--- /dev/null
+/*
+ * Hampshire serial touchscreen driver
+ *
+ * Copyright (c) 2010 Adam Bennett
+ * Based on the dynapro driver (c) Tias Guns
+ *
+ */
+
+/*
+ * 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.
+ */
+
+/*
+ * 2010/04/08 Adam Bennett <abennett72@gmail.com>
+ * Copied dynapro.c and edited for Hampshire 4-byte 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 "Hampshire serial touchscreen driver"
+
+MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+/*
+ * Definitions & global arrays.
+ */
+
+#define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40
+#define HAMPSHIRE_FORMAT_LENGTH 4
+#define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80
+
+#define HAMPSHIRE_MIN_XC 0
+#define HAMPSHIRE_MAX_XC 0x1000
+#define HAMPSHIRE_MIN_YC 0
+#define HAMPSHIRE_MAX_YC 0x1000
+
+#define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6))
+#define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9))
+#define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0])
+
+/*
+ * Per-touchscreen data.
+ */
+
+struct hampshire {
+ struct input_dev *dev;
+ struct serio *serio;
+ int idx;
+ unsigned char data[HAMPSHIRE_FORMAT_LENGTH];
+ char phys[32];
+};
+
+static void hampshire_process_data(struct hampshire *phampshire)
+{
+ struct input_dev *dev = phampshire->dev;
+
+ if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) {
+ input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data));
+ input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data));
+ input_report_key(dev, BTN_TOUCH,
+ HAMPSHIRE_GET_TOUCHED(phampshire->data));
+ input_sync(dev);
+
+ phampshire->idx = 0;
+ }
+}
+
+static irqreturn_t hampshire_interrupt(struct serio *serio,
+ unsigned char data, unsigned int flags)
+{
+ struct hampshire *phampshire = serio_get_drvdata(serio);
+
+ phampshire->data[phampshire->idx] = data;
+
+ if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0])
+ hampshire_process_data(phampshire);
+ else
+ dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
+ phampshire->data[0]);
+
+ return IRQ_HANDLED;
+}
+
+static void hampshire_disconnect(struct serio *serio)
+{
+ struct hampshire *phampshire = serio_get_drvdata(serio);
+
+ input_get_device(phampshire->dev);
+ input_unregister_device(phampshire->dev);
+ serio_close(serio);
+ serio_set_drvdata(serio, NULL);
+ input_put_device(phampshire->dev);
+ kfree(phampshire);
+}
+
+/*
+ * hampshire_connect() is the routine that is called when someone adds a
+ * new serio device that supports hampshire protocol and registers it as
+ * an input device. This is usually accomplished using inputattach.
+ */
+
+static int hampshire_connect(struct serio *serio, struct serio_driver *drv)
+{
+ struct hampshire *phampshire;
+ struct input_dev *input_dev;
+ int err;
+
+ phampshire = kzalloc(sizeof(struct hampshire), GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!phampshire || !input_dev) {
+ err = -ENOMEM;
+ goto fail1;
+ }
+
+ phampshire->serio = serio;
+ phampshire->dev = input_dev;
+ snprintf(phampshire->phys, sizeof(phampshire->phys),
+ "%s/input0", serio->phys);
+
+ input_dev->name = "Hampshire Serial TouchScreen";
+ input_dev->phys = phampshire->phys;
+ input_dev->id.bustype = BUS_RS232;
+ input_dev->id.vendor = SERIO_HAMPSHIRE;
+ input_dev->id.product = 0;
+ input_dev->id.version = 0x0001;
+ input_dev->dev.parent = &serio->dev;
+ input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+ input_set_abs_params(phampshire->dev, ABS_X,
+ HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0);
+ input_set_abs_params(phampshire->dev, ABS_Y,
+ HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0);
+
+ serio_set_drvdata(serio, phampshire);
+
+ err = serio_open(serio, drv);
+ if (err)
+ goto fail2;
+
+ err = input_register_device(phampshire->dev);
+ if (err)
+ goto fail3;
+
+ return 0;
+
+ fail3: serio_close(serio);
+ fail2: serio_set_drvdata(serio, NULL);
+ fail1: input_free_device(input_dev);
+ kfree(phampshire);
+ return err;
+}
+
+/*
+ * The serio driver structure.
+ */
+
+static struct serio_device_id hampshire_serio_ids[] = {
+ {
+ .type = SERIO_RS232,
+ .proto = SERIO_HAMPSHIRE,
+ .id = SERIO_ANY,
+ .extra = SERIO_ANY,
+ },
+ { 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, hampshire_serio_ids);
+
+static struct serio_driver hampshire_drv = {
+ .driver = {
+ .name = "hampshire",
+ },
+ .description = DRIVER_DESC,
+ .id_table = hampshire_serio_ids,
+ .interrupt = hampshire_interrupt,
+ .connect = hampshire_connect,
+ .disconnect = hampshire_disconnect,
+};
+
+/*
+ * The functions for inserting/removing us as a module.
+ */
+
+static int __init hampshire_init(void)
+{
+ return serio_register_driver(&hampshire_drv);
+}
+
+static void __exit hampshire_exit(void)
+{
+ serio_unregister_driver(&hampshire_drv);
+}
+
+module_init(hampshire_init);
+module_exit(hampshire_exit);