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 25 #define DRIVER_DESC "Sahara TouchIT-213 serial touchscreen driver" 26 27 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>"); 28 MODULE_DESCRIPTION(DRIVER_DESC); 29 MODULE_LICENSE("GPL"); 30 31 /* 32 * Definitions & global arrays. 33 */ 34 35 /* 36 * Data is received through COM1 at 9600bit/s,8bit,no parity in packets 37 * of 5 byte each. 38 * 39 * +--------+ +--------+ +--------+ +--------+ +--------+ 40 * |1000000p| |0xxxxxxx| |0xxxxxxx| |0yyyyyyy| |0yyyyyyy| 41 * +--------+ +--------+ +--------+ +--------+ +--------+ 42 * MSB LSB MSB LSB 43 * 44 * The value of p is 1 as long as the screen is touched and 0 when 45 * reporting the location where touching stopped, e.g. where the pen was 46 * lifted from the screen. 47 * 48 * When holding the screen in landscape mode as the BIOS text output is 49 * presented, x is the horizontal axis with values growing from left to 50 * right and y is the vertical axis with values growing from top to 51 * bottom. 52 * 53 * When holding the screen in portrait mode with the Sahara logo in its 54 * correct position, x ist the vertical axis with values growing from 55 * top to bottom and y is the horizontal axis with values growing from 56 * right to left. 57 */ 58 59 #define T213_FORMAT_TOUCH_BIT 0x01 60 #define T213_FORMAT_STATUS_BYTE 0x80 61 #define T213_FORMAT_STATUS_MASK ~T213_FORMAT_TOUCH_BIT 62 63 /* 64 * On my Sahara Touch-IT 213 I have observed x values from 0 to 0x7f0 65 * and y values from 0x1d to 0x7e9, so the actual measurement is 66 * probably done with an 11 bit precision. 67 */ 68 #define T213_MIN_XC 0 69 #define T213_MAX_XC 0x07ff 70 #define T213_MIN_YC 0 71 #define T213_MAX_YC 0x07ff 72 73 /* 74 * Per-touchscreen data. 75 */ 76 77 struct touchit213 { 78 struct input_dev *dev; 79 struct serio *serio; 80 int idx; 81 unsigned char csum; 82 unsigned char data[5]; 83 char phys[32]; 84 }; 85 86 static irqreturn_t touchit213_interrupt(struct serio *serio, 87 unsigned char data, unsigned int flags) 88 { 89 struct touchit213 *touchit213 = serio_get_drvdata(serio); 90 struct input_dev *dev = touchit213->dev; 91 92 touchit213->data[touchit213->idx] = data; 93 94 switch (touchit213->idx++) { 95 case 0: 96 if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) != 97 T213_FORMAT_STATUS_BYTE) { 98 pr_debug("unsynchronized data: 0x%02x\n", data); 99 touchit213->idx = 0; 100 } 101 break; 102 103 case 4: 104 touchit213->idx = 0; 105 input_report_abs(dev, ABS_X, 106 (touchit213->data[1] << 7) | touchit213->data[2]); 107 input_report_abs(dev, ABS_Y, 108 (touchit213->data[3] << 7) | touchit213->data[4]); 109 input_report_key(dev, BTN_TOUCH, 110 touchit213->data[0] & T213_FORMAT_TOUCH_BIT); 111 input_sync(dev); 112 break; 113 } 114 115 return IRQ_HANDLED; 116 } 117 118 /* 119 * touchit213_disconnect() is the opposite of touchit213_connect() 120 */ 121 122 static void touchit213_disconnect(struct serio *serio) 123 { 124 struct touchit213 *touchit213 = serio_get_drvdata(serio); 125 126 input_get_device(touchit213->dev); 127 input_unregister_device(touchit213->dev); 128 serio_close(serio); 129 serio_set_drvdata(serio, NULL); 130 input_put_device(touchit213->dev); 131 kfree(touchit213); 132 } 133 134 /* 135 * touchit213_connect() is the routine that is called when someone adds a 136 * new serio device that supports the Touchright protocol and registers it as 137 * an input device. 138 */ 139 140 static int touchit213_connect(struct serio *serio, struct serio_driver *drv) 141 { 142 struct touchit213 *touchit213; 143 struct input_dev *input_dev; 144 int err; 145 146 touchit213 = kzalloc(sizeof(struct touchit213), GFP_KERNEL); 147 input_dev = input_allocate_device(); 148 if (!touchit213 || !input_dev) { 149 err = -ENOMEM; 150 goto fail1; 151 } 152 153 touchit213->serio = serio; 154 touchit213->dev = input_dev; 155 snprintf(touchit213->phys, sizeof(touchit213->phys), 156 "%s/input0", serio->phys); 157 158 input_dev->name = "Sahara Touch-iT213 Serial TouchScreen"; 159 input_dev->phys = touchit213->phys; 160 input_dev->id.bustype = BUS_RS232; 161 input_dev->id.vendor = SERIO_TOUCHIT213; 162 input_dev->id.product = 0; 163 input_dev->id.version = 0x0100; 164 input_dev->dev.parent = &serio->dev; 165 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 166 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 167 input_set_abs_params(touchit213->dev, ABS_X, 168 T213_MIN_XC, T213_MAX_XC, 0, 0); 169 input_set_abs_params(touchit213->dev, ABS_Y, 170 T213_MIN_YC, T213_MAX_YC, 0, 0); 171 172 serio_set_drvdata(serio, touchit213); 173 174 err = serio_open(serio, drv); 175 if (err) 176 goto fail2; 177 178 err = input_register_device(touchit213->dev); 179 if (err) 180 goto fail3; 181 182 return 0; 183 184 fail3: serio_close(serio); 185 fail2: serio_set_drvdata(serio, NULL); 186 fail1: input_free_device(input_dev); 187 kfree(touchit213); 188 return err; 189 } 190 191 /* 192 * The serio driver structure. 193 */ 194 195 static const struct serio_device_id touchit213_serio_ids[] = { 196 { 197 .type = SERIO_RS232, 198 .proto = SERIO_TOUCHIT213, 199 .id = SERIO_ANY, 200 .extra = SERIO_ANY, 201 }, 202 { 0 } 203 }; 204 205 MODULE_DEVICE_TABLE(serio, touchit213_serio_ids); 206 207 static struct serio_driver touchit213_drv = { 208 .driver = { 209 .name = "touchit213", 210 }, 211 .description = DRIVER_DESC, 212 .id_table = touchit213_serio_ids, 213 .interrupt = touchit213_interrupt, 214 .connect = touchit213_connect, 215 .disconnect = touchit213_disconnect, 216 }; 217 218 module_serio_driver(touchit213_drv); 219