1/* 2 * Touchwindow serial touchscreen driver 3 * 4 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com> 5 * 6 * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c) 7 * Copyright (c) 2004 Vojtech Pavlik 8 * and Dan Streetman <ddstreet@ieee.org> 9 */ 10 11/* 12 * This program is free software; you can redistribute it and/or modify it 13 * under the terms of the GNU General Public License version 2 as published 14 * by the Free Software Foundation. 15 */ 16 17/* 18 * 2005/02/19 Rick Koch: 19 * The Touchwindow I used is made by Edmark Corp. and 20 * constantly outputs a stream of 0's unless it is touched. 21 * It then outputs 3 bytes: X, Y, and a copy of Y. 22 */ 23 24#include <linux/errno.h> 25#include <linux/kernel.h> 26#include <linux/module.h> 27#include <linux/slab.h> 28#include <linux/input.h> 29#include <linux/serio.h> 30#include <linux/init.h> 31 32#define DRIVER_DESC "Touchwindow serial touchscreen driver" 33 34MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>"); 35MODULE_DESCRIPTION(DRIVER_DESC); 36MODULE_LICENSE("GPL"); 37 38/* 39 * Definitions & global arrays. 40 */ 41 42#define TW_LENGTH 3 43 44#define TW_MIN_XC 0 45#define TW_MAX_XC 0xff 46#define TW_MIN_YC 0 47#define TW_MAX_YC 0xff 48 49/* 50 * Per-touchscreen data. 51 */ 52 53struct tw { 54 struct input_dev *dev; 55 struct serio *serio; 56 int idx; 57 int touched; 58 unsigned char data[TW_LENGTH]; 59 char phys[32]; 60}; 61 62static irqreturn_t tw_interrupt(struct serio *serio, 63 unsigned char data, unsigned int flags) 64{ 65 struct tw *tw = serio_get_drvdata(serio); 66 struct input_dev *dev = tw->dev; 67 68 if (data) { /* touch */ 69 tw->touched = 1; 70 tw->data[tw->idx++] = data; 71 /* verify length and that the two Y's are the same */ 72 if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) { 73 input_report_abs(dev, ABS_X, tw->data[0]); 74 input_report_abs(dev, ABS_Y, tw->data[1]); 75 input_report_key(dev, BTN_TOUCH, 1); 76 input_sync(dev); 77 tw->idx = 0; 78 } 79 } else if (tw->touched) { /* untouch */ 80 input_report_key(dev, BTN_TOUCH, 0); 81 input_sync(dev); 82 tw->idx = 0; 83 tw->touched = 0; 84 } 85 86 return IRQ_HANDLED; 87} 88 89/* 90 * tw_disconnect() is the opposite of tw_connect() 91 */ 92 93static void tw_disconnect(struct serio *serio) 94{ 95 struct tw *tw = serio_get_drvdata(serio); 96 97 input_get_device(tw->dev); 98 input_unregister_device(tw->dev); 99 serio_close(serio); 100 serio_set_drvdata(serio, NULL); 101 input_put_device(tw->dev); 102 kfree(tw); 103} 104 105/* 106 * tw_connect() is the routine that is called when someone adds a 107 * new serio device that supports the Touchwin protocol and registers it as 108 * an input device. 109 */ 110 111static int tw_connect(struct serio *serio, struct serio_driver *drv) 112{ 113 struct tw *tw; 114 struct input_dev *input_dev; 115 int err; 116 117 tw = kzalloc(sizeof(struct tw), GFP_KERNEL); 118 input_dev = input_allocate_device(); 119 if (!tw || !input_dev) { 120 err = -ENOMEM; 121 goto fail1; 122 } 123 124 tw->serio = serio; 125 tw->dev = input_dev; 126 snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys); 127 128 input_dev->name = "Touchwindow Serial TouchScreen"; 129 input_dev->phys = tw->phys; 130 input_dev->id.bustype = BUS_RS232; 131 input_dev->id.vendor = SERIO_TOUCHWIN; 132 input_dev->id.product = 0; 133 input_dev->id.version = 0x0100; 134 input_dev->dev.parent = &serio->dev; 135 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 136 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 137 input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0); 138 input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0); 139 140 serio_set_drvdata(serio, tw); 141 142 err = serio_open(serio, drv); 143 if (err) 144 goto fail2; 145 146 err = input_register_device(tw->dev); 147 if (err) 148 goto fail3; 149 150 return 0; 151 152 fail3: serio_close(serio); 153 fail2: serio_set_drvdata(serio, NULL); 154 fail1: input_free_device(input_dev); 155 kfree(tw); 156 return err; 157} 158 159/* 160 * The serio driver structure. 161 */ 162 163static struct serio_device_id tw_serio_ids[] = { 164 { 165 .type = SERIO_RS232, 166 .proto = SERIO_TOUCHWIN, 167 .id = SERIO_ANY, 168 .extra = SERIO_ANY, 169 }, 170 { 0 } 171}; 172 173MODULE_DEVICE_TABLE(serio, tw_serio_ids); 174 175static struct serio_driver tw_drv = { 176 .driver = { 177 .name = "touchwin", 178 }, 179 .description = DRIVER_DESC, 180 .id_table = tw_serio_ids, 181 .interrupt = tw_interrupt, 182 .connect = tw_connect, 183 .disconnect = tw_disconnect, 184}; 185 186/* 187 * The functions for inserting/removing us as a module. 188 */ 189 190static int __init tw_init(void) 191{ 192 return serio_register_driver(&tw_drv); 193} 194 195static void __exit tw_exit(void) 196{ 197 serio_unregister_driver(&tw_drv); 198} 199 200module_init(tw_init); 201module_exit(tw_exit); 202