1/* 2 * Hampshire serial touchscreen driver 3 * 4 * Copyright (c) 2010 Adam Bennett 5 * Based on the dynapro driver (c) Tias Guns 6 * 7 */ 8 9/* 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License version 2 as published by 12 * the Free Software Foundation. 13 */ 14 15/* 16 * 2010/04/08 Adam Bennett <abennett72@gmail.com> 17 * Copied dynapro.c and edited for Hampshire 4-byte protocol 18 */ 19 20#include <linux/errno.h> 21#include <linux/kernel.h> 22#include <linux/module.h> 23#include <linux/slab.h> 24#include <linux/input.h> 25#include <linux/serio.h> 26#include <linux/init.h> 27 28#define DRIVER_DESC "Hampshire serial touchscreen driver" 29 30MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>"); 31MODULE_DESCRIPTION(DRIVER_DESC); 32MODULE_LICENSE("GPL"); 33 34/* 35 * Definitions & global arrays. 36 */ 37 38#define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40 39#define HAMPSHIRE_FORMAT_LENGTH 4 40#define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80 41 42#define HAMPSHIRE_MIN_XC 0 43#define HAMPSHIRE_MAX_XC 0x1000 44#define HAMPSHIRE_MIN_YC 0 45#define HAMPSHIRE_MAX_YC 0x1000 46 47#define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6)) 48#define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9)) 49#define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0]) 50 51/* 52 * Per-touchscreen data. 53 */ 54 55struct hampshire { 56 struct input_dev *dev; 57 struct serio *serio; 58 int idx; 59 unsigned char data[HAMPSHIRE_FORMAT_LENGTH]; 60 char phys[32]; 61}; 62 63static void hampshire_process_data(struct hampshire *phampshire) 64{ 65 struct input_dev *dev = phampshire->dev; 66 67 if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) { 68 input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data)); 69 input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data)); 70 input_report_key(dev, BTN_TOUCH, 71 HAMPSHIRE_GET_TOUCHED(phampshire->data)); 72 input_sync(dev); 73 74 phampshire->idx = 0; 75 } 76} 77 78static irqreturn_t hampshire_interrupt(struct serio *serio, 79 unsigned char data, unsigned int flags) 80{ 81 struct hampshire *phampshire = serio_get_drvdata(serio); 82 83 phampshire->data[phampshire->idx] = data; 84 85 if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0]) 86 hampshire_process_data(phampshire); 87 else 88 dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", 89 phampshire->data[0]); 90 91 return IRQ_HANDLED; 92} 93 94static void hampshire_disconnect(struct serio *serio) 95{ 96 struct hampshire *phampshire = serio_get_drvdata(serio); 97 98 input_get_device(phampshire->dev); 99 input_unregister_device(phampshire->dev); 100 serio_close(serio); 101 serio_set_drvdata(serio, NULL); 102 input_put_device(phampshire->dev); 103 kfree(phampshire); 104} 105 106/* 107 * hampshire_connect() is the routine that is called when someone adds a 108 * new serio device that supports hampshire protocol and registers it as 109 * an input device. This is usually accomplished using inputattach. 110 */ 111 112static int hampshire_connect(struct serio *serio, struct serio_driver *drv) 113{ 114 struct hampshire *phampshire; 115 struct input_dev *input_dev; 116 int err; 117 118 phampshire = kzalloc(sizeof(struct hampshire), GFP_KERNEL); 119 input_dev = input_allocate_device(); 120 if (!phampshire || !input_dev) { 121 err = -ENOMEM; 122 goto fail1; 123 } 124 125 phampshire->serio = serio; 126 phampshire->dev = input_dev; 127 snprintf(phampshire->phys, sizeof(phampshire->phys), 128 "%s/input0", serio->phys); 129 130 input_dev->name = "Hampshire Serial TouchScreen"; 131 input_dev->phys = phampshire->phys; 132 input_dev->id.bustype = BUS_RS232; 133 input_dev->id.vendor = SERIO_HAMPSHIRE; 134 input_dev->id.product = 0; 135 input_dev->id.version = 0x0001; 136 input_dev->dev.parent = &serio->dev; 137 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 138 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 139 input_set_abs_params(phampshire->dev, ABS_X, 140 HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0); 141 input_set_abs_params(phampshire->dev, ABS_Y, 142 HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0); 143 144 serio_set_drvdata(serio, phampshire); 145 146 err = serio_open(serio, drv); 147 if (err) 148 goto fail2; 149 150 err = input_register_device(phampshire->dev); 151 if (err) 152 goto fail3; 153 154 return 0; 155 156 fail3: serio_close(serio); 157 fail2: serio_set_drvdata(serio, NULL); 158 fail1: input_free_device(input_dev); 159 kfree(phampshire); 160 return err; 161} 162 163/* 164 * The serio driver structure. 165 */ 166 167static struct serio_device_id hampshire_serio_ids[] = { 168 { 169 .type = SERIO_RS232, 170 .proto = SERIO_HAMPSHIRE, 171 .id = SERIO_ANY, 172 .extra = SERIO_ANY, 173 }, 174 { 0 } 175}; 176 177MODULE_DEVICE_TABLE(serio, hampshire_serio_ids); 178 179static struct serio_driver hampshire_drv = { 180 .driver = { 181 .name = "hampshire", 182 }, 183 .description = DRIVER_DESC, 184 .id_table = hampshire_serio_ids, 185 .interrupt = hampshire_interrupt, 186 .connect = hampshire_connect, 187 .disconnect = hampshire_disconnect, 188}; 189 190/* 191 * The functions for inserting/removing us as a module. 192 */ 193 194static int __init hampshire_init(void) 195{ 196 return serio_register_driver(&hampshire_drv); 197} 198 199static void __exit hampshire_exit(void) 200{ 201 serio_unregister_driver(&hampshire_drv); 202} 203 204module_init(hampshire_init); 205module_exit(hampshire_exit); 206