linux/drivers/hid/hid-cougar.c
Thomas Weißschuh fe73965d07 HID: change return type of report_fixup() to const
By allowing the drivers to return a "const *" they can constify their
static report arrays.
This makes it clear to driver authors that the HID core will not modify
those reports and they can be reused for multiple devices.
Furthermore security is slightly improved as those reports are protected
against accidental or malicious modifications.

[bentiss: fixup hid-cougar.c and hid-multitouch.c for latest version of
the master branch]

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20240803-hid-const-fixup-v2-6-f53d7a7b29d8@weissschuh.net
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-08-27 16:29:55 +02:00

342 lines
8.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* HID driver for Cougar 500k Gaming Keyboard
*
* Copyright (c) 2018 Daniel M. Lambea <dmlambea@gmail.com>
*/
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/printk.h>
#include "hid-ids.h"
MODULE_AUTHOR("Daniel M. Lambea <dmlambea@gmail.com>");
MODULE_DESCRIPTION("Cougar 500k Gaming Keyboard");
MODULE_LICENSE("GPL");
MODULE_INFO(key_mappings, "G1-G6 are mapped to F13-F18");
static bool g6_is_space = true;
MODULE_PARM_DESC(g6_is_space,
"If true, G6 programmable key sends SPACE instead of F18 (default=true)");
#define COUGAR_VENDOR_USAGE 0xff00ff00
#define COUGAR_FIELD_CODE 1
#define COUGAR_FIELD_ACTION 2
#define COUGAR_KEY_G1 0x83
#define COUGAR_KEY_G2 0x84
#define COUGAR_KEY_G3 0x85
#define COUGAR_KEY_G4 0x86
#define COUGAR_KEY_G5 0x87
#define COUGAR_KEY_G6 0x78
#define COUGAR_KEY_FN 0x0d
#define COUGAR_KEY_MR 0x6f
#define COUGAR_KEY_M1 0x80
#define COUGAR_KEY_M2 0x81
#define COUGAR_KEY_M3 0x82
#define COUGAR_KEY_LEDS 0x67
#define COUGAR_KEY_LOCK 0x6e
/* Default key mappings. The special key COUGAR_KEY_G6 is defined first
* because it is more frequent to use the spacebar rather than any other
* special keys. Depending on the value of the parameter 'g6_is_space',
* the mapping will be updated in the probe function.
*/
static unsigned char cougar_mapping[][2] = {
{ COUGAR_KEY_G6, KEY_SPACE },
{ COUGAR_KEY_G1, KEY_F13 },
{ COUGAR_KEY_G2, KEY_F14 },
{ COUGAR_KEY_G3, KEY_F15 },
{ COUGAR_KEY_G4, KEY_F16 },
{ COUGAR_KEY_G5, KEY_F17 },
{ COUGAR_KEY_LOCK, KEY_SCREENLOCK },
/* The following keys are handled by the hardware itself, so no special
* treatment is required:
{ COUGAR_KEY_FN, KEY_RESERVED },
{ COUGAR_KEY_MR, KEY_RESERVED },
{ COUGAR_KEY_M1, KEY_RESERVED },
{ COUGAR_KEY_M2, KEY_RESERVED },
{ COUGAR_KEY_M3, KEY_RESERVED },
{ COUGAR_KEY_LEDS, KEY_RESERVED },
*/
{ 0, 0 },
};
struct cougar_shared {
struct list_head list;
struct kref kref;
bool enabled;
struct hid_device *dev;
struct input_dev *input;
};
struct cougar {
bool special_intf;
struct cougar_shared *shared;
};
static LIST_HEAD(cougar_udev_list);
static DEFINE_MUTEX(cougar_udev_list_lock);
/**
* cougar_fix_g6_mapping - configure the mapping for key G6/Spacebar
*/
static void cougar_fix_g6_mapping(void)
{
int i;
for (i = 0; cougar_mapping[i][0]; i++) {
if (cougar_mapping[i][0] == COUGAR_KEY_G6) {
cougar_mapping[i][1] =
g6_is_space ? KEY_SPACE : KEY_F18;
pr_info("cougar: G6 mapped to %s\n",
g6_is_space ? "space" : "F18");
return;
}
}
pr_warn("cougar: no mappings defined for G6/spacebar");
}
/*
* Constant-friendly rdesc fixup for mouse interface
*/
static const __u8 *cougar_report_fixup(struct hid_device *hdev, __u8 *rdesc,
unsigned int *rsize)
{
if (*rsize >= 117 && rdesc[2] == 0x09 && rdesc[3] == 0x02 &&
(rdesc[115] | rdesc[116] << 8) >= HID_MAX_USAGES) {
hid_info(hdev,
"usage count exceeds max: fixing up report descriptor\n");
rdesc[115] = ((HID_MAX_USAGES-1) & 0xff);
rdesc[116] = ((HID_MAX_USAGES-1) >> 8);
}
return rdesc;
}
static struct cougar_shared *cougar_get_shared_data(struct hid_device *hdev)
{
struct cougar_shared *shared;
/* Try to find an already-probed interface from the same device */
list_for_each_entry(shared, &cougar_udev_list, list) {
if (hid_compare_device_paths(hdev, shared->dev, '/')) {
kref_get(&shared->kref);
return shared;
}
}
return NULL;
}
static void cougar_release_shared_data(struct kref *kref)
{
struct cougar_shared *shared = container_of(kref,
struct cougar_shared, kref);
mutex_lock(&cougar_udev_list_lock);
list_del(&shared->list);
mutex_unlock(&cougar_udev_list_lock);
kfree(shared);
}
static void cougar_remove_shared_data(void *resource)
{
struct cougar *cougar = resource;
if (cougar->shared) {
kref_put(&cougar->shared->kref, cougar_release_shared_data);
cougar->shared = NULL;
}
}
/*
* Bind the device group's shared data to this cougar struct.
* If no shared data exists for this group, create and initialize it.
*/
static int cougar_bind_shared_data(struct hid_device *hdev,
struct cougar *cougar)
{
struct cougar_shared *shared;
int error = 0;
mutex_lock(&cougar_udev_list_lock);
shared = cougar_get_shared_data(hdev);
if (!shared) {
shared = kzalloc(sizeof(*shared), GFP_KERNEL);
if (!shared) {
error = -ENOMEM;
goto out;
}
kref_init(&shared->kref);
shared->dev = hdev;
list_add_tail(&shared->list, &cougar_udev_list);
}
cougar->shared = shared;
error = devm_add_action_or_reset(&hdev->dev, cougar_remove_shared_data, cougar);
if (error) {
mutex_unlock(&cougar_udev_list_lock);
return error;
}
out:
mutex_unlock(&cougar_udev_list_lock);
return error;
}
static int cougar_probe(struct hid_device *hdev,
const struct hid_device_id *id)
{
struct cougar *cougar;
struct hid_input *next, *hidinput = NULL;
unsigned int connect_mask;
int error;
cougar = devm_kzalloc(&hdev->dev, sizeof(*cougar), GFP_KERNEL);
if (!cougar)
return -ENOMEM;
hid_set_drvdata(hdev, cougar);
error = hid_parse(hdev);
if (error) {
hid_err(hdev, "parse failed\n");
return error;
}
if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
cougar->special_intf = true;
connect_mask = HID_CONNECT_HIDRAW;
} else
connect_mask = HID_CONNECT_DEFAULT;
error = hid_hw_start(hdev, connect_mask);
if (error) {
hid_err(hdev, "hw start failed\n");
return error;
}
error = cougar_bind_shared_data(hdev, cougar);
if (error)
goto fail_stop_and_cleanup;
/* The custom vendor interface will use the hid_input registered
* for the keyboard interface, in order to send translated key codes
* to it.
*/
if (hdev->collection->usage == HID_GD_KEYBOARD) {
list_for_each_entry_safe(hidinput, next, &hdev->inputs, list) {
if (hidinput->registered && hidinput->input != NULL) {
cougar->shared->input = hidinput->input;
cougar->shared->enabled = true;
break;
}
}
} else if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
/* Preinit the mapping table */
cougar_fix_g6_mapping();
error = hid_hw_open(hdev);
if (error)
goto fail_stop_and_cleanup;
}
return 0;
fail_stop_and_cleanup:
hid_hw_stop(hdev);
return error;
}
/*
* Convert events from vendor intf to input key events
*/
static int cougar_raw_event(struct hid_device *hdev, struct hid_report *report,
u8 *data, int size)
{
struct cougar *cougar;
struct cougar_shared *shared;
unsigned char code, action;
int i;
cougar = hid_get_drvdata(hdev);
shared = cougar->shared;
if (!cougar->special_intf || !shared)
return 0;
if (!shared->enabled || !shared->input)
return -EPERM;
code = data[COUGAR_FIELD_CODE];
action = data[COUGAR_FIELD_ACTION];
for (i = 0; cougar_mapping[i][0]; i++) {
if (code == cougar_mapping[i][0]) {
input_event(shared->input, EV_KEY,
cougar_mapping[i][1], action);
input_sync(shared->input);
return -EPERM;
}
}
/* Avoid warnings on the same unmapped key twice */
if (action != 0)
hid_warn(hdev, "unmapped special key code %0x: ignoring\n", code);
return -EPERM;
}
static void cougar_remove(struct hid_device *hdev)
{
struct cougar *cougar = hid_get_drvdata(hdev);
if (cougar) {
/* Stop the vendor intf to process more events */
if (cougar->shared)
cougar->shared->enabled = false;
if (cougar->special_intf)
hid_hw_close(hdev);
}
hid_hw_stop(hdev);
}
static int cougar_param_set_g6_is_space(const char *val,
const struct kernel_param *kp)
{
int ret;
ret = param_set_bool(val, kp);
if (ret)
return ret;
cougar_fix_g6_mapping();
return 0;
}
static const struct kernel_param_ops cougar_g6_is_space_ops = {
.set = cougar_param_set_g6_is_space,
.get = param_get_bool,
};
module_param_cb(g6_is_space, &cougar_g6_is_space_ops, &g6_is_space, 0644);
static const struct hid_device_id cougar_id_table[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
USB_DEVICE_ID_COUGAR_500K_GAMING_KEYBOARD) },
{ HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
USB_DEVICE_ID_COUGAR_700K_GAMING_KEYBOARD) },
{}
};
MODULE_DEVICE_TABLE(hid, cougar_id_table);
static struct hid_driver cougar_driver = {
.name = "cougar",
.id_table = cougar_id_table,
.report_fixup = cougar_report_fixup,
.probe = cougar_probe,
.remove = cougar_remove,
.raw_event = cougar_raw_event,
};
module_hid_driver(cougar_driver);