drivers/platform/x86/surface3-wmi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Driver for the LID cover switch of the Surface 3
   4  *
   5  *  Copyright (c) 2016 Red Hat Inc.
   6  */
   7
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/slab.h>
  12
  13 #include <linux/acpi.h>
  14 #include <linux/dmi.h>
  15 #include <linux/input.h>
  16 #include <linux/mutex.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/spi/spi.h>
  19
  20 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
  21 MODULE_DESCRIPTION("Surface 3 platform driver");
  22 MODULE_LICENSE("GPL");
  23
  24 #define ACPI_BUTTON_HID_LID             "PNP0C0D"
  25 #define SPI_CTL_OBJ_NAME                "SPI"
  26 #define SPI_TS_OBJ_NAME                 "NTRG"
  27
  28 #define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"
  29
  30 MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
  31
  32 static const struct dmi_system_id surface3_dmi_table[] = {
  33 #if defined(CONFIG_X86)
  34         {
  35                 .matches = {
  36                         DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
  37                         DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),
  38                 },
  39         },
  40 #endif
  41         { }
  42 };
  43
  44 struct surface3_wmi {
  45         struct acpi_device *touchscreen_adev;
  46         struct acpi_device *pnp0c0d_adev;
  47         struct acpi_hotplug_context hp;
  48         struct input_dev *input;
  49 };
  50
  51 static struct platform_device *s3_wmi_pdev;
  52
  53 static struct surface3_wmi s3_wmi;
  54
  55 static DEFINE_MUTEX(s3_wmi_lock);
  56
  57 static int s3_wmi_query_block(const char *guid, int instance, int *ret)
  58 {
  59         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
  60         acpi_status status;
  61         union acpi_object *obj;
  62         int error = 0;
  63
  64         mutex_lock(&s3_wmi_lock);
  65         status = wmi_query_block(guid, instance, &output);
  66
  67         obj = output.pointer;
  68
  69         if (!obj || obj->type != ACPI_TYPE_INTEGER) {
  70                 if (obj) {
  71                         pr_err("query block returned object type: %d - buffer length:%d\n",
  72                                obj->type,
  73                                obj->type == ACPI_TYPE_BUFFER ?
  74                                                 obj->buffer.length : 0);
  75                 }
  76                 error = -EINVAL;
  77                 goto out_free_unlock;
  78         }
  79         *ret = obj->integer.value;
  80  out_free_unlock:
  81         kfree(obj);
  82         mutex_unlock(&s3_wmi_lock);
  83         return error;
  84 }
  85
  86 static inline int s3_wmi_query_lid(int *ret)
  87 {
  88         return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
  89 }
  90
  91 static int s3_wmi_send_lid_state(void)
  92 {
  93         int ret, lid_sw;
  94
  95         ret = s3_wmi_query_lid(&lid_sw);
  96         if (ret)
  97                 return ret;
  98
  99         input_report_switch(s3_wmi.input, SW_LID, lid_sw);
 100         input_sync(s3_wmi.input);
 101
 102         return 0;
 103 }
 104
 105 static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
 106 {
 107         return s3_wmi_send_lid_state();
 108 }
 109
 110 static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
 111                                             u32 level,
 112                                             void *data,
 113                                             void **return_value)
 114 {
 115         struct acpi_device *adev, **ts_adev;
 116
 117         if (acpi_bus_get_device(handle, &adev))
 118                 return AE_OK;
 119
 120         ts_adev = data;
 121
 122         if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
 123             strlen(SPI_TS_OBJ_NAME)))
 124                 return AE_OK;
 125
 126         if (*ts_adev) {
 127                 pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
 128                 return AE_OK;
 129         }
 130
 131         *ts_adev = adev;
 132
 133         return AE_OK;
 134 }
 135
 136 static int s3_wmi_check_platform_device(struct device *dev, void *data)
 137 {
 138         struct acpi_device *adev, *ts_adev = NULL;
 139         acpi_handle handle;
 140         acpi_status status;
 141
 142         /* ignore non ACPI devices */
 143         handle = ACPI_HANDLE(dev);
 144         if (!handle || acpi_bus_get_device(handle, &adev))
 145                 return 0;
 146
 147         /* check for LID ACPI switch */
 148         if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
 149                 s3_wmi.pnp0c0d_adev = adev;
 150                 return 0;
 151         }
 152
 153         /* ignore non SPI controllers */
 154         if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
 155             strlen(SPI_CTL_OBJ_NAME)))
 156                 return 0;
 157
 158         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 159                                      s3_wmi_attach_spi_device, NULL,
 160                                      &ts_adev, NULL);
 161         if (ACPI_FAILURE(status))
 162                 dev_warn(dev, "failed to enumerate SPI slaves\n");
 163
 164         if (!ts_adev)
 165                 return 0;
 166
 167         s3_wmi.touchscreen_adev = ts_adev;
 168
 169         return 0;
 170 }
 171
 172 static int s3_wmi_create_and_register_input(struct platform_device *pdev)
 173 {
 174         struct input_dev *input;
 175         int error;
 176
 177         input = devm_input_allocate_device(&pdev->dev);
 178         if (!input)
 179                 return -ENOMEM;
 180
 181         input->name = "Lid Switch";
 182         input->phys = "button/input0";
 183         input->id.bustype = BUS_HOST;
 184         input->id.product = 0x0005;
 185
 186         input_set_capability(input, EV_SW, SW_LID);
 187
 188         error = input_register_device(input);
 189         if (error)
 190                 goto out_err;
 191
 192         s3_wmi.input = input;
 193
 194         return 0;
 195  out_err:
 196         input_free_device(s3_wmi.input);
 197         return error;
 198 }
 199
 200 static int __init s3_wmi_probe(struct platform_device *pdev)
 201 {
 202         int error;
 203
 204         if (!dmi_check_system(surface3_dmi_table))
 205                 return -ENODEV;
 206
 207         memset(&s3_wmi, 0, sizeof(s3_wmi));
 208
 209         bus_for_each_dev(&platform_bus_type, NULL, NULL,
 210                          s3_wmi_check_platform_device);
 211
 212         if (!s3_wmi.touchscreen_adev)
 213                 return -ENODEV;
 214
 215         acpi_bus_trim(s3_wmi.pnp0c0d_adev);
 216
 217         error = s3_wmi_create_and_register_input(pdev);
 218         if (error)
 219                 goto restore_acpi_lid;
 220
 221         acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
 222                                    s3_wmi_hp_notify, NULL);
 223
 224         s3_wmi_send_lid_state();
 225
 226         return 0;
 227
 228  restore_acpi_lid:
 229         acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
 230         return error;
 231 }
 232
 233 static int s3_wmi_remove(struct platform_device *device)
 234 {
 235         /* remove the hotplug context from the acpi device */
 236         s3_wmi.touchscreen_adev->hp = NULL;
 237
 238         /* reinstall the actual PNPC0C0D LID default handle */
 239         acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
 240         return 0;
 241 }
 242
 243 static int __maybe_unused s3_wmi_resume(struct device *dev)
 244 {
 245         s3_wmi_send_lid_state();
 246         return 0;
 247 }
 248 static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
 249
 250 static struct platform_driver s3_wmi_driver = {
 251         .driver = {
 252                 .name = "surface3-wmi",
 253                 .pm = &s3_wmi_pm,
 254         },
 255         .remove = s3_wmi_remove,
 256 };
 257
 258 static int __init s3_wmi_init(void)
 259 {
 260         int error;
 261
 262         s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
 263         if (!s3_wmi_pdev)
 264                 return -ENOMEM;
 265
 266         error = platform_device_add(s3_wmi_pdev);
 267         if (error)
 268                 goto err_device_put;
 269
 270         error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
 271         if (error)
 272                 goto err_device_del;
 273
 274         pr_info("Surface 3 WMI Extras loaded\n");
 275         return 0;
 276
 277  err_device_del:
 278         platform_device_del(s3_wmi_pdev);
 279  err_device_put:
 280         platform_device_put(s3_wmi_pdev);
 281         return error;
 282 }
 283
 284 static void __exit s3_wmi_exit(void)
 285 {
 286         platform_device_unregister(s3_wmi_pdev);
 287         platform_driver_unregister(&s3_wmi_driver);
 288 }
 289
 290 module_init(s3_wmi_init);
 291 module_exit(s3_wmi_exit);