1/* 2 * Sahara TouchIT-213 serial touchscreen driver 3 * 4 * Copyright (c) 2007-2008 Claudio Nieder <private@claudio.ch> 5 * 6 * Based on Touchright driver (drivers/input/touchscreen/touchright.c) 7 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com> 8 * Copyright (c) 2004 Vojtech Pavlik 9 * and Dan Streetman <ddstreet@ieee.org> 10 */ 11 12/* 13 * This program is free software; you can redistribute it and/or modify it 14 * under the terms of the GNU General Public License version 2 as published 15 * by the Free Software Foundation. 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 "Sahara TouchIT-213 serial touchscreen driver" 27 28MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>"); 29MODULE_DESCRIPTION(DRIVER_DESC); 30MODULE_LICENSE("GPL"); 31 32/* 33 * Definitions & global arrays. 34 */ 35 36/* 37 * Data is received through COM1 at 9600bit/s,8bit,no parity in packets 38 * of 5 byte each. 39 * 40 * +--------+ +--------+ +--------+ +--------+ +--------+ 41 * |1000000p| |0xxxxxxx| |0xxxxxxx| |0yyyyyyy| |0yyyyyyy| 42 * +--------+ +--------+ +--------+ +--------+ +--------+ 43 * MSB LSB MSB LSB 44 * 45 * The value of p is 1 as long as the screen is touched and 0 when 46 * reporting the location where touching stopped, e.g. where the pen was 47 * lifted from the screen. 48 * 49 * When holding the screen in landscape mode as the BIOS text output is 50 * presented, x is the horizontal axis with values growing from left to 51 * right and y is the vertical axis with values growing from top to 52 * bottom. 53 * 54 * When holding the screen in portrait mode with the Sahara logo in its 55 * correct position, x ist the vertical axis with values growing from 56 * top to bottom and y is the horizontal axis with values growing from 57 * right to left. 58 */ 59 60#define T213_FORMAT_TOUCH_BIT 0x01 61#define T213_FORMAT_STATUS_BYTE 0x80 62#define T213_FORMAT_STATUS_MASK ~T213_FORMAT_TOUCH_BIT 63 64/* 65 * On my Sahara Touch-IT 213 I have observed x values from 0 to 0x7f0 66 * and y values from 0x1d to 0x7e9, so the actual measurement is 67 * probably done with an 11 bit precision. 68 */ 69#define T213_MIN_XC 0 70#define T213_MAX_XC 0x07ff 71#define T213_MIN_YC 0 72#define T213_MAX_YC 0x07ff 73 74/* 75 * Per-touchscreen data. 76 */ 77 78struct touchit213 { 79 struct input_dev *dev; 80 struct serio *serio; 81 int idx; 82 unsigned char csum; 83 unsigned char data[5]; 84 char phys[32]; 85}; 86 87static irqreturn_t touchit213_interrupt(struct serio *serio, 88 unsigned char data, unsigned int flags) 89{ 90 struct touchit213 *touchit213 = serio_get_drvdata(serio); 91 struct input_dev *dev = touchit213->dev; 92 93 touchit213->data[touchit213->idx] = data; 94 95 switch (touchit213->idx++) { 96 case 0: 97 if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) != 98 T213_FORMAT_STATUS_BYTE) { 99 pr_debug("unsynchronized data: 0x%02x\n", data); 100 touchit213->idx = 0; 101 } 102 break; 103 104 case 4: 105 touchit213->idx = 0; 106 input_report_abs(dev, ABS_X, 107 (touchit213->data[1] << 7) | touchit213->data[2]); 108 input_report_abs(dev, ABS_Y, 109 (touchit213->data[3] << 7) | touchit213->data[4]); 110 input_report_key(dev, BTN_TOUCH, 111 touchit213->data[0] & T213_FORMAT_TOUCH_BIT); 112 input_sync(dev); 113 break; 114 } 115 116 return IRQ_HANDLED; 117} 118 119/* 120 * touchit213_disconnect() is the opposite of touchit213_connect() 121 */ 122 123static void touchit213_disconnect(struct serio *serio) 124{ 125 struct touchit213 *touchit213 = serio_get_drvdata(serio); 126 127 input_get_device(touchit213->dev); 128 input_unregister_device(touchit213->dev); 129 serio_close(serio); 130 serio_set_drvdata(serio, NULL); 131 input_put_device(touchit213->dev); 132 kfree(touchit213); 133} 134 135/* 136 * touchit213_connect() is the routine that is called when someone adds a 137 * new serio device that supports the Touchright protocol and registers it as 138 * an input device. 139 */ 140 141static int touchit213_connect(struct serio *serio, struct serio_driver *drv) 142{ 143 struct touchit213 *touchit213; 144 struct input_dev *input_dev; 145 int err; 146 147 touchit213 = kzalloc(sizeof(struct touchit213), GFP_KERNEL); 148 input_dev = input_allocate_device(); 149 if (!touchit213 || !input_dev) { 150 err = -ENOMEM; 151 goto fail1; 152 } 153 154 touchit213->serio = serio; 155 touchit213->dev = input_dev; 156 snprintf(touchit213->phys, sizeof(touchit213->phys), 157 "%s/input0", serio->phys); 158 159 input_dev->name = "Sahara Touch-iT213 Serial TouchScreen"; 160 input_dev->phys = touchit213->phys; 161 input_dev->id.bustype = BUS_RS232; 162 input_dev->id.vendor = SERIO_TOUCHIT213; 163 input_dev->id.product = 0; 164 input_dev->id.version = 0x0100; 165 input_dev->dev.parent = &serio->dev; 166 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 167 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 168 input_set_abs_params(touchit213->dev, ABS_X, 169 T213_MIN_XC, T213_MAX_XC, 0, 0); 170 input_set_abs_params(touchit213->dev, ABS_Y, 171 T213_MIN_YC, T213_MAX_YC, 0, 0); 172 173 serio_set_drvdata(serio, touchit213); 174 175 err = serio_open(serio, drv); 176 if (err) 177 goto fail2; 178 179 err = input_register_device(touchit213->dev); 180 if (err) 181 goto fail3; 182 183 return 0; 184 185 fail3: serio_close(serio); 186 fail2: serio_set_drvdata(serio, NULL); 187 fail1: input_free_device(input_dev); 188 kfree(touchit213); 189 return err; 190} 191 192/* 193 * The serio driver structure. 194 */ 195 196static struct serio_device_id touchit213_serio_ids[] = { 197 { 198 .type = SERIO_RS232, 199 .proto = SERIO_TOUCHIT213, 200 .id = SERIO_ANY, 201 .extra = SERIO_ANY, 202 }, 203 { 0 } 204}; 205 206MODULE_DEVICE_TABLE(serio, touchit213_serio_ids); 207 208static struct serio_driver touchit213_drv = { 209 .driver = { 210 .name = "touchit213", 211 }, 212 .description = DRIVER_DESC, 213 .id_table = touchit213_serio_ids, 214 .interrupt = touchit213_interrupt, 215 .connect = touchit213_connect, 216 .disconnect = touchit213_disconnect, 217}; 218 219/* 220 * The functions for inserting/removing us as a module. 221 */ 222 223static int __init touchit213_init(void) 224{ 225 return serio_register_driver(&touchit213_drv); 226} 227 228static void __exit touchit213_exit(void) 229{ 230 serio_unregister_driver(&touchit213_drv); 231} 232 233module_init(touchit213_init); 234module_exit(touchit213_exit); 235