diff options
Diffstat (limited to 'drivers/platform/x86/intel-vbtn.c')
| -rw-r--r-- | drivers/platform/x86/intel-vbtn.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel-vbtn.c b/drivers/platform/x86/intel-vbtn.c new file mode 100644 index 000000000000..146d02f8c9bc --- /dev/null +++ b/drivers/platform/x86/intel-vbtn.c @@ -0,0 +1,188 @@ +/* + * Intel Virtual Button driver for Windows 8.1+ + * + * Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com> + * Copyright (C) 2016 Alex Hung <alex.hung@canonical.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. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/platform_device.h> +#include <linux/input/sparse-keymap.h> +#include <linux/acpi.h> +#include <acpi/acpi_bus.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("AceLan Kao"); + +static const struct acpi_device_id intel_vbtn_ids[] = { + {"INT33D6", 0}, + {"", 0}, +}; + +/* In theory, these are HID usages. */ +static const struct key_entry intel_vbtn_keymap[] = { + { KE_IGNORE, 0xC0, { KEY_POWER } }, /* power key press */ + { KE_KEY, 0xC1, { KEY_POWER } }, /* power key release */ + { KE_END }, +}; + +struct intel_vbtn_priv { + struct input_dev *input_dev; +}; + +static int intel_vbtn_input_setup(struct platform_device *device) +{ + struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev); + int ret; + + priv->input_dev = input_allocate_device(); + if (!priv->input_dev) + return -ENOMEM; + + ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL); + if (ret) + goto err_free_device; + + priv->input_dev->dev.parent = &device->dev; + priv->input_dev->name = "Intel Virtual Button driver"; + priv->input_dev->id.bustype = BUS_HOST; + + ret = input_register_device(priv->input_dev); + if (ret) + goto err_free_device; + + return 0; + +err_free_device: + input_free_device(priv->input_dev); + return ret; +} + +static void intel_vbtn_input_destroy(struct platform_device *device) +{ + struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev); + + input_unregister_device(priv->input_dev); +} + +static void notify_handler(acpi_handle handle, u32 event, void *context) +{ + struct platform_device *device = context; + struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev); + + if (!sparse_keymap_report_event(priv->input_dev, event, 1, true)) + dev_info(&device->dev, "unknown event index 0x%x\n", + event); +} + +static int intel_vbtn_probe(struct platform_device *device) +{ + acpi_handle handle = ACPI_HANDLE(&device->dev); + struct intel_vbtn_priv *priv; + acpi_status status; + int err; + + status = acpi_evaluate_object(handle, "VBDL", NULL, NULL); + if (!ACPI_SUCCESS(status)) { + dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n"); + return -ENODEV; + } + + priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + dev_set_drvdata(&device->dev, priv); + + err = intel_vbtn_input_setup(device); + if (err) { + pr_err("Failed to setup Intel Virtual Button\n"); + return err; + } + + status = acpi_install_notify_handler(handle, + ACPI_DEVICE_NOTIFY, + notify_handler, + device); + if (ACPI_FAILURE(status)) { + err = -EBUSY; + goto err_remove_input; + } + + return 0; + +err_remove_input: + intel_vbtn_input_destroy(device); + + return err; +} + +static int intel_vbtn_remove(struct platform_device *device) +{ + acpi_handle handle = ACPI_HANDLE(&device->dev); + + intel_vbtn_input_destroy(device); + acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler); + + /* + * Even if we failed to shut off the event stream, we can still + * safely detach from the device. + */ + return 0; +} + +static struct platform_driver intel_vbtn_pl_driver = { + .driver = { + .name = "intel-vbtn", + .acpi_match_table = intel_vbtn_ids, + }, + .probe = intel_vbtn_probe, + .remove = intel_vbtn_remove, +}; +MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids); + +static acpi_status __init +check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv) +{ + const struct acpi_device_id *ids = context; + struct acpi_device *dev; + + if (acpi_bus_get_device(handle, &dev) != 0) + return AE_OK; + + if (acpi_match_device_ids(dev, ids) == 0) + if (acpi_create_platform_device(dev)) + dev_info(&dev->dev, + "intel-vbtn: created platform device\n"); + + return AE_OK; +} + +static int __init intel_vbtn_init(void) +{ + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, check_acpi_dev, NULL, + (void *)intel_vbtn_ids, NULL); + + return platform_driver_register(&intel_vbtn_pl_driver); +} +module_init(intel_vbtn_init); + +static void __exit intel_vbtn_exit(void) +{ + platform_driver_unregister(&intel_vbtn_pl_driver); +} +module_exit(intel_vbtn_exit); |