input: Add MicroTouch (3M) serial touchscreen driver

From: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>

drivers/input/touchscreen/Kconfig

@@ -60,6 +60,17 @@ config TOUCHSCREEN_ELO
 	  To compile this driver as a module, choose M here: the
 	  module will be called gunze.
 
+config TOUCHSCREEN_MTOUCH
+	tristate "MicroTouch serial touchscreens"
+	select SERIO
+	help
+	  Say Y here if you have a MicroTouch (3M) serial touchscreen connected to
+	  your system.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mtouch.
 
 config TOUCHSCREEN_MK712
 	tristate "ICS MicroClock MK712 touchscreen"

drivers/input/touchscreen/Makefile

@@ -8,4 +8,5 @@ obj-$(CONFIG_TOUCHSCREEN_BITSY)	+= h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_CORGI)	+= corgi_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)	+= gunze.o
 obj-$(CONFIG_TOUCHSCREEN_ELO)	+= elo.o
+obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)	+= mk712.o

drivers/input/touchscreen/mtouch.c

+/*
+ * MicroTouch (3M) serial touchscreen driver
+ *
+ * Copyright (c) 2004 Vojtech Pavlik
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+/*
+ * 2005/02/19 Dan Streetman <ddstreet@ieee.org>
+ *   Copied elo.c and edited for MicroTouch protocol
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/init.h>
+
+#define DRIVER_DESC	"MicroTouch serial touchscreen driver"
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+/*
+ * Definitions & global arrays.
+ */
+
+#define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80
+#define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40
+#define MTOUCH_FORMAT_TABLET_LENGTH 5
+#define MTOUCH_RESPONSE_BEGIN_BYTE 0x01
+#define MTOUCH_RESPONSE_END_BYTE 0x0d
+
+/* todo: check specs for max length of all responses */
+#define MTOUCH_MAX_LENGTH 16
+
+#define MTOUCH_MIN_XC 0
+#define MTOUCH_MAX_XC 0x3fff
+#define MTOUCH_MIN_YC 0
+#define MTOUCH_MAX_YC 0x3fff
+
+#define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1])
+#define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3])
+#define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0])
+
+static char *mtouch_name = "MicroTouch Serial TouchScreen";
+
+/*
+ * Per-touchscreen data.
+ */
+
+struct mtouch {
+	struct input_dev dev;
+	struct serio *serio;
+	int idx;
+	unsigned char data[MTOUCH_MAX_LENGTH];
+	char phys[32];
+};
+
+static void mtouch_process_format_tablet(struct mtouch *mtouch, struct pt_regs *regs)
+{
+	struct input_dev *dev = &mtouch->dev;
+
+	if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
+		input_regs(dev, regs);
+		input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
+		input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
+		input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
+		input_sync(dev);
+
+		mtouch->idx = 0;
+	}
+}
+
+static void mtouch_process_response(struct mtouch *mtouch, struct pt_regs *regs)
+{
+	if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
+		/* FIXME - process response */
+		mtouch->idx = 0;
+	} else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
+		printk(KERN_ERR "mtouch.c: too many response bytes\n");
+		mtouch->idx = 0;
+	}
+}
+
+static irqreturn_t mtouch_interrupt(struct serio *serio,
+		unsigned char data, unsigned int flags, struct pt_regs *regs)
+{
+	struct mtouch* mtouch = serio_get_drvdata(serio);
+
+	mtouch->data[mtouch->idx] = data;
+
+	if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
+		mtouch_process_format_tablet(mtouch, regs);
+	else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
+		mtouch_process_response(mtouch, regs);
+	else
+		printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * mtouch_disconnect() is the opposite of mtouch_connect()
+ */
+
+static void mtouch_disconnect(struct serio *serio)
+{
+	struct mtouch* mtouch = serio_get_drvdata(serio);
+
+	input_unregister_device(&mtouch->dev);
+	serio_close(serio);
+	serio_set_drvdata(serio, NULL);
+	kfree(mtouch);
+}
+
+/*
+ * mtouch_connect() is the routine that is called when someone adds a
+ * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as
+ * an input device.
+ */
+
+static int mtouch_connect(struct serio *serio, struct serio_driver *drv)
+{
+	struct mtouch *mtouch;
+	int err;
+
+	if (!(mtouch = kmalloc(sizeof(*mtouch), GFP_KERNEL)))
+		return -ENOMEM;
+
+	memset(mtouch, 0, sizeof(*mtouch));
+
+	init_input_dev(&mtouch->dev);
+	mtouch->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
+	mtouch->dev.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
+
+	input_set_abs_params(&mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
+	input_set_abs_params(&mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);
+
+	mtouch->serio = serio;
+
+	sprintf(mtouch->phys, "%s/input0", serio->phys);
+
+	mtouch->dev.private = mtouch;
+	mtouch->dev.name = mtouch_name;
+	mtouch->dev.phys = mtouch->phys;
+	mtouch->dev.id.bustype = BUS_RS232;
+	mtouch->dev.id.vendor = SERIO_MICROTOUCH;
+	mtouch->dev.id.product = 0;
+	mtouch->dev.id.version = 0x0100;
+
+	serio_set_drvdata(serio, mtouch);
+
+	err = serio_open(serio, drv);
+	if (err) {
+		serio_set_drvdata(serio, NULL);
+		kfree(mtouch);
+		return err;
+	}
+
+	input_register_device(&mtouch->dev);
+
+	printk(KERN_INFO "input: %s on %s\n", mtouch->dev.name, serio->phys);
+
+	return 0;
+}
+
+/*
+ * The serio driver structure.
+ */
+
+static struct serio_device_id mtouch_serio_ids[] = {
+	{
+		.type	= SERIO_RS232,
+		.proto	= SERIO_MICROTOUCH,
+		.id	= SERIO_ANY,
+		.extra	= SERIO_ANY,
+	},
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);
+
+static struct serio_driver mtouch_drv = {
+	.driver		= {
+		.name	= "mtouch",
+	},
+	.description	= DRIVER_DESC,
+	.id_table	= mtouch_serio_ids,
+	.interrupt	= mtouch_interrupt,
+	.connect	= mtouch_connect,
+	.disconnect	= mtouch_disconnect,
+};
+
+/*
+ * The functions for inserting/removing us as a module.
+ */
+
+static int __init mtouch_init(void)
+{
+	serio_register_driver(&mtouch_drv);
+	return 0;
+}
+
+static void __exit mtouch_exit(void)
+{
+	serio_unregister_driver(&mtouch_drv);
+}
+
+module_init(mtouch_init);
+module_exit(mtouch_exit);

include/linux/serio.h

@@ -209,5 +209,6 @@ static inline void serio_unpin_driver(struct serio *serio)
 #define SERIO_SEMTECH	0x27
 #define SERIO_LKKBD	0x28
 #define SERIO_ELO	0x29
+#define SERIO_MICROTOUCH	0x30
 
 #endif