1 /* 2 * MicroTouch (3M) serial touchscreen driver 3 * 4 * Copyright (c) 2004 Vojtech Pavlik 5 */ 6 7 /* 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 as published by 10 * the Free Software Foundation. 11 */ 12 13 /* 14 * 2005/02/19 Dan Streetman <ddstreet@ieee.org> 15 * Copied elo.c and edited for MicroTouch protocol 16 */ 17 18 #include <linux/errno.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/input.h> 23 #include <linux/serio.h> 24 #include <linux/init.h> 25 26 #define DRIVER_DESC "MicroTouch serial touchscreen driver" 27 28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 29 MODULE_DESCRIPTION(DRIVER_DESC); 30 MODULE_LICENSE("GPL"); 31 32 /* 33 * Definitions & global arrays. 34 */ 35 36 #define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80 37 #define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40 38 #define MTOUCH_FORMAT_TABLET_LENGTH 5 39 #define MTOUCH_RESPONSE_BEGIN_BYTE 0x01 40 #define MTOUCH_RESPONSE_END_BYTE 0x0d 41 42 /* todo: check specs for max length of all responses */ 43 #define MTOUCH_MAX_LENGTH 16 44 45 #define MTOUCH_MIN_XC 0 46 #define MTOUCH_MAX_XC 0x3fff 47 #define MTOUCH_MIN_YC 0 48 #define MTOUCH_MAX_YC 0x3fff 49 50 #define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1]) 51 #define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3]) 52 #define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0]) 53 54 /* 55 * Per-touchscreen data. 56 */ 57 58 struct mtouch { 59 struct input_dev *dev; 60 struct serio *serio; 61 int idx; 62 unsigned char data[MTOUCH_MAX_LENGTH]; 63 char phys[32]; 64 }; 65 66 static void mtouch_process_format_tablet(struct mtouch *mtouch, struct pt_regs *regs) 67 { 68 struct input_dev *dev = mtouch->dev; 69 70 if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) { 71 input_regs(dev, regs); 72 input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data)); 73 input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data)); 74 input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data)); 75 input_sync(dev); 76 77 mtouch->idx = 0; 78 } 79 } 80 81 static void mtouch_process_response(struct mtouch *mtouch, struct pt_regs *regs) 82 { 83 if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) { 84 /* FIXME - process response */ 85 mtouch->idx = 0; 86 } else if (MTOUCH_MAX_LENGTH == mtouch->idx) { 87 printk(KERN_ERR "mtouch.c: too many response bytes\n"); 88 mtouch->idx = 0; 89 } 90 } 91 92 static irqreturn_t mtouch_interrupt(struct serio *serio, 93 unsigned char data, unsigned int flags, struct pt_regs *regs) 94 { 95 struct mtouch* mtouch = serio_get_drvdata(serio); 96 97 mtouch->data[mtouch->idx] = data; 98 99 if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0]) 100 mtouch_process_format_tablet(mtouch, regs); 101 else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0]) 102 mtouch_process_response(mtouch, regs); 103 else 104 printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]); 105 106 return IRQ_HANDLED; 107 } 108 109 /* 110 * mtouch_disconnect() is the opposite of mtouch_connect() 111 */ 112 113 static void mtouch_disconnect(struct serio *serio) 114 { 115 struct mtouch* mtouch = serio_get_drvdata(serio); 116 117 input_get_device(mtouch->dev); 118 input_unregister_device(mtouch->dev); 119 serio_close(serio); 120 serio_set_drvdata(serio, NULL); 121 input_put_device(mtouch->dev); 122 kfree(mtouch); 123 } 124 125 /* 126 * mtouch_connect() is the routine that is called when someone adds a 127 * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as 128 * an input device. 129 */ 130 131 static int mtouch_connect(struct serio *serio, struct serio_driver *drv) 132 { 133 struct mtouch *mtouch; 134 struct input_dev *input_dev; 135 int err; 136 137 mtouch = kzalloc(sizeof(struct mtouch), GFP_KERNEL); 138 input_dev = input_allocate_device(); 139 if (!mtouch || !input_dev) { 140 err = -ENOMEM; 141 goto fail; 142 } 143 144 mtouch->serio = serio; 145 mtouch->dev = input_dev; 146 sprintf(mtouch->phys, "%s/input0", serio->phys); 147 148 input_dev->private = mtouch; 149 input_dev->name = "MicroTouch Serial TouchScreen"; 150 input_dev->phys = mtouch->phys; 151 input_dev->id.bustype = BUS_RS232; 152 input_dev->id.vendor = SERIO_MICROTOUCH; 153 input_dev->id.product = 0; 154 input_dev->id.version = 0x0100; 155 input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS); 156 input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH); 157 input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0); 158 input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0); 159 160 serio_set_drvdata(serio, mtouch); 161 162 err = serio_open(serio, drv); 163 if (err) 164 goto fail; 165 166 input_register_device(mtouch->dev); 167 168 return 0; 169 170 fail: serio_set_drvdata(serio, NULL); 171 input_free_device(input_dev); 172 kfree(mtouch); 173 return err; 174 } 175 176 /* 177 * The serio driver structure. 178 */ 179 180 static struct serio_device_id mtouch_serio_ids[] = { 181 { 182 .type = SERIO_RS232, 183 .proto = SERIO_MICROTOUCH, 184 .id = SERIO_ANY, 185 .extra = SERIO_ANY, 186 }, 187 { 0 } 188 }; 189 190 MODULE_DEVICE_TABLE(serio, mtouch_serio_ids); 191 192 static struct serio_driver mtouch_drv = { 193 .driver = { 194 .name = "mtouch", 195 }, 196 .description = DRIVER_DESC, 197 .id_table = mtouch_serio_ids, 198 .interrupt = mtouch_interrupt, 199 .connect = mtouch_connect, 200 .disconnect = mtouch_disconnect, 201 }; 202 203 /* 204 * The functions for inserting/removing us as a module. 205 */ 206 207 static int __init mtouch_init(void) 208 { 209 serio_register_driver(&mtouch_drv); 210 return 0; 211 } 212 213 static void __exit mtouch_exit(void) 214 { 215 serio_unregister_driver(&mtouch_drv); 216 } 217 218 module_init(mtouch_init); 219 module_exit(mtouch_exit); 220