Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  WMI hotkeys support for Dell All-In-One series
 */
 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/acpi.h>
#include <linux/string.h>
 
MODULE_DESCRIPTION("WMI hotkeys driver for Dell All-In-One series");
MODULE_LICENSE("GPL");
 
#define EVENT_GUID1 "284A0E6B-380E-472A-921F-E52786257FB4"
#define EVENT_GUID2 "02314822-307C-4F66-BF0E-48AEAEB26CC8"
 
struct dell_wmi_event {
<------>u16	length;
<------>/* 0x000: A hot key pressed or an event occurred
<------> * 0x00F: A sequence of hot keys are pressed */
<------>u16	type;
<------>u16	event[];
};
 
static const char *dell_wmi_aio_guids[] = {
<------>EVENT_GUID1,
<------>EVENT_GUID2,
<------>NULL
};
 
MODULE_ALIAS("wmi:"EVENT_GUID1);
MODULE_ALIAS("wmi:"EVENT_GUID2);
 
static const struct key_entry dell_wmi_aio_keymap[] = {
<------>{ KE_KEY, 0xc0, { KEY_VOLUMEUP } },
<------>{ KE_KEY, 0xc1, { KEY_VOLUMEDOWN } },
<------>{ KE_KEY, 0xe030, { KEY_VOLUMEUP } },
<------>{ KE_KEY, 0xe02e, { KEY_VOLUMEDOWN } },
<------>{ KE_KEY, 0xe020, { KEY_MUTE } },
<------>{ KE_KEY, 0xe027, { KEY_DISPLAYTOGGLE } },
<------>{ KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
<------>{ KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
<------>{ KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
<------>{ KE_END, 0 }
};
 
static struct input_dev *dell_wmi_aio_input_dev;
 
/*
 * The new WMI event data format will follow the dell_wmi_event structure
 * So, we will check if the buffer matches the format
 */
static bool dell_wmi_aio_event_check(u8 *buffer, int length)
{
<------>struct dell_wmi_event *event = (struct dell_wmi_event *)buffer;
 
<------>if (event == NULL || length < 6)
<------><------>return false;
 
<------>if ((event->type == 0 || event->type == 0xf) &&
<------><------><------>event->length >= 2)
<------><------>return true;
 
<------>return false;
}
 
static void dell_wmi_aio_notify(u32 value, void *context)
{
<------>struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
<------>union acpi_object *obj;
<------>struct dell_wmi_event *event;
<------>acpi_status status;
 
<------>status = wmi_get_event_data(value, &response);
<------>if (status != AE_OK) {
<------><------>pr_info("bad event status 0x%x\n", status);
<------><------>return;
<------>}
 
<------>obj = (union acpi_object *)response.pointer;
<------>if (obj) {
<------><------>unsigned int scancode = 0;
 
<------><------>switch (obj->type) {
<------><------>case ACPI_TYPE_INTEGER:
<------><------><------>/* Most All-In-One correctly return integer scancode */
<------><------><------>scancode = obj->integer.value;
<------><------><------>sparse_keymap_report_event(dell_wmi_aio_input_dev,
<------><------><------><------>scancode, 1, true);
<------><------><------>break;
<------><------>case ACPI_TYPE_BUFFER:
<------><------><------>if (dell_wmi_aio_event_check(obj->buffer.pointer,
<------><------><------><------><------><------>obj->buffer.length)) {
<------><------><------><------>event = (struct dell_wmi_event *)
<------><------><------><------><------>obj->buffer.pointer;
<------><------><------><------>scancode = event->event[0];
<------><------><------>} else {
<------><------><------><------>/* Broken machines return the scancode in a
<------><------><------><------>   buffer */
<------><------><------><------>if (obj->buffer.pointer &&
<------><------><------><------><------><------>obj->buffer.length > 0)
<------><------><------><------><------>scancode = obj->buffer.pointer[0];
<------><------><------>}
<------><------><------>if (scancode)
<------><------><------><------>sparse_keymap_report_event(
<------><------><------><------><------>dell_wmi_aio_input_dev,
<------><------><------><------><------>scancode, 1, true);
<------><------><------>break;
<------><------>}
<------>}
<------>kfree(obj);
}
 
static int __init dell_wmi_aio_input_setup(void)
{
<------>int err;
 
<------>dell_wmi_aio_input_dev = input_allocate_device();
 
<------>if (!dell_wmi_aio_input_dev)
<------><------>return -ENOMEM;
 
<------>dell_wmi_aio_input_dev->name = "Dell AIO WMI hotkeys";
<------>dell_wmi_aio_input_dev->phys = "wmi/input0";
<------>dell_wmi_aio_input_dev->id.bustype = BUS_HOST;
 
<------>err = sparse_keymap_setup(dell_wmi_aio_input_dev,
<------><------><------>dell_wmi_aio_keymap, NULL);
<------>if (err) {
<------><------>pr_err("Unable to setup input device keymap\n");
<------><------>goto err_free_dev;
<------>}
<------>err = input_register_device(dell_wmi_aio_input_dev);
<------>if (err) {
<------><------>pr_info("Unable to register input device\n");
<------><------>goto err_free_dev;
<------>}
<------>return 0;
 
err_free_dev:
<------>input_free_device(dell_wmi_aio_input_dev);
<------>return err;
}
 
static const char *dell_wmi_aio_find(void)
{
<------>int i;
 
<------>for (i = 0; dell_wmi_aio_guids[i] != NULL; i++)
<------><------>if (wmi_has_guid(dell_wmi_aio_guids[i]))
<------><------><------>return dell_wmi_aio_guids[i];
 
<------>return NULL;
}
 
static int __init dell_wmi_aio_init(void)
{
<------>int err;
<------>const char *guid;
 
<------>guid = dell_wmi_aio_find();
<------>if (!guid) {
<------><------>pr_warn("No known WMI GUID found\n");
<------><------>return -ENXIO;
<------>}
 
<------>err = dell_wmi_aio_input_setup();
<------>if (err)
<------><------>return err;
 
<------>err = wmi_install_notify_handler(guid, dell_wmi_aio_notify, NULL);
<------>if (err) {
<------><------>pr_err("Unable to register notify handler - %d\n", err);
<------><------>input_unregister_device(dell_wmi_aio_input_dev);
<------><------>return err;
<------>}
 
<------>return 0;
}
 
static void __exit dell_wmi_aio_exit(void)
{
<------>const char *guid;
 
<------>guid = dell_wmi_aio_find();
<------>wmi_remove_notify_handler(guid);
<------>input_unregister_device(dell_wmi_aio_input_dev);
}
 
module_init(dell_wmi_aio_init);
module_exit(dell_wmi_aio_exit);