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 31 #define DRIVER_DESC "Touchwindow serial touchscreen driver" 32 33 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>"); 34 MODULE_DESCRIPTION(DRIVER_DESC); 35 MODULE_LICENSE("GPL"); 36 37 /* 38 * Definitions & global arrays. 39 */ 40 41 #define TW_LENGTH 3 42 43 #define TW_MIN_XC 0 44 #define TW_MAX_XC 0xff 45 #define TW_MIN_YC 0 46 #define TW_MAX_YC 0xff 47 48 /* 49 * Per-touchscreen data. 50 */ 51 52 struct tw { 53 struct input_dev *dev; 54 struct serio *serio; 55 int idx; 56 int touched; 57 unsigned char data[TW_LENGTH]; 58 char phys[32]; 59 }; 60 61 static irqreturn_t tw_interrupt(struct serio *serio, 62 unsigned char data, unsigned int flags) 63 { 64 struct tw *tw = serio_get_drvdata(serio); 65 struct input_dev *dev = tw->dev; 66 67 if (data) { /* touch */ 68 tw->touched = 1; 69 tw->data[tw->idx++] = data; 70 /* verify length and that the two Y's are the same */ 71 if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) { 72 input_report_abs(dev, ABS_X, tw->data[0]); 73 input_report_abs(dev, ABS_Y, tw->data[1]); 74 input_report_key(dev, BTN_TOUCH, 1); 75 input_sync(dev); 76 tw->idx = 0; 77 } 78 } else if (tw->touched) { /* untouch */ 79 input_report_key(dev, BTN_TOUCH, 0); 80 input_sync(dev); 81 tw->idx = 0; 82 tw->touched = 0; 83 } 84 85 return IRQ_HANDLED; 86 } 87 88 /* 89 * tw_disconnect() is the opposite of tw_connect() 90 */ 91 92 static void tw_disconnect(struct serio *serio) 93 { 94 struct tw *tw = serio_get_drvdata(serio); 95 96 input_get_device(tw->dev); 97 input_unregister_device(tw->dev); 98 serio_close(serio); 99 serio_set_drvdata(serio, NULL); 100 input_put_device(tw->dev); 101 kfree(tw); 102 } 103 104 /* 105 * tw_connect() is the routine that is called when someone adds a 106 * new serio device that supports the Touchwin protocol and registers it as 107 * an input device. 108 */ 109 110 static int tw_connect(struct serio *serio, struct serio_driver *drv) 111 { 112 struct tw *tw; 113 struct input_dev *input_dev; 114 int err; 115 116 tw = kzalloc(sizeof(struct tw), GFP_KERNEL); 117 input_dev = input_allocate_device(); 118 if (!tw || !input_dev) { 119 err = -ENOMEM; 120 goto fail1; 121 } 122 123 tw->serio = serio; 124 tw->dev = input_dev; 125 snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys); 126 127 input_dev->name = "Touchwindow Serial TouchScreen"; 128 input_dev->phys = tw->phys; 129 input_dev->id.bustype = BUS_RS232; 130 input_dev->id.vendor = SERIO_TOUCHWIN; 131 input_dev->id.product = 0; 132 input_dev->id.version = 0x0100; 133 input_dev->dev.parent = &serio->dev; 134 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 135 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 136 input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0); 137 input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0); 138 139 serio_set_drvdata(serio, tw); 140 141 err = serio_open(serio, drv); 142 if (err) 143 goto fail2; 144 145 err = input_register_device(tw->dev); 146 if (err) 147 goto fail3; 148 149 return 0; 150 151 fail3: serio_close(serio); 152 fail2: serio_set_drvdata(serio, NULL); 153 fail1: input_free_device(input_dev); 154 kfree(tw); 155 return err; 156 } 157 158 /* 159 * The serio driver structure. 160 */ 161 162 static const struct serio_device_id tw_serio_ids[] = { 163 { 164 .type = SERIO_RS232, 165 .proto = SERIO_TOUCHWIN, 166 .id = SERIO_ANY, 167 .extra = SERIO_ANY, 168 }, 169 { 0 } 170 }; 171 172 MODULE_DEVICE_TABLE(serio, tw_serio_ids); 173 174 static struct serio_driver tw_drv = { 175 .driver = { 176 .name = "touchwin", 177 }, 178 .description = DRIVER_DESC, 179 .id_table = tw_serio_ids, 180 .interrupt = tw_interrupt, 181 .connect = tw_connect, 182 .disconnect = tw_disconnect, 183 }; 184 185 module_serio_driver(tw_drv); 186