Input: add support for Wacom protocol 4 serial tablets

S:	Maintained

F:	drivers/mmc/host/wbsd.*

WACOM PROTOCOL 4 SERIAL TABLETS

M:	Julian Squires <julian@cipht.net>

M:	Hans de Goede <hdegoede@redhat.com>

L:	linux-input@vger.kernel.org

S:	Maintained

F:	drivers/input/tablet/wacom_serial4.c

WATCHDOG DEVICE DRIVERS

M:	Wim Van Sebroeck <wim@iguana.be>

L:	linux-watchdog@vger.kernel.org

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

	  module will be called wacom.

config TABLET_SERIAL_WACOM4

	tristate "Wacom protocol 4 serial tablet support"

	select SERIO

	help

	  Say Y here if you want to use Wacom protocol 4 serial tablets.

	  E.g. serial versions of the Cintiq, Graphire or Penpartner.

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

	  module will be called wacom_serial4.

endif

obj-$(CONFIG_TABLET_USB_HANWANG) += hanwang.o

obj-$(CONFIG_TABLET_USB_KBTAB)	+= kbtab.o

obj-$(CONFIG_TABLET_USB_WACOM)	+= wacom.o

obj-$(CONFIG_TABLET_SERIAL_WACOM4) += wacom_serial4.o

/*

 * Wacom protocol 4 serial tablet driver

 *

 * Copyright 2014      Hans de Goede <hdegoede@redhat.com>

 * Copyright 2011-2012 Julian Squires <julian@cipht.net>

 *

 * 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. See the file COPYING in the main directory of

 * this archive for more details.

 *

 * Many thanks to Bill Seremetis, without whom PenPartner support

 * would not have been possible. Thanks to Patrick Mahoney.

 *

 * This driver was developed with reference to much code written by others,

 * particularly:

 *  - elo, gunze drivers by Vojtech Pavlik <vojtech@ucw.cz>;

 *  - wacom_w8001 driver by Jaya Kumar <jayakumar.lkml@gmail.com>;

 *  - the USB wacom input driver, credited to many people

 *    (see drivers/input/tablet/wacom.h);

 *  - new and old versions of linuxwacom / xf86-input-wacom credited to

 *    Frederic Lepied, France. <Lepied@XFree86.org> and

 *    Ping Cheng, Wacom. <pingc@wacom.com>;

 *  - and xf86wacom.c (a presumably ancient version of the linuxwacom code),

 *    by Frederic Lepied and Raph Levien <raph@gtk.org>.

 *

 * To do:

 *  - support pad buttons; (requires access to a model with pad buttons)

 *  - support (protocol 4-style) tilt (requires access to a > 1.4 rom model)

 */

/*

 * Wacom serial protocol 4 documentation taken from linuxwacom-0.9.9 code,

 * protocol 4 uses 7 or 9 byte of data in the following format:

 *

 *	Byte 1

 *	bit 7  Sync bit always 1

 *	bit 6  Pointing device detected

 *	bit 5  Cursor = 0 / Stylus = 1

 *	bit 4  Reserved

 *	bit 3  1 if a button on the pointing device has been pressed

 *	bit 2  P0 (optional)

 *	bit 1  X15

 *	bit 0  X14

 *

 *	Byte 2

 *	bit 7  Always 0

 *	bits 6-0 = X13 - X7

 *

 *	Byte 3

 *	bit 7  Always 0

 *	bits 6-0 = X6 - X0

 *

 *	Byte 4

 *	bit 7  Always 0

 *	bit 6  B3

 *	bit 5  B2

 *	bit 4  B1

 *	bit 3  B0

 *	bit 2  P1 (optional)

 *	bit 1  Y15

 *	bit 0  Y14

 *

 *	Byte 5

 *	bit 7  Always 0

 *	bits 6-0 = Y13 - Y7

 *

 *	Byte 6

 *	bit 7  Always 0

 *	bits 6-0 = Y6 - Y0

 *

 *	Byte 7

 *	bit 7 Always 0

 *	bit 6  Sign of pressure data; or wheel-rel for cursor tool

 *	bit 5  P7; or REL1 for cursor tool

 *	bit 4  P6; or REL0 for cursor tool

 *	bit 3  P5

 *	bit 2  P4

 *	bit 1  P3

 *	bit 0  P2

 *

 *	byte 8 and 9 are optional and present only

 *	in tilt mode.

 *

 *	Byte 8

 *	bit 7 Always 0

 *	bit 6 Sign of tilt X

 *	bit 5  Xt6

 *	bit 4  Xt5

 *	bit 3  Xt4

 *	bit 2  Xt3

 *	bit 1  Xt2

 *	bit 0  Xt1

 *

 *	Byte 9

 *	bit 7 Always 0

 *	bit 6 Sign of tilt Y

 *	bit 5  Yt6

 *	bit 4  Yt5

 *	bit 3  Yt4

 *	bit 2  Yt3

 *	bit 1  Yt2

 *	bit 0  Yt1

 */

#include <linux/completion.h>

#include <linux/init.h>

#include <linux/input.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/serio.h>

#include <linux/slab.h>

#include <linux/string.h>

#include "wacom_wac.h"

MODULE_AUTHOR("Julian Squires <julian@cipht.net>, Hans de Goede <hdegoede@redhat.com>");

MODULE_DESCRIPTION("Wacom protocol 4 serial tablet driver");

MODULE_LICENSE("GPL");

#define REQUEST_MODEL_AND_ROM_VERSION	"~#"

#define REQUEST_MAX_COORDINATES		"~C\r"

#define REQUEST_CONFIGURATION_STRING	"~R\r"

#define REQUEST_RESET_TO_PROTOCOL_IV	"\r#"

/*

 * Note: sending "\r$\r" causes at least the Digitizer II to send

 * packets in ASCII instead of binary.  "\r#" seems to undo that.

 */

#define COMMAND_START_SENDING_PACKETS		"ST\r"

#define COMMAND_STOP_SENDING_PACKETS		"SP\r"

#define COMMAND_MULTI_MODE_INPUT		"MU1\r"

#define COMMAND_ORIGIN_IN_UPPER_LEFT		"OC1\r"

#define COMMAND_ENABLE_ALL_MACRO_BUTTONS	"~M0\r"

#define COMMAND_DISABLE_GROUP_1_MACRO_BUTTONS	"~M1\r"

#define COMMAND_TRANSMIT_AT_MAX_RATE		"IT0\r"

#define COMMAND_DISABLE_INCREMENTAL_MODE	"IN0\r"

#define COMMAND_ENABLE_CONTINUOUS_MODE		"SR\r"

#define COMMAND_ENABLE_PRESSURE_MODE		"PH1\r"

#define COMMAND_Z_FILTER			"ZF1\r"

/* Note that this is a protocol 4 packet without tilt information. */

#define PACKET_LENGTH		7

#define DATA_SIZE		32

/* flags */

#define F_COVERS_SCREEN		0x01

#define F_HAS_STYLUS2		0x02

#define F_HAS_SCROLLWHEEL	0x04

enum { STYLUS = 1, ERASER, CURSOR };

static const struct {

	int device_id;

	int input_id;

} tools[] = {

	{ 0, 0 },

	{ STYLUS_DEVICE_ID, BTN_TOOL_PEN },

	{ ERASER_DEVICE_ID, BTN_TOOL_RUBBER },

	{ CURSOR_DEVICE_ID, BTN_TOOL_MOUSE },

};

struct wacom {

	struct input_dev *dev;

	struct completion cmd_done;

	int result;

	u8 expect;

	u8 eraser_mask;

	unsigned int extra_z_bits;

	unsigned int flags;

	unsigned int res_x, res_y;

	unsigned int max_x, max_y;

	unsigned int tool;

	unsigned int idx;

	u8 data[DATA_SIZE];

	char phys[32];

};

enum {

	MODEL_CINTIQ		= 0x504C, /* PL */

	MODEL_CINTIQ2		= 0x4454, /* DT */

	MODEL_DIGITIZER_II	= 0x5544, /* UD */

	MODEL_GRAPHIRE		= 0x4554, /* ET */

	MODEL_PENPARTNER	= 0x4354, /* CT */

};

static void wacom_handle_model_response(struct wacom *wacom)

{

	int major_v, minor_v, r = 0;

	char *p;

	p = strrchr(wacom->data, 'V');

	if (p)

		r = sscanf(p + 1, "%u.%u", &major_v, &minor_v);

	if (r != 2)

		major_v = minor_v = 0;

	switch (wacom->data[2] << 8 | wacom->data[3]) {

	case MODEL_CINTIQ:	/* UNTESTED */

	case MODEL_CINTIQ2:

		if ((wacom->data[2] << 8 | wacom->data[3]) == MODEL_CINTIQ) {

			wacom->dev->name = "Wacom Cintiq";

			wacom->dev->id.version = MODEL_CINTIQ;

		} else {

			wacom->dev->name = "Wacom Cintiq II";

			wacom->dev->id.version = MODEL_CINTIQ2;

		}

		wacom->res_x = 508;

		wacom->res_y = 508;

		switch (wacom->data[5] << 8 | wacom->data[6]) {

		case 0x3731: /* PL-710 */

			wacom->res_x = 2540;

			wacom->res_y = 2540;

			/* fall through */

		case 0x3535: /* PL-550 */

		case 0x3830: /* PL-800 */

			wacom->extra_z_bits = 2;

		}

		wacom->flags = F_COVERS_SCREEN;

		break;

	case MODEL_PENPARTNER:

		wacom->dev->name = "Wacom Penpartner";

		wacom->dev->id.version = MODEL_PENPARTNER;

		wacom->res_x = 1000;

		wacom->res_y = 1000;

		break;

	case MODEL_GRAPHIRE:

		wacom->dev->name = "Wacom Graphire";

		wacom->dev->id.version = MODEL_GRAPHIRE;

		wacom->res_x = 1016;

		wacom->res_y = 1016;

		wacom->max_x = 5103;

		wacom->max_y = 3711;

		wacom->extra_z_bits = 2;

		wacom->eraser_mask = 0x08;

		wacom->flags = F_HAS_STYLUS2 | F_HAS_SCROLLWHEEL;

		break;

	case MODEL_DIGITIZER_II:

		wacom->dev->name = "Wacom Digitizer II";

		wacom->dev->id.version = MODEL_DIGITIZER_II;

		if (major_v == 1 && minor_v <= 2)

			wacom->extra_z_bits = 0; /* UNTESTED */

		break;

	default:

		dev_err(&wacom->dev->dev, "Unsupported Wacom model %s\n",

			wacom->data);

		wacom->result = -ENODEV;

		return;

	}

	dev_info(&wacom->dev->dev, "%s tablet, version %u.%u\n",

		 wacom->dev->name, major_v, minor_v);

}

static void wacom_handle_configuration_response(struct wacom *wacom)

{

	int r, skip;

	dev_dbg(&wacom->dev->dev, "Configuration string: %s\n", wacom->data);

	r = sscanf(wacom->data, "~R%x,%u,%u,%u,%u", &skip, &skip, &skip,

		   &wacom->res_x, &wacom->res_y);

	if (r != 5)

		dev_warn(&wacom->dev->dev, "could not get resolution\n");

}

static void wacom_handle_coordinates_response(struct wacom *wacom)

{

	int r;

	dev_dbg(&wacom->dev->dev, "Coordinates string: %s\n", wacom->data);

	r = sscanf(wacom->data, "~C%u,%u", &wacom->max_x, &wacom->max_y);

	if (r != 2)

		dev_warn(&wacom->dev->dev, "could not get max coordinates\n");

}

static void wacom_handle_response(struct wacom *wacom)

{

	if (wacom->data[0] != '~' || wacom->data[1] != wacom->expect) {

		dev_err(&wacom->dev->dev,

			"Wacom got an unexpected response: %s\n", wacom->data);

		wacom->result = -EIO;

	} else {

		wacom->result = 0;

		switch (wacom->data[1]) {

		case '#':

			wacom_handle_model_response(wacom);

			break;

		case 'R':

			wacom_handle_configuration_response(wacom);

			break;

		case 'C':

			wacom_handle_coordinates_response(wacom);

			break;

		}

	}

	complete(&wacom->cmd_done);

}

static void wacom_handle_packet(struct wacom *wacom)

{

	u8 in_proximity_p, stylus_p, button;

	unsigned int tool;

	int x, y, z;

	in_proximity_p = wacom->data[0] & 0x40;

	stylus_p = wacom->data[0] & 0x20;

	button = (wacom->data[3] & 0x78) >> 3;

	x = (wacom->data[0] & 3) << 14 | wacom->data[1]<<7 | wacom->data[2];

	y = (wacom->data[3] & 3) << 14 | wacom->data[4]<<7 | wacom->data[5];

	if (in_proximity_p && stylus_p) {

		z = wacom->data[6] & 0x7f;

		if (wacom->extra_z_bits >= 1)

			z = z << 1 | (wacom->data[3] & 0x4) >> 2;

		if (wacom->extra_z_bits > 1)

			z = z << 1 | (wacom->data[0] & 0x4) >> 2;

		z = z ^ (0x40 << wacom->extra_z_bits);

	} else {

		z = -1;

	}

	if (stylus_p)

		tool = (button & wacom->eraser_mask) ? ERASER : STYLUS;

	else

		tool = CURSOR;

	if (tool != wacom->tool && wacom->tool != 0) {

		input_report_key(wacom->dev, tools[wacom->tool].input_id, 0);

		input_sync(wacom->dev);

	}

	wacom->tool = tool;

	input_report_key(wacom->dev, tools[tool].input_id, in_proximity_p);

	input_report_abs(wacom->dev, ABS_MISC,

			 in_proximity_p ? tools[tool].device_id : 0);

	input_report_abs(wacom->dev, ABS_X, x);

	input_report_abs(wacom->dev, ABS_Y, y);

	input_report_abs(wacom->dev, ABS_PRESSURE, z);

	if (stylus_p) {

		input_report_key(wacom->dev, BTN_TOUCH, button & 1);

		input_report_key(wacom->dev, BTN_STYLUS, button & 2);

		input_report_key(wacom->dev, BTN_STYLUS2, button & 4);

	} else {

		input_report_key(wacom->dev, BTN_LEFT, button & 1);

		input_report_key(wacom->dev, BTN_RIGHT, button & 2);

		input_report_key(wacom->dev, BTN_MIDDLE, button & 4);

		/* handle relative wheel for non-stylus device */

		z = (wacom->data[6] & 0x30) >> 4;

		if (wacom->data[6] & 0x40)

			z = -z;

		input_report_rel(wacom->dev, REL_WHEEL, z);

	}

	input_sync(wacom->dev);

}

static void wacom_clear_data_buf(struct wacom *wacom)

{

	memset(wacom->data, 0, DATA_SIZE);

	wacom->idx = 0;

}

static irqreturn_t wacom_interrupt(struct serio *serio, unsigned char data,

				   unsigned int flags)

{

	struct wacom *wacom = serio_get_drvdata(serio);

	if (data & 0x80)

		wacom->idx = 0;

	/*

	 * We're either expecting a carriage return-terminated ASCII

	 * response string, or a seven-byte packet with the MSB set on

	 * the first byte.

	 *

	 * Note however that some tablets (the PenPartner, for

	 * example) don't send a carriage return at the end of a

	 * command.  We handle these by waiting for timeout.

	 */

	if (data == '\r' && !(wacom->data[0] & 0x80)) {

		wacom_handle_response(wacom);

		wacom_clear_data_buf(wacom);

		return IRQ_HANDLED;

	}

	/* Leave place for 0 termination */

	if (wacom->idx > (DATA_SIZE - 2)) {

		dev_dbg(&wacom->dev->dev,

			"throwing away %d bytes of garbage\n", wacom->idx);

		wacom_clear_data_buf(wacom);

	}

	wacom->data[wacom->idx++] = data;

	if (wacom->idx == PACKET_LENGTH && (wacom->data[0] & 0x80)) {

		wacom_handle_packet(wacom);

		wacom_clear_data_buf(wacom);

	}

	return IRQ_HANDLED;

}

static void wacom_disconnect(struct serio *serio)

{

	struct wacom *wacom = serio_get_drvdata(serio);

	serio_close(serio);

	serio_set_drvdata(serio, NULL);

	input_unregister_device(wacom->dev);

	kfree(wacom);

}

static int wacom_send(struct serio *serio, const u8 *command)

{

	int err = 0;

	for (; !err && *command; command++)

		err = serio_write(serio, *command);

	return err;

}

static int wacom_send_setup_string(struct wacom *wacom, struct serio *serio)

{

	const u8 *cmd;

	switch (wacom->dev->id.version) {

	case MODEL_CINTIQ:	/* UNTESTED */

		cmd = COMMAND_ORIGIN_IN_UPPER_LEFT

			COMMAND_TRANSMIT_AT_MAX_RATE

			COMMAND_ENABLE_CONTINUOUS_MODE

			COMMAND_START_SENDING_PACKETS;

		break;

	case MODEL_PENPARTNER:

		cmd = COMMAND_ENABLE_PRESSURE_MODE

			COMMAND_START_SENDING_PACKETS;

		break;

	default:

		cmd = COMMAND_MULTI_MODE_INPUT

			COMMAND_ORIGIN_IN_UPPER_LEFT

			COMMAND_ENABLE_ALL_MACRO_BUTTONS

			COMMAND_DISABLE_GROUP_1_MACRO_BUTTONS

			COMMAND_TRANSMIT_AT_MAX_RATE

			COMMAND_DISABLE_INCREMENTAL_MODE

			COMMAND_ENABLE_CONTINUOUS_MODE

			COMMAND_Z_FILTER

			COMMAND_START_SENDING_PACKETS;

		break;

	}

	return wacom_send(serio, cmd);

}

static int wacom_send_and_wait(struct wacom *wacom, struct serio *serio,

			       const u8 *cmd, const char *desc)

{

	int err;

	unsigned long u;

	wacom->expect = cmd[1];

	init_completion(&wacom->cmd_done);

	err = wacom_send(serio, cmd);

	if (err)

		return err;

	u = wait_for_completion_timeout(&wacom->cmd_done, HZ);

	if (u == 0) {

		/* Timeout, process what we've received. */

		wacom_handle_response(wacom);

	}

	wacom->expect = 0;

	return wacom->result;

}

static int wacom_setup(struct wacom *wacom, struct serio *serio)

{

	int err;

	/* Note that setting the link speed is the job of inputattach.

	 * We assume that reset negotiation has already happened,

	 * here. */

	err = wacom_send_and_wait(wacom, serio, REQUEST_MODEL_AND_ROM_VERSION,

				  "model and version");

	if (err)

		return err;

	if (!(wacom->res_x && wacom->res_y)) {

		err = wacom_send_and_wait(wacom, serio,

					  REQUEST_CONFIGURATION_STRING,

					  "configuration string");

		if (err)

			return err;

	}

	if (!(wacom->max_x && wacom->max_y)) {

		err = wacom_send_and_wait(wacom, serio,

					  REQUEST_MAX_COORDINATES,

					  "coordinates string");

		if (err)

			return err;

	}

	return wacom_send_setup_string(wacom, serio);

}

static int wacom_connect(struct serio *serio, struct serio_driver *drv)

{

	struct wacom *wacom;

	struct input_dev *input_dev;

	int err = -ENOMEM;

	wacom = kzalloc(sizeof(struct wacom), GFP_KERNEL);

	input_dev = input_allocate_device();

	if (!wacom || !input_dev)

		goto free_device;

	wacom->dev = input_dev;

	wacom->extra_z_bits = 1;

	wacom->eraser_mask = 0x04;

	wacom->tool = wacom->idx = 0;

	snprintf(wacom->phys, sizeof(wacom->phys), "%s/input0", serio->phys);

	input_dev->phys = wacom->phys;

	input_dev->id.bustype = BUS_RS232;

	input_dev->id.vendor  = SERIO_WACOM_IV;

	input_dev->id.product = serio->id.extra;

	input_dev->dev.parent = &serio->dev;

	input_dev->evbit[0] =

		BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) | BIT_MASK(EV_REL);

	set_bit(ABS_MISC, input_dev->absbit);

	set_bit(BTN_TOOL_PEN, input_dev->keybit);

	set_bit(BTN_TOOL_RUBBER, input_dev->keybit);

	set_bit(BTN_TOOL_MOUSE, input_dev->keybit);

	set_bit(BTN_TOUCH, input_dev->keybit);

	set_bit(BTN_STYLUS, input_dev->keybit);

	set_bit(BTN_LEFT, input_dev->keybit);

	set_bit(BTN_RIGHT, input_dev->keybit);

	set_bit(BTN_MIDDLE, input_dev->keybit);

	serio_set_drvdata(serio, wacom);

	err = serio_open(serio, drv);

	if (err)

		goto free_device;

	err = wacom_setup(wacom, serio);

	if (err)

		goto close_serio;

	set_bit(INPUT_PROP_DIRECT, input_dev->propbit);

	if (!(wacom->flags & F_COVERS_SCREEN))

		__set_bit(INPUT_PROP_POINTER, input_dev->propbit);

	if (wacom->flags & F_HAS_STYLUS2)

		__set_bit(BTN_STYLUS2, input_dev->keybit);

	if (wacom->flags & F_HAS_SCROLLWHEEL)

		__set_bit(REL_WHEEL, input_dev->relbit);

	input_abs_set_res(wacom->dev, ABS_X, wacom->res_x);

	input_abs_set_res(wacom->dev, ABS_Y, wacom->res_y);

	input_set_abs_params(wacom->dev, ABS_X, 0, wacom->max_x, 0, 0);

	input_set_abs_params(wacom->dev, ABS_Y, 0, wacom->max_y, 0, 0);

	input_set_abs_params(wacom->dev, ABS_PRESSURE, -1,

			     (1 << (7 + wacom->extra_z_bits)) - 1, 0, 0);

	err = input_register_device(wacom->dev);

	if (err)

		goto close_serio;

	return 0;

close_serio:

	serio_close(serio);

free_device:

	serio_set_drvdata(serio, NULL);

	input_free_device(input_dev);

	kfree(wacom);

	return err;

}

static struct serio_device_id wacom_serio_ids[] = {

	{

		.type	= SERIO_RS232,

		.proto	= SERIO_WACOM_IV,

		.id	= SERIO_ANY,

		.extra	= SERIO_ANY,

	},

	{ 0 }

};

MODULE_DEVICE_TABLE(serio, wacom_serio_ids);

static struct serio_driver wacom_drv = {

	.driver		= {

		.name	= "wacom_serial4",

	},

	.description	= "Wacom protocol 4 serial tablet driver",

	.id_table	= wacom_serio_ids,

	.interrupt	= wacom_interrupt,

	.connect	= wacom_connect,

	.disconnect	= wacom_disconnect,

};

module_serio_driver(wacom_drv);

#define SERIO_HAMPSHIRE	0x3b

#define SERIO_PS2MULT	0x3c

#define SERIO_TSC40	0x3d

#define SERIO_WACOM_IV	0x3e

#endif /* _UAPI_SERIO_H */