client;



	disable_irq(client->irq);

}



static int __devinit wacom_i2c_probe(struct i2c_client *client,

				     const struct i2c_device_id *id)

{

	struct wacom_i2c *wac_i2c;

	struct input_dev *input;

	struct wacom_features features;

	int gpio;

	int error;



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

		dev_err(&client->dev, "i2c_check_functionality error\n");

		return -EIO;

	}



	gpio = irq_to_gpio(client->irq);

	if (gpio < 0) {

		error = gpio;

		dev_err(&client->dev,

			"irq_to_gpio() failed, error: %d\n", error);

		return error;

	}



	error = wacom_query_device(client, &features);

	if (error)

		return error;



	wac_i2c = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);

	input = input_allocate_device();

	if (!wac_i2c || !input) {

		error = -ENOMEM;

		goto err_free_mem;

	}



	wac_i2c->client = client;

	wac_i2c->input = input;

	wac_i2c->gpio = gpio;



	input->name = "Wacom I2C Digitizer";

	input->id.bustype = BUS_I2C;

	input->id.vendor = 0x56a;

	input->id.version = features.fw_version;

	input->dev.parent = &client->dev;

	input->open = wacom_i2c_open;

	input->close = wacom_i2c_close;



	input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);



	__set_bit(BTN_TOOL_PEN, input->keybit);

	__set_bit(BTN_TOOL_RUBBER, input->keybit);

	__set_bit(BTN_STYLUS, input->keybit);

	__set_bit(BTN_STYLUS2, input->keybit);

	__set_bit(BTN_TOUCH, input->keybit);



	input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);

	input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);

	input_set_abs_params(input, ABS_PRESSURE,

			     0, features.pressure_max, 0, 0);



	input_set_drvdata(input, wac_i2c);



	error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,

				     IRQF_TRIGGER_FALLING,

				     "wacom_i2c", wac_i2c);

	if (error) {

		dev_err(&client->dev,

			"Failed to enable IRQ, error: %d\n", error);

		goto err_free_mem;

	}



	/* Disable the IRQ, we'll enable it in wac_i2c_open() */

	disable_irq(client->irq);



	error = input_register_device(wac_i2c->input);

	if (error) {

		dev_err(&client->dev,

			"Failed to register input device, error: %d\n", error);

		goto err_free_irq;

	}



	i2c_set_clientdata(client, wac_i2c);

	return 0;



err_free_irq:

	free_irq(client->irq, wac_i2c);

err_free_mem:

	input_free_device(input);

	kfree(wac_i2c);



	return error;

}



static int __devexit wacom_i2c_remove(struct i2c_client *client)

{

	struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);



	free_irq(client->irq, wac_i2c);

	input_unregister_device(wac_i2c->input);

	kfree(wac_i2c);



	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int wacom_i2c_suspend(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);



	disable_irq(client->irq);



	return 0;

}



static int wacom_i2c_resume(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);



	enable_irq(client->irq);



	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);



static const struct i2c_device_id wacom_i2c_id[] = {

	{ "WAC_I2C_EMR", 0 },

	{ },

};

MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);



static struct i2c_driver wacom_i2c_driver = {

	.driver	= {

		.name	= "wacom_i2c",

		.owner	= THIS_MODULE,

		.pm	= &wacom_i2c_pm,

	},



	.probe		= wacom_i2c_probe,

	.remove		= __devexit_p(wacom_i2c_remove),

	.id_table	= wacom_i2c_id,

};

module_i2c_driver(wacom_i2c_driver);



MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");

MODULE_DESCRIPTION("WACOM EMR I2C Driver");

MODULE_LICENSE("GPL");