2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-26 06:04:14 +08:00
linux-next/drivers/hid/hid-lgff.c
Julia Lawall 3040c8203d HID: Drop NULL test on list_entry result
list_entry, which is an alias for container_of, cannot return NULL, as
there is no way to add a NULL value to a doubly linked list.

A simplified version of the semantic match that findds this problem is as
follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r@
expression x,E;
statement S1,S2;
position p,p1;
@@

*x = list_entry@p(...)
... when != x = E
*if@p1 (x == NULL) S1 else S2
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-07-23 01:28:02 +02:00

182 lines
5.0 KiB
C

/*
* Force feedback support for hid-compliant for some of the devices from
* Logitech, namely:
* - WingMan Cordless RumblePad
* - WingMan Force 3D
*
* Copyright (c) 2002-2004 Johann Deneux
* Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Should you need to contact me, the author, you can do so by
* e-mail - mail your message to <johann.deneux@it.uu.se>
*/
#include <linux/input.h>
#include <linux/usb.h>
#include <linux/hid.h>
#include "usbhid/usbhid.h"
#include "hid-lg.h"
struct dev_type {
u16 idVendor;
u16 idProduct;
const signed short *ff;
};
static const signed short ff_rumble[] = {
FF_RUMBLE,
-1
};
static const signed short ff_joystick[] = {
FF_CONSTANT,
-1
};
static const signed short ff_joystick_ac[] = {
FF_CONSTANT,
FF_AUTOCENTER,
-1
};
static const signed short ff_wheel[] = {
FF_CONSTANT,
FF_AUTOCENTER,
-1
};
static const struct dev_type devices[] = {
{ 0x046d, 0xc211, ff_rumble },
{ 0x046d, 0xc219, ff_rumble },
{ 0x046d, 0xc283, ff_joystick },
{ 0x046d, 0xc286, ff_joystick_ac },
{ 0x046d, 0xc293, ff_joystick },
{ 0x046d, 0xc294, ff_wheel },
{ 0x046d, 0xc295, ff_joystick },
{ 0x046d, 0xca03, ff_wheel },
};
static int hid_lgff_play(struct input_dev *dev, void *data, struct ff_effect *effect)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
int x, y;
unsigned int left, right;
#define CLAMP(x) if (x < 0) x = 0; if (x > 0xff) x = 0xff
switch (effect->type) {
case FF_CONSTANT:
x = effect->u.ramp.start_level + 0x7f; /* 0x7f is center */
y = effect->u.ramp.end_level + 0x7f;
CLAMP(x);
CLAMP(y);
report->field[0]->value[0] = 0x51;
report->field[0]->value[1] = 0x08;
report->field[0]->value[2] = x;
report->field[0]->value[3] = y;
dbg_hid("(x, y)=(%04x, %04x)\n", x, y);
usbhid_submit_report(hid, report, USB_DIR_OUT);
break;
case FF_RUMBLE:
right = effect->u.rumble.strong_magnitude;
left = effect->u.rumble.weak_magnitude;
right = right * 0xff / 0xffff;
left = left * 0xff / 0xffff;
CLAMP(left);
CLAMP(right);
report->field[0]->value[0] = 0x42;
report->field[0]->value[1] = 0x00;
report->field[0]->value[2] = left;
report->field[0]->value[3] = right;
dbg_hid("(left, right)=(%04x, %04x)\n", left, right);
usbhid_submit_report(hid, report, USB_DIR_OUT);
break;
}
return 0;
}
static void hid_lgff_set_autocenter(struct input_dev *dev, u16 magnitude)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__s32 *value = report->field[0]->value;
magnitude = (magnitude >> 12) & 0xf;
*value++ = 0xfe;
*value++ = 0x0d;
*value++ = magnitude; /* clockwise strength */
*value++ = magnitude; /* counter-clockwise strength */
*value++ = 0x80;
*value++ = 0x00;
*value = 0x00;
usbhid_submit_report(hid, report, USB_DIR_OUT);
}
int lgff_init(struct hid_device* hid)
{
struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct input_dev *dev = hidinput->input;
struct hid_report *report;
struct hid_field *field;
const signed short *ff_bits = ff_joystick;
int error;
int i;
/* Find the report to use */
if (list_empty(report_list)) {
err_hid("No output report found");
return -1;
}
/* Check that the report looks ok */
report = list_entry(report_list->next, struct hid_report, list);
field = report->field[0];
if (!field) {
err_hid("NULL field");
return -1;
}
for (i = 0; i < ARRAY_SIZE(devices); i++) {
if (dev->id.vendor == devices[i].idVendor &&
dev->id.product == devices[i].idProduct) {
ff_bits = devices[i].ff;
break;
}
}
for (i = 0; ff_bits[i] >= 0; i++)
set_bit(ff_bits[i], dev->ffbit);
error = input_ff_create_memless(dev, NULL, hid_lgff_play);
if (error)
return error;
if ( test_bit(FF_AUTOCENTER, dev->ffbit) )
dev->ff->set_autocenter = hid_lgff_set_autocenter;
printk(KERN_INFO "Force feedback for Logitech force feedback devices by Johann Deneux <johann.deneux@it.uu.se>\n");
return 0;
}