/* * Hampshire serial touchscreen driver * * Copyright (c) 2010 Adam Bennett * Based on the dynapro driver (c) Tias Guns * */ /* * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. */ /* * 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);