--- /dev/null
+/*
+ * power/home/volume button support for
+ * Microsoft Surface Pro 3 tablet.
+ *
+ * Copyright (c) 2015 Intel Corporation.
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/input.h>
+#include <linux/acpi.h>
+#include <acpi/button.h>
+
+#define SURFACE_BUTTON_HID "MSHW0028"
+#define SURFACE_BUTTON_OBJ_NAME "VGBI"
+#define SURFACE_BUTTON_DEVICE_NAME "Surface Pro 3 Buttons"
+
+#define SURFACE_BUTTON_NOTIFY_PRESS_POWER 0xc6
+#define SURFACE_BUTTON_NOTIFY_RELEASE_POWER 0xc7
+
+#define SURFACE_BUTTON_NOTIFY_PRESS_HOME 0xc4
+#define SURFACE_BUTTON_NOTIFY_RELEASE_HOME 0xc5
+
+#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP 0xc0
+#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP 0xc1
+
+#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN 0xc2
+#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN 0xc3
+
+ACPI_MODULE_NAME("surface pro 3 button");
+
+MODULE_AUTHOR("Chen Yu");
+MODULE_DESCRIPTION("Surface Pro3 Button Driver");
+MODULE_LICENSE("GPL v2");
+
+/*
+ * Power button, Home button, Volume buttons support is supposed to
+ * be covered by drivers/input/misc/soc_button_array.c, which is implemented
+ * according to "Windows ACPI Design Guide for SoC Platforms".
+ * However surface pro3 seems not to obey the specs, instead it uses
+ * device VGBI(MSHW0028) for dispatching the events.
+ * We choose acpi_driver rather than platform_driver/i2c_driver because
+ * although VGBI has an i2c resource connected to i2c controller, it
+ * is not embedded in any i2c controller's scope, thus neither platform_device
+ * will be created, nor i2c_client will be enumerated, we have to use
+ * acpi_driver.
+ */
+static const struct acpi_device_id surface_button_device_ids[] = {
+ {SURFACE_BUTTON_HID, 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, surface_button_device_ids);
+
+struct surface_button {
+ unsigned int type;
+ struct input_dev *input;
+ char phys[32]; /* for input device */
+ unsigned long pushed;
+ bool suspended;
+};
+
+static void surface_button_notify(struct acpi_device *device, u32 event)
+{
+ struct surface_button *button = acpi_driver_data(device);
+ struct input_dev *input;
+ int key_code = KEY_RESERVED;
+ bool pressed = false;
+
+ switch (event) {
+ /* Power button press,release handle */
+ case SURFACE_BUTTON_NOTIFY_PRESS_POWER:
+ pressed = true;
+ /*fall through*/
+ case SURFACE_BUTTON_NOTIFY_RELEASE_POWER:
+ key_code = KEY_POWER;
+ break;
+ /* Home button press,release handle */
+ case SURFACE_BUTTON_NOTIFY_PRESS_HOME:
+ pressed = true;
+ /*fall through*/
+ case SURFACE_BUTTON_NOTIFY_RELEASE_HOME:
+ key_code = KEY_LEFTMETA;
+ break;
+ /* Volume up button press,release handle */
+ case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP:
+ pressed = true;
+ /*fall through*/
+ case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP:
+ key_code = KEY_VOLUMEUP;
+ break;
+ /* Volume down button press,release handle */
+ case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN:
+ pressed = true;
+ /*fall through*/
+ case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN:
+ key_code = KEY_VOLUMEDOWN;
+ break;
+ default:
+ dev_info_ratelimited(&device->dev,
+ "Unsupported event [0x%x]\n", event);
+ break;
+ }
+ input = button->input;
+ if (KEY_RESERVED == key_code)
+ return;
+ if (pressed)
+ pm_wakeup_event(&device->dev, 0);
+ if (button->suspended)
+ return;
+ input_report_key(input, key_code, pressed?1:0);
+ input_sync(input);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int surface_button_suspend(struct device *dev)
+{
+ struct acpi_device *device = to_acpi_device(dev);
+ struct surface_button *button = acpi_driver_data(device);
+
+ button->suspended = true;
+ return 0;
+}
+
+static int surface_button_resume(struct device *dev)
+{
+ struct acpi_device *device = to_acpi_device(dev);
+ struct surface_button *button = acpi_driver_data(device);
+
+ button->suspended = false;
+ return 0;
+}
+#endif
+
+static int surface_button_add(struct acpi_device *device)
+{
+ struct surface_button *button;
+ struct input_dev *input;
+ const char *hid = acpi_device_hid(device);
+ char *name;
+ int error;
+
+ if (strncmp(acpi_device_bid(device), SURFACE_BUTTON_OBJ_NAME,
+ strlen(SURFACE_BUTTON_OBJ_NAME)))
+ return -ENODEV;
+
+ button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
+ if (!button)
+ return -ENOMEM;
+
+ device->driver_data = button;
+ button->input = input = input_allocate_device();
+ if (!input) {
+ error = -ENOMEM;
+ goto err_free_button;
+ }
+
+ name = acpi_device_name(device);
+ strcpy(name, SURFACE_BUTTON_DEVICE_NAME);
+ snprintf(button->phys, sizeof(button->phys), "%s/buttons", hid);
+
+ input->name = name;
+ input->phys = button->phys;
+ input->id.bustype = BUS_HOST;
+ input->dev.parent = &device->dev;
+ input_set_capability(input, EV_KEY, KEY_POWER);
+ input_set_capability(input, EV_KEY, KEY_LEFTMETA);
+ input_set_capability(input, EV_KEY, KEY_VOLUMEUP);
+ input_set_capability(input, EV_KEY, KEY_VOLUMEDOWN);
+
+ error = input_register_device(input);
+ if (error)
+ goto err_free_input;
+ dev_info(&device->dev,
+ "%s [%s]\n", name, acpi_device_bid(device));
+ return 0;
+
+ err_free_input:
+ input_free_device(input);
+ err_free_button:
+ kfree(button);
+ return error;
+}
+
+static int surface_button_remove(struct acpi_device *device)
+{
+ struct surface_button *button = acpi_driver_data(device);
+
+ input_unregister_device(button->input);
+ kfree(button);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(surface_button_pm,
+ surface_button_suspend, surface_button_resume);
+
+static struct acpi_driver surface_button_driver = {
+ .name = "surface_pro3_button",
+ .class = "SurfacePro3",
+ .ids = surface_button_device_ids,
+ .ops = {
+ .add = surface_button_add,
+ .remove = surface_button_remove,
+ .notify = surface_button_notify,
+ },
+ .drv.pm = &surface_button_pm,
+};
+
+module_acpi_driver(surface_button_driver);
projects / karo-tx-linux.git / commitdiff