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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | // SPDX-License-Identifier: GPL-2.0-only /* * EETI Egalax serial touchscreen driver * * Copyright (c) 2015 Zoltán Böszörményi <zboszor@pr.hu> * * based on the * * Hampshire serial touchscreen driver (Copyright (c) 2010 Adam Bennett) */ #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 "EETI Egalax serial touchscreen driver" /* * Definitions & global arrays. */ #define EGALAX_FORMAT_MAX_LENGTH 6 #define EGALAX_FORMAT_START_BIT BIT(7) #define EGALAX_FORMAT_PRESSURE_BIT BIT(6) #define EGALAX_FORMAT_TOUCH_BIT BIT(0) #define EGALAX_FORMAT_RESOLUTION_MASK 0x06 #define EGALAX_MIN_XC 0 #define EGALAX_MAX_XC 0x4000 #define EGALAX_MIN_YC 0 #define EGALAX_MAX_YC 0x4000 /* * Per-touchscreen data. */ struct egalax { struct input_dev *input; struct serio *serio; int idx; u8 data[EGALAX_FORMAT_MAX_LENGTH]; char phys[32]; }; static void egalax_process_data(struct egalax *egalax) { struct input_dev *dev = egalax->input; u8 *data = egalax->data; u16 x, y; u8 shift; u8 mask; shift = 3 - ((data[0] & EGALAX_FORMAT_RESOLUTION_MASK) >> 1); mask = 0xff >> (shift + 1); x = (((u16)(data[1] & mask) << 7) | (data[2] & 0x7f)) << shift; y = (((u16)(data[3] & mask) << 7) | (data[4] & 0x7f)) << shift; input_report_key(dev, BTN_TOUCH, data[0] & EGALAX_FORMAT_TOUCH_BIT); input_report_abs(dev, ABS_X, x); input_report_abs(dev, ABS_Y, y); input_sync(dev); } static irqreturn_t egalax_interrupt(struct serio *serio, unsigned char data, unsigned int flags) { struct egalax *egalax = serio_get_drvdata(serio); int pkt_len; egalax->data[egalax->idx++] = data; if (likely(egalax->data[0] & EGALAX_FORMAT_START_BIT)) { pkt_len = egalax->data[0] & EGALAX_FORMAT_PRESSURE_BIT ? 6 : 5; if (pkt_len == egalax->idx) { egalax_process_data(egalax); egalax->idx = 0; } } else { dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", egalax->data[0]); egalax->idx = 0; } return IRQ_HANDLED; } /* * egalax_connect() is the routine that is called when someone adds a * new serio device that supports egalax protocol and registers it as * an input device. This is usually accomplished using inputattach. */ static int egalax_connect(struct serio *serio, struct serio_driver *drv) { struct egalax *egalax; struct input_dev *input_dev; int error; egalax = kzalloc(sizeof(struct egalax), GFP_KERNEL); input_dev = input_allocate_device(); if (!egalax || !input_dev) { error = -ENOMEM; goto err_free_mem; } egalax->serio = serio; egalax->input = input_dev; snprintf(egalax->phys, sizeof(egalax->phys), "%s/input0", serio->phys); input_dev->name = "EETI eGalaxTouch Serial TouchScreen"; input_dev->phys = egalax->phys; input_dev->id.bustype = BUS_RS232; input_dev->id.vendor = SERIO_EGALAX; input_dev->id.product = 0; input_dev->id.version = 0x0001; input_dev->dev.parent = &serio->dev; input_set_capability(input_dev, EV_KEY, BTN_TOUCH); input_set_abs_params(input_dev, ABS_X, EGALAX_MIN_XC, EGALAX_MAX_XC, 0, 0); input_set_abs_params(input_dev, ABS_Y, EGALAX_MIN_YC, EGALAX_MAX_YC, 0, 0); serio_set_drvdata(serio, egalax); error = serio_open(serio, drv); if (error) goto err_reset_drvdata; error = input_register_device(input_dev); if (error) goto err_close_serio; return 0; err_close_serio: serio_close(serio); err_reset_drvdata: serio_set_drvdata(serio, NULL); err_free_mem: input_free_device(input_dev); kfree(egalax); return error; } static void egalax_disconnect(struct serio *serio) { struct egalax *egalax = serio_get_drvdata(serio); serio_close(serio); serio_set_drvdata(serio, NULL); input_unregister_device(egalax->input); kfree(egalax); } /* * The serio driver structure. */ static const struct serio_device_id egalax_serio_ids[] = { { .type = SERIO_RS232, .proto = SERIO_EGALAX, .id = SERIO_ANY, .extra = SERIO_ANY, }, { 0 } }; MODULE_DEVICE_TABLE(serio, egalax_serio_ids); static struct serio_driver egalax_drv = { .driver = { .name = "egalax", }, .description = DRIVER_DESC, .id_table = egalax_serio_ids, .interrupt = egalax_interrupt, .connect = egalax_connect, .disconnect = egalax_disconnect, }; module_serio_driver(egalax_drv); MODULE_AUTHOR("Zoltán Böszörményi <zboszor@pr.hu>"); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL v2"); |