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 <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         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 = acpi_fetch_acpi_dev(handle);
 120         struct acpi_device **ts_adev = data;
 121
 122         if (!adev || 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 = ACPI_COMPANION(dev);
 139         struct acpi_device *ts_adev = NULL;
 140         acpi_status status;
 141
 142         /* ignore non ACPI devices */
 143         if (!adev)
 144                 return 0;
 145
 146         /* check for LID ACPI switch */
 147         if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
 148                 s3_wmi.pnp0c0d_adev = adev;
 149                 return 0;
 150         }
 151
 152         /* ignore non SPI controllers */
 153         if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
 154             strlen(SPI_CTL_OBJ_NAME)))
 155                 return 0;
 156
 157         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, adev->handle, 1,
 158                                      s3_wmi_attach_spi_device, NULL,
 159                                      &ts_adev, NULL);
 160         if (ACPI_FAILURE(status))
 161                 dev_warn(dev, "failed to enumerate SPI slaves\n");
 162
 163         if (!ts_adev)
 164                 return 0;
 165
 166         s3_wmi.touchscreen_adev = ts_adev;
 167
 168         return 0;
 169 }
 170
 171 static int s3_wmi_create_and_register_input(struct platform_device *pdev)
 172 {
 173         struct input_dev *input;
 174         int error;
 175
 176         input = devm_input_allocate_device(&pdev->dev);
 177         if (!input)
 178                 return -ENOMEM;
 179
 180         input->name = "Lid Switch";
 181         input->phys = "button/input0";
 182         input->id.bustype = BUS_HOST;
 183         input->id.product = 0x0005;
 184
 185         input_set_capability(input, EV_SW, SW_LID);
 186
 187         error = input_register_device(input);
 188         if (error)
 189                 return error;
 190
 191         s3_wmi.input = input;
 192
 193         return 0;
 194 }
 195
 196 static int __init s3_wmi_probe(struct platform_device *pdev)
 197 {
 198         int error;
 199
 200         if (!dmi_check_system(surface3_dmi_table))
 201                 return -ENODEV;
 202
 203         memset(&s3_wmi, 0, sizeof(s3_wmi));
 204
 205         bus_for_each_dev(&platform_bus_type, NULL, NULL,
 206                          s3_wmi_check_platform_device);
 207
 208         if (!s3_wmi.touchscreen_adev)
 209                 return -ENODEV;
 210
 211         acpi_bus_trim(s3_wmi.pnp0c0d_adev);
 212
 213         error = s3_wmi_create_and_register_input(pdev);
 214         if (error)
 215                 goto restore_acpi_lid;
 216
 217         acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
 218                                    s3_wmi_hp_notify, NULL);
 219
 220         s3_wmi_send_lid_state();
 221
 222         return 0;
 223
 224  restore_acpi_lid:
 225         acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
 226         return error;
 227 }
 228
 229 static void s3_wmi_remove(struct platform_device *device)
 230 {
 231         /* remove the hotplug context from the acpi device */
 232         s3_wmi.touchscreen_adev->hp = NULL;
 233
 234         /* reinstall the actual PNPC0C0D LID default handle */
 235         acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
 236 }
 237
 238 static int __maybe_unused s3_wmi_resume(struct device *dev)
 239 {
 240         s3_wmi_send_lid_state();
 241         return 0;
 242 }
 243 static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
 244
 245 static struct platform_driver s3_wmi_driver = {
 246         .driver = {
 247                 .name = "surface3-wmi",
 248                 .pm = &s3_wmi_pm,
 249         },
 250         .remove = s3_wmi_remove,
 251 };
 252
 253 static int __init s3_wmi_init(void)
 254 {
 255         int error;
 256
 257         s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
 258         if (!s3_wmi_pdev)
 259                 return -ENOMEM;
 260
 261         error = platform_device_add(s3_wmi_pdev);
 262         if (error)
 263                 goto err_device_put;
 264
 265         error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
 266         if (error)
 267                 goto err_device_del;
 268
 269         pr_info("Surface 3 WMI Extras loaded\n");
 270         return 0;
 271
 272  err_device_del:
 273         platform_device_del(s3_wmi_pdev);
 274  err_device_put:
 275         platform_device_put(s3_wmi_pdev);
 276         return error;
 277 }
 278
 279 static void __exit s3_wmi_exit(void)
 280 {
 281         platform_device_unregister(s3_wmi_pdev);
 282         platform_driver_unregister(&s3_wmi_driver);
 283 }
 284
 285 module_init(s3_wmi_init);
 286 module_exit(s3_wmi_exit);