drivers/platform/surface/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 <[email protected]>");
  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         union acpi_object *obj = NULL;
  61         acpi_status status;
  62         int error = 0;
  63
  64         mutex_lock(&s3_wmi_lock);
  65         status = wmi_query_block(guid, instance, &output);
  66         if (ACPI_FAILURE(status)) {
  67                 error = -EIO;
  68                 goto out_free_unlock;
  69         }
  70
  71         obj = output.pointer;
  72
  73         if (!obj || obj->type != ACPI_TYPE_INTEGER) {
  74                 if (obj) {
  75                         pr_err("query block returned object type: %d - buffer length:%d\n",
  76                                obj->type,
  77                                obj->type == ACPI_TYPE_BUFFER ?
  78                                                 obj->buffer.length : 0);
  79                 }
  80                 error = -EINVAL;
  81                 goto out_free_unlock;
  82         }
  83         *ret = obj->integer.value;
  84  out_free_unlock:
  85         kfree(obj);
  86         mutex_unlock(&s3_wmi_lock);
  87         return error;
  88 }
  89
  90 static inline int s3_wmi_query_lid(int *ret)
  91 {
  92         return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
  93 }
  94
  95 static int s3_wmi_send_lid_state(void)
  96 {
  97         int ret, lid_sw;
  98
  99         ret = s3_wmi_query_lid(&lid_sw);
 100         if (ret)
 101                 return ret;
 102
 103         input_report_switch(s3_wmi.input, SW_LID, lid_sw);
 104         input_sync(s3_wmi.input);
 105
 106         return 0;
 107 }
 108
 109 static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
 110 {
 111         return s3_wmi_send_lid_state();
 112 }
 113
 114 static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
 115                                             u32 level,
 116                                             void *data,
 117                                             void **return_value)
 118 {
 119         struct acpi_device *adev, **ts_adev;
 120
 121         if (acpi_bus_get_device(handle, &adev))
 122                 return AE_OK;
 123
 124         ts_adev = data;
 125
 126         if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
 127             strlen(SPI_TS_OBJ_NAME)))
 128                 return AE_OK;
 129
 130         if (*ts_adev) {
 131                 pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
 132                 return AE_OK;
 133         }
 134
 135         *ts_adev = adev;
 136
 137         return AE_OK;
 138 }
 139
 140 static int s3_wmi_check_platform_device(struct device *dev, void *data)
 141 {
 142         struct acpi_device *adev = ACPI_COMPANION(dev);
 143         struct acpi_device *ts_adev = NULL;
 144         acpi_status status;
 145
 146         /* ignore non ACPI devices */
 147         if (!adev)
 148                 return 0;
 149
 150         /* check for LID ACPI switch */
 151         if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
 152                 s3_wmi.pnp0c0d_adev = adev;
 153                 return 0;
 154         }
 155
 156         /* ignore non SPI controllers */
 157         if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
 158             strlen(SPI_CTL_OBJ_NAME)))
 159                 return 0;
 160
 161         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, adev->handle, 1,
 162                                      s3_wmi_attach_spi_device, NULL,
 163                                      &ts_adev, NULL);
 164         if (ACPI_FAILURE(status))
 165                 dev_warn(dev, "failed to enumerate SPI slaves\n");
 166
 167         if (!ts_adev)
 168                 return 0;
 169
 170         s3_wmi.touchscreen_adev = ts_adev;
 171
 172         return 0;
 173 }
 174
 175 static int s3_wmi_create_and_register_input(struct platform_device *pdev)
 176 {
 177         struct input_dev *input;
 178         int error;
 179
 180         input = devm_input_allocate_device(&pdev->dev);
 181         if (!input)
 182                 return -ENOMEM;
 183
 184         input->name = "Lid Switch";
 185         input->phys = "button/input0";
 186         input->id.bustype = BUS_HOST;
 187         input->id.product = 0x0005;
 188
 189         input_set_capability(input, EV_SW, SW_LID);
 190
 191         error = input_register_device(input);
 192         if (error)
 193                 goto out_err;
 194
 195         s3_wmi.input = input;
 196
 197         return 0;
 198  out_err:
 199         input_free_device(s3_wmi.input);
 200         return error;
 201 }
 202
 203 static int __init s3_wmi_probe(struct platform_device *pdev)
 204 {
 205         int error;
 206
 207         if (!dmi_check_system(surface3_dmi_table))
 208                 return -ENODEV;
 209
 210         memset(&s3_wmi, 0, sizeof(s3_wmi));
 211
 212         bus_for_each_dev(&platform_bus_type, NULL, NULL,
 213                          s3_wmi_check_platform_device);
 214
 215         if (!s3_wmi.touchscreen_adev)
 216                 return -ENODEV;
 217
 218         acpi_bus_trim(s3_wmi.pnp0c0d_adev);
 219
 220         error = s3_wmi_create_and_register_input(pdev);
 221         if (error)
 222                 goto restore_acpi_lid;
 223
 224         acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
 225                                    s3_wmi_hp_notify, NULL);
 226
 227         s3_wmi_send_lid_state();
 228
 229         return 0;
 230
 231  restore_acpi_lid:
 232         acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
 233         return error;
 234 }
 235
 236 static int s3_wmi_remove(struct platform_device *device)
 237 {
 238         /* remove the hotplug context from the acpi device */
 239         s3_wmi.touchscreen_adev->hp = NULL;
 240
 241         /* reinstall the actual PNPC0C0D LID default handle */
 242         acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
 243         return 0;
 244 }
 245
 246 static int __maybe_unused s3_wmi_resume(struct device *dev)
 247 {
 248         s3_wmi_send_lid_state();
 249         return 0;
 250 }
 251 static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
 252
 253 static struct platform_driver s3_wmi_driver = {
 254         .driver = {
 255                 .name = "surface3-wmi",
 256                 .pm = &s3_wmi_pm,
 257         },
 258         .remove = s3_wmi_remove,
 259 };
 260
 261 static int __init s3_wmi_init(void)
 262 {
 263         int error;
 264
 265         s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
 266         if (!s3_wmi_pdev)
 267                 return -ENOMEM;
 268
 269         error = platform_device_add(s3_wmi_pdev);
 270         if (error)
 271                 goto err_device_put;
 272
 273         error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
 274         if (error)
 275                 goto err_device_del;
 276
 277         pr_info("Surface 3 WMI Extras loaded\n");
 278         return 0;
 279
 280  err_device_del:
 281         platform_device_del(s3_wmi_pdev);
 282  err_device_put:
 283         platform_device_put(s3_wmi_pdev);
 284         return error;
 285 }
 286
 287 static void __exit s3_wmi_exit(void)
 288 {
 289         platform_device_unregister(s3_wmi_pdev);
 290         platform_driver_unregister(&s3_wmi_driver);
 291 }
 292
 293 module_init(s3_wmi_init);
 294 module_exit(s3_wmi_exit);