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8dcb3c7628
We didn't check input_allocate_device() for failures so it could lead to
a NULL deref.
Fixes: 6b0f8f9c52
('Input: add eGalaxTouch serial touchscreen driver')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
195 lines
4.5 KiB
C
195 lines
4.5 KiB
C
/*
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* EETI Egalax serial touchscreen driver
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*
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* Copyright (c) 2015 Zoltán Böszörményi <zboszor@pr.hu>
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*
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* based on the
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*
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* Hampshire serial touchscreen driver (Copyright (c) 2010 Adam Bennett)
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*/
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/*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/input.h>
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#include <linux/serio.h>
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#define DRIVER_DESC "EETI Egalax serial touchscreen driver"
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/*
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* Definitions & global arrays.
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*/
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#define EGALAX_FORMAT_MAX_LENGTH 6
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#define EGALAX_FORMAT_START_BIT BIT(7)
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#define EGALAX_FORMAT_PRESSURE_BIT BIT(6)
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#define EGALAX_FORMAT_TOUCH_BIT BIT(0)
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#define EGALAX_FORMAT_RESOLUTION_MASK 0x06
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#define EGALAX_MIN_XC 0
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#define EGALAX_MAX_XC 0x4000
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#define EGALAX_MIN_YC 0
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#define EGALAX_MAX_YC 0x4000
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/*
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* Per-touchscreen data.
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*/
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struct egalax {
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struct input_dev *input;
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struct serio *serio;
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int idx;
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u8 data[EGALAX_FORMAT_MAX_LENGTH];
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char phys[32];
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};
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static void egalax_process_data(struct egalax *egalax)
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{
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struct input_dev *dev = egalax->input;
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u8 *data = egalax->data;
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u16 x, y;
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u8 shift;
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u8 mask;
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shift = 3 - ((data[0] & EGALAX_FORMAT_RESOLUTION_MASK) >> 1);
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mask = 0xff >> (shift + 1);
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x = (((u16)(data[1] & mask) << 7) | (data[2] & 0x7f)) << shift;
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y = (((u16)(data[3] & mask) << 7) | (data[4] & 0x7f)) << shift;
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input_report_key(dev, BTN_TOUCH, data[0] & EGALAX_FORMAT_TOUCH_BIT);
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input_report_abs(dev, ABS_X, x);
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input_report_abs(dev, ABS_Y, y);
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input_sync(dev);
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}
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static irqreturn_t egalax_interrupt(struct serio *serio,
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unsigned char data, unsigned int flags)
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{
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struct egalax *egalax = serio_get_drvdata(serio);
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int pkt_len;
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egalax->data[egalax->idx++] = data;
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if (likely(egalax->data[0] & EGALAX_FORMAT_START_BIT)) {
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pkt_len = egalax->data[0] & EGALAX_FORMAT_PRESSURE_BIT ? 6 : 5;
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if (pkt_len == egalax->idx) {
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egalax_process_data(egalax);
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egalax->idx = 0;
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}
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} else {
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dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
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egalax->data[0]);
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egalax->idx = 0;
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}
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return IRQ_HANDLED;
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}
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/*
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* egalax_connect() is the routine that is called when someone adds a
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* new serio device that supports egalax protocol and registers it as
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* an input device. This is usually accomplished using inputattach.
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*/
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static int egalax_connect(struct serio *serio, struct serio_driver *drv)
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{
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struct egalax *egalax;
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struct input_dev *input_dev;
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int error;
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egalax = kzalloc(sizeof(struct egalax), GFP_KERNEL);
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input_dev = input_allocate_device();
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if (!egalax || !input_dev) {
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error = -ENOMEM;
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goto err_free_mem;
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}
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egalax->serio = serio;
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egalax->input = input_dev;
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snprintf(egalax->phys, sizeof(egalax->phys),
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"%s/input0", serio->phys);
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input_dev->name = "EETI eGalaxTouch Serial TouchScreen";
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input_dev->phys = egalax->phys;
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input_dev->id.bustype = BUS_RS232;
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input_dev->id.vendor = SERIO_EGALAX;
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input_dev->id.product = 0;
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input_dev->id.version = 0x0001;
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input_dev->dev.parent = &serio->dev;
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input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
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input_set_abs_params(input_dev, ABS_X,
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EGALAX_MIN_XC, EGALAX_MAX_XC, 0, 0);
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input_set_abs_params(input_dev, ABS_Y,
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EGALAX_MIN_YC, EGALAX_MAX_YC, 0, 0);
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serio_set_drvdata(serio, egalax);
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error = serio_open(serio, drv);
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if (error)
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goto err_reset_drvdata;
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error = input_register_device(input_dev);
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if (error)
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goto err_close_serio;
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return 0;
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err_close_serio:
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serio_close(serio);
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err_reset_drvdata:
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serio_set_drvdata(serio, NULL);
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err_free_mem:
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input_free_device(input_dev);
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kfree(egalax);
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return error;
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}
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static void egalax_disconnect(struct serio *serio)
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{
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struct egalax *egalax = serio_get_drvdata(serio);
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serio_close(serio);
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serio_set_drvdata(serio, NULL);
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input_unregister_device(egalax->input);
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kfree(egalax);
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}
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/*
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* The serio driver structure.
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*/
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static const struct serio_device_id egalax_serio_ids[] = {
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{
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.type = SERIO_RS232,
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.proto = SERIO_EGALAX,
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.id = SERIO_ANY,
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.extra = SERIO_ANY,
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},
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{ 0 }
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};
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MODULE_DEVICE_TABLE(serio, egalax_serio_ids);
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static struct serio_driver egalax_drv = {
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.driver = {
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.name = "egalax",
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},
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.description = DRIVER_DESC,
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.id_table = egalax_serio_ids,
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.interrupt = egalax_interrupt,
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.connect = egalax_connect,
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.disconnect = egalax_disconnect,
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};
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module_serio_driver(egalax_drv);
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MODULE_AUTHOR("Zoltán Böszörményi <zboszor@pr.hu>");
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MODULE_DESCRIPTION(DRIVER_DESC);
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MODULE_LICENSE("GPL v2");
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