platform/surface/surface3-wmi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *  Driver for the LID cover switch of the Surface 3
0004  *
0005  *  Copyright (c) 2016 Red Hat Inc.
0006  */
0007
0008
0009 #include <linux/kernel.h>
0010 #include <linux/module.h>
0011 #include <linux/slab.h>
0012
0013 #include <linux/acpi.h>
0014 #include <linux/dmi.h>
0015 #include <linux/input.h>
0016 #include <linux/mutex.h>
0017 #include <linux/platform_device.h>
0018 #include <linux/spi/spi.h>
0019
0020 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
0021 MODULE_DESCRIPTION("Surface 3 platform driver");
0022 MODULE_LICENSE("GPL");
0023
0024 #define ACPI_BUTTON_HID_LID     "PNP0C0D"
0025 #define SPI_CTL_OBJ_NAME        "SPI"
0026 #define SPI_TS_OBJ_NAME         "NTRG"
0027
0028 #define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"
0029
0030 MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
0031
0032 static const struct dmi_system_id surface3_dmi_table[] = {
0033 #if defined(CONFIG_X86)
0034     {
0035         .matches = {
0036             DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
0037             DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),
0038         },
0039     },
0040 #endif
0041     { }
0042 };
0043
0044 struct surface3_wmi {
0045     struct acpi_device *touchscreen_adev;
0046     struct acpi_device *pnp0c0d_adev;
0047     struct acpi_hotplug_context hp;
0048     struct input_dev *input;
0049 };
0050
0051 static struct platform_device *s3_wmi_pdev;
0052
0053 static struct surface3_wmi s3_wmi;
0054
0055 static DEFINE_MUTEX(s3_wmi_lock);
0056
0057 static int s3_wmi_query_block(const char *guid, int instance, int *ret)
0058 {
0059     struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
0060     union acpi_object *obj = NULL;
0061     acpi_status status;
0062     int error = 0;
0063
0064     mutex_lock(&s3_wmi_lock);
0065     status = wmi_query_block(guid, instance, &output);
0066     if (ACPI_FAILURE(status)) {
0067         error = -EIO;
0068         goto out_free_unlock;
0069     }
0070
0071     obj = output.pointer;
0072
0073     if (!obj || obj->type != ACPI_TYPE_INTEGER) {
0074         if (obj) {
0075             pr_err("query block returned object type: %d - buffer length:%d\n",
0076                    obj->type,
0077                    obj->type == ACPI_TYPE_BUFFER ?
0078                         obj->buffer.length : 0);
0079         }
0080         error = -EINVAL;
0081         goto out_free_unlock;
0082     }
0083     *ret = obj->integer.value;
0084  out_free_unlock:
0085     kfree(obj);
0086     mutex_unlock(&s3_wmi_lock);
0087     return error;
0088 }
0089
0090 static inline int s3_wmi_query_lid(int *ret)
0091 {
0092     return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
0093 }
0094
0095 static int s3_wmi_send_lid_state(void)
0096 {
0097     int ret, lid_sw;
0098
0099     ret = s3_wmi_query_lid(&lid_sw);
0100     if (ret)
0101         return ret;
0102
0103     input_report_switch(s3_wmi.input, SW_LID, lid_sw);
0104     input_sync(s3_wmi.input);
0105
0106     return 0;
0107 }
0108
0109 static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
0110 {
0111     return s3_wmi_send_lid_state();
0112 }
0113
0114 static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
0115                         u32 level,
0116                         void *data,
0117                         void **return_value)
0118 {
0119     struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
0120     struct acpi_device **ts_adev = data;
0121
0122     if (!adev || strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
0123                  strlen(SPI_TS_OBJ_NAME)))
0124         return AE_OK;
0125
0126     if (*ts_adev) {
0127         pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
0128         return AE_OK;
0129     }
0130
0131     *ts_adev = adev;
0132
0133     return AE_OK;
0134 }
0135
0136 static int s3_wmi_check_platform_device(struct device *dev, void *data)
0137 {
0138     struct acpi_device *adev = ACPI_COMPANION(dev);
0139     struct acpi_device *ts_adev = NULL;
0140     acpi_status status;
0141
0142     /* ignore non ACPI devices */
0143     if (!adev)
0144         return 0;
0145
0146     /* check for LID ACPI switch */
0147     if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
0148         s3_wmi.pnp0c0d_adev = adev;
0149         return 0;
0150     }
0151
0152     /* ignore non SPI controllers */
0153     if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
0154         strlen(SPI_CTL_OBJ_NAME)))
0155         return 0;
0156
0157     status = acpi_walk_namespace(ACPI_TYPE_DEVICE, adev->handle, 1,
0158                      s3_wmi_attach_spi_device, NULL,
0159                      &ts_adev, NULL);
0160     if (ACPI_FAILURE(status))
0161         dev_warn(dev, "failed to enumerate SPI slaves\n");
0162
0163     if (!ts_adev)
0164         return 0;
0165
0166     s3_wmi.touchscreen_adev = ts_adev;
0167
0168     return 0;
0169 }
0170
0171 static int s3_wmi_create_and_register_input(struct platform_device *pdev)
0172 {
0173     struct input_dev *input;
0174     int error;
0175
0176     input = devm_input_allocate_device(&pdev->dev);
0177     if (!input)
0178         return -ENOMEM;
0179
0180     input->name = "Lid Switch";
0181     input->phys = "button/input0";
0182     input->id.bustype = BUS_HOST;
0183     input->id.product = 0x0005;
0184
0185     input_set_capability(input, EV_SW, SW_LID);
0186
0187     error = input_register_device(input);
0188     if (error)
0189         return error;
0190
0191     s3_wmi.input = input;
0192
0193     return 0;
0194 }
0195
0196 static int __init s3_wmi_probe(struct platform_device *pdev)
0197 {
0198     int error;
0199
0200     if (!dmi_check_system(surface3_dmi_table))
0201         return -ENODEV;
0202
0203     memset(&s3_wmi, 0, sizeof(s3_wmi));
0204
0205     bus_for_each_dev(&platform_bus_type, NULL, NULL,
0206              s3_wmi_check_platform_device);
0207
0208     if (!s3_wmi.touchscreen_adev)
0209         return -ENODEV;
0210
0211     acpi_bus_trim(s3_wmi.pnp0c0d_adev);
0212
0213     error = s3_wmi_create_and_register_input(pdev);
0214     if (error)
0215         goto restore_acpi_lid;
0216
0217     acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
0218                    s3_wmi_hp_notify, NULL);
0219
0220     s3_wmi_send_lid_state();
0221
0222     return 0;
0223
0224  restore_acpi_lid:
0225     acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
0226     return error;
0227 }
0228
0229 static int s3_wmi_remove(struct platform_device *device)
0230 {
0231     /* remove the hotplug context from the acpi device */
0232     s3_wmi.touchscreen_adev->hp = NULL;
0233
0234     /* reinstall the actual PNPC0C0D LID default handle */
0235     acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
0236     return 0;
0237 }
0238
0239 static int __maybe_unused s3_wmi_resume(struct device *dev)
0240 {
0241     s3_wmi_send_lid_state();
0242     return 0;
0243 }
0244 static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
0245
0246 static struct platform_driver s3_wmi_driver = {
0247     .driver = {
0248         .name = "surface3-wmi",
0249         .pm = &s3_wmi_pm,
0250     },
0251     .remove = s3_wmi_remove,
0252 };
0253
0254 static int __init s3_wmi_init(void)
0255 {
0256     int error;
0257
0258     s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
0259     if (!s3_wmi_pdev)
0260         return -ENOMEM;
0261
0262     error = platform_device_add(s3_wmi_pdev);
0263     if (error)
0264         goto err_device_put;
0265
0266     error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
0267     if (error)
0268         goto err_device_del;
0269
0270     pr_info("Surface 3 WMI Extras loaded\n");
0271     return 0;
0272
0273  err_device_del:
0274     platform_device_del(s3_wmi_pdev);
0275  err_device_put:
0276     platform_device_put(s3_wmi_pdev);
0277     return error;
0278 }
0279
0280 static void __exit s3_wmi_exit(void)
0281 {
0282     platform_device_unregister(s3_wmi_pdev);
0283     platform_driver_unregister(&s3_wmi_driver);
0284 }
0285
0286 module_init(s3_wmi_init);
0287 module_exit(s3_wmi_exit);