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 27 #define DRIVER_DESC "Hampshire serial touchscreen driver" 28 29 MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>"); 30 MODULE_DESCRIPTION(DRIVER_DESC); 31 MODULE_LICENSE("GPL"); 32 33 /* 34 * Definitions & global arrays. 35 */ 36 37 #define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40 38 #define HAMPSHIRE_FORMAT_LENGTH 4 39 #define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80 40 41 #define HAMPSHIRE_MIN_XC 0 42 #define HAMPSHIRE_MAX_XC 0x1000 43 #define HAMPSHIRE_MIN_YC 0 44 #define HAMPSHIRE_MAX_YC 0x1000 45 46 #define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6)) 47 #define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9)) 48 #define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0]) 49 50 /* 51 * Per-touchscreen data. 52 */ 53 54 struct hampshire { 55 struct input_dev *dev; 56 struct serio *serio; 57 int idx; 58 unsigned char data[HAMPSHIRE_FORMAT_LENGTH]; 59 char phys[32]; 60 }; 61 62 static void hampshire_process_data(struct hampshire *phampshire) 63 { 64 struct input_dev *dev = phampshire->dev; 65 66 if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) { 67 input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data)); 68 input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data)); 69 input_report_key(dev, BTN_TOUCH, 70 HAMPSHIRE_GET_TOUCHED(phampshire->data)); 71 input_sync(dev); 72 73 phampshire->idx = 0; 74 } 75 } 76 77 static irqreturn_t hampshire_interrupt(struct serio *serio, 78 unsigned char data, unsigned int flags) 79 { 80 struct hampshire *phampshire = serio_get_drvdata(serio); 81 82 phampshire->data[phampshire->idx] = data; 83 84 if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0]) 85 hampshire_process_data(phampshire); 86 else 87 dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", 88 phampshire->data[0]); 89 90 return IRQ_HANDLED; 91 } 92 93 static void hampshire_disconnect(struct serio *serio) 94 { 95 struct hampshire *phampshire = serio_get_drvdata(serio); 96 97 input_get_device(phampshire->dev); 98 input_unregister_device(phampshire->dev); 99 serio_close(serio); 100 serio_set_drvdata(serio, NULL); 101 input_put_device(phampshire->dev); 102 kfree(phampshire); 103 } 104 105 /* 106 * hampshire_connect() is the routine that is called when someone adds a 107 * new serio device that supports hampshire protocol and registers it as 108 * an input device. This is usually accomplished using inputattach. 109 */ 110 111 static int hampshire_connect(struct serio *serio, struct serio_driver *drv) 112 { 113 struct hampshire *phampshire; 114 struct input_dev *input_dev; 115 int err; 116 117 phampshire = kzalloc(sizeof(struct hampshire), GFP_KERNEL); 118 input_dev = input_allocate_device(); 119 if (!phampshire || !input_dev) { 120 err = -ENOMEM; 121 goto fail1; 122 } 123 124 phampshire->serio = serio; 125 phampshire->dev = input_dev; 126 snprintf(phampshire->phys, sizeof(phampshire->phys), 127 "%s/input0", serio->phys); 128 129 input_dev->name = "Hampshire Serial TouchScreen"; 130 input_dev->phys = phampshire->phys; 131 input_dev->id.bustype = BUS_RS232; 132 input_dev->id.vendor = SERIO_HAMPSHIRE; 133 input_dev->id.product = 0; 134 input_dev->id.version = 0x0001; 135 input_dev->dev.parent = &serio->dev; 136 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 137 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 138 input_set_abs_params(phampshire->dev, ABS_X, 139 HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0); 140 input_set_abs_params(phampshire->dev, ABS_Y, 141 HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0); 142 143 serio_set_drvdata(serio, phampshire); 144 145 err = serio_open(serio, drv); 146 if (err) 147 goto fail2; 148 149 err = input_register_device(phampshire->dev); 150 if (err) 151 goto fail3; 152 153 return 0; 154 155 fail3: serio_close(serio); 156 fail2: serio_set_drvdata(serio, NULL); 157 fail1: input_free_device(input_dev); 158 kfree(phampshire); 159 return err; 160 } 161 162 /* 163 * The serio driver structure. 164 */ 165 166 static struct serio_device_id hampshire_serio_ids[] = { 167 { 168 .type = SERIO_RS232, 169 .proto = SERIO_HAMPSHIRE, 170 .id = SERIO_ANY, 171 .extra = SERIO_ANY, 172 }, 173 { 0 } 174 }; 175 176 MODULE_DEVICE_TABLE(serio, hampshire_serio_ids); 177 178 static struct serio_driver hampshire_drv = { 179 .driver = { 180 .name = "hampshire", 181 }, 182 .description = DRIVER_DESC, 183 .id_table = hampshire_serio_ids, 184 .interrupt = hampshire_interrupt, 185 .connect = hampshire_connect, 186 .disconnect = hampshire_disconnect, 187 }; 188 189 module_serio_driver(hampshire_drv); 190