/* * Sahara TouchIT-213 serial touchscreen driver * * Copyright (c) 2007-2008 Claudio Nieder <private@claudio.ch> * * Based on Touchright driver (drivers/input/touchscreen/touchright.c) * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com> * Copyright (c) 2004 Vojtech Pavlik * and Dan Streetman <ddstreet@ieee.org> */ /* * 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. */ #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 "Sahara TouchIT-213 serial touchscreen driver" MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>"); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); /* * Definitions & global arrays. */ /* * Data is received through COM1 at 9600bit/s,8bit,no parity in packets * of 5 byte each. * * +--------+ +--------+ +--------+ +--------+ +--------+ * |1000000p| |0xxxxxxx| |0xxxxxxx| |0yyyyyyy| |0yyyyyyy| * +--------+ +--------+ +--------+ +--------+ +--------+ * MSB LSB MSB LSB * * The value of p is 1 as long as the screen is touched and 0 when * reporting the location where touching stopped, e.g. where the pen was * lifted from the screen. * * When holding the screen in landscape mode as the BIOS text output is * presented, x is the horizontal axis with values growing from left to * right and y is the vertical axis with values growing from top to * bottom. * * When holding the screen in portrait mode with the Sahara logo in its * correct position, x ist the vertical axis with values growing from * top to bottom and y is the horizontal axis with values growing from * right to left. */ #define T213_FORMAT_TOUCH_BIT 0x01 #define T213_FORMAT_STATUS_BYTE 0x80 #define T213_FORMAT_STATUS_MASK ~T213_FORMAT_TOUCH_BIT /* * On my Sahara Touch-IT 213 I have observed x values from 0 to 0x7f0 * and y values from 0x1d to 0x7e9, so the actual measurement is * probably done with an 11 bit precision. */ #define T213_MIN_XC 0 #define T213_MAX_XC 0x07ff #define T213_MIN_YC 0 #define T213_MAX_YC 0x07ff /* * Per-touchscreen data. */ struct touchit213 { struct input_dev *dev; struct serio *serio; int idx; unsigned char csum; unsigned char data[5]; char phys[32]; }; static irqreturn_t touchit213_interrupt(struct serio *serio, unsigned char data, unsigned int flags) { struct touchit213 *touchit213 = serio_get_drvdata(serio); struct input_dev *dev = touchit213->dev; touchit213->data[touchit213->idx] = data; switch (touchit213->idx++) { case 0: if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) != T213_FORMAT_STATUS_BYTE) { pr_debug("unsynchronized data: 0x%02x\n", data); touchit213->idx = 0; } break; case 4: touchit213->idx = 0; input_report_abs(dev, ABS_X, (touchit213->data[1] << 7) | touchit213->data[2]); input_report_abs(dev, ABS_Y, (touchit213->data[3] << 7) | touchit213->data[4]); input_report_key(dev, BTN_TOUCH, touchit213->data[0] & T213_FORMAT_TOUCH_BIT); input_sync(dev); break; } return IRQ_HANDLED; } /* * touchit213_disconnect() is the opposite of touchit213_connect() */ static void touchit213_disconnect(struct serio *serio) { struct touchit213 *touchit213 = serio_get_drvdata(serio); input_get_device(touchit213->dev); input_unregister_device(touchit213->dev); serio_close(serio); serio_set_drvdata(serio, NULL); input_put_device(touchit213->dev); kfree(touchit213); } /* * touchit213_connect() is the routine that is called when someone adds a * new serio device that supports the Touchright protocol and registers it as * an input device. */ static int touchit213_connect(struct serio *serio, struct serio_driver *drv) { struct touchit213 *touchit213; struct input_dev *input_dev; int err; touchit213 = kzalloc(sizeof(struct touchit213), GFP_KERNEL); input_dev = input_allocate_device(); if (!touchit213 || !input_dev) { err = -ENOMEM; goto fail1; } touchit213->serio = serio; touchit213->dev = input_dev; snprintf(touchit213->phys, sizeof(touchit213->phys), "%s/input0", serio->phys); input_dev->name = "Sahara Touch-iT213 Serial TouchScreen"; input_dev->phys = touchit213->phys; input_dev->id.bustype = BUS_RS232; input_dev->id.vendor = SERIO_TOUCHIT213; input_dev->id.product = 0; input_dev->id.version = 0x0100; 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(touchit213->dev, ABS_X, T213_MIN_XC, T213_MAX_XC, 0, 0); input_set_abs_params(touchit213->dev, ABS_Y, T213_MIN_YC, T213_MAX_YC, 0, 0); serio_set_drvdata(serio, touchit213); err = serio_open(serio, drv); if (err) goto fail2; err = input_register_device(touchit213->dev); if (err) goto fail3; return 0; fail3: serio_close(serio); fail2: serio_set_drvdata(serio, NULL); fail1: input_free_device(input_dev); kfree(touchit213); return err; } /* * The serio driver structure. */ static struct serio_device_id touchit213_serio_ids[] = { { .type = SERIO_RS232, .proto = SERIO_TOUCHIT213, .id = SERIO_ANY, .extra = SERIO_ANY, }, { 0 } }; MODULE_DEVICE_TABLE(serio, touchit213_serio_ids); static struct serio_driver touchit213_drv = { .driver = { .name = "touchit213", }, .description = DRIVER_DESC, .id_table = touchit213_serio_ids, .interrupt = touchit213_interrupt, .connect = touchit213_connect, .disconnect = touchit213_disconnect, }; /* * The functions for inserting/removing us as a module. */ static int __init touchit213_init(void) { return serio_register_driver(&touchit213_drv); } static void __exit touchit213_exit(void) { serio_unregister_driver(&touchit213_drv); } module_init(touchit213_init); module_exit(touchit213_exit);