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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for the LID cover switch of the Surface 34 *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 20MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");21MODULE_DESCRIPTION("Surface 3 platform driver");22MODULE_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 30MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);31 32static 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#endif41 { }42};43 44struct 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 51static struct platform_device *s3_wmi_pdev;52 53static struct surface3_wmi s3_wmi;54 55static DEFINE_MUTEX(s3_wmi_lock);56 57static 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 90static inline int s3_wmi_query_lid(int *ret)91{92 return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);93}94 95static 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 109static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)110{111 return s3_wmi_send_lid_state();112}113 114static 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 136static 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 171static 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 196static 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 229static 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 238static int __maybe_unused s3_wmi_resume(struct device *dev)239{240 s3_wmi_send_lid_state();241 return 0;242}243static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);244 245static struct platform_driver s3_wmi_driver = {246 .driver = {247 .name = "surface3-wmi",248 .pm = &s3_wmi_pm,249 },250 .remove_new = s3_wmi_remove,251};252 253static 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 279static void __exit s3_wmi_exit(void)280{281 platform_device_unregister(s3_wmi_pdev);282 platform_driver_unregister(&s3_wmi_driver);283}284 285module_init(s3_wmi_init);286module_exit(s3_wmi_exit);287