diff options
Diffstat (limited to 'drivers/platform/x86/quickstart.c')
| -rw-r--r-- | drivers/platform/x86/quickstart.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/platform/x86/quickstart.c b/drivers/platform/x86/quickstart.c new file mode 100644 index 000000000000..df496c7e7171 --- /dev/null +++ b/drivers/platform/x86/quickstart.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ACPI Direct App Launch driver + * + * Copyright (C) 2024 Armin Wolf <W_Armin@gmx.de> + * Copyright (C) 2022 Arvid Norlander <lkml@vorapal.se> + * Copyright (C) 2007-2010 Angelo Arrifano <miknix@gmail.com> + * + * Information gathered from disassembled dsdt and from here: + * <https://archive.org/details/microsoft-acpi-dirapplaunch> + */ + +#include <linux/acpi.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/input/sparse-keymap.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/pm_wakeup.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/types.h> + +#include <asm/unaligned.h> + +#define DRIVER_NAME "quickstart" + +/* + * There will be two events: + * 0x02 - Button was pressed while device was off/sleeping. + * 0x80 - Button was pressed while device was up. + */ +#define QUICKSTART_EVENT_RUNTIME 0x80 + +struct quickstart_data { + struct device *dev; + struct mutex input_lock; /* Protects input sequence during notify */ + struct input_dev *input_device; + char input_name[32]; + char phys[32]; + u32 id; +}; + +/* + * Knowing what these buttons do require system specific knowledge. + * This could be done by matching on DMI data in a long quirk table. + * However, it is easier to leave it up to user space to figure this out. + * + * Using for example udev hwdb the scancode 0x1 can be remapped suitably. + */ +static const struct key_entry quickstart_keymap[] = { + { KE_KEY, 0x1, { KEY_UNKNOWN } }, + { KE_END, 0 }, +}; + +static ssize_t button_id_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct quickstart_data *data = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%u\n", data->id); +} +static DEVICE_ATTR_RO(button_id); + +static struct attribute *quickstart_attrs[] = { + &dev_attr_button_id.attr, + NULL +}; +ATTRIBUTE_GROUPS(quickstart); + +static void quickstart_notify(acpi_handle handle, u32 event, void *context) +{ + struct quickstart_data *data = context; + + switch (event) { + case QUICKSTART_EVENT_RUNTIME: + mutex_lock(&data->input_lock); + sparse_keymap_report_event(data->input_device, 0x1, 1, true); + mutex_unlock(&data->input_lock); + + acpi_bus_generate_netlink_event(DRIVER_NAME, dev_name(data->dev), event, 0); + break; + default: + dev_err(data->dev, FW_INFO "Unexpected ACPI notify event (%u)\n", event); + break; + } +} + +/* + * The GHID ACPI method is used to indicate the "role" of the button. + * However, all the meanings of these values are vendor defined. + * + * We do however expose this value to user space. + */ +static int quickstart_get_ghid(struct quickstart_data *data) +{ + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + acpi_handle handle = ACPI_HANDLE(data->dev); + union acpi_object *obj; + acpi_status status; + int ret = 0; + + /* + * This returns a buffer telling the button usage ID, + * and triggers pending notify events (The ones before booting). + */ + status = acpi_evaluate_object_typed(handle, "GHID", NULL, &buffer, ACPI_TYPE_BUFFER); + if (ACPI_FAILURE(status)) + return -EIO; + + obj = buffer.pointer; + if (!obj) + return -ENODATA; + + /* + * Quoting the specification: + * "The GHID method can return a BYTE, WORD, or DWORD. + * The value must be encoded in little-endian byte + * order (least significant byte first)." + */ + switch (obj->buffer.length) { + case 1: + data->id = obj->buffer.pointer[0]; + break; + case 2: + data->id = get_unaligned_le16(obj->buffer.pointer); + break; + case 4: + data->id = get_unaligned_le32(obj->buffer.pointer); + break; + default: + dev_err(data->dev, + FW_BUG "GHID method returned buffer of unexpected length %u\n", + obj->buffer.length); + ret = -EIO; + break; + } + + kfree(obj); + + return ret; +} + +static void quickstart_notify_remove(void *context) +{ + struct quickstart_data *data = context; + acpi_handle handle; + + handle = ACPI_HANDLE(data->dev); + + acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, quickstart_notify); +} + +static void quickstart_mutex_destroy(void *data) +{ + struct mutex *lock = data; + + mutex_destroy(lock); +} + +static int quickstart_probe(struct platform_device *pdev) +{ + struct quickstart_data *data; + acpi_handle handle; + acpi_status status; + int ret; + + handle = ACPI_HANDLE(&pdev->dev); + if (!handle) + return -ENODEV; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->dev = &pdev->dev; + dev_set_drvdata(&pdev->dev, data); + + mutex_init(&data->input_lock); + ret = devm_add_action_or_reset(&pdev->dev, quickstart_mutex_destroy, &data->input_lock); + if (ret < 0) + return ret; + + /* + * We have to initialize the device wakeup before evaluating GHID because + * doing so will notify the device if the button was used to wake the machine + * from S5. + */ + device_init_wakeup(&pdev->dev, true); + + ret = quickstart_get_ghid(data); + if (ret < 0) + return ret; + + data->input_device = devm_input_allocate_device(&pdev->dev); + if (!data->input_device) + return -ENOMEM; + + ret = sparse_keymap_setup(data->input_device, quickstart_keymap, NULL); + if (ret < 0) + return ret; + + snprintf(data->input_name, sizeof(data->input_name), "Quickstart Button %u", data->id); + snprintf(data->phys, sizeof(data->phys), DRIVER_NAME "/input%u", data->id); + + data->input_device->name = data->input_name; + data->input_device->phys = data->phys; + data->input_device->id.bustype = BUS_HOST; + + ret = input_register_device(data->input_device); + if (ret < 0) + return ret; + + status = acpi_install_notify_handler(handle, ACPI_DEVICE_NOTIFY, quickstart_notify, data); + if (ACPI_FAILURE(status)) + return -EIO; + + return devm_add_action_or_reset(&pdev->dev, quickstart_notify_remove, data); +} + +static const struct acpi_device_id quickstart_device_ids[] = { + { "PNP0C32" }, + { } +}; +MODULE_DEVICE_TABLE(acpi, quickstart_device_ids); + +static struct platform_driver quickstart_platform_driver = { + .driver = { + .name = DRIVER_NAME, + .dev_groups = quickstart_groups, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .acpi_match_table = quickstart_device_ids, + }, + .probe = quickstart_probe, +}; +module_platform_driver(quickstart_platform_driver); + +MODULE_AUTHOR("Armin Wolf <W_Armin@gmx.de>"); +MODULE_AUTHOR("Arvid Norlander <lkml@vorpal.se>"); +MODULE_AUTHOR("Angelo Arrifano"); +MODULE_DESCRIPTION("ACPI Direct App Launch driver"); +MODULE_LICENSE("GPL"); |