/*
   *  HID driver for Lenovo ThinkPad USB Keyboard with TrackPoint
   *
   *  Copyright (c) 2012 Bernhard Seibold
   */
  
  /*
   * 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; either version 2 of the License, or (at your option)
   * any later version.
   */
  
  #include <linux/module.h>
  #include <linux/sysfs.h>
  #include <linux/device.h>
  #include <linux/hid.h>
  #include <linux/input.h>
  #include <linux/leds.h>
  
  #include "hid-ids.h"
  
  /* This is only used for the trackpoint part of the driver, hence _tp */
  struct tpkbd_data_pointer {
  	int led_state;
  	struct led_classdev led_mute;
  	struct led_classdev led_micmute;
  	int press_to_select;
  	int dragging;
  	int release_to_select;
  	int select_right;
  	int sensitivity;
  	int press_speed;
  };
  
  #define map_key_clear(c) hid_map_usage_clear(hi, usage, bit, max, EV_KEY, (c))
  
  static int tpkbd_input_mapping(struct hid_device *hdev,
  		struct hid_input *hi, struct hid_field *field,
  		struct hid_usage *usage, unsigned long **bit, int *max)
  {
  	if (usage->hid == (HID_UP_BUTTON | 0x0010)) {
  		/* mark the device as pointer */
  		hid_set_drvdata(hdev, (void *)1);
  		map_key_clear(KEY_MICMUTE);
  		return 1;
  	}
  	return 0;
  }
  
  #undef map_key_clear
  
  static int tpkbd_features_set(struct hid_device *hdev)
  {
  	struct hid_report *report;
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[4];
  
  	report->field[0]->value[0]  = data_pointer->press_to_select   ? 0x01 : 0x02;
  	report->field[0]->value[0] |= data_pointer->dragging          ? 0x04 : 0x08;
  	report->field[0]->value[0] |= data_pointer->release_to_select ? 0x10 : 0x20;
  	report->field[0]->value[0] |= data_pointer->select_right      ? 0x80 : 0x40;
  	report->field[1]->value[0] = 0x03; // unknown setting, imitate windows driver
  	report->field[2]->value[0] = data_pointer->sensitivity;
  	report->field[3]->value[0] = data_pointer->press_speed;
  
  	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
  	return 0;
  }
  
  static ssize_t pointer_press_to_select_show(struct device *dev,
  		struct device_attribute *attr,
  		char *buf)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	return snprintf(buf, PAGE_SIZE, "%u
  ", data_pointer->press_to_select);
  }
  
  static ssize_t pointer_press_to_select_store(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf,
  		size_t count)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int value;
  
  	if (kstrtoint(buf, 10, &value))
  		return -EINVAL;
  	if (value < 0 || value > 1)
  		return -EINVAL;
  
  	data_pointer->press_to_select = value;
  	tpkbd_features_set(hdev);
  
  	return count;
  }
  
  static ssize_t pointer_dragging_show(struct device *dev,
  		struct device_attribute *attr,
  		char *buf)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	return snprintf(buf, PAGE_SIZE, "%u
  ", data_pointer->dragging);
  }
  
  static ssize_t pointer_dragging_store(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf,
  		size_t count)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int value;
  
  	if (kstrtoint(buf, 10, &value))
  		return -EINVAL;
  	if (value < 0 || value > 1)
  		return -EINVAL;
  
  	data_pointer->dragging = value;
  	tpkbd_features_set(hdev);
  
  	return count;
  }
  
  static ssize_t pointer_release_to_select_show(struct device *dev,
  		struct device_attribute *attr,
  		char *buf)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	return snprintf(buf, PAGE_SIZE, "%u
  ", data_pointer->release_to_select);
  }
  
  static ssize_t pointer_release_to_select_store(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf,
  		size_t count)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int value;
  
  	if (kstrtoint(buf, 10, &value))
  		return -EINVAL;
  	if (value < 0 || value > 1)
  		return -EINVAL;
  
  	data_pointer->release_to_select = value;
  	tpkbd_features_set(hdev);
  
  	return count;
  }
  
  static ssize_t pointer_select_right_show(struct device *dev,
  		struct device_attribute *attr,
  		char *buf)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	return snprintf(buf, PAGE_SIZE, "%u
  ", data_pointer->select_right);
  }
  
  static ssize_t pointer_select_right_store(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf,
  		size_t count)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int value;
  
  	if (kstrtoint(buf, 10, &value))
  		return -EINVAL;
  	if (value < 0 || value > 1)
  		return -EINVAL;
  
  	data_pointer->select_right = value;
  	tpkbd_features_set(hdev);
  
  	return count;
  }
  
  static ssize_t pointer_sensitivity_show(struct device *dev,
  		struct device_attribute *attr,
  		char *buf)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	return snprintf(buf, PAGE_SIZE, "%u
  ",
  		data_pointer->sensitivity);
  }
  
  static ssize_t pointer_sensitivity_store(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf,
  		size_t count)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int value;
  
  	if (kstrtoint(buf, 10, &value) || value < 1 || value > 255)
  		return -EINVAL;
  
  	data_pointer->sensitivity = value;
  	tpkbd_features_set(hdev);
  
  	return count;
  }
  
  static ssize_t pointer_press_speed_show(struct device *dev,
  		struct device_attribute *attr,
  		char *buf)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	return snprintf(buf, PAGE_SIZE, "%u
  ",
  		data_pointer->press_speed);
  }
  
  static ssize_t pointer_press_speed_store(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf,
  		size_t count)
  {
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int value;
  
  	if (kstrtoint(buf, 10, &value) || value < 1 || value > 255)
  		return -EINVAL;
  
  	data_pointer->press_speed = value;
  	tpkbd_features_set(hdev);
  
  	return count;
  }
  
  static struct device_attribute dev_attr_pointer_press_to_select =
  	__ATTR(press_to_select, S_IWUSR | S_IRUGO,
  			pointer_press_to_select_show,
  			pointer_press_to_select_store);
  
  static struct device_attribute dev_attr_pointer_dragging =
  	__ATTR(dragging, S_IWUSR | S_IRUGO,
  			pointer_dragging_show,
  			pointer_dragging_store);
  
  static struct device_attribute dev_attr_pointer_release_to_select =
  	__ATTR(release_to_select, S_IWUSR | S_IRUGO,
  			pointer_release_to_select_show,
  			pointer_release_to_select_store);
  
  static struct device_attribute dev_attr_pointer_select_right =
  	__ATTR(select_right, S_IWUSR | S_IRUGO,
  			pointer_select_right_show,
  			pointer_select_right_store);
  
  static struct device_attribute dev_attr_pointer_sensitivity =
  	__ATTR(sensitivity, S_IWUSR | S_IRUGO,
  			pointer_sensitivity_show,
  			pointer_sensitivity_store);
  
  static struct device_attribute dev_attr_pointer_press_speed =
  	__ATTR(press_speed, S_IWUSR | S_IRUGO,
  			pointer_press_speed_show,
  			pointer_press_speed_store);
  
  static struct attribute *tpkbd_attributes_pointer[] = {
  	&dev_attr_pointer_press_to_select.attr,
  	&dev_attr_pointer_dragging.attr,
  	&dev_attr_pointer_release_to_select.attr,
  	&dev_attr_pointer_select_right.attr,
  	&dev_attr_pointer_sensitivity.attr,
  	&dev_attr_pointer_press_speed.attr,
  	NULL
  };
  
  static const struct attribute_group tpkbd_attr_group_pointer = {
  	.attrs = tpkbd_attributes_pointer,
  };
  
  static enum led_brightness tpkbd_led_brightness_get(
  			struct led_classdev *led_cdev)
  {
  	struct device *dev = led_cdev->dev->parent;
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	int led_nr = 0;
  
  	if (led_cdev == &data_pointer->led_micmute)
  		led_nr = 1;
  
  	return data_pointer->led_state & (1 << led_nr)
  				? LED_FULL
  				: LED_OFF;
  }
  
  static void tpkbd_led_brightness_set(struct led_classdev *led_cdev,
  			enum led_brightness value)
  {
  	struct device *dev = led_cdev->dev->parent;
  	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  	struct hid_report *report;
  	int led_nr = 0;
  
  	if (led_cdev == &data_pointer->led_micmute)
  		led_nr = 1;
  
  	if (value == LED_OFF)
  		data_pointer->led_state &= ~(1 << led_nr);
  	else
  		data_pointer->led_state |= 1 << led_nr;
  
  	report = hdev->report_enum[HID_OUTPUT_REPORT].report_id_hash[3];
  	report->field[0]->value[0] = (data_pointer->led_state >> 0) & 1;
  	report->field[0]->value[1] = (data_pointer->led_state >> 1) & 1;
  	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
  }
  
  static int tpkbd_probe_tp(struct hid_device *hdev)
  {
  	struct device *dev = &hdev->dev;
  	struct tpkbd_data_pointer *data_pointer;
  	size_t name_sz = strlen(dev_name(dev)) + 16;
  	char *name_mute, *name_micmute;
  	int i;
  
  	/* Validate required reports. */
  	for (i = 0; i < 4; i++) {
  		if (!hid_validate_values(hdev, HID_FEATURE_REPORT, 4, i, 1))
  			return -ENODEV;
  	}
  	if (!hid_validate_values(hdev, HID_OUTPUT_REPORT, 3, 0, 2))
  		return -ENODEV;
  
  	if (sysfs_create_group(&hdev->dev.kobj,
  				&tpkbd_attr_group_pointer)) {
  		hid_warn(hdev, "Could not create sysfs group
  ");
  	}
  
  	data_pointer = devm_kzalloc(&hdev->dev,
  				    sizeof(struct tpkbd_data_pointer),
  				    GFP_KERNEL);
  	if (data_pointer == NULL) {
  		hid_err(hdev, "Could not allocate memory for driver data
  ");
  		return -ENOMEM;
  	}
  
  	// set same default values as windows driver
  	data_pointer->sensitivity = 0xa0;
  	data_pointer->press_speed = 0x38;
  
  	name_mute = devm_kzalloc(&hdev->dev, name_sz, GFP_KERNEL);
  	name_micmute = devm_kzalloc(&hdev->dev, name_sz, GFP_KERNEL);
  	if (name_mute == NULL || name_micmute == NULL) {
  		hid_err(hdev, "Could not allocate memory for led data
  ");
  		return -ENOMEM;
  	}
  	snprintf(name_mute, name_sz, "%s:amber:mute", dev_name(dev));
  	snprintf(name_micmute, name_sz, "%s:amber:micmute", dev_name(dev));
  
  	hid_set_drvdata(hdev, data_pointer);
  
  	data_pointer->led_mute.name = name_mute;
  	data_pointer->led_mute.brightness_get = tpkbd_led_brightness_get;
  	data_pointer->led_mute.brightness_set = tpkbd_led_brightness_set;
  	data_pointer->led_mute.dev = dev;
  	led_classdev_register(dev, &data_pointer->led_mute);
  
  	data_pointer->led_micmute.name = name_micmute;
  	data_pointer->led_micmute.brightness_get = tpkbd_led_brightness_get;
  	data_pointer->led_micmute.brightness_set = tpkbd_led_brightness_set;
  	data_pointer->led_micmute.dev = dev;
  	led_classdev_register(dev, &data_pointer->led_micmute);
  
  	tpkbd_features_set(hdev);
  
  	return 0;
  }
  
  static int tpkbd_probe(struct hid_device *hdev,
  		const struct hid_device_id *id)
  {
  	int ret;
  
  	ret = hid_parse(hdev);
  	if (ret) {
  		hid_err(hdev, "hid_parse failed
  ");
  		goto err;
  	}
  
  	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
  	if (ret) {
  		hid_err(hdev, "hid_hw_start failed
  ");
  		goto err;
  	}
  
  	if (hid_get_drvdata(hdev)) {
  		hid_set_drvdata(hdev, NULL);
  		ret = tpkbd_probe_tp(hdev);
  		if (ret)
  			goto err_hid;
  	}
  
  	return 0;
  err_hid:
  	hid_hw_stop(hdev);
  err:
  	return ret;
  }
  
  static void tpkbd_remove_tp(struct hid_device *hdev)
  {
  	struct tpkbd_data_pointer *data_pointer = hid_get_drvdata(hdev);
  
  	sysfs_remove_group(&hdev->dev.kobj,
  			&tpkbd_attr_group_pointer);
  
  	led_classdev_unregister(&data_pointer->led_micmute);
  	led_classdev_unregister(&data_pointer->led_mute);
  
  	hid_set_drvdata(hdev, NULL);
  }
  
  static void tpkbd_remove(struct hid_device *hdev)
  {
  	if (hid_get_drvdata(hdev))
  		tpkbd_remove_tp(hdev);
  
  	hid_hw_stop(hdev);
  }
  
  static const struct hid_device_id tpkbd_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_TPKBD) },
  	{ }
  };
  
  MODULE_DEVICE_TABLE(hid, tpkbd_devices);
  
  static struct hid_driver tpkbd_driver = {
  	.name = "lenovo_tpkbd",
  	.id_table = tpkbd_devices,
  	.input_mapping = tpkbd_input_mapping,
  	.probe = tpkbd_probe,
  	.remove = tpkbd_remove,
  };
  module_hid_driver(tpkbd_driver);
  
  MODULE_LICENSE("GPL");