Liyitec PS/2 touch panel driver [PATCH]

[Shaun Jackman <sjackman@gmail.com>]

I've written an input driver for the Liyitec PS/2 touch panel. The
patch follows. As this is my first input driver, I'd appreciate any
feedback.

Please cc me in your reply. Cheers,
Shaun

2006-01-31  Shaun Jackman  <sjackman@gmail.com>

	* drivers/input/touchscreen/Kconfig (TOUCHSCREEN_LIYITEC): New item.
	* drivers/input/touchscreen/Makefile: Add liyitec driver.
	* drivers/input/touchscreen/liyitec.c: New file.
	* include/linux/serio.h (SERIO_LIYITEC): New constant.

--- linux-2.6.15.orig/drivers/input/touchscreen/Kconfig	2006-01-02
20:21:10.000000000 -0700
+++ linux-2.6.15/drivers/input/touchscreen/Kconfig	2006-01-31
15:56:36.000000000 -0700
@@ -60,6 +60,19 @@
 	  To compile this driver as a module, choose M here: the
  	  module will be called elo.

+config TOUCHSCREEN_LIYITEC
+	tristate "Lyitec PS/2 touchscreen"
+	select SERIO
+	select SERIO_I8042 if X86_PC
+	help
+	  Say Y here if you have a Liyitec PS/2 touchscreen connected to
+	  your system.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called liyitec.
+
  config TOUCHSCREEN_MTOUCH
  	tristate "MicroTouch serial touchscreens"
  	select SERIO
--- linux-2.6.15.orig/drivers/input/touchscreen/Makefile	2006-01-02
20:21:10.000000000 -0700
+++ linux-2.6.15/drivers/input/touchscreen/Makefile	2006-01-27
16:01:39.000000000 -0700
@@ -8,6 +8,7 @@
 obj-$(CONFIG_TOUCHSCREEN_CORGI)	+= corgi_ts.o
  obj-$(CONFIG_TOUCHSCREEN_GUNZE)	+= gunze.o
  obj-$(CONFIG_TOUCHSCREEN_ELO)	+= elo.o
+obj-$(CONFIG_TOUCHSCREEN_LIYITEC) += liyitec.o
  obj-$(CONFIG_TOUCHSCREEN_MTOUCH) += mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)	+= mk712.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)	+= hp680_ts_input.o
--- linux-2.6.15.orig/drivers/input/touchscreen/liyitec.c	1969-12-31
17:00:00.000000000 -0700
+++ linux-2.6.15/drivers/input/touchscreen/liyitec.c	2006-01-31
15:06:49.000000000 -0700
@@ -0,0 +1,188 @@
+/* Liyitec PS/2 touch panel driver
+ * Written by Shaun Jackman <sjackman@gmail.com>.
+ * Copyright 2006 Pathway Connectivity
+ *
+ * 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.
+ *
+ * This driver was derived from mtouch.c.
+ */
+
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/serio.h>
+
+#define DRIVER_DESC "Liyitec PS/2 touch panel driver"
+
+MODULE_AUTHOR("Shaun Jackman <sjackman@gmail.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define LIYITEC_MAX_X 0x3ff
+#define LIYITEC_MAX_Y 0x3ff
+
+#define LIYITEC_Y9    0x80
+#define LIYITEC_X9    0x40
+#define LIYITEC_Y8    0x20
+#define LIYITEC_X8    0x10
+#define LIYITEC_SYNC  0x08
+#define LIYITEC_ABS   0x04
+#define LIYITEC_RIGHT 0x02
+#define LIYITEC_TOUCH 0x01
+
+#define LIYITEC_PACKET_SIZE 3
+#define LIYITEC_CMD_ENABLE    0xf4
+#define LIYITEC_CMD_SETSTREAM 0xea
+#define LIYITEC_RET_ACK       0xfa
+
+struct liyitec {
+	struct input_dev *dev;
+	struct serio *serio;
+	char phys[32];
+	signed char count;
+	unsigned char data[LIYITEC_PACKET_SIZE];
+};
+
+static irqreturn_t liyitec_interrupt(struct serio *serio,
+		unsigned char data, unsigned int flags, struct pt_regs *regs)
+{
+	struct liyitec *liyitec = serio_get_drvdata(serio);
+
+	if (liyitec->count < 0) {
+		if (data != LIYITEC_RET_ACK)
+			printk(KERN_DEBUG "liyitec: expected ACK: 0x%02x\n", data);
+	} else
+		liyitec->data[liyitec->count] = data;
+	liyitec->count++;
+
+	if (liyitec->count == 1 && !(data & LIYITEC_SYNC)) {
+		printk(KERN_DEBUG "liyitec: unsynchronized data: 0x%02x\n", data);
+		liyitec->count = 0;
+	}
+	else if (liyitec->count == LIYITEC_PACKET_SIZE) {
+		struct input_dev *dev = liyitec->dev;
+		input_regs(dev, regs);
+		if (liyitec->data[0] & LIYITEC_ABS) {
+			unsigned x = liyitec->data[1] +
+				(liyitec->data[0] & LIYITEC_X8 ? 0x100 : 0) +
+				(liyitec->data[0] & LIYITEC_X9 ? 0x200 : 0);
+			unsigned y = liyitec->data[2] +
+				(liyitec->data[0] & LIYITEC_Y8 ? 0x100 : 0) +
+				(liyitec->data[0] & LIYITEC_Y9 ? 0x200 : 0);
+			input_report_abs(dev, ABS_X, x);
+			input_report_abs(dev, ABS_Y, y);
+			printk(KERN_DEBUG "liyitec: (%d,%d)\n", x, y); //xxx
+		}
+		input_report_key(dev, BTN_TOUCH, liyitec->data[0] & LIYITEC_TOUCH);
+		input_report_key(dev, BTN_RIGHT, liyitec->data[0] & LIYITEC_RIGHT);
+		printk(KERN_DEBUG "liyitec: %02x\n", liyitec->data[0]); //xxx
+		input_sync(dev);
+		liyitec->count = 0;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int liyitec_connect(struct serio *serio, struct serio_driver *drv)
+{
+	struct liyitec *liyitec;
+	struct input_dev *input_dev;
+	int retval;
+
+	liyitec = kzalloc(sizeof *liyitec, GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (liyitec == NULL || input_dev == NULL) {
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	liyitec->serio = serio;
+	liyitec->dev = input_dev;
+	sprintf(liyitec->phys, "%s/input0", serio->phys);
+
+	input_dev->private = liyitec;
+	input_dev->name = "Liyitec PS/2 touch screen";
+	input_dev->phys = liyitec->phys;
+	input_dev->id.bustype = BUS_I8042;
+	input_dev->id.vendor = SERIO_LIYITEC;
+	input_dev->id.product = 0;
+	input_dev->id.version = 0x0100;
+	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
+	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
+	input_dev->keybit[LONG(BTN_MOUSE)] = BIT(BTN_RIGHT);
+	input_set_abs_params(liyitec->dev, ABS_X, 0, LIYITEC_MAX_X, 0, 0);
+	input_set_abs_params(liyitec->dev, ABS_Y, 0, LIYITEC_MAX_Y, 0, 0);
+
+	serio_set_drvdata(serio, liyitec);
+	retval = serio_open(serio, drv);
+	if (retval)
+		goto out;
+	input_register_device(liyitec->dev);
+
+	liyitec->count = -2;
+	retval = serio_write(serio, LIYITEC_CMD_SETSTREAM);
+	if (retval)
+		goto out;
+	retval = serio_write(serio, LIYITEC_CMD_ENABLE);
+
+out:
+	if (retval) {
+		serio_set_drvdata(serio, NULL);
+		input_free_device(input_dev);
+		kfree(liyitec);
+	}
+	return retval;
+}
+
+static void liyitec_disconnect(struct serio *serio)
+{
+	struct liyitec *liyitec = serio_get_drvdata(serio);
+
+	input_get_device(liyitec->dev);
+	input_unregister_device(liyitec->dev);
+	serio_close(serio);
+	serio_set_drvdata(serio, NULL);
+	input_put_device(liyitec->dev);
+	kfree(liyitec);
+}
+
+static struct serio_device_id liyitec_serio_ids[] = {
+	{
+		.type  = SERIO_8042,
+		.proto = SERIO_ANY,
+		.id    = SERIO_ANY,
+		.extra = SERIO_ANY,
+	},
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, liyitec_serio_ids);
+
+static struct serio_driver liyitec_drv = {
+	.driver = {
+		.name = "liyitec",
+	},
+	.description = DRIVER_DESC,
+	.id_table    = liyitec_serio_ids,
+	.interrupt   = liyitec_interrupt,
+	.connect     = liyitec_connect,
+	.disconnect  = liyitec_disconnect,
+};
+
+static int __init liyitec_init(void)
+{
+	printk(KERN_INFO "liyitec: %s\n", DRIVER_DESC);
+	serio_register_driver(&liyitec_drv);
+	return 0;
+}
+
+static void __exit liyitec_exit(void)
+{
+	printk(KERN_INFO "liyitec: %s\n", __func__);
+	serio_unregister_driver(&liyitec_drv);
+}
+
+module_init(liyitec_init);
+module_exit(liyitec_exit);
--- linux-2.6.15.orig/include/linux/serio.h	2006-01-02 20:21:10.000000000 -0700
+++ linux-2.6.15/include/linux/serio.h	2006-01-27 16:57:57.000000000 -0700
@@ -216,5 +216,6 @@
 #define SERIO_LKKBD	0x28
 #define SERIO_ELO	0x29
 #define SERIO_MICROTOUCH	0x30
+#define SERIO_LIYITEC	0x31

  #endif
-
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