/*
 * Driver for USB Windows Media Center Ed. eHome Infrared Transceivers
 *
 * Copyright (c) 2010-2011, Jarod Wilson <jarod@redhat.com>
 *
 * Based on the original lirc_mceusb and lirc_mceusb2 drivers, by Dan
 * Conti, Martin Blatter and Daniel Melander, the latter of which was
 * in turn also based on the lirc_atiusb driver by Paul Miller. The
 * two mce drivers were merged into one by Jarod Wilson, with transmit
 * support for the 1st-gen device added primarily by Patrick Calhoun,
 * with a bit of tweaks by Jarod. Debugging improvements and proper
 * support for what appears to be 3rd-gen hardware added by Jarod.
 * Initial port from lirc driver to ir-core drivery by Jarod, based
 * partially on a port to an earlier proposed IR infrastructure by
 * Jon Smirl, which included enhancements and simplifications to the
 * incoming IR buffer parsing routines.
 *
 * Updated in July of 2011 with the aid of Microsoft's official
 * remote/transceiver requirements and specification document, found at
 * download.microsoft.com, title
 * Windows-Media-Center-RC-IR-Collection-Green-Button-Specification-03-08-2011-V2.pdf
 *
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/usb.h>
#include <linux/usb/input.h>
#include <linux/pm_wakeup.h>
#include <media/rc-core.h>

#define DRIVER_VERSION  "1.94"
#define DRIVER_AUTHOR   "Jarod Wilson <jarod@redhat.com>"
#define DRIVER_DESC     "Windows Media Center Ed. eHome Infrared Transceiver " \
                        "device driver"
#define DRIVER_NAME     "mceusb"

#define USB_CTRL_MSG_SZ         2  /* Size of usb ctrl msg on gen1 hw */
#define MCE_G1_INIT_MSGS        40 /* Init messages on gen1 hw to throw out */

/* MCE constants */
#define MCE_CMDBUF_SIZE         384  /* MCE Command buffer length */
#define MCE_TIME_UNIT           50   /* Approx 50us resolution */
#define MCE_CODE_LENGTH         5    /* Normal length of packet (with header) */
#define MCE_PACKET_SIZE         4    /* Normal length of packet (without header) */
#define MCE_IRDATA_HEADER       0x84 /* Actual header format is 0x80 + num_bytes */
#define MCE_IRDATA_TRAILER      0x80 /* End of IR data */
#define MCE_MAX_CHANNELS        2    /* Two transmitters, hardware dependent? */
#define MCE_DEFAULT_TX_MASK     0x03 /* Vals: TX1=0x01, TX2=0x02, ALL=0x03 */
#define MCE_PULSE_BIT           0x80 /* Pulse bit, MSB set == PULSE else SPACE */
#define MCE_PULSE_MASK          0x7f /* Pulse mask */
#define MCE_MAX_PULSE_LENGTH    0x7f /* Longest transmittable pulse symbol */

/*
 * The interface between the host and the IR hardware is command-response
 * based. All commands and responses have a consistent format, where a lead
 * byte always identifies the type of data following it. The lead byte has
 * a port value in the 3 highest bits and a length value in the 5 lowest
 * bits.
 *
 * The length field is overloaded, with a value of 11111 indicating that the
 * following byte is a command or response code, and the length of the entire
 * message is determined by the code. If the length field is not 11111, then
 * it specifies the number of bytes of port data that follow.
 */
#define MCE_CMD                 0x1f
#define MCE_PORT_IR             0x4     /* (0x4 << 5) | MCE_CMD = 0x9f */
#define MCE_PORT_SYS            0x7     /* (0x7 << 5) | MCE_CMD = 0xff */
#define MCE_PORT_SER            0x6     /* 0xc0 thru 0xdf flush & 0x1f bytes */
#define MCE_PORT_MASK           0xe0    /* Mask out command bits */

/* Command port headers */
#define MCE_CMD_PORT_IR         0x9f    /* IR-related cmd/rsp */
#define MCE_CMD_PORT_SYS        0xff    /* System (non-IR) device cmd/rsp */

/* Commands that set device state  (2-4 bytes in length) */
#define MCE_CMD_RESET           0xfe    /* Reset device, 2 bytes */
#define MCE_CMD_RESUME          0xaa    /* Resume device after error, 2 bytes */
#define MCE_CMD_SETIRCFS        0x06    /* Set tx carrier, 4 bytes */
#define MCE_CMD_SETIRTIMEOUT    0x0c    /* Set timeout, 4 bytes */
#define MCE_CMD_SETIRTXPORTS    0x08    /* Set tx ports, 3 bytes */
#define MCE_CMD_SETIRRXPORTEN   0x14    /* Set rx ports, 3 bytes */
#define MCE_CMD_FLASHLED        0x23    /* Flash receiver LED, 2 bytes */

/* Commands that query device state (all 2 bytes, unless noted) */
#define MCE_CMD_GETIRCFS        0x07    /* Get carrier */
#define MCE_CMD_GETIRTIMEOUT    0x0d    /* Get timeout */
#define MCE_CMD_GETIRTXPORTS    0x13    /* Get tx ports */
#define MCE_CMD_GETIRRXPORTEN   0x15    /* Get rx ports */
#define MCE_CMD_GETPORTSTATUS   0x11    /* Get tx port status, 3 bytes */
#define MCE_CMD_GETIRNUMPORTS   0x16    /* Get number of ports */
#define MCE_CMD_GETWAKESOURCE   0x17    /* Get wake source */
#define MCE_CMD_GETEMVER        0x22    /* Get emulator interface version */
#define MCE_CMD_GETDEVDETAILS   0x21    /* Get device details (em ver2 only) */
#define MCE_CMD_GETWAKESUPPORT  0x20    /* Get wake details (em ver2 only) */
#define MCE_CMD_GETWAKEVERSION  0x18    /* Get wake pattern (em ver2 only) */

/* Misc commands */
#define MCE_CMD_NOP             0xff    /* No operation */

/* Responses to commands (non-error cases) */
#define MCE_RSP_EQIRCFS         0x06    /* tx carrier, 4 bytes */
#define MCE_RSP_EQIRTIMEOUT     0x0c    /* rx timeout, 4 bytes */
#define MCE_RSP_GETWAKESOURCE   0x17    /* wake source, 3 bytes */
#define MCE_RSP_EQIRTXPORTS     0x08    /* tx port mask, 3 bytes */
#define MCE_RSP_EQIRRXPORTEN    0x14    /* rx port mask, 3 bytes */
#define MCE_RSP_GETPORTSTATUS   0x11    /* tx port status, 7 bytes */
#define MCE_RSP_EQIRRXCFCNT     0x15    /* rx carrier count, 4 bytes */
#define MCE_RSP_EQIRNUMPORTS    0x16    /* number of ports, 4 bytes */
#define MCE_RSP_EQWAKESUPPORT   0x20    /* wake capabilities, 3 bytes */
#define MCE_RSP_EQWAKEVERSION   0x18    /* wake pattern details, 6 bytes */
#define MCE_RSP_EQDEVDETAILS    0x21    /* device capabilities, 3 bytes */
#define MCE_RSP_EQEMVER         0x22    /* emulator interface ver, 3 bytes */
#define MCE_RSP_FLASHLED        0x23    /* success flashing LED, 2 bytes */

/* Responses to error cases, must send MCE_CMD_RESUME to clear them */
#define MCE_RSP_CMD_ILLEGAL     0xfe    /* illegal command for port, 2 bytes */
#define MCE_RSP_TX_TIMEOUT      0x81    /* tx timed out, 2 bytes */

/* Misc commands/responses not defined in the MCE remote/transceiver spec */
#define MCE_CMD_SIG_END         0x01    /* End of signal */
#define MCE_CMD_PING            0x03    /* Ping device */
#define MCE_CMD_UNKNOWN         0x04    /* Unknown */
#define MCE_CMD_UNKNOWN2        0x05    /* Unknown */
#define MCE_CMD_UNKNOWN3        0x09    /* Unknown */
#define MCE_CMD_UNKNOWN4        0x0a    /* Unknown */
#define MCE_CMD_G_REVISION      0x0b    /* Get hw/sw revision */
#define MCE_CMD_UNKNOWN5        0x0e    /* Unknown */
#define MCE_CMD_UNKNOWN6        0x0f    /* Unknown */
#define MCE_CMD_UNKNOWN8        0x19    /* Unknown */
#define MCE_CMD_UNKNOWN9        0x1b    /* Unknown */
#define MCE_CMD_NULL            0x00    /* These show up various places... */

/* if buf[i] & MCE_PORT_MASK == 0x80 and buf[i] != MCE_CMD_PORT_IR,
 * then we're looking at a raw IR data sample */
#define MCE_COMMAND_IRDATA      0x80
#define MCE_PACKET_LENGTH_MASK  0x1f /* Packet length mask */

#define VENDOR_PHILIPS          0x0471
#define VENDOR_SMK              0x0609
#define VENDOR_TATUNG           0x1460
#define VENDOR_GATEWAY          0x107b
#define VENDOR_SHUTTLE          0x1308
#define VENDOR_SHUTTLE2         0x051c
#define VENDOR_MITSUMI          0x03ee
#define VENDOR_TOPSEED          0x1784
#define VENDOR_RICAVISION       0x179d
#define VENDOR_ITRON            0x195d
#define VENDOR_FIC              0x1509
#define VENDOR_LG               0x043e
#define VENDOR_MICROSOFT        0x045e
#define VENDOR_FORMOSA          0x147a
#define VENDOR_FINTEK           0x1934
#define VENDOR_PINNACLE         0x2304
#define VENDOR_ECS              0x1019
#define VENDOR_WISTRON          0x0fb8
#define VENDOR_COMPRO           0x185b
#define VENDOR_NORTHSTAR        0x04eb
#define VENDOR_REALTEK          0x0bda
#define VENDOR_TIVO             0x105a
#define VENDOR_CONEXANT         0x0572
#define VENDOR_TWISTEDMELON     0x2596
#define VENDOR_HAUPPAUGE        0x2040
#define VENDOR_PCTV             0x2013
#define VENDOR_ADAPTEC          0x03f3

enum mceusb_model_type {
        MCE_GEN2 = 0,           /* Most boards */
        MCE_GEN1,
        MCE_GEN3,
        MCE_GEN3_BROKEN_IRTIMEOUT,
        MCE_GEN2_TX_INV,
        MCE_GEN2_TX_INV_RX_GOOD,
        POLARIS_EVK,
        CX_HYBRID_TV,
        MULTIFUNCTION,
        TIVO_KIT,
        MCE_GEN2_NO_TX,
        HAUPPAUGE_CX_HYBRID_TV,
        EVROMEDIA_FULL_HYBRID_FULLHD,
        ASTROMETA_T2HYBRID,
};

struct mceusb_model {
        u32 mce_gen1:1;
        u32 mce_gen2:1;
        u32 mce_gen3:1;
        u32 tx_mask_normal:1;
        u32 no_tx:1;
        u32 broken_irtimeout:1;
        /*
         * 2nd IR receiver (short-range, wideband) for learning mode:
         *     0, absent 2nd receiver (rx2)
         *     1, rx2 present
         *     2, rx2 which under counts IR carrier cycles
         */
        u32 rx2;

        int ir_intfnum;

        const char *rc_map;     /* Allow specify a per-board map */
        const char *name;       /* per-board name */
};

static const struct mceusb_model mceusb_model[] = {
        [MCE_GEN1] = {
                .mce_gen1 = 1,
                .tx_mask_normal = 1,
                .rx2 = 2,
        },
        [MCE_GEN2] = {
                .mce_gen2 = 1,
                .rx2 = 2,
        },
        [MCE_GEN2_NO_TX] = {
                .mce_gen2 = 1,
                .no_tx = 1,
        },
        [MCE_GEN2_TX_INV] = {
                .mce_gen2 = 1,
                .tx_mask_normal = 1,
                .rx2 = 1,
        },
        [MCE_GEN2_TX_INV_RX_GOOD] = {
                .mce_gen2 = 1,
                .tx_mask_normal = 1,
                .rx2 = 2,
        },
        [MCE_GEN3] = {
                .mce_gen3 = 1,
                .tx_mask_normal = 1,
                .rx2 = 2,
        },
        [MCE_GEN3_BROKEN_IRTIMEOUT] = {
                .mce_gen3 = 1,
                .tx_mask_normal = 1,
                .rx2 = 2,
                .broken_irtimeout = 1
        },
        [POLARIS_EVK] = {
                /*
                 * In fact, the EVK is shipped without
                 * remotes, but we should have something handy,
                 * to allow testing it
                 */
                .name = "Conexant Hybrid TV (cx231xx) MCE IR",
                .rx2 = 2,
        },
        [CX_HYBRID_TV] = {
                .no_tx = 1, /* tx isn't wired up at all */
                .name = "Conexant Hybrid TV (cx231xx) MCE IR",
        },
        [HAUPPAUGE_CX_HYBRID_TV] = {
                .no_tx = 1, /* eeprom says it has no tx */
                .name = "Conexant Hybrid TV (cx231xx) MCE IR no TX",
        },
        [MULTIFUNCTION] = {
                .mce_gen2 = 1,
                .ir_intfnum = 2,
                .rx2 = 2,
        },
        [TIVO_KIT] = {
                .mce_gen2 = 1,
                .rc_map = RC_MAP_TIVO,
                .rx2 = 2,
        },
        [EVROMEDIA_FULL_HYBRID_FULLHD] = {
                .name = "Evromedia USB Full Hybrid Full HD",
                .no_tx = 1,
                .rc_map = RC_MAP_MSI_DIGIVOX_III,
        },
        [ASTROMETA_T2HYBRID] = {
                .name = "Astrometa T2Hybrid",
                .no_tx = 1,
                .rc_map = RC_MAP_ASTROMETA_T2HYBRID,
        }
};

static const struct usb_device_id mceusb_dev_table[] = {
        /* Original Microsoft MCE IR Transceiver (often HP-branded) */
        { USB_DEVICE(VENDOR_MICROSOFT, 0x006d),
          .driver_info = MCE_GEN1 },
        /* Philips Infrared Transceiver - Sahara branded */
        { USB_DEVICE(VENDOR_PHILIPS, 0x0608) },
        /* Philips Infrared Transceiver - HP branded */
        { USB_DEVICE(VENDOR_PHILIPS, 0x060c),
          .driver_info = MCE_GEN2_TX_INV },
        /* Philips SRM5100 */
        { USB_DEVICE(VENDOR_PHILIPS, 0x060d) },
        /* Philips Infrared Transceiver - Omaura */
        { USB_DEVICE(VENDOR_PHILIPS, 0x060f) },
        /* Philips Infrared Transceiver - Spinel plus */
        { USB_DEVICE(VENDOR_PHILIPS, 0x0613) },
        /* Philips eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_PHILIPS, 0x0815) },
        /* Philips/Spinel plus IR transceiver for ASUS */
        { USB_DEVICE(VENDOR_PHILIPS, 0x206c) },
        /* Philips/Spinel plus IR transceiver for ASUS */
        { USB_DEVICE(VENDOR_PHILIPS, 0x2088) },
        /* Philips IR transceiver (Dell branded) */
        { USB_DEVICE(VENDOR_PHILIPS, 0x2093),
          .driver_info = MCE_GEN2_TX_INV },
        /* Realtek MCE IR Receiver and card reader */
        { USB_DEVICE(VENDOR_REALTEK, 0x0161),
          .driver_info = MULTIFUNCTION },
        /* SMK/Toshiba G83C0004D410 */
        { USB_DEVICE(VENDOR_SMK, 0x031d),
          .driver_info = MCE_GEN2_TX_INV_RX_GOOD },
        /* SMK eHome Infrared Transceiver (Sony VAIO) */
        { USB_DEVICE(VENDOR_SMK, 0x0322),
          .driver_info = MCE_GEN2_TX_INV },
        /* bundled with Hauppauge PVR-150 */
        { USB_DEVICE(VENDOR_SMK, 0x0334),
          .driver_info = MCE_GEN2_TX_INV },
        /* SMK eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_SMK, 0x0338) },
        /* SMK/I-O Data GV-MC7/RCKIT Receiver */
        { USB_DEVICE(VENDOR_SMK, 0x0353),
          .driver_info = MCE_GEN2_NO_TX },
        /* SMK RXX6000 Infrared Receiver */
        { USB_DEVICE(VENDOR_SMK, 0x0357),
          .driver_info = MCE_GEN2_NO_TX },
        /* Tatung eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TATUNG, 0x9150) },
        /* Shuttle eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_SHUTTLE, 0xc001) },
        /* Shuttle eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_SHUTTLE2, 0xc001) },
        /* Gateway eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_GATEWAY, 0x3009) },
        /* Mitsumi */
        { USB_DEVICE(VENDOR_MITSUMI, 0x2501) },
        /* Topseed eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TOPSEED, 0x0001),
          .driver_info = MCE_GEN2_TX_INV },
        /* Topseed HP eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TOPSEED, 0x0006),
          .driver_info = MCE_GEN2_TX_INV },
        /* Topseed eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TOPSEED, 0x0007),
          .driver_info = MCE_GEN2_TX_INV },
        /* Topseed eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TOPSEED, 0x0008),
          .driver_info = MCE_GEN3 },
        /* Topseed eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TOPSEED, 0x000a),
          .driver_info = MCE_GEN2_TX_INV },
        /* Topseed eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_TOPSEED, 0x0011),
          .driver_info = MCE_GEN3_BROKEN_IRTIMEOUT },
        /* Ricavision internal Infrared Transceiver */
        { USB_DEVICE(VENDOR_RICAVISION, 0x0010) },
        /* Itron ione Libra Q-11 */
        { USB_DEVICE(VENDOR_ITRON, 0x7002) },
        /* FIC eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_FIC, 0x9242) },
        /* LG eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_LG, 0x9803) },
        /* Microsoft MCE Infrared Transceiver */
        { USB_DEVICE(VENDOR_MICROSOFT, 0x00a0) },
        /* Formosa eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe015) },
        /* Formosa21 / eHome Infrared Receiver */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe016) },
        /* Formosa aim / Trust MCE Infrared Receiver */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe017),
          .driver_info = MCE_GEN2_NO_TX },
        /* Formosa Industrial Computing / Beanbag Emulation Device */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe018) },
        /* Formosa21 / eHome Infrared Receiver */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe03a) },
        /* Formosa Industrial Computing AIM IR605/A */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe03c) },
        /* Formosa Industrial Computing */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe03e) },
        /* Formosa Industrial Computing */
        { USB_DEVICE(VENDOR_FORMOSA, 0xe042) },
        /* Fintek eHome Infrared Transceiver (HP branded) */
        { USB_DEVICE(VENDOR_FINTEK, 0x5168),
          .driver_info = MCE_GEN2_TX_INV },
        /* Fintek eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_FINTEK, 0x0602) },
        /* Fintek eHome Infrared Transceiver (in the AOpen MP45) */
        { USB_DEVICE(VENDOR_FINTEK, 0x0702) },
        /* Pinnacle Remote Kit */
        { USB_DEVICE(VENDOR_PINNACLE, 0x0225),
          .driver_info = MCE_GEN3 },
        /* Elitegroup Computer Systems IR */
        { USB_DEVICE(VENDOR_ECS, 0x0f38) },
        /* Wistron Corp. eHome Infrared Receiver */
        { USB_DEVICE(VENDOR_WISTRON, 0x0002) },
        /* Compro K100 */
        { USB_DEVICE(VENDOR_COMPRO, 0x3020) },
        /* Compro K100 v2 */
        { USB_DEVICE(VENDOR_COMPRO, 0x3082) },
        /* Northstar Systems, Inc. eHome Infrared Transceiver */
        { USB_DEVICE(VENDOR_NORTHSTAR, 0xe004) },
        /* TiVo PC IR Receiver */
        { USB_DEVICE(VENDOR_TIVO, 0x2000),
          .driver_info = TIVO_KIT },
        /* Conexant Hybrid TV "Shelby" Polaris SDK */
        { USB_DEVICE(VENDOR_CONEXANT, 0x58a1),
          .driver_info = POLARIS_EVK },
        /* Conexant Hybrid TV RDU253S Polaris */
        { USB_DEVICE(VENDOR_CONEXANT, 0x58a5),
          .driver_info = CX_HYBRID_TV },
        /* Twisted Melon Inc. - Manta Mini Receiver */
        { USB_DEVICE(VENDOR_TWISTEDMELON, 0x8008) },
        /* Twisted Melon Inc. - Manta Pico Receiver */
        { USB_DEVICE(VENDOR_TWISTEDMELON, 0x8016) },
        /* Twisted Melon Inc. - Manta Transceiver */
        { USB_DEVICE(VENDOR_TWISTEDMELON, 0x8042) },
        /* Hauppauge WINTV-HVR-HVR 930C-HD - based on cx231xx */
        { USB_DEVICE(VENDOR_HAUPPAUGE, 0xb130),
          .driver_info = HAUPPAUGE_CX_HYBRID_TV },
        { USB_DEVICE(VENDOR_HAUPPAUGE, 0xb131),
          .driver_info = HAUPPAUGE_CX_HYBRID_TV },
        { USB_DEVICE(VENDOR_HAUPPAUGE, 0xb138),
          .driver_info = HAUPPAUGE_CX_HYBRID_TV },
        { USB_DEVICE(VENDOR_HAUPPAUGE, 0xb139),
          .driver_info = HAUPPAUGE_CX_HYBRID_TV },
        { USB_DEVICE(VENDOR_PCTV, 0x0259),
          .driver_info = HAUPPAUGE_CX_HYBRID_TV },
        { USB_DEVICE(VENDOR_PCTV, 0x025e),
          .driver_info = HAUPPAUGE_CX_HYBRID_TV },
        /* Adaptec / HP eHome Receiver */
        { USB_DEVICE(VENDOR_ADAPTEC, 0x0094) },
        /* Evromedia USB Full Hybrid Full HD */
        { USB_DEVICE(0x1b80, 0xd3b2),
          .driver_info = EVROMEDIA_FULL_HYBRID_FULLHD },
        /* Astrometa T2hybrid */
        { USB_DEVICE(0x15f4, 0x0135),
          .driver_info = ASTROMETA_T2HYBRID },

        /* Terminating entry */
        { }
};

/* data structure for each usb transceiver */
struct mceusb_dev {
        /* ir-core bits */
        struct rc_dev *rc;

        /* optional features we can enable */
        bool carrier_report_enabled;
        bool wideband_rx_enabled;       /* aka learning mode, short-range rx */

        /* core device bits */
        struct device *dev;

        /* usb */
        struct usb_device *usbdev;
        struct urb *urb_in;
        unsigned int pipe_in;
        struct usb_endpoint_descriptor *usb_ep_out;
        unsigned int pipe_out;

        /* buffers and dma */
        unsigned char *buf_in;
        unsigned int len_in;
        dma_addr_t dma_in;

        enum {
                CMD_HEADER = 0,
                SUBCMD,
                CMD_DATA,
                PARSE_IRDATA,
        } parser_state;

        u8 cmd, rem;            /* Remaining IR data bytes in packet */

        struct {
                u32 connected:1;
                u32 tx_mask_normal:1;
                u32 microsoft_gen1:1;
                u32 no_tx:1;
                u32 rx2;
        } flags;

        /* transmit support */
        u32 carrier;
        unsigned char tx_mask;

        char name[128];
        char phys[64];
        enum mceusb_model_type model;

        bool need_reset;        /* flag to issue a device resume cmd */
        u8 emver;               /* emulator interface version */
        u8 num_txports;         /* number of transmit ports */
        u8 num_rxports;         /* number of receive sensors */
        u8 txports_cabled;      /* bitmask of transmitters with cable */
        u8 rxports_active;      /* bitmask of active receive sensors */
        bool learning_active;   /* wideband rx is active */

        /* receiver carrier frequency detection support */
        u32 pulse_tunit;        /* IR pulse "on" cumulative time units */
        u32 pulse_count;        /* pulse "on" count in measurement interval */

        /*
         * support for async error handler mceusb_deferred_kevent()
         * where usb_clear_halt(), usb_reset_configuration(),
         * usb_reset_device(), etc. must be done in process context
         */
        struct work_struct kevent;
        unsigned long kevent_flags;
#               define EVENT_TX_HALT    0
#               define EVENT_RX_HALT    1
};

/* MCE Device Command Strings, generally a port and command pair */
static char DEVICE_RESUME[]     = {MCE_CMD_NULL, MCE_CMD_PORT_SYS,
                                   MCE_CMD_RESUME};
static char GET_REVISION[]      = {MCE_CMD_PORT_SYS, MCE_CMD_G_REVISION};
static char GET_EMVER[]         = {MCE_CMD_PORT_SYS, MCE_CMD_GETEMVER};
static char GET_WAKEVERSION[]   = {MCE_CMD_PORT_SYS, MCE_CMD_GETWAKEVERSION};
static char FLASH_LED[]         = {MCE_CMD_PORT_SYS, MCE_CMD_FLASHLED};
static char GET_UNKNOWN2[]      = {MCE_CMD_PORT_IR, MCE_CMD_UNKNOWN2};
static char GET_CARRIER_FREQ[]  = {MCE_CMD_PORT_IR, MCE_CMD_GETIRCFS};
static char GET_RX_TIMEOUT[]    = {MCE_CMD_PORT_IR, MCE_CMD_GETIRTIMEOUT};
static char GET_NUM_PORTS[]     = {MCE_CMD_PORT_IR, MCE_CMD_GETIRNUMPORTS};
static char GET_TX_BITMASK[]    = {MCE_CMD_PORT_IR, MCE_CMD_GETIRTXPORTS};
static char GET_RX_SENSOR[]     = {MCE_CMD_PORT_IR, MCE_CMD_GETIRRXPORTEN};
/* sub in desired values in lower byte or bytes for full command */
/* FIXME: make use of these for transmit.
static char SET_CARRIER_FREQ[]  = {MCE_CMD_PORT_IR,
                                   MCE_CMD_SETIRCFS, 0x00, 0x00};
static char SET_TX_BITMASK[]    = {MCE_CMD_PORT_IR, MCE_CMD_SETIRTXPORTS, 0x00};
static char SET_RX_TIMEOUT[]    = {MCE_CMD_PORT_IR,
                                   MCE_CMD_SETIRTIMEOUT, 0x00, 0x00};
static char SET_RX_SENSOR[]     = {MCE_CMD_PORT_IR,
                                   MCE_RSP_EQIRRXPORTEN, 0x00};
*/

static int mceusb_cmd_datasize(u8 cmd, u8 subcmd)
{
        int datasize = 0;

        switch (cmd) {
        case MCE_CMD_NULL:
                if (subcmd == MCE_CMD_PORT_SYS)
                        datasize = 1;
                break;
        case MCE_CMD_PORT_SYS:
                switch (subcmd) {
                case MCE_RSP_GETPORTSTATUS:
                        datasize = 5;
                        break;
                case MCE_RSP_EQWAKEVERSION:
                        datasize = 4;
                        break;
                case MCE_CMD_G_REVISION:
                        datasize = 2;
                        break;
                case MCE_RSP_EQWAKESUPPORT:
                case MCE_RSP_GETWAKESOURCE:
                case MCE_RSP_EQDEVDETAILS:
                case MCE_RSP_EQEMVER:
                        datasize = 1;
                        break;
                }
                break;
        case MCE_CMD_PORT_IR:
                switch (subcmd) {
                case MCE_CMD_UNKNOWN:
                case MCE_RSP_EQIRCFS:
                case MCE_RSP_EQIRTIMEOUT:
                case MCE_RSP_EQIRRXCFCNT:
                case MCE_RSP_EQIRNUMPORTS:
                        datasize = 2;
                        break;
                case MCE_CMD_SIG_END:
                case MCE_RSP_EQIRTXPORTS:
                case MCE_RSP_EQIRRXPORTEN:
                        datasize = 1;
                        break;
                }
        }
        return datasize;
}

static void mceusb_dev_printdata(struct mceusb_dev *ir, u8 *buf, int buf_len,
                                 int offset, int len, bool out)
{
#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
        char *inout;
        u8 cmd, subcmd, *data;
        struct device *dev = ir->dev;
        int start, skip = 0;
        u32 carrier, period;

        /* skip meaningless 0xb1 0x60 header bytes on orig receiver */
        if (ir->flags.microsoft_gen1 && !out && !offset)
                skip = 2;

        if (len <= skip)
                return;

        dev_dbg(dev, "%cx data: %*ph (length=%d)",
                (out ? 't' : 'r'),
                min(len, buf_len - offset), buf + offset, len);

        inout = out ? "Request" : "Got";

        start  = offset + skip;
        cmd    = buf[start] & 0xff;
        subcmd = buf[start + 1] & 0xff;
        data = buf + start + 2;

        switch (cmd) {
        case MCE_CMD_NULL:
                if (subcmd == MCE_CMD_NULL)
                        break;
                if ((subcmd == MCE_CMD_PORT_SYS) &&
                    (data[0] == MCE_CMD_RESUME))
                        dev_dbg(dev, "Device resume requested");
                else
                        dev_dbg(dev, "Unknown command 0x%02x 0x%02x",
                                 cmd, subcmd);
                break;
        case MCE_CMD_PORT_SYS:
                switch (subcmd) {
                case MCE_RSP_EQEMVER:
                        if (!out)
                                dev_dbg(dev, "Emulator interface version %x",
                                         data[0]);
                        break;
                case MCE_CMD_G_REVISION:
                        if (len == 2)
                                dev_dbg(dev, "Get hw/sw rev?");
                        else
                                dev_dbg(dev, "hw/sw rev %*ph",
                                        4, &buf[start + 2]);
                        break;
                case MCE_CMD_RESUME:
                        dev_dbg(dev, "Device resume requested");
                        break;
                case MCE_RSP_CMD_ILLEGAL:
                        dev_dbg(dev, "Illegal PORT_SYS command");
                        break;
                case MCE_RSP_EQWAKEVERSION:
                        if (!out)
                                dev_dbg(dev, "Wake version, proto: 0x%02x, payload: 0x%02x, address: 0x%02x, version: 0x%02x",
                                        data[0], data[1], data[2], data[3]);
                        break;
                case MCE_RSP_GETPORTSTATUS:
                        if (!out)
                                /* We use data1 + 1 here, to match hw labels */
                                dev_dbg(dev, "TX port %d: blaster is%s connected",
                                         data[0] + 1, data[3] ? " not" : "");
                        break;
                case MCE_CMD_FLASHLED:
                        dev_dbg(dev, "Attempting to flash LED");
                        break;
                default:
                        dev_dbg(dev, "Unknown command 0x%02x 0x%02x",
                                 cmd, subcmd);
                        break;
                }
                break;
        case MCE_CMD_PORT_IR:
                switch (subcmd) {
                case MCE_CMD_SIG_END:
                        dev_dbg(dev, "End of signal");
                        break;
                case MCE_CMD_PING:
                        dev_dbg(dev, "Ping");
                        break;
                case MCE_CMD_UNKNOWN:
                        dev_dbg(dev, "Resp to 9f 05 of 0x%02x 0x%02x",
                                data[0], data[1]);
                        break;
                case MCE_RSP_EQIRCFS:
                        period = DIV_ROUND_CLOSEST((1U << data[0] * 2) *
                                                   (data[1] + 1), 10);
                        if (!period)
                                break;
                        carrier = (1000 * 1000) / period;
                        dev_dbg(dev, "%s carrier of %u Hz (period %uus)",
                                 inout, carrier, period);
                        break;
                case MCE_CMD_GETIRCFS:
                        dev_dbg(dev, "Get carrier mode and freq");
                        break;
                case MCE_RSP_EQIRTXPORTS:
                        dev_dbg(dev, "%s transmit blaster mask of 0x%02x",
                                 inout, data[0]);
                        break;
                case MCE_RSP_EQIRTIMEOUT:
                        /* value is in units of 50us, so x*50/1000 ms */
                        period = ((data[0] << 8) | data[1]) *
                                  MCE_TIME_UNIT / 1000;
                        dev_dbg(dev, "%s receive timeout of %d ms",
                                 inout, period);
                        break;
                case MCE_CMD_GETIRTIMEOUT:
                        dev_dbg(dev, "Get receive timeout");
                        break;
                case MCE_CMD_GETIRTXPORTS:
                        dev_dbg(dev, "Get transmit blaster mask");
                        break;
                case MCE_RSP_EQIRRXPORTEN:
                        dev_dbg(dev, "%s %s-range receive sensor in use",
                                 inout, data[0] == 0x02 ? "short" : "long");
                        break;
                case MCE_CMD_GETIRRXPORTEN:
                /* aka MCE_RSP_EQIRRXCFCNT */
                        if (out)
                                dev_dbg(dev, "Get receive sensor");
                        else
                                dev_dbg(dev, "RX carrier cycle count: %d",
                                        ((data[0] << 8) | data[1]));
                        break;
                case MCE_RSP_EQIRNUMPORTS:
                        if (out)
                                break;
                        dev_dbg(dev, "Num TX ports: %x, num RX ports: %x",
                                data[0], data[1]);
                        break;
                case MCE_RSP_CMD_ILLEGAL:
                        dev_dbg(dev, "Illegal PORT_IR command");
                        break;
                default:
                        dev_dbg(dev, "Unknown command 0x%02x 0x%02x",
                                 cmd, subcmd);
                        break;
                }
                break;
        default:
                break;
        }

        if (cmd == MCE_IRDATA_TRAILER)
                dev_dbg(dev, "End of raw IR data");
        else if ((cmd != MCE_CMD_PORT_IR) &&
                 ((cmd & MCE_PORT_MASK) == MCE_COMMAND_IRDATA))
                dev_dbg(dev, "Raw IR data, %d pulse/space samples", ir->rem);
#endif
}

/*
 * Schedule work that can't be done in interrupt handlers
 * (mceusb_dev_recv() and mce_async_callback()) nor tasklets.
 * Invokes mceusb_deferred_kevent() for recovering from
 * error events specified by the kevent bit field.
 */
static void mceusb_defer_kevent(struct mceusb_dev *ir, int kevent)
{
        set_bit(kevent, &ir->kevent_flags);
        if (!schedule_work(&ir->kevent))
                dev_err(ir->dev, "kevent %d may have been dropped", kevent);
        else
                dev_dbg(ir->dev, "kevent %d scheduled", kevent);
}

static void mce_async_callback(struct urb *urb)
{
        struct mceusb_dev *ir;
        int len;

        if (!urb)
                return;

        ir = urb->context;

        switch (urb->status) {
        /* success */
        case 0:
                len = urb->actual_length;

                mceusb_dev_printdata(ir, urb->transfer_buffer, len,
                                     0, len, true);
                break;

        case -ECONNRESET:
        case -ENOENT:
        case -EILSEQ:
        case -ESHUTDOWN:
                break;

        case -EPIPE:
                dev_err(ir->dev, "Error: request urb status = %d (TX HALT)",
                        urb->status);
                mceusb_defer_kevent(ir, EVENT_TX_HALT);
                break;

        default:
                dev_err(ir->dev, "Error: request urb status = %d", urb->status);
                break;
        }

        /* the transfer buffer and urb were allocated in mce_request_packet */
        kfree(urb->transfer_buffer);
        usb_free_urb(urb);
}

/* request outgoing (send) usb packet - used to initialize remote */
static void mce_request_packet(struct mceusb_dev *ir, unsigned char *data,
                                                                int size)
{
        int res;
        struct urb *async_urb;
        struct device *dev = ir->dev;
        unsigned char *async_buf;

        async_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (unlikely(!async_urb)) {
                dev_err(dev, "Error, couldn't allocate urb!");
                return;
        }

        async_buf = kmalloc(size, GFP_KERNEL);
        if (!async_buf) {
                usb_free_urb(async_urb);
                return;
        }

        /* outbound data */
        if (usb_endpoint_xfer_int(ir->usb_ep_out))
                usb_fill_int_urb(async_urb, ir->usbdev, ir->pipe_out,
                                 async_buf, size, mce_async_callback, ir,
                                 ir->usb_ep_out->bInterval);
        else
                usb_fill_bulk_urb(async_urb, ir->usbdev, ir->pipe_out,
                                  async_buf, size, mce_async_callback, ir);

        memcpy(async_buf, data, size);

        dev_dbg(dev, "send request called (size=%#x)", size);

        res = usb_submit_urb(async_urb, GFP_ATOMIC);
        if (res) {
                dev_err(dev, "send request FAILED! (res=%d)", res);
                kfree(async_buf);
                usb_free_urb(async_urb);
                return;
        }
        dev_dbg(dev, "send request complete (res=%d)", res);
}

static void mce_async_out(struct mceusb_dev *ir, unsigned char *data, int size)
{
        int rsize = sizeof(DEVICE_RESUME);

        if (ir->need_reset) {
                ir->need_reset = false;
                mce_request_packet(ir, DEVICE_RESUME, rsize);
                msleep(10);
        }

        mce_request_packet(ir, data, size);
        msleep(10);
}

/* Send data out the IR blaster port(s) */
static int mceusb_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
{
        struct mceusb_dev *ir = dev->priv;
        int i, length, ret = 0;
        int cmdcount = 0;
        unsigned char cmdbuf[MCE_CMDBUF_SIZE];

        /* MCE tx init header */
        cmdbuf[cmdcount++] = MCE_CMD_PORT_IR;
        cmdbuf[cmdcount++] = MCE_CMD_SETIRTXPORTS;
        cmdbuf[cmdcount++] = ir->tx_mask;

        /* Send the set TX ports command */
        mce_async_out(ir, cmdbuf, cmdcount);
        cmdcount = 0;

        /* Generate mce packet data */
        for (i = 0; (i < count) && (cmdcount < MCE_CMDBUF_SIZE); i++) {
                txbuf[i] = txbuf[i] / MCE_TIME_UNIT;

                do { /* loop to support long pulses/spaces > 127*50us=6.35ms */

                        /* Insert mce packet header every 4th entry */
                        if ((cmdcount < MCE_CMDBUF_SIZE) &&
                            (cmdcount % MCE_CODE_LENGTH) == 0)
                                cmdbuf[cmdcount++] = MCE_IRDATA_HEADER;

                        /* Insert mce packet data */
                        if (cmdcount < MCE_CMDBUF_SIZE)
                                cmdbuf[cmdcount++] =
                                        (txbuf[i] < MCE_PULSE_BIT ?
                                         txbuf[i] : MCE_MAX_PULSE_LENGTH) |
                                         (i & 1 ? 0x00 : MCE_PULSE_BIT);
                        else {
                                ret = -EINVAL;
                                goto out;
                        }

                } while ((txbuf[i] > MCE_MAX_PULSE_LENGTH) &&
                         (txbuf[i] -= MCE_MAX_PULSE_LENGTH));
        }

        /* Check if we have room for the empty packet at the end */
        if (cmdcount >= MCE_CMDBUF_SIZE) {
                ret = -EINVAL;
                goto out;
        }

        /* Fix packet length in last header */
        length = cmdcount % MCE_CODE_LENGTH;
        cmdbuf[cmdcount - length] -= MCE_CODE_LENGTH - length;

        /* All mce commands end with an empty packet (0x80) */
        cmdbuf[cmdcount++] = MCE_IRDATA_TRAILER;

        /* Transmit the command to the mce device */
        mce_async_out(ir, cmdbuf, cmdcount);

out:
        return ret ? ret : count;
}

/* Sets active IR outputs -- mce devices typically have two */
static int mceusb_set_tx_mask(struct rc_dev *dev, u32 mask)
{
        struct mceusb_dev *ir = dev->priv;

        /* return number of transmitters */
        int emitters = ir->num_txports ? ir->num_txports : 2;

        if (mask >= (1 << emitters))
                return emitters;

        if (ir->flags.tx_mask_normal)
                ir->tx_mask = mask;
        else
                ir->tx_mask = (mask != MCE_DEFAULT_TX_MASK ?
                                mask ^ MCE_DEFAULT_TX_MASK : mask) << 1;

        return 0;
}

/* Sets the send carrier frequency and mode */
static int mceusb_set_tx_carrier(struct rc_dev *dev, u32 carrier)
{
        struct mceusb_dev *ir = dev->priv;
        int clk = 10000000;
        int prescaler = 0, divisor = 0;
        unsigned char cmdbuf[4] = { MCE_CMD_PORT_IR,
                                    MCE_CMD_SETIRCFS, 0x00, 0x00 };

        /* Carrier has changed */
        if (ir->carrier != carrier) {

                if (carrier == 0) {
                        ir->carrier = carrier;
                        cmdbuf[2] = MCE_CMD_SIG_END;
                        cmdbuf[3] = MCE_IRDATA_TRAILER;
                        dev_dbg(ir->dev, "disabling carrier modulation");
                        mce_async_out(ir, cmdbuf, sizeof(cmdbuf));
                        return 0;
                }

                for (prescaler = 0; prescaler < 4; ++prescaler) {
                        divisor = (clk >> (2 * prescaler)) / carrier;
                        if (divisor <= 0xff) {
                                ir->carrier = carrier;
                                cmdbuf[2] = prescaler;
                                cmdbuf[3] = divisor;
                                dev_dbg(ir->dev, "requesting %u HZ carrier",
                                                                carrier);

                                /* Transmit new carrier to mce device */
                                mce_async_out(ir, cmdbuf, sizeof(cmdbuf));
                                return 0;
                        }
                }

                return -EINVAL;

        }

        return 0;
}

static int mceusb_set_timeout(struct rc_dev *dev, unsigned int timeout)
{
        u8 cmdbuf[4] = { MCE_CMD_PORT_IR, MCE_CMD_SETIRTIMEOUT, 0, 0 };
        struct mceusb_dev *ir = dev->priv;
        unsigned int units;

        units = DIV_ROUND_CLOSEST(timeout, US_TO_NS(MCE_TIME_UNIT));

        cmdbuf[2] = units >> 8;
        cmdbuf[3] = units;

        mce_async_out(ir, cmdbuf, sizeof(cmdbuf));

        /* get receiver timeout value */
        mce_async_out(ir, GET_RX_TIMEOUT, sizeof(GET_RX_TIMEOUT));

        return 0;
}

/*
 * Select or deselect the 2nd receiver port.
 * Second receiver is learning mode, wide-band, short-range receiver.
 * Only one receiver (long or short range) may be active at a time.
 */
static int mceusb_set_rx_wideband(struct rc_dev *dev, int enable)
{
        struct mceusb_dev *ir = dev->priv;
        unsigned char cmdbuf[3] = { MCE_CMD_PORT_IR,
                                    MCE_CMD_SETIRRXPORTEN, 0x00 };

        dev_dbg(ir->dev, "select %s-range receive sensor",
                enable ? "short" : "long");
        if (enable) {
                ir->wideband_rx_enabled = true;
                cmdbuf[2] = 2;  /* port 2 is short range receiver */
        } else {
                ir->wideband_rx_enabled = false;
                cmdbuf[2] = 1;  /* port 1 is long range receiver */
        }
        mce_async_out(ir, cmdbuf, sizeof(cmdbuf));
        /* response from device sets ir->learning_active */

        return 0;
}

/*
 * Enable/disable receiver carrier frequency pass through reporting.
 * Only the short-range receiver has carrier frequency measuring capability.
 * Implicitly select this receiver when enabling carrier frequency reporting.
 */
static int mceusb_set_rx_carrier_report(struct rc_dev *dev, int enable)
{
        struct mceusb_dev *ir = dev->priv;
        unsigned char cmdbuf[3] = { MCE_CMD_PORT_IR,
                                    MCE_CMD_SETIRRXPORTEN, 0x00 };

        dev_dbg(ir->dev, "%s short-range receiver carrier reporting",
                enable ? "enable" : "disable");
        if (enable) {
                ir->carrier_report_enabled = true;
                if (!ir->learning_active) {
                        cmdbuf[2] = 2;  /* port 2 is short range receiver */
                        mce_async_out(ir, cmdbuf, sizeof(cmdbuf));
                }
        } else {
                ir->carrier_report_enabled = false;
                /*
                 * Revert to normal (long-range) receiver only if the
                 * wideband (short-range) receiver wasn't explicitly
                 * enabled.
                 */
                if (ir->learning_active && !ir->wideband_rx_enabled) {
                        cmdbuf[2] = 1;  /* port 1 is long range receiver */
                        mce_async_out(ir, cmdbuf, sizeof(cmdbuf));
                }
        }

        return 0;
}

/*
 * We don't do anything but print debug spew for many of the command bits
 * we receive from the hardware, but some of them are useful information
 * we want to store so that we can use them.
 */
static void mceusb_handle_command(struct mceusb_dev *ir, int index)
{
        DEFINE_IR_RAW_EVENT(rawir);
        u8 hi = ir->buf_in[index + 1] & 0xff;
        u8 lo = ir->buf_in[index + 2] & 0xff;
        u32 carrier_cycles;
        u32 cycles_fix;

        switch (ir->buf_in[index]) {
        /* the one and only 5-byte return value command */
        case MCE_RSP_GETPORTSTATUS:
                if ((ir->buf_in[index + 4] & 0xff) == 0x00)
                        ir->txports_cabled |= 1 << hi;
                break;

        /* 2-byte return value commands */
        case MCE_RSP_EQIRTIMEOUT:
                ir->rc->timeout = US_TO_NS((hi << 8 | lo) * MCE_TIME_UNIT);
                break;
        case MCE_RSP_EQIRNUMPORTS:
                ir->num_txports = hi;
                ir->num_rxports = lo;
                break;
        case MCE_RSP_EQIRRXCFCNT:
                /*
                 * The carrier cycle counter can overflow and wrap around
                 * without notice from the device. So frequency measurement
                 * will be inaccurate with long duration IR.
                 *
                 * The long-range (non learning) receiver always reports
                 * zero count so we always ignore its report.
                 */
                if (ir->carrier_report_enabled && ir->learning_active &&
                    ir->pulse_tunit > 0) {
                        carrier_cycles = (hi << 8 | lo);
                        /*
                         * Adjust carrier cycle count by adding
                         * 1 missed count per pulse "on"
                         */
                        cycles_fix = ir->flags.rx2 == 2 ? ir->pulse_count : 0;
                        rawir.carrier_report = 1;
                        rawir.carrier = (1000000u / MCE_TIME_UNIT) *
                                        (carrier_cycles + cycles_fix) /
                                        ir->pulse_tunit;
                        dev_dbg(ir->dev, "RX carrier frequency %u Hz (pulse count = %u, cycles = %u, duration = %u, rx2 = %u)",
                                rawir.carrier, ir->pulse_count, carrier_cycles,
                                ir->pulse_tunit, ir->flags.rx2);
                        ir_raw_event_store(ir->rc, &rawir);
                }
                break;

        /* 1-byte return value commands */
        case MCE_RSP_EQEMVER:
                ir->emver = hi;
                break;
        case MCE_RSP_EQIRTXPORTS:
                ir->tx_mask = hi;
                break;
        case MCE_RSP_EQIRRXPORTEN:
                ir->learning_active = ((hi & 0x02) == 0x02);
                if (ir->rxports_active != hi) {
                        dev_info(ir->dev, "%s-range (0x%x) receiver active",
                                 ir->learning_active ? "short" : "long", hi);
                        ir->rxports_active = hi;
                }
                break;
        case MCE_RSP_CMD_ILLEGAL:
                ir->need_reset = true;
                break;
        default:
                break;
        }
}

static void mceusb_process_ir_data(struct mceusb_dev *ir, int buf_len)
{
        DEFINE_IR_RAW_EVENT(rawir);
        bool event = false;
        int i = 0;

        /* skip meaningless 0xb1 0x60 header bytes on orig receiver */
        if (ir->flags.microsoft_gen1)
                i = 2;

        /* if there's no data, just return now */
        if (buf_len <= i)
                return;

        for (; i < buf_len; i++) {
                switch (ir->parser_state) {
                case SUBCMD:
                        ir->rem = mceusb_cmd_datasize(ir->cmd, ir->buf_in[i]);
                        mceusb_dev_printdata(ir, ir->buf_in, buf_len, i - 1,
                                             ir->rem + 2, false);
                        mceusb_handle_command(ir, i);
                        ir->parser_state = CMD_DATA;
                        break;
                case PARSE_IRDATA:
                        ir->rem--;
                        init_ir_raw_event(&rawir);
                        rawir.pulse = ((ir->buf_in[i] & MCE_PULSE_BIT) != 0);
                        rawir.duration = (ir->buf_in[i] & MCE_PULSE_MASK);
                        if (unlikely(!rawir.duration)) {
                                dev_warn(ir->dev, "nonsensical irdata %02x with duration 0",
                                         ir->buf_in[i]);
                                break;
                        }
                        if (rawir.pulse) {
                                ir->pulse_tunit += rawir.duration;
                                ir->pulse_count++;
                        }
                        rawir.duration *= US_TO_NS(MCE_TIME_UNIT);

                        dev_dbg(ir->dev, "Storing %s %u ns (%02x)",
                                rawir.pulse ? "pulse" : "space",
                                rawir.duration, ir->buf_in[i]);

                        if (ir_raw_event_store_with_filter(ir->rc, &rawir))
                                event = true;
                        break;
                case CMD_DATA:
                        ir->rem--;
                        break;
                case CMD_HEADER:
                        /* decode mce packets of the form (84),AA,BB,CC,DD */
                        /* IR data packets can span USB messages - rem */
                        ir->cmd = ir->buf_in[i];
                        if ((ir->cmd == MCE_CMD_PORT_IR) ||
                            ((ir->cmd & MCE_PORT_MASK) !=
                             MCE_COMMAND_IRDATA)) {
                                ir->parser_state = SUBCMD;
                                continue;
                        }
                        ir->rem = (ir->cmd & MCE_PACKET_LENGTH_MASK);
                        mceusb_dev_printdata(ir, ir->buf_in, buf_len,
                                             i, ir->rem + 1, false);
                        if (ir->rem) {
                                ir->parser_state = PARSE_IRDATA;
                        } else {
                                init_ir_raw_event(&rawir);
                                rawir.timeout = 1;
                                rawir.duration = ir->rc->timeout;
                                if (ir_raw_event_store_with_filter(ir->rc,
                                                                   &rawir))
                                        event = true;
                                ir->pulse_tunit = 0;
                                ir->pulse_count = 0;
                        }
                        break;
                }

                if (ir->parser_state != CMD_HEADER && !ir->rem)
                        ir->parser_state = CMD_HEADER;
        }
        if (event) {
                dev_dbg(ir->dev, "processed IR data");
                ir_raw_event_handle(ir->rc);
        }
}

static void mceusb_dev_recv(struct urb *urb)
{
        struct mceusb_dev *ir;

        if (!urb)
                return;

        ir = urb->context;
        if (!ir) {
                usb_unlink_urb(urb);
                return;
        }

        switch (urb->status) {
        /* success */
        case 0:
                mceusb_process_ir_data(ir, urb->actual_length);
                break;

        case -ECONNRESET:
        case -ENOENT:
        case -EILSEQ:
        case -ESHUTDOWN:
                usb_unlink_urb(urb);
                return;

        case -EPIPE:
                dev_err(ir->dev, "Error: urb status = %d (RX HALT)",
                        urb->status);
                mceusb_defer_kevent(ir, EVENT_RX_HALT);
                return;

        default:
                dev_err(ir->dev, "Error: urb status = %d", urb->status);
                break;
        }

        usb_submit_urb(urb, GFP_ATOMIC);
}

static void mceusb_get_emulator_version(struct mceusb_dev *ir)
{
        /* If we get no reply or an illegal command reply, its ver 1, says MS */
        ir->emver = 1;
        mce_async_out(ir, GET_EMVER, sizeof(GET_EMVER));
}

static void mceusb_gen1_init(struct mceusb_dev *ir)
{
        int ret;
        struct device *dev = ir->dev;
        char *data;

        data = kzalloc(USB_CTRL_MSG_SZ, GFP_KERNEL);
        if (!data) {
                dev_err(dev, "%s: memory allocation failed!", __func__);
                return;
        }

        /*
         * This is a strange one. Windows issues a set address to the device
         * on the receive control pipe and expect a certain value pair back
         */
        ret = usb_control_msg(ir->usbdev, usb_rcvctrlpipe(ir->usbdev, 0),
                              USB_REQ_SET_ADDRESS, USB_TYPE_VENDOR, 0, 0,
                              data, USB_CTRL_MSG_SZ, HZ * 3);
        dev_dbg(dev, "set address - ret = %d", ret);
        dev_dbg(dev, "set address - data[0] = %d, data[1] = %d",
                                                data[0], data[1]);

        /* set feature: bit rate 38400 bps */
        ret = usb_control_msg(ir->usbdev, usb_sndctrlpipe(ir->usbdev, 0),
                              USB_REQ_SET_FEATURE, USB_TYPE_VENDOR,
                              0xc04e, 0x0000, NULL, 0, HZ * 3);

        dev_dbg(dev, "set feature - ret = %d", ret);

        /* bRequest 4: set char length to 8 bits */
        ret = usb_control_msg(ir->usbdev, usb_sndctrlpipe(ir->usbdev, 0),
                              4, USB_TYPE_VENDOR,
                              0x0808, 0x0000, NULL, 0, HZ * 3);
        dev_dbg(dev, "set char length - retB = %d", ret);

        /* bRequest 2: set handshaking to use DTR/DSR */
        ret = usb_control_msg(ir->usbdev, usb_sndctrlpipe(ir->usbdev, 0),
                              2, USB_TYPE_VENDOR,
                              0x0000, 0x0100, NULL, 0, HZ * 3);
        dev_dbg(dev, "set handshake  - retC = %d", ret);

        /* device resume */
        mce_async_out(ir, DEVICE_RESUME, sizeof(DEVICE_RESUME));

        /* get hw/sw revision? */
        mce_async_out(ir, GET_REVISION, sizeof(GET_REVISION));

        kfree(data);
}

static void mceusb_gen2_init(struct mceusb_dev *ir)
{
        /* device resume */
        mce_async_out(ir, DEVICE_RESUME, sizeof(DEVICE_RESUME));

        /* get wake version (protocol, key, address) */
        mce_async_out(ir, GET_WAKEVERSION, sizeof(GET_WAKEVERSION));

        /* unknown what this one actually returns... */
        mce_async_out(ir, GET_UNKNOWN2, sizeof(GET_UNKNOWN2));
}

static void mceusb_get_parameters(struct mceusb_dev *ir)
{
        int i;
        unsigned char cmdbuf[3] = { MCE_CMD_PORT_SYS,
                                    MCE_CMD_GETPORTSTATUS, 0x00 };

        /* defaults, if the hardware doesn't support querying */
        ir->num_txports = 2;
        ir->num_rxports = 2;

        /* get number of tx and rx ports */
        mce_async_out(ir, GET_NUM_PORTS, sizeof(GET_NUM_PORTS));

        /* get the carrier and frequency */
        mce_async_out(ir, GET_CARRIER_FREQ, sizeof(GET_CARRIER_FREQ));

        if (ir->num_txports && !ir->flags.no_tx)
                /* get the transmitter bitmask */
                mce_async_out(ir, GET_TX_BITMASK, sizeof(GET_TX_BITMASK));

        /* get receiver timeout value */
        mce_async_out(ir, GET_RX_TIMEOUT, sizeof(GET_RX_TIMEOUT));

        /* get receiver sensor setting */
        mce_async_out(ir, GET_RX_SENSOR, sizeof(GET_RX_SENSOR));

        for (i = 0; i < ir->num_txports; i++) {
                cmdbuf[2] = i;
                mce_async_out(ir, cmdbuf, sizeof(cmdbuf));
        }
}

static void mceusb_flash_led(struct mceusb_dev *ir)
{
        if (ir->emver < 2)
                return;

        mce_async_out(ir, FLASH_LED, sizeof(FLASH_LED));
}

/*
 * Workqueue function
 * for resetting or recovering device after occurrence of error events
 * specified in ir->kevent bit field.
 * Function runs (via schedule_work()) in non-interrupt context, for
 * calls here (such as usb_clear_halt()) requiring non-interrupt context.
 */
static void mceusb_deferred_kevent(struct work_struct *work)
{
        struct mceusb_dev *ir =
                container_of(work, struct mceusb_dev, kevent);
        int status;

        if (test_bit(EVENT_RX_HALT, &ir->kevent_flags)) {
                usb_unlink_urb(ir->urb_in);
                status = usb_clear_halt(ir->usbdev, ir->pipe_in);
                if (status < 0) {
                        dev_err(ir->dev, "rx clear halt error %d",
                                status);
                }
                clear_bit(EVENT_RX_HALT, &ir->kevent_flags);
                if (status == 0) {
                        status = usb_submit_urb(ir->urb_in, GFP_KERNEL);
                        if (status < 0) {
                                dev_err(ir->dev,
                                        "rx unhalt submit urb error %d",
                                        status);
                        }
                }
        }

        if (test_bit(EVENT_TX_HALT, &ir->kevent_flags)) {
                status = usb_clear_halt(ir->usbdev, ir->pipe_out);
                if (status < 0)
                        dev_err(ir->dev, "tx clear halt error %d", status);
                clear_bit(EVENT_TX_HALT, &ir->kevent_flags);
        }
}

static struct rc_dev *mceusb_init_rc_dev(struct mceusb_dev *ir)
{
        struct usb_device *udev = ir->usbdev;
        struct device *dev = ir->dev;
        struct rc_dev *rc;
        int ret;

        rc = rc_allocate_device(RC_DRIVER_IR_RAW);
        if (!rc) {
                dev_err(dev, "remote dev allocation failed");
                goto out;
        }

        snprintf(ir->name, sizeof(ir->name), "%s (%04x:%04x)",
                 mceusb_model[ir->model].name ?
                        mceusb_model[ir->model].name :
                        "Media Center Ed. eHome Infrared Remote Transceiver",
                 le16_to_cpu(ir->usbdev->descriptor.idVendor),
                 le16_to_cpu(ir->usbdev->descriptor.idProduct));

        usb_make_path(ir->usbdev, ir->phys, sizeof(ir->phys));

        rc->device_name = ir->name;
        rc->input_phys = ir->phys;
        usb_to_input_id(ir->usbdev, &rc->input_id);
        rc->dev.parent = dev;
        rc->priv = ir;
        rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
        rc->min_timeout = US_TO_NS(MCE_TIME_UNIT);
        rc->timeout = MS_TO_NS(100);
        if (!mceusb_model[ir->model].broken_irtimeout) {
                rc->s_timeout = mceusb_set_timeout;
                rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
        } else {
                /*
                 * If we can't set the timeout using CMD_SETIRTIMEOUT, we can
                 * rely on software timeouts for timeouts < 100ms.
                 */
                rc->max_timeout = rc->timeout;
        }
        if (!ir->flags.no_tx) {
                rc->s_tx_mask = mceusb_set_tx_mask;
                rc->s_tx_carrier = mceusb_set_tx_carrier;
                rc->tx_ir = mceusb_tx_ir;
        }
        if (ir->flags.rx2 > 0) {
                rc->s_learning_mode = mceusb_set_rx_wideband;
                rc->s_carrier_report = mceusb_set_rx_carrier_report;
        }
        rc->driver_name = DRIVER_NAME;

        switch (le16_to_cpu(udev->descriptor.idVendor)) {
        case VENDOR_HAUPPAUGE:
                rc->map_name = RC_MAP_HAUPPAUGE;
                break;
        case VENDOR_PCTV:
                rc->map_name = RC_MAP_PINNACLE_PCTV_HD;
                break;
        default:
                rc->map_name = RC_MAP_RC6_MCE;
        }
        if (mceusb_model[ir->model].rc_map)
                rc->map_name = mceusb_model[ir->model].rc_map;

        ret = rc_register_device(rc);
        if (ret < 0) {
                dev_err(dev, "remote dev registration failed");
                goto out;
        }

        return rc;

out:
        rc_free_device(rc);
        return NULL;
}

static int mceusb_dev_probe(struct usb_interface *intf,
                            const struct usb_device_id *id)
{
        struct usb_device *dev = interface_to_usbdev(intf);
        struct usb_host_interface *idesc;
        struct usb_endpoint_descriptor *ep = NULL;
        struct usb_endpoint_descriptor *ep_in = NULL;
        struct usb_endpoint_descriptor *ep_out = NULL;
        struct mceusb_dev *ir = NULL;
        int pipe, maxp, i, res;
        char buf[63], name[128] = "";
        enum mceusb_model_type model = id->driver_info;
        bool is_gen3;
        bool is_microsoft_gen1;
        bool tx_mask_normal;
        int ir_intfnum;

        dev_dbg(&intf->dev, "%s called", __func__);

        idesc  = intf->cur_altsetting;

        is_gen3 = mceusb_model[model].mce_gen3;
        is_microsoft_gen1 = mceusb_model[model].mce_gen1;
        tx_mask_normal = mceusb_model[model].tx_mask_normal;
        ir_intfnum = mceusb_model[model].ir_intfnum;

        /* There are multi-function devices with non-IR interfaces */
        if (idesc->desc.bInterfaceNumber != ir_intfnum)
                return -ENODEV;

        /* step through the endpoints to find first bulk in and out endpoint */
        for (i = 0; i < idesc->desc.bNumEndpoints; ++i) {
                ep = &idesc->endpoint[i].desc;

                if (ep_in == NULL) {
                        if (usb_endpoint_is_bulk_in(ep)) {
                                ep_in = ep;
                                dev_dbg(&intf->dev, "acceptable bulk inbound endpoint found\n");
                        } else if (usb_endpoint_is_int_in(ep)) {
                                ep_in = ep;
                                ep_in->bInterval = 1;
                                dev_dbg(&intf->dev, "acceptable interrupt inbound endpoint found\n");
                        }
                }

                if (ep_out == NULL) {
                        if (usb_endpoint_is_bulk_out(ep)) {
                                ep_out = ep;
                                dev_dbg(&intf->dev, "acceptable bulk outbound endpoint found\n");
                        } else if (usb_endpoint_is_int_out(ep)) {
                                ep_out = ep;
                                ep_out->bInterval = 1;
                                dev_dbg(&intf->dev, "acceptable interrupt outbound endpoint found\n");
                        }
                }
        }
        if (!ep_in || !ep_out) {
                dev_dbg(&intf->dev, "required endpoints not found\n");
                return -ENODEV;
        }

        if (usb_endpoint_xfer_int(ep_in))
                pipe = usb_rcvintpipe(dev, ep_in->bEndpointAddress);
        else
                pipe = usb_rcvbulkpipe(dev, ep_in->bEndpointAddress);
        maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));

        ir = kzalloc(sizeof(struct mceusb_dev), GFP_KERNEL);
        if (!ir)
                goto mem_alloc_fail;

        ir->pipe_in = pipe;
        ir->buf_in = usb_alloc_coherent(dev, maxp, GFP_ATOMIC, &ir->dma_in);
        if (!ir->buf_in)
                goto buf_in_alloc_fail;

        ir->urb_in = usb_alloc_urb(0, GFP_KERNEL);
        if (!ir->urb_in)
                goto urb_in_alloc_fail;

        ir->usbdev = usb_get_dev(dev);
        ir->dev = &intf->dev;
        ir->len_in = maxp;
        ir->flags.microsoft_gen1 = is_microsoft_gen1;
        ir->flags.tx_mask_normal = tx_mask_normal;
        ir->flags.no_tx = mceusb_model[model].no_tx;
        ir->flags.rx2 = mceusb_model[model].rx2;
        ir->model = model;

        /* Saving usb interface data for use by the transmitter routine */
        ir->usb_ep_out = ep_out;
        if (usb_endpoint_xfer_int(ep_out))
                ir->pipe_out = usb_sndintpipe(ir->usbdev,
                                              ep_out->bEndpointAddress);
        else
                ir->pipe_out = usb_sndbulkpipe(ir->usbdev,
                                               ep_out->bEndpointAddress);

        if (dev->descriptor.iManufacturer
            && usb_string(dev, dev->descriptor.iManufacturer,
                          buf, sizeof(buf)) > 0)
                strscpy(name, buf, sizeof(name));
        if (dev->descriptor.iProduct
            && usb_string(dev, dev->descriptor.iProduct,
                          buf, sizeof(buf)) > 0)
                snprintf(name + strlen(name), sizeof(name) - strlen(name),
                         " %s", buf);

        /*
         * Initialize async USB error handler before registering
         * or activating any mceusb RX and TX functions
         */
        INIT_WORK(&ir->kevent, mceusb_deferred_kevent);

        ir->rc = mceusb_init_rc_dev(ir);
        if (!ir->rc)
                goto rc_dev_fail;

        /* wire up inbound data handler */
        if (usb_endpoint_xfer_int(ep_in))
                usb_fill_int_urb(ir->urb_in, dev, pipe, ir->buf_in, maxp,
                                 mceusb_dev_recv, ir, ep_in->bInterval);
        else
                usb_fill_bulk_urb(ir->urb_in, dev, pipe, ir->buf_in, maxp,
                                  mceusb_dev_recv, ir);

        ir->urb_in->transfer_dma = ir->dma_in;
        ir->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

        /* flush buffers on the device */
        dev_dbg(&intf->dev, "Flushing receive buffers");
        res = usb_submit_urb(ir->urb_in, GFP_KERNEL);
        if (res)
                dev_err(&intf->dev, "failed to flush buffers: %d", res);

        /* figure out which firmware/emulator version this hardware has */
        mceusb_get_emulator_version(ir);

        /* initialize device */
        if (ir->flags.microsoft_gen1)
                mceusb_gen1_init(ir);
        else if (!is_gen3)
                mceusb_gen2_init(ir);

        mceusb_get_parameters(ir);

        mceusb_flash_led(ir);

        if (!ir->flags.no_tx)
                mceusb_set_tx_mask(ir->rc, MCE_DEFAULT_TX_MASK);

        usb_set_intfdata(intf, ir);

        /* enable wake via this device */
        device_set_wakeup_capable(ir->dev, true);
        device_set_wakeup_enable(ir->dev, true);

        dev_info(&intf->dev, "Registered %s with mce emulator interface version %x",
                name, ir->emver);
        dev_info(&intf->dev, "%x tx ports (0x%x cabled) and %x rx sensors (0x%x active)",
                 ir->num_txports, ir->txports_cabled,
                 ir->num_rxports, ir->rxports_active);

        return 0;

        /* Error-handling path */
rc_dev_fail:
        cancel_work_sync(&ir->kevent);
        usb_put_dev(ir->usbdev);
        usb_kill_urb(ir->urb_in);
        usb_free_urb(ir->urb_in);
urb_in_alloc_fail:
        usb_free_coherent(dev, maxp, ir->buf_in, ir->dma_in);
buf_in_alloc_fail:
        kfree(ir);
mem_alloc_fail:
        dev_err(&intf->dev, "%s: device setup failed!", __func__);

        return -ENOMEM;
}


static void mceusb_dev_disconnect(struct usb_interface *intf)
{
        struct usb_device *dev = interface_to_usbdev(intf);
        struct mceusb_dev *ir = usb_get_intfdata(intf);

        usb_set_intfdata(intf, NULL);

        if (!ir)
                return;

        ir->usbdev = NULL;
        cancel_work_sync(&ir->kevent);
        rc_unregister_device(ir->rc);
        usb_kill_urb(ir->urb_in);
        usb_free_urb(ir->urb_in);
        usb_free_coherent(dev, ir->len_in, ir->buf_in, ir->dma_in);
        usb_put_dev(dev);

        kfree(ir);
}

static int mceusb_dev_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct mceusb_dev *ir = usb_get_intfdata(intf);
        dev_info(ir->dev, "suspend");
        usb_kill_urb(ir->urb_in);
        return 0;
}

static int mceusb_dev_resume(struct usb_interface *intf)
{
        struct mceusb_dev *ir = usb_get_intfdata(intf);
        dev_info(ir->dev, "resume");
        if (usb_submit_urb(ir->urb_in, GFP_ATOMIC))
                return -EIO;
        return 0;
}

static struct usb_driver mceusb_dev_driver = {
        .name =         DRIVER_NAME,
        .probe =        mceusb_dev_probe,
        .disconnect =   mceusb_dev_disconnect,
        .suspend =      mceusb_dev_suspend,
        .resume =       mceusb_dev_resume,
        .reset_resume = mceusb_dev_resume,
        .id_table =     mceusb_dev_table
};

module_usb_driver(mceusb_dev_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, mceusb_dev_table);