diff options
Diffstat (limited to 'drivers/platform/x86/dell-wmi-aio.c')
| -rw-r--r-- | drivers/platform/x86/dell-wmi-aio.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell-wmi-aio.c b/drivers/platform/x86/dell-wmi-aio.c new file mode 100644 index 000000000..c7b7f1e40 --- /dev/null +++ b/drivers/platform/x86/dell-wmi-aio.c @@ -0,0 +1,197 @@ +// 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); |