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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 | // SPDX-License-Identifier: GPL-2.0-only /* * Hampshire serial touchscreen driver * * Copyright (c) 2010 Adam Bennett * Based on the dynapro driver (c) Tias Guns */ /* * 2010/04/08 Adam Bennett <abennett72@gmail.com> * Copied dynapro.c and edited for Hampshire 4-byte protocol */ #include <linux/errno.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/input.h> #include <linux/serio.h> #define DRIVER_DESC "Hampshire serial touchscreen driver" MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>"); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); /* * Definitions & global arrays. */ #define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40 #define HAMPSHIRE_FORMAT_LENGTH 4 #define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80 #define HAMPSHIRE_MIN_XC 0 #define HAMPSHIRE_MAX_XC 0x1000 #define HAMPSHIRE_MIN_YC 0 #define HAMPSHIRE_MAX_YC 0x1000 #define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6)) #define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9)) #define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0]) /* * Per-touchscreen data. */ struct hampshire { struct input_dev *dev; struct serio *serio; int idx; unsigned char data[HAMPSHIRE_FORMAT_LENGTH]; char phys[32]; }; static void hampshire_process_data(struct hampshire *phampshire) { struct input_dev *dev = phampshire->dev; if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) { input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data)); input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data)); input_report_key(dev, BTN_TOUCH, HAMPSHIRE_GET_TOUCHED(phampshire->data)); input_sync(dev); phampshire->idx = 0; } } static irqreturn_t hampshire_interrupt(struct serio *serio, unsigned char data, unsigned int flags) { struct hampshire *phampshire = serio_get_drvdata(serio); phampshire->data[phampshire->idx] = data; if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0]) hampshire_process_data(phampshire); else dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", phampshire->data[0]); return IRQ_HANDLED; } static void hampshire_disconnect(struct serio *serio) { struct hampshire *phampshire = serio_get_drvdata(serio); input_get_device(phampshire->dev); input_unregister_device(phampshire->dev); serio_close(serio); serio_set_drvdata(serio, NULL); input_put_device(phampshire->dev); kfree(phampshire); } /* * hampshire_connect() is the routine that is called when someone adds a * new serio device that supports hampshire protocol and registers it as * an input device. This is usually accomplished using inputattach. */ static int hampshire_connect(struct serio *serio, struct serio_driver *drv) { struct hampshire *phampshire; struct input_dev *input_dev; int err; phampshire = kzalloc(sizeof(struct hampshire), GFP_KERNEL); input_dev = input_allocate_device(); if (!phampshire || !input_dev) { err = -ENOMEM; goto fail1; } phampshire->serio = serio; phampshire->dev = input_dev; snprintf(phampshire->phys, sizeof(phampshire->phys), "%s/input0", serio->phys); input_dev->name = "Hampshire Serial TouchScreen"; input_dev->phys = phampshire->phys; input_dev->id.bustype = BUS_RS232; input_dev->id.vendor = SERIO_HAMPSHIRE; input_dev->id.product = 0; input_dev->id.version = 0x0001; input_dev->dev.parent = &serio->dev; input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); input_set_abs_params(phampshire->dev, ABS_X, HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0); input_set_abs_params(phampshire->dev, ABS_Y, HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0); serio_set_drvdata(serio, phampshire); err = serio_open(serio, drv); if (err) goto fail2; err = input_register_device(phampshire->dev); if (err) goto fail3; return 0; fail3: serio_close(serio); fail2: serio_set_drvdata(serio, NULL); fail1: input_free_device(input_dev); kfree(phampshire); return err; } /* * The serio driver structure. */ static const struct serio_device_id hampshire_serio_ids[] = { { .type = SERIO_RS232, .proto = SERIO_HAMPSHIRE, .id = SERIO_ANY, .extra = SERIO_ANY, }, { 0 } }; MODULE_DEVICE_TABLE(serio, hampshire_serio_ids); static struct serio_driver hampshire_drv = { .driver = { .name = "hampshire", }, .description = DRIVER_DESC, .id_table = hampshire_serio_ids, .interrupt = hampshire_interrupt, .connect = hampshire_connect, .disconnect = hampshire_disconnect, }; module_serio_driver(hampshire_drv); |