Merge tag 'platform-drivers-x86-v3.20-1' of git://git.infradead.org/users/dvhart...

[mirror_ubuntu-artful-kernel.git] / drivers / hid / hid-logitech-hidpp.c

/*
 *  HIDPP protocol for Logitech Unifying receivers
 *
 *  Copyright (c) 2011 Logitech (c)
 *  Copyright (c) 2012-2013 Google (c)
 *  Copyright (c) 2013-2014 Red Hat Inc.
 */

/*
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kfifo.h>
#include <linux/input/mt.h>
#include <asm/unaligned.h>
#include "hid-ids.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_AUTHOR("Nestor Lopez Casado <nlopezcasad@logitech.com>");

#define REPORT_ID_HIDPP_SHORT                   0x10
#define REPORT_ID_HIDPP_LONG                    0x11

#define HIDPP_REPORT_SHORT_LENGTH               7
#define HIDPP_REPORT_LONG_LENGTH                20

#define HIDPP_QUIRK_CLASS_WTP                   BIT(0)

/* bits 1..20 are reserved for classes */
#define HIDPP_QUIRK_DELAYED_INIT                BIT(21)
#define HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS        BIT(22)
#define HIDPP_QUIRK_MULTI_INPUT                 BIT(23)

/*
 * There are two hidpp protocols in use, the first version hidpp10 is known
 * as register access protocol or RAP, the second version hidpp20 is known as
 * feature access protocol or FAP
 *
 * Most older devices (including the Unifying usb receiver) use the RAP protocol
 * where as most newer devices use the FAP protocol. Both protocols are
 * compatible with the underlying transport, which could be usb, Unifiying, or
 * bluetooth. The message lengths are defined by the hid vendor specific report
 * descriptor for the HIDPP_SHORT report type (total message lenth 7 bytes) and
 * the HIDPP_LONG report type (total message length 20 bytes)
 *
 * The RAP protocol uses both report types, whereas the FAP only uses HIDPP_LONG
 * messages. The Unifying receiver itself responds to RAP messages (device index
 * is 0xFF for the receiver), and all messages (short or long) with a device
 * index between 1 and 6 are passed untouched to the corresponding paired
 * Unifying device.
 *
 * The paired device can be RAP or FAP, it will receive the message untouched
 * from the Unifiying receiver.
 */

struct fap {
        u8 feature_index;
        u8 funcindex_clientid;
        u8 params[HIDPP_REPORT_LONG_LENGTH - 4U];
};

struct rap {
        u8 sub_id;
        u8 reg_address;
        u8 params[HIDPP_REPORT_LONG_LENGTH - 4U];
};

struct hidpp_report {
        u8 report_id;
        u8 device_index;
        union {
                struct fap fap;
                struct rap rap;
                u8 rawbytes[sizeof(struct fap)];
        };
} __packed;

struct hidpp_device {
        struct hid_device *hid_dev;
        struct mutex send_mutex;
        void *send_receive_buf;
        char *name;             /* will never be NULL and should not be freed */
        wait_queue_head_t wait;
        bool answer_available;
        u8 protocol_major;
        u8 protocol_minor;

        void *private_data;

        struct work_struct work;
        struct kfifo delayed_work_fifo;
        atomic_t connected;
        struct input_dev *delayed_input;

        unsigned long quirks;
};


/* HID++ 1.0 error codes */
#define HIDPP_ERROR                             0x8f
#define HIDPP_ERROR_SUCCESS                     0x00
#define HIDPP_ERROR_INVALID_SUBID               0x01
#define HIDPP_ERROR_INVALID_ADRESS              0x02
#define HIDPP_ERROR_INVALID_VALUE               0x03
#define HIDPP_ERROR_CONNECT_FAIL                0x04
#define HIDPP_ERROR_TOO_MANY_DEVICES            0x05
#define HIDPP_ERROR_ALREADY_EXISTS              0x06
#define HIDPP_ERROR_BUSY                        0x07
#define HIDPP_ERROR_UNKNOWN_DEVICE              0x08
#define HIDPP_ERROR_RESOURCE_ERROR              0x09
#define HIDPP_ERROR_REQUEST_UNAVAILABLE         0x0a
#define HIDPP_ERROR_INVALID_PARAM_VALUE         0x0b
#define HIDPP_ERROR_WRONG_PIN_CODE              0x0c
/* HID++ 2.0 error codes */
#define HIDPP20_ERROR                           0xff

static void hidpp_connect_event(struct hidpp_device *hidpp_dev);

static int __hidpp_send_report(struct hid_device *hdev,
                                struct hidpp_report *hidpp_report)
{
        int fields_count, ret;

        switch (hidpp_report->report_id) {
        case REPORT_ID_HIDPP_SHORT:
                fields_count = HIDPP_REPORT_SHORT_LENGTH;
                break;
        case REPORT_ID_HIDPP_LONG:
                fields_count = HIDPP_REPORT_LONG_LENGTH;
                break;
        default:
                return -ENODEV;
        }

        /*
         * set the device_index as the receiver, it will be overwritten by
         * hid_hw_request if needed
         */
        hidpp_report->device_index = 0xff;

        ret = hid_hw_raw_request(hdev, hidpp_report->report_id,
                (u8 *)hidpp_report, fields_count, HID_OUTPUT_REPORT,
                HID_REQ_SET_REPORT);

        return ret == fields_count ? 0 : -1;
}

/**
 * hidpp_send_message_sync() returns 0 in case of success, and something else
 * in case of a failure.
 * - If ' something else' is positive, that means that an error has been raised
 *   by the protocol itself.
 * - If ' something else' is negative, that means that we had a classic error
 *   (-ENOMEM, -EPIPE, etc...)
 */
static int hidpp_send_message_sync(struct hidpp_device *hidpp,
        struct hidpp_report *message,
        struct hidpp_report *response)
{
        int ret;

        mutex_lock(&hidpp->send_mutex);

        hidpp->send_receive_buf = response;
        hidpp->answer_available = false;

        /*
         * So that we can later validate the answer when it arrives
         * in hidpp_raw_event
         */
        *response = *message;

        ret = __hidpp_send_report(hidpp->hid_dev, message);

        if (ret) {
                dbg_hid("__hidpp_send_report returned err: %d\n", ret);
                memset(response, 0, sizeof(struct hidpp_report));
                goto exit;
        }

        if (!wait_event_timeout(hidpp->wait, hidpp->answer_available,
                                5*HZ)) {
                dbg_hid("%s:timeout waiting for response\n", __func__);
                memset(response, 0, sizeof(struct hidpp_report));
                ret = -ETIMEDOUT;
        }

        if (response->report_id == REPORT_ID_HIDPP_SHORT &&
            response->rap.sub_id == HIDPP_ERROR) {
                ret = response->rap.params[1];
                dbg_hid("%s:got hidpp error %02X\n", __func__, ret);
                goto exit;
        }

        if (response->report_id == REPORT_ID_HIDPP_LONG &&
            response->fap.feature_index == HIDPP20_ERROR) {
                ret = response->fap.params[1];
                dbg_hid("%s:got hidpp 2.0 error %02X\n", __func__, ret);
                goto exit;
        }

exit:
        mutex_unlock(&hidpp->send_mutex);
        return ret;

}

static int hidpp_send_fap_command_sync(struct hidpp_device *hidpp,
        u8 feat_index, u8 funcindex_clientid, u8 *params, int param_count,
        struct hidpp_report *response)
{
        struct hidpp_report *message;
        int ret;

        if (param_count > sizeof(message->fap.params))
                return -EINVAL;

        message = kzalloc(sizeof(struct hidpp_report), GFP_KERNEL);
        if (!message)
                return -ENOMEM;
        message->report_id = REPORT_ID_HIDPP_LONG;
        message->fap.feature_index = feat_index;
        message->fap.funcindex_clientid = funcindex_clientid;
        memcpy(&message->fap.params, params, param_count);

        ret = hidpp_send_message_sync(hidpp, message, response);
        kfree(message);
        return ret;
}

static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
        u8 report_id, u8 sub_id, u8 reg_address, u8 *params, int param_count,
        struct hidpp_report *response)
{
        struct hidpp_report *message;
        int ret;

        if ((report_id != REPORT_ID_HIDPP_SHORT) &&
            (report_id != REPORT_ID_HIDPP_LONG))
                return -EINVAL;

        if (param_count > sizeof(message->rap.params))
                return -EINVAL;

        message = kzalloc(sizeof(struct hidpp_report), GFP_KERNEL);
        if (!message)
                return -ENOMEM;
        message->report_id = report_id;
        message->rap.sub_id = sub_id;
        message->rap.reg_address = reg_address;
        memcpy(&message->rap.params, params, param_count);

        ret = hidpp_send_message_sync(hidpp_dev, message, response);
        kfree(message);
        return ret;
}

static void delayed_work_cb(struct work_struct *work)
{
        struct hidpp_device *hidpp = container_of(work, struct hidpp_device,
                                                        work);
        hidpp_connect_event(hidpp);
}

static inline bool hidpp_match_answer(struct hidpp_report *question,
                struct hidpp_report *answer)
{
        return (answer->fap.feature_index == question->fap.feature_index) &&
           (answer->fap.funcindex_clientid == question->fap.funcindex_clientid);
}

static inline bool hidpp_match_error(struct hidpp_report *question,
                struct hidpp_report *answer)
{
        return ((answer->rap.sub_id == HIDPP_ERROR) ||
            (answer->fap.feature_index == HIDPP20_ERROR)) &&
            (answer->fap.funcindex_clientid == question->fap.feature_index) &&
            (answer->fap.params[0] == question->fap.funcindex_clientid);
}

static inline bool hidpp_report_is_connect_event(struct hidpp_report *report)
{
        return (report->report_id == REPORT_ID_HIDPP_SHORT) &&
                (report->rap.sub_id == 0x41);
}

/**
 * hidpp_prefix_name() prefixes the current given name with "Logitech ".
 */
static void hidpp_prefix_name(char **name, int name_length)
{
#define PREFIX_LENGTH 9 /* "Logitech " */

        int new_length;
        char *new_name;

        if (name_length > PREFIX_LENGTH &&
            strncmp(*name, "Logitech ", PREFIX_LENGTH) == 0)
                /* The prefix has is already in the name */
                return;

        new_length = PREFIX_LENGTH + name_length;
        new_name = kzalloc(new_length, GFP_KERNEL);
        if (!new_name)
                return;

        snprintf(new_name, new_length, "Logitech %s", *name);

        kfree(*name);

        *name = new_name;
}

/* -------------------------------------------------------------------------- */
/* HIDP++ 1.0 commands                                                        */
/* -------------------------------------------------------------------------- */

#define HIDPP_SET_REGISTER                              0x80
#define HIDPP_GET_REGISTER                              0x81
#define HIDPP_SET_LONG_REGISTER                         0x82
#define HIDPP_GET_LONG_REGISTER                         0x83

#define HIDPP_REG_PAIRING_INFORMATION                   0xB5
#define DEVICE_NAME                                     0x40

static char *hidpp_get_unifying_name(struct hidpp_device *hidpp_dev)
{
        struct hidpp_report response;
        int ret;
        /* hid-logitech-dj is in charge of setting the right device index */
        u8 params[1] = { DEVICE_NAME };
        char *name;
        int len;

        ret = hidpp_send_rap_command_sync(hidpp_dev,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_GET_LONG_REGISTER,
                                        HIDPP_REG_PAIRING_INFORMATION,
                                        params, 1, &response);
        if (ret)
                return NULL;

        len = response.rap.params[1];

        if (2 + len > sizeof(response.rap.params))
                return NULL;

        name = kzalloc(len + 1, GFP_KERNEL);
        if (!name)
                return NULL;

        memcpy(name, &response.rap.params[2], len);

        /* include the terminating '\0' */
        hidpp_prefix_name(&name, len + 1);

        return name;
}

/* -------------------------------------------------------------------------- */
/* 0x0000: Root                                                               */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_ROOT                                 0x0000
#define HIDPP_PAGE_ROOT_IDX                             0x00

#define CMD_ROOT_GET_FEATURE                            0x01
#define CMD_ROOT_GET_PROTOCOL_VERSION                   0x11

static int hidpp_root_get_feature(struct hidpp_device *hidpp, u16 feature,
        u8 *feature_index, u8 *feature_type)
{
        struct hidpp_report response;
        int ret;
        u8 params[2] = { feature >> 8, feature & 0x00FF };

        ret = hidpp_send_fap_command_sync(hidpp,
                        HIDPP_PAGE_ROOT_IDX,
                        CMD_ROOT_GET_FEATURE,
                        params, 2, &response);
        if (ret)
                return ret;

        *feature_index = response.fap.params[0];
        *feature_type = response.fap.params[1];

        return ret;
}

static int hidpp_root_get_protocol_version(struct hidpp_device *hidpp)
{
        struct hidpp_report response;
        int ret;

        ret = hidpp_send_fap_command_sync(hidpp,
                        HIDPP_PAGE_ROOT_IDX,
                        CMD_ROOT_GET_PROTOCOL_VERSION,
                        NULL, 0, &response);

        if (ret == HIDPP_ERROR_INVALID_SUBID) {
                hidpp->protocol_major = 1;
                hidpp->protocol_minor = 0;
                return 0;
        }

        /* the device might not be connected */
        if (ret == HIDPP_ERROR_RESOURCE_ERROR)
                return -EIO;

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        hidpp->protocol_major = response.fap.params[0];
        hidpp->protocol_minor = response.fap.params[1];

        return ret;
}

static bool hidpp_is_connected(struct hidpp_device *hidpp)
{
        int ret;

        ret = hidpp_root_get_protocol_version(hidpp);
        if (!ret)
                hid_dbg(hidpp->hid_dev, "HID++ %u.%u device connected.\n",
                        hidpp->protocol_major, hidpp->protocol_minor);
        return ret == 0;
}

/* -------------------------------------------------------------------------- */
/* 0x0005: GetDeviceNameType                                                  */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_GET_DEVICE_NAME_TYPE                 0x0005

#define CMD_GET_DEVICE_NAME_TYPE_GET_COUNT              0x01
#define CMD_GET_DEVICE_NAME_TYPE_GET_DEVICE_NAME        0x11
#define CMD_GET_DEVICE_NAME_TYPE_GET_TYPE               0x21

static int hidpp_devicenametype_get_count(struct hidpp_device *hidpp,
        u8 feature_index, u8 *nameLength)
{
        struct hidpp_report response;
        int ret;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_GET_DEVICE_NAME_TYPE_GET_COUNT, NULL, 0, &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        *nameLength = response.fap.params[0];

        return ret;
}

static int hidpp_devicenametype_get_device_name(struct hidpp_device *hidpp,
        u8 feature_index, u8 char_index, char *device_name, int len_buf)
{
        struct hidpp_report response;
        int ret, i;
        int count;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_GET_DEVICE_NAME_TYPE_GET_DEVICE_NAME, &char_index, 1,
                &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        if (response.report_id == REPORT_ID_HIDPP_LONG)
                count = HIDPP_REPORT_LONG_LENGTH - 4;
        else
                count = HIDPP_REPORT_SHORT_LENGTH - 4;

        if (len_buf < count)
                count = len_buf;

        for (i = 0; i < count; i++)
                device_name[i] = response.fap.params[i];

        return count;
}

static char *hidpp_get_device_name(struct hidpp_device *hidpp)
{
        u8 feature_type;
        u8 feature_index;
        u8 __name_length;
        char *name;
        unsigned index = 0;
        int ret;

        ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_GET_DEVICE_NAME_TYPE,
                &feature_index, &feature_type);
        if (ret)
                return NULL;

        ret = hidpp_devicenametype_get_count(hidpp, feature_index,
                &__name_length);
        if (ret)
                return NULL;

        name = kzalloc(__name_length + 1, GFP_KERNEL);
        if (!name)
                return NULL;

        while (index < __name_length) {
                ret = hidpp_devicenametype_get_device_name(hidpp,
                        feature_index, index, name + index,
                        __name_length - index);
                if (ret <= 0) {
                        kfree(name);
                        return NULL;
                }
                index += ret;
        }

        /* include the terminating '\0' */
        hidpp_prefix_name(&name, __name_length + 1);

        return name;
}

/* -------------------------------------------------------------------------- */
/* 0x6100: TouchPadRawXY                                                      */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_TOUCHPAD_RAW_XY                      0x6100

#define CMD_TOUCHPAD_GET_RAW_INFO                       0x01
#define CMD_TOUCHPAD_SET_RAW_REPORT_STATE               0x21

#define EVENT_TOUCHPAD_RAW_XY                           0x00

#define TOUCHPAD_RAW_XY_ORIGIN_LOWER_LEFT               0x01
#define TOUCHPAD_RAW_XY_ORIGIN_UPPER_LEFT               0x03

struct hidpp_touchpad_raw_info {
        u16 x_size;
        u16 y_size;
        u8 z_range;
        u8 area_range;
        u8 timestamp_unit;
        u8 maxcontacts;
        u8 origin;
        u16 res;
};

struct hidpp_touchpad_raw_xy_finger {
        u8 contact_type;
        u8 contact_status;
        u16 x;
        u16 y;
        u8 z;
        u8 area;
        u8 finger_id;
};

struct hidpp_touchpad_raw_xy {
        u16 timestamp;
        struct hidpp_touchpad_raw_xy_finger fingers[2];
        u8 spurious_flag;
        u8 end_of_frame;
        u8 finger_count;
        u8 button;
};

static int hidpp_touchpad_get_raw_info(struct hidpp_device *hidpp,
        u8 feature_index, struct hidpp_touchpad_raw_info *raw_info)
{
        struct hidpp_report response;
        int ret;
        u8 *params = (u8 *)response.fap.params;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_TOUCHPAD_GET_RAW_INFO, NULL, 0, &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        raw_info->x_size = get_unaligned_be16(&params[0]);
        raw_info->y_size = get_unaligned_be16(&params[2]);
        raw_info->z_range = params[4];
        raw_info->area_range = params[5];
        raw_info->maxcontacts = params[7];
        raw_info->origin = params[8];
        /* res is given in unit per inch */
        raw_info->res = get_unaligned_be16(&params[13]) * 2 / 51;

        return ret;
}

static int hidpp_touchpad_set_raw_report_state(struct hidpp_device *hidpp_dev,
                u8 feature_index, bool send_raw_reports,
                bool sensor_enhanced_settings)
{
        struct hidpp_report response;

        /*
         * Params:
         *   bit 0 - enable raw
         *   bit 1 - 16bit Z, no area
         *   bit 2 - enhanced sensitivity
         *   bit 3 - width, height (4 bits each) instead of area
         *   bit 4 - send raw + gestures (degrades smoothness)
         *   remaining bits - reserved
         */
        u8 params = send_raw_reports | (sensor_enhanced_settings << 2);

        return hidpp_send_fap_command_sync(hidpp_dev, feature_index,
                CMD_TOUCHPAD_SET_RAW_REPORT_STATE, &params, 1, &response);
}

static void hidpp_touchpad_touch_event(u8 *data,
        struct hidpp_touchpad_raw_xy_finger *finger)
{
        u8 x_m = data[0] << 2;
        u8 y_m = data[2] << 2;

        finger->x = x_m << 6 | data[1];
        finger->y = y_m << 6 | data[3];

        finger->contact_type = data[0] >> 6;
        finger->contact_status = data[2] >> 6;

        finger->z = data[4];
        finger->area = data[5];
        finger->finger_id = data[6] >> 4;
}

static void hidpp_touchpad_raw_xy_event(struct hidpp_device *hidpp_dev,
                u8 *data, struct hidpp_touchpad_raw_xy *raw_xy)
{
        memset(raw_xy, 0, sizeof(struct hidpp_touchpad_raw_xy));
        raw_xy->end_of_frame = data[8] & 0x01;
        raw_xy->spurious_flag = (data[8] >> 1) & 0x01;
        raw_xy->finger_count = data[15] & 0x0f;
        raw_xy->button = (data[8] >> 2) & 0x01;

        if (raw_xy->finger_count) {
                hidpp_touchpad_touch_event(&data[2], &raw_xy->fingers[0]);
                hidpp_touchpad_touch_event(&data[9], &raw_xy->fingers[1]);
        }
}

/* ************************************************************************** */
/*                                                                            */
/* Device Support                                                             */
/*                                                                            */
/* ************************************************************************** */

/* -------------------------------------------------------------------------- */
/* Touchpad HID++ devices                                                     */
/* -------------------------------------------------------------------------- */

#define WTP_MANUAL_RESOLUTION                           39

struct wtp_data {
        struct input_dev *input;
        u16 x_size, y_size;
        u8 finger_count;
        u8 mt_feature_index;
        u8 button_feature_index;
        u8 maxcontacts;
        bool flip_y;
        unsigned int resolution;
};

static int wtp_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        if ((hidpp->quirks & HIDPP_QUIRK_MULTI_INPUT) &&
            (field->application == HID_GD_KEYBOARD))
                return 0;

        return -1;
}

static void wtp_populate_input(struct hidpp_device *hidpp,
                struct input_dev *input_dev, bool origin_is_hid_core)
{
        struct wtp_data *wd = hidpp->private_data;

        if ((hidpp->quirks & HIDPP_QUIRK_MULTI_INPUT) && origin_is_hid_core)
                /* this is the generic hid-input call */
                return;

        __set_bit(EV_ABS, input_dev->evbit);
        __set_bit(EV_KEY, input_dev->evbit);
        __clear_bit(EV_REL, input_dev->evbit);
        __clear_bit(EV_LED, input_dev->evbit);

        input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, wd->x_size, 0, 0);
        input_abs_set_res(input_dev, ABS_MT_POSITION_X, wd->resolution);
        input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, wd->y_size, 0, 0);
        input_abs_set_res(input_dev, ABS_MT_POSITION_Y, wd->resolution);

        /* Max pressure is not given by the devices, pick one */
        input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 50, 0, 0);

        input_set_capability(input_dev, EV_KEY, BTN_LEFT);

        if (hidpp->quirks & HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS)
                input_set_capability(input_dev, EV_KEY, BTN_RIGHT);
        else
                __set_bit(INPUT_PROP_BUTTONPAD, input_dev->propbit);

        input_mt_init_slots(input_dev, wd->maxcontacts, INPUT_MT_POINTER |
                INPUT_MT_DROP_UNUSED);

        wd->input = input_dev;
}

static void wtp_touch_event(struct wtp_data *wd,
        struct hidpp_touchpad_raw_xy_finger *touch_report)
{
        int slot;

        if (!touch_report->finger_id || touch_report->contact_type)
                /* no actual data */
                return;

        slot = input_mt_get_slot_by_key(wd->input, touch_report->finger_id);

        input_mt_slot(wd->input, slot);
        input_mt_report_slot_state(wd->input, MT_TOOL_FINGER,
                                        touch_report->contact_status);
        if (touch_report->contact_status) {
                input_event(wd->input, EV_ABS, ABS_MT_POSITION_X,
                                touch_report->x);
                input_event(wd->input, EV_ABS, ABS_MT_POSITION_Y,
                                wd->flip_y ? wd->y_size - touch_report->y :
                                             touch_report->y);
                input_event(wd->input, EV_ABS, ABS_MT_PRESSURE,
                                touch_report->area);
        }
}

static void wtp_send_raw_xy_event(struct hidpp_device *hidpp,
                struct hidpp_touchpad_raw_xy *raw)
{
        struct wtp_data *wd = hidpp->private_data;
        int i;

        for (i = 0; i < 2; i++)
                wtp_touch_event(wd, &(raw->fingers[i]));

        if (raw->end_of_frame &&
            !(hidpp->quirks & HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS))
                input_event(wd->input, EV_KEY, BTN_LEFT, raw->button);

        if (raw->end_of_frame || raw->finger_count <= 2) {
                input_mt_sync_frame(wd->input);
                input_sync(wd->input);
        }
}

static int wtp_mouse_raw_xy_event(struct hidpp_device *hidpp, u8 *data)
{
        struct wtp_data *wd = hidpp->private_data;
        u8 c1_area = ((data[7] & 0xf) * (data[7] & 0xf) +
                      (data[7] >> 4) * (data[7] >> 4)) / 2;
        u8 c2_area = ((data[13] & 0xf) * (data[13] & 0xf) +
                      (data[13] >> 4) * (data[13] >> 4)) / 2;
        struct hidpp_touchpad_raw_xy raw = {
                .timestamp = data[1],
                .fingers = {
                        {
                                .contact_type = 0,
                                .contact_status = !!data[7],
                                .x = get_unaligned_le16(&data[3]),
                                .y = get_unaligned_le16(&data[5]),
                                .z = c1_area,
                                .area = c1_area,
                                .finger_id = data[2],
                        }, {
                                .contact_type = 0,
                                .contact_status = !!data[13],
                                .x = get_unaligned_le16(&data[9]),
                                .y = get_unaligned_le16(&data[11]),
                                .z = c2_area,
                                .area = c2_area,
                                .finger_id = data[8],
                        }
                },
                .finger_count = wd->maxcontacts,
                .spurious_flag = 0,
                .end_of_frame = (data[0] >> 7) == 0,
                .button = data[0] & 0x01,
        };

        wtp_send_raw_xy_event(hidpp, &raw);

        return 1;
}

static int wtp_raw_event(struct hid_device *hdev, u8 *data, int size)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct wtp_data *wd = hidpp->private_data;
        struct hidpp_report *report = (struct hidpp_report *)data;
        struct hidpp_touchpad_raw_xy raw;

        if (!wd || !wd->input)
                return 1;

        switch (data[0]) {
        case 0x02:
                if (size < 2) {
                        hid_err(hdev, "Received HID report of bad size (%d)",
                                size);
                        return 1;
                }
                if (hidpp->quirks & HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS) {
                        input_event(wd->input, EV_KEY, BTN_LEFT,
                                        !!(data[1] & 0x01));
                        input_event(wd->input, EV_KEY, BTN_RIGHT,
                                        !!(data[1] & 0x02));
                        input_sync(wd->input);
                        return 0;
                } else {
                        if (size < 21)
                                return 1;
                        return wtp_mouse_raw_xy_event(hidpp, &data[7]);
                }
        case REPORT_ID_HIDPP_LONG:
                /* size is already checked in hidpp_raw_event. */
                if ((report->fap.feature_index != wd->mt_feature_index) ||
                    (report->fap.funcindex_clientid != EVENT_TOUCHPAD_RAW_XY))
                        return 1;
                hidpp_touchpad_raw_xy_event(hidpp, data + 4, &raw);

                wtp_send_raw_xy_event(hidpp, &raw);
                return 0;
        }

        return 0;
}

static int wtp_get_config(struct hidpp_device *hidpp)
{
        struct wtp_data *wd = hidpp->private_data;
        struct hidpp_touchpad_raw_info raw_info = {0};
        u8 feature_type;
        int ret;

        ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_TOUCHPAD_RAW_XY,
                &wd->mt_feature_index, &feature_type);
        if (ret)
                /* means that the device is not powered up */
                return ret;

        ret = hidpp_touchpad_get_raw_info(hidpp, wd->mt_feature_index,
                &raw_info);
        if (ret)
                return ret;

        wd->x_size = raw_info.x_size;
        wd->y_size = raw_info.y_size;
        wd->maxcontacts = raw_info.maxcontacts;
        wd->flip_y = raw_info.origin == TOUCHPAD_RAW_XY_ORIGIN_LOWER_LEFT;
        wd->resolution = raw_info.res;
        if (!wd->resolution)
                wd->resolution = WTP_MANUAL_RESOLUTION;

        return 0;
}

static int wtp_allocate(struct hid_device *hdev, const struct hid_device_id *id)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct wtp_data *wd;

        wd = devm_kzalloc(&hdev->dev, sizeof(struct wtp_data),
                        GFP_KERNEL);
        if (!wd)
                return -ENOMEM;

        hidpp->private_data = wd;

        return 0;
};

static int wtp_connect(struct hid_device *hdev, bool connected)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct wtp_data *wd = hidpp->private_data;
        int ret;

        if (!connected)
                return 0;

        if (!wd->x_size) {
                ret = wtp_get_config(hidpp);
                if (ret) {
                        hid_err(hdev, "Can not get wtp config: %d\n", ret);
                        return ret;
                }
        }

        return hidpp_touchpad_set_raw_report_state(hidpp, wd->mt_feature_index,
                        true, true);
}

/* -------------------------------------------------------------------------- */
/* Generic HID++ devices                                                      */
/* -------------------------------------------------------------------------- */

static int hidpp_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)
                return wtp_input_mapping(hdev, hi, field, usage, bit, max);

        return 0;
}

static void hidpp_populate_input(struct hidpp_device *hidpp,
                struct input_dev *input, bool origin_is_hid_core)
{
        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)
                wtp_populate_input(hidpp, input, origin_is_hid_core);
}

static void hidpp_input_configured(struct hid_device *hdev,
                                struct hid_input *hidinput)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct input_dev *input = hidinput->input;

        hidpp_populate_input(hidpp, input, true);
}

static int hidpp_raw_hidpp_event(struct hidpp_device *hidpp, u8 *data,
                int size)
{
        struct hidpp_report *question = hidpp->send_receive_buf;
        struct hidpp_report *answer = hidpp->send_receive_buf;
        struct hidpp_report *report = (struct hidpp_report *)data;

        /*
         * If the mutex is locked then we have a pending answer from a
         * previously sent command.
         */
        if (unlikely(mutex_is_locked(&hidpp->send_mutex))) {
                /*
                 * Check for a correct hidpp20 answer or the corresponding
                 * error
                 */
                if (hidpp_match_answer(question, report) ||
                                hidpp_match_error(question, report)) {
                        *answer = *report;
                        hidpp->answer_available = true;
                        wake_up(&hidpp->wait);
                        /*
                         * This was an answer to a command that this driver sent
                         * We return 1 to hid-core to avoid forwarding the
                         * command upstream as it has been treated by the driver
                         */

                        return 1;
                }
        }

        if (unlikely(hidpp_report_is_connect_event(report))) {
                atomic_set(&hidpp->connected,
                                !(report->rap.params[0] & (1 << 6)));
                if ((hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT) &&
                    (schedule_work(&hidpp->work) == 0))
                        dbg_hid("%s: connect event already queued\n", __func__);
                return 1;
        }

        return 0;
}

static int hidpp_raw_event(struct hid_device *hdev, struct hid_report *report,
                u8 *data, int size)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        int ret = 0;

        /* Generic HID++ processing. */
        switch (data[0]) {
        case REPORT_ID_HIDPP_LONG:
                if (size != HIDPP_REPORT_LONG_LENGTH) {
                        hid_err(hdev, "received hid++ report of bad size (%d)",
                                size);
                        return 1;
                }
                ret = hidpp_raw_hidpp_event(hidpp, data, size);
                break;
        case REPORT_ID_HIDPP_SHORT:
                if (size != HIDPP_REPORT_SHORT_LENGTH) {
                        hid_err(hdev, "received hid++ report of bad size (%d)",
                                size);
                        return 1;
                }
                ret = hidpp_raw_hidpp_event(hidpp, data, size);
                break;
        }

        /* If no report is available for further processing, skip calling
         * raw_event of subclasses. */
        if (ret != 0)
                return ret;

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)
                return wtp_raw_event(hdev, data, size);

        return 0;
}

static void hidpp_overwrite_name(struct hid_device *hdev, bool use_unifying)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        char *name;

        if (use_unifying)
                /*
                 * the device is connected through an Unifying receiver, and
                 * might not be already connected.
                 * Ask the receiver for its name.
                 */
                name = hidpp_get_unifying_name(hidpp);
        else
                name = hidpp_get_device_name(hidpp);

        if (!name)
                hid_err(hdev, "unable to retrieve the name of the device");
        else
                snprintf(hdev->name, sizeof(hdev->name), "%s", name);

        kfree(name);
}

static int hidpp_input_open(struct input_dev *dev)
{
        struct hid_device *hid = input_get_drvdata(dev);

        return hid_hw_open(hid);
}

static void hidpp_input_close(struct input_dev *dev)
{
        struct hid_device *hid = input_get_drvdata(dev);

        hid_hw_close(hid);
}

static struct input_dev *hidpp_allocate_input(struct hid_device *hdev)
{
        struct input_dev *input_dev = devm_input_allocate_device(&hdev->dev);
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        if (!input_dev)
                return NULL;

        input_set_drvdata(input_dev, hdev);
        input_dev->open = hidpp_input_open;
        input_dev->close = hidpp_input_close;

        input_dev->name = hidpp->name;
        input_dev->phys = hdev->phys;
        input_dev->uniq = hdev->uniq;
        input_dev->id.bustype = hdev->bus;
        input_dev->id.vendor  = hdev->vendor;
        input_dev->id.product = hdev->product;
        input_dev->id.version = hdev->version;
        input_dev->dev.parent = &hdev->dev;

        return input_dev;
}

static void hidpp_connect_event(struct hidpp_device *hidpp)
{
        struct hid_device *hdev = hidpp->hid_dev;
        int ret = 0;
        bool connected = atomic_read(&hidpp->connected);
        struct input_dev *input;
        char *name, *devm_name;

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP) {
                ret = wtp_connect(hdev, connected);
                if (ret)
                        return;
        }

        if (!connected || hidpp->delayed_input)
                return;

        if (!hidpp->protocol_major) {
                ret = !hidpp_is_connected(hidpp);
                if (ret) {
                        hid_err(hdev, "Can not get the protocol version.\n");
                        return;
                }
        }

        /* the device is already connected, we can ask for its name and
         * protocol */
        hid_info(hdev, "HID++ %u.%u device connected.\n",
                 hidpp->protocol_major, hidpp->protocol_minor);

        if (!hidpp->name || hidpp->name == hdev->name) {
                name = hidpp_get_device_name(hidpp);
                if (!name) {
                        hid_err(hdev,
                                "unable to retrieve the name of the device");
                        return;
                }

                devm_name = devm_kasprintf(&hdev->dev, GFP_KERNEL, "%s", name);
                kfree(name);
                if (!devm_name)
                        return;

                hidpp->name = devm_name;
        }

        input = hidpp_allocate_input(hdev);
        if (!input) {
                hid_err(hdev, "cannot allocate new input device: %d\n", ret);
                return;
        }

        hidpp_populate_input(hidpp, input, false);

        ret = input_register_device(input);
        if (ret)
                input_free_device(input);

        hidpp->delayed_input = input;
}

static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        struct hidpp_device *hidpp;
        int ret;
        bool connected;
        unsigned int connect_mask = HID_CONNECT_DEFAULT;

        hidpp = devm_kzalloc(&hdev->dev, sizeof(struct hidpp_device),
                        GFP_KERNEL);
        if (!hidpp)
                return -ENOMEM;

        hidpp->hid_dev = hdev;
        hidpp->name = hdev->name;
        hid_set_drvdata(hdev, hidpp);

        hidpp->quirks = id->driver_data;

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP) {
                ret = wtp_allocate(hdev, id);
                if (ret)
                        goto wtp_allocate_fail;
        }

        INIT_WORK(&hidpp->work, delayed_work_cb);
        mutex_init(&hidpp->send_mutex);
        init_waitqueue_head(&hidpp->wait);

        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "%s:parse failed\n", __func__);
                goto hid_parse_fail;
        }

        /* Allow incoming packets */
        hid_device_io_start(hdev);

        connected = hidpp_is_connected(hidpp);
        if (id->group != HID_GROUP_LOGITECH_DJ_DEVICE) {
                if (!connected) {
                        hid_err(hdev, "Device not connected");
                        hid_device_io_stop(hdev);
                        goto hid_parse_fail;
                }

                hid_info(hdev, "HID++ %u.%u device connected.\n",
                         hidpp->protocol_major, hidpp->protocol_minor);
        }

        hidpp_overwrite_name(hdev, id->group == HID_GROUP_LOGITECH_DJ_DEVICE);
        atomic_set(&hidpp->connected, connected);

        if (connected && (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)) {
                ret = wtp_get_config(hidpp);
                if (ret)
                        goto hid_parse_fail;
        }

        /* Block incoming packets */
        hid_device_io_stop(hdev);

        if (hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT)
                connect_mask &= ~HID_CONNECT_HIDINPUT;

        /* Re-enable hidinput for multi-input devices */
        if (hidpp->quirks & HIDPP_QUIRK_MULTI_INPUT)
                connect_mask |= HID_CONNECT_HIDINPUT;

        ret = hid_hw_start(hdev, connect_mask);
        if (ret) {
                hid_err(hdev, "%s:hid_hw_start returned error\n", __func__);
                goto hid_hw_start_fail;
        }

        if (hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT) {
                /* Allow incoming packets */
                hid_device_io_start(hdev);

                hidpp_connect_event(hidpp);
        }

        return ret;

hid_hw_start_fail:
hid_parse_fail:
        cancel_work_sync(&hidpp->work);
        mutex_destroy(&hidpp->send_mutex);
wtp_allocate_fail:
        hid_set_drvdata(hdev, NULL);
        return ret;
}

static void hidpp_remove(struct hid_device *hdev)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        cancel_work_sync(&hidpp->work);
        mutex_destroy(&hidpp->send_mutex);
        hid_hw_stop(hdev);
}

static const struct hid_device_id hidpp_devices[] = {
        { /* wireless touchpad */
          HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE,
                USB_VENDOR_ID_LOGITECH, 0x4011),
          .driver_data = HIDPP_QUIRK_CLASS_WTP | HIDPP_QUIRK_DELAYED_INIT |
                         HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS },
        { /* wireless touchpad T650 */
          HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE,
                USB_VENDOR_ID_LOGITECH, 0x4101),
          .driver_data = HIDPP_QUIRK_CLASS_WTP | HIDPP_QUIRK_DELAYED_INIT },
        { /* wireless touchpad T651 */
          HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_T651),
          .driver_data = HIDPP_QUIRK_CLASS_WTP },
        { /* Keyboard TK820 */
          HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE,
                USB_VENDOR_ID_LOGITECH, 0x4102),
          .driver_data = HIDPP_QUIRK_DELAYED_INIT | HIDPP_QUIRK_MULTI_INPUT |
                         HIDPP_QUIRK_CLASS_WTP },

        { HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE,
                USB_VENDOR_ID_LOGITECH, HID_ANY_ID)},
        {}
};

MODULE_DEVICE_TABLE(hid, hidpp_devices);

static struct hid_driver hidpp_driver = {
        .name = "logitech-hidpp-device",
        .id_table = hidpp_devices,
        .probe = hidpp_probe,
        .remove = hidpp_remove,
        .raw_event = hidpp_raw_event,
        .input_configured = hidpp_input_configured,
        .input_mapping = hidpp_input_mapping,
};

module_hid_driver(hidpp_driver);