hid-lenovo-tpkbd.c

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/*
 *  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/usb.h>
#include <linux/hid.h>
#include <linux/input.h>
#include <linux/leds.h>
#include "usbhid/usbhid.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)
{
    struct usbhid_device *uhdev;

    uhdev = (struct usbhid_device *) hdev->driver_data;
    if (uhdev->ifnum == 1 && usage->hid == (HID_UP_BUTTON | 0x0010)) {
        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;

    usbhid_submit_report(hdev, report, USB_DIR_OUT);
    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\n", 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\n", 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\n", 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\n", 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\n",
        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);

    data_pointer = hid_get_drvdata(hdev);

    return snprintf(buf, PAGE_SIZE, "%u\n",
        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;
    usbhid_submit_report(hdev, report, USB_DIR_OUT);
}

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 ret;

    if (sysfs_create_group(&hdev->dev.kobj,
                &tpkbd_attr_group_pointer)) {
        hid_warn(hdev, "Could not create sysfs group\n");
    }

    data_pointer = kzalloc(sizeof(struct tpkbd_data_pointer), GFP_KERNEL);
    if (data_pointer == NULL) {
        hid_err(hdev, "Could not allocate memory for driver data\n");
        return -ENOMEM;
    }

    // set same default values as windows driver
    data_pointer->sensitivity = 0xa0;
    data_pointer->press_speed = 0x38;

    name_mute = kzalloc(name_sz, GFP_KERNEL);
    if (name_mute == NULL) {
        hid_err(hdev, "Could not allocate memory for led data\n");
        ret = -ENOMEM;
        goto err;
    }
    snprintf(name_mute, name_sz, "%s:amber:mute", dev_name(dev));

    name_micmute = kzalloc(name_sz, GFP_KERNEL);
    if (name_micmute == NULL) {
        hid_err(hdev, "Could not allocate memory for led data\n");
        ret = -ENOMEM;
        goto err2;
    }
    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;

err2:
    kfree(name_mute);
err:
    kfree(data_pointer);
    return ret;
}

static int tpkbd_probe(struct hid_device *hdev,
        const struct hid_device_id *id)
{
    int ret;
    struct usbhid_device *uhdev;

    ret = hid_parse(hdev);
    if (ret) {
        hid_err(hdev, "hid_parse failed\n");
        goto err_free;
    }

    ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
    if (ret) {
        hid_err(hdev, "hid_hw_start failed\n");
        goto err_free;
    }

    uhdev = (struct usbhid_device *) hdev->driver_data;

    if (uhdev->ifnum == 1)
        return tpkbd_probe_tp(hdev);

    return 0;
err_free:
    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);
    kfree(data_pointer->led_micmute.name);
    kfree(data_pointer->led_mute.name);
    kfree(data_pointer);
}

static void tpkbd_remove(struct hid_device *hdev)
{
    struct usbhid_device *uhdev;

    uhdev = (struct usbhid_device *) hdev->driver_data;
    if (uhdev->ifnum == 1)
        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,
};

static int __init tpkbd_init(void)
{
    return hid_register_driver(&tpkbd_driver);
}

static void __exit tpkbd_exit(void)
{
    hid_unregister_driver(&tpkbd_driver);
}

module_init(tpkbd_init);
module_exit(tpkbd_exit);

MODULE_LICENSE("GPL");