// SPDX-License-Identifier: GPL-2.0-only /* * Driver for the LID cover switch of the Surface 3 * * Copyright (c) 2016 Red Hat Inc. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/acpi.h> #include <linux/dmi.h> #include <linux/input.h> #include <linux/mutex.h> #include <linux/platform_device.h> #include <linux/spi/spi.h> MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>"); MODULE_DESCRIPTION("Surface 3 platform driver"); MODULE_LICENSE("GPL"); #define ACPI_BUTTON_HID_LID "PNP0C0D" #define SPI_CTL_OBJ_NAME "SPI" #define SPI_TS_OBJ_NAME "NTRG" #define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE" MODULE_ALIAS("wmi:" SURFACE3_LID_GUID); static const struct dmi_system_id surface3_dmi_table[] = { #if defined(CONFIG_X86) { .matches = { DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"), DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"), }, }, #endif { } }; struct surface3_wmi { struct acpi_device *touchscreen_adev; struct acpi_device *pnp0c0d_adev; struct acpi_hotplug_context hp; struct input_dev *input; }; static struct platform_device *s3_wmi_pdev; static struct surface3_wmi s3_wmi; static DEFINE_MUTEX(s3_wmi_lock); static int s3_wmi_query_block(const char *guid, int instance, int *ret) { struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *obj = NULL; acpi_status status; int error = 0; mutex_lock(&s3_wmi_lock); status = wmi_query_block(guid, instance, &output); if (ACPI_FAILURE(status)) { error = -EIO; goto out_free_unlock; } obj = output.pointer; if (!obj || obj->type != ACPI_TYPE_INTEGER) { if (obj) { pr_err("query block returned object type: %d - buffer length:%d\n", obj->type, obj->type == ACPI_TYPE_BUFFER ? obj->buffer.length : 0); } error = -EINVAL; goto out_free_unlock; } *ret = obj->integer.value; out_free_unlock: kfree(obj); mutex_unlock(&s3_wmi_lock); return error; } static inline int s3_wmi_query_lid(int *ret) { return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret); } static int s3_wmi_send_lid_state(void) { int ret, lid_sw; ret = s3_wmi_query_lid(&lid_sw); if (ret) return ret; input_report_switch(s3_wmi.input, SW_LID, lid_sw); input_sync(s3_wmi.input); return 0; } static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value) { return s3_wmi_send_lid_state(); } static acpi_status s3_wmi_attach_spi_device(acpi_handle handle, u32 level, void *data, void **return_value) { struct acpi_device *adev = acpi_fetch_acpi_dev(handle); struct acpi_device **ts_adev = data; if (!adev || strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME, strlen(SPI_TS_OBJ_NAME))) return AE_OK; if (*ts_adev) { pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME); return AE_OK; } *ts_adev = adev; return AE_OK; } static int s3_wmi_check_platform_device(struct device *dev, void *data) { struct acpi_device *adev = ACPI_COMPANION(dev); struct acpi_device *ts_adev = NULL; acpi_status status; /* ignore non ACPI devices */ if (!adev) return 0; /* check for LID ACPI switch */ if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) { s3_wmi.pnp0c0d_adev = adev; return 0; } /* ignore non SPI controllers */ if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME, strlen(SPI_CTL_OBJ_NAME))) return 0; status = acpi_walk_namespace(ACPI_TYPE_DEVICE, adev->handle, 1, s3_wmi_attach_spi_device, NULL, &ts_adev, NULL); if (ACPI_FAILURE(status)) dev_warn(dev, "failed to enumerate SPI slaves\n"); if (!ts_adev) return 0; s3_wmi.touchscreen_adev = ts_adev; return 0; } static int s3_wmi_create_and_register_input(struct platform_device *pdev) { struct input_dev *input; int error; input = devm_input_allocate_device(&pdev->dev); if (!input) return -ENOMEM; input->name = "Lid Switch"; input->phys = "button/input0"; input->id.bustype = BUS_HOST; input->id.product = 0x0005; input_set_capability(input, EV_SW, SW_LID); error = input_register_device(input); if (error) return error; s3_wmi.input = input; return 0; } static int __init s3_wmi_probe(struct platform_device *pdev) { int error; if (!dmi_check_system(surface3_dmi_table)) return -ENODEV; memset(&s3_wmi, 0, sizeof(s3_wmi)); bus_for_each_dev(&platform_bus_type, NULL, NULL, s3_wmi_check_platform_device); if (!s3_wmi.touchscreen_adev) return -ENODEV; acpi_bus_trim(s3_wmi.pnp0c0d_adev); error = s3_wmi_create_and_register_input(pdev); if (error) goto restore_acpi_lid; acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp, s3_wmi_hp_notify, NULL); s3_wmi_send_lid_state(); return 0; restore_acpi_lid: acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle); return error; } static int s3_wmi_remove(struct platform_device *device) { /* remove the hotplug context from the acpi device */ s3_wmi.touchscreen_adev->hp = NULL; /* reinstall the actual PNPC0C0D LID default handle */ acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle); return 0; } static int __maybe_unused s3_wmi_resume(struct device *dev) { s3_wmi_send_lid_state(); return 0; } static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume); static struct platform_driver s3_wmi_driver = { .driver = { .name = "surface3-wmi", .pm = &s3_wmi_pm, }, .remove = s3_wmi_remove, }; static int __init s3_wmi_init(void) { int error; s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1); if (!s3_wmi_pdev) return -ENOMEM; error = platform_device_add(s3_wmi_pdev); if (error) goto err_device_put; error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe); if (error) goto err_device_del; pr_info("Surface 3 WMI Extras loaded\n"); return 0; err_device_del: platform_device_del(s3_wmi_pdev); err_device_put: platform_device_put(s3_wmi_pdev); return error; } static void __exit s3_wmi_exit(void) { platform_device_unregister(s3_wmi_pdev); platform_driver_unregister(&s3_wmi_driver); } module_init(s3_wmi_init); module_exit(s3_wmi_exit);