redrat3.c

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/*
 * USB RedRat3 IR Transceiver rc-core driver
 *
 * Copyright (c) 2011 by Jarod Wilson <[email protected]>
 *  based heavily on the work of Stephen Cox, with additional
 *  help from RedRat Ltd.
 *
 * This driver began life based an an old version of the first-generation
 * lirc_mceusb driver from the lirc 0.7.2 distribution. It was then
 * significantly rewritten by Stephen Cox with the aid of RedRat Ltd's
 * Chris Dodge.
 *
 * The driver was then ported to rc-core and significantly rewritten again,
 * by Jarod, using the in-kernel mceusb driver as a guide, after an initial
 * port effort was started by Stephen.
 *
 * TODO LIST:
 * - fix lirc not showing repeats properly
 * --
 *
 * The RedRat3 is a USB transceiver with both send & receive,
 * with 2 separate sensors available for receive to enable
 * both good long range reception for general use, and good
 * short range reception when required for learning a signal.
 *
 * http://www.redrat.co.uk/
 *
 * It uses its own little protocol to communicate, the required
 * parts of which are embedded within this driver.
 * --
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

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

/* Driver Information */
#define DRIVER_VERSION "0.70"
#define DRIVER_AUTHOR "Jarod Wilson <[email protected]>"
#define DRIVER_AUTHOR2 "The Dweller, Stephen Cox"
#define DRIVER_DESC "RedRat3 USB IR Transceiver Driver"
#define DRIVER_NAME "redrat3"

/* module parameters */
#ifdef CONFIG_USB_DEBUG
static int debug = 1;
#else
static int debug;
#endif

#define RR3_DEBUG_STANDARD      0x1
#define RR3_DEBUG_FUNCTION_TRACE    0x2

#define rr3_dbg(dev, fmt, ...)                  \
    do {                            \
        if (debug & RR3_DEBUG_STANDARD)         \
            dev_info(dev, fmt, ## __VA_ARGS__); \
    } while (0)

#define rr3_ftr(dev, fmt, ...)                  \
    do {                            \
        if (debug & RR3_DEBUG_FUNCTION_TRACE)       \
            dev_info(dev, fmt, ## __VA_ARGS__); \
    } while (0)

/* bulk data transfer types */
#define RR3_ERROR       0x01
#define RR3_MOD_SIGNAL_IN   0x20
#define RR3_MOD_SIGNAL_OUT  0x21

/* Get the RR firmware version */
#define RR3_FW_VERSION      0xb1
#define RR3_FW_VERSION_LEN  64
/* Send encoded signal bulk-sent earlier*/
#define RR3_TX_SEND_SIGNAL  0xb3
#define RR3_SET_IR_PARAM    0xb7
#define RR3_GET_IR_PARAM    0xb8
/* Blink the red LED on the device */
#define RR3_BLINK_LED       0xb9
/* Read serial number of device */
#define RR3_READ_SER_NO     0xba
#define RR3_SER_NO_LEN      4
/* Start capture with the RC receiver */
#define RR3_RC_DET_ENABLE   0xbb
/* Stop capture with the RC receiver */
#define RR3_RC_DET_DISABLE  0xbc
/* Return the status of RC detector capture */
#define RR3_RC_DET_STATUS   0xbd
/* Reset redrat */
#define RR3_RESET       0xa0

/* Max number of lengths in the signal. */
#define RR3_IR_IO_MAX_LENGTHS   0x01
/* Periods to measure mod. freq. */
#define RR3_IR_IO_PERIODS_MF    0x02
/* Size of memory for main signal data */
#define RR3_IR_IO_SIG_MEM_SIZE  0x03
/* Delta value when measuring lengths */
#define RR3_IR_IO_LENGTH_FUZZ   0x04
/* Timeout for end of signal detection */
#define RR3_IR_IO_SIG_TIMEOUT   0x05
/* Minumum value for pause recognition. */
#define RR3_IR_IO_MIN_PAUSE 0x06

/* Clock freq. of EZ-USB chip */
#define RR3_CLK         24000000
/* Clock periods per timer count */
#define RR3_CLK_PER_COUNT   12
/* (RR3_CLK / RR3_CLK_PER_COUNT) */
#define RR3_CLK_CONV_FACTOR 2000000
/* USB bulk-in IR data endpoint address */
#define RR3_BULK_IN_EP_ADDR 0x82

/* Raw Modulated signal data value offsets */
#define RR3_PAUSE_OFFSET    0
#define RR3_FREQ_COUNT_OFFSET   4
#define RR3_NUM_PERIOD_OFFSET   6
#define RR3_MAX_LENGTHS_OFFSET  8
#define RR3_NUM_LENGTHS_OFFSET  9
#define RR3_MAX_SIGS_OFFSET 10
#define RR3_NUM_SIGS_OFFSET 12
#define RR3_REPEATS_OFFSET  14

/* Size of the fixed-length portion of the signal */
#define RR3_HEADER_LENGTH   15
#define RR3_DRIVER_MAXLENS  128
#define RR3_MAX_SIG_SIZE    512
#define RR3_MAX_BUF_SIZE    \
    ((2 * RR3_HEADER_LENGTH) + RR3_DRIVER_MAXLENS + RR3_MAX_SIG_SIZE)
#define RR3_TIME_UNIT       50
#define RR3_END_OF_SIGNAL   0x7f
#define RR3_TX_HEADER_OFFSET    4
#define RR3_TX_TRAILER_LEN  2
#define RR3_RX_MIN_TIMEOUT  5
#define RR3_RX_MAX_TIMEOUT  2000

/* The 8051's CPUCS Register address */
#define RR3_CPUCS_REG_ADDR  0x7f92

#define USB_RR3USB_VENDOR_ID    0x112a
#define USB_RR3USB_PRODUCT_ID   0x0001
#define USB_RR3IIUSB_PRODUCT_ID 0x0005

/* table of devices that work with this driver */
static struct usb_device_id redrat3_dev_table[] = {
    /* Original version of the RedRat3 */
    {USB_DEVICE(USB_RR3USB_VENDOR_ID, USB_RR3USB_PRODUCT_ID)},
    /* Second Version/release of the RedRat3 - RetRat3-II */
    {USB_DEVICE(USB_RR3USB_VENDOR_ID, USB_RR3IIUSB_PRODUCT_ID)},
    {}          /* Terminating entry */
};

/* Structure to hold all of our device specific stuff */
struct redrat3_dev {
    /* core device bits */
    struct rc_dev *rc;
    struct device *dev;

    /* save off the usb device pointer */
    struct usb_device *udev;

    /* the receive endpoint */
    struct usb_endpoint_descriptor *ep_in;
    /* the buffer to receive data */
    unsigned char *bulk_in_buf;
    /* urb used to read ir data */
    struct urb *read_urb;

    /* the send endpoint */
    struct usb_endpoint_descriptor *ep_out;
    /* the buffer to send data */
    unsigned char *bulk_out_buf;
    /* the urb used to send data */
    struct urb *write_urb;

    /* usb dma */
    dma_addr_t dma_in;
    dma_addr_t dma_out;

    /* locks this structure */
    struct mutex lock;

    /* rx signal timeout timer */
    struct timer_list rx_timeout;
    u32 hw_timeout;

    /* is the detector enabled*/
    bool det_enabled;
    /* Is the device currently transmitting?*/
    bool transmitting;

    /* store for current packet */
    char pbuf[RR3_MAX_BUF_SIZE];
    u16 pktlen;
    u16 pkttype;
    u16 bytes_read;
    /* indicate whether we are going to reprocess
     * the USB callback with a bigger buffer */
    int buftoosmall;
    char *datap;

    u32 carrier;

    char name[128];
    char phys[64];
};

/* All incoming data buffers adhere to a very specific data format */
struct redrat3_signal_header {
    u16 length; /* Length of data being transferred */
    u16 transfer_type; /* Type of data transferred */
    u32 pause;  /* Pause between main and repeat signals */
    u16 mod_freq_count; /* Value of timer on mod. freq. measurement */
    u16 no_periods; /* No. of periods over which mod. freq. is measured */
    u8 max_lengths; /* Max no. of lengths (i.e. size of array) */
    u8 no_lengths;  /* Actual no. of elements in lengths array */
    u16 max_sig_size; /* Max no. of values in signal data array */
    u16 sig_size;   /* Acuto no. of values in signal data array */
    u8 no_repeats;  /* No. of repeats of repeat signal section */
    /* Here forward is the lengths and signal data */
};

static void redrat3_dump_signal_header(struct redrat3_signal_header *header)
{
    pr_info("%s:\n", __func__);
    pr_info(" * length: %u, transfer_type: 0x%02x\n",
        header->length, header->transfer_type);
    pr_info(" * pause: %u, freq_count: %u, no_periods: %u\n",
        header->pause, header->mod_freq_count, header->no_periods);
    pr_info(" * lengths: %u (max: %u)\n",
        header->no_lengths, header->max_lengths);
    pr_info(" * sig_size: %u (max: %u)\n",
        header->sig_size, header->max_sig_size);
    pr_info(" * repeats: %u\n", header->no_repeats);
}

static void redrat3_dump_signal_data(char *buffer, u16 len)
{
    int offset, i;
    char *data_vals;

    pr_info("%s:", __func__);

    offset = RR3_TX_HEADER_OFFSET + RR3_HEADER_LENGTH
         + (RR3_DRIVER_MAXLENS * sizeof(u16));

    /* read RR3_DRIVER_MAXLENS from ctrl msg */
    data_vals = buffer + offset;

    for (i = 0; i < len; i++) {
        if (i % 10 == 0)
            pr_cont("\n * ");
        pr_cont("%02x ", *data_vals++);
    }

    pr_cont("\n");
}

/*
 * redrat3_issue_async
 *
 *  Issues an async read to the ir data in port..
 *  sets the callback to be redrat3_handle_async
 */
static void redrat3_issue_async(struct redrat3_dev *rr3)
{
    int res;

    rr3_ftr(rr3->dev, "Entering %s\n", __func__);

    memset(rr3->bulk_in_buf, 0, rr3->ep_in->wMaxPacketSize);
    res = usb_submit_urb(rr3->read_urb, GFP_ATOMIC);
    if (res)
        rr3_dbg(rr3->dev, "%s: receive request FAILED! "
            "(res %d, len %d)\n", __func__, res,
            rr3->read_urb->transfer_buffer_length);
}

static void redrat3_dump_fw_error(struct redrat3_dev *rr3, int code)
{
    if (!rr3->transmitting && (code != 0x40))
        dev_info(rr3->dev, "fw error code 0x%02x: ", code);

    switch (code) {
    case 0x00:
        pr_cont("No Error\n");
        break;

    /* Codes 0x20 through 0x2f are IR Firmware Errors */
    case 0x20:
        pr_cont("Initial signal pulse not long enough "
            "to measure carrier frequency\n");
        break;
    case 0x21:
        pr_cont("Not enough length values allocated for signal\n");
        break;
    case 0x22:
        pr_cont("Not enough memory allocated for signal data\n");
        break;
    case 0x23:
        pr_cont("Too many signal repeats\n");
        break;
    case 0x28:
        pr_cont("Insufficient memory available for IR signal "
            "data memory allocation\n");
        break;
    case 0x29:
        pr_cont("Insufficient memory available "
            "for IrDa signal data memory allocation\n");
        break;

    /* Codes 0x30 through 0x3f are USB Firmware Errors */
    case 0x30:
        pr_cont("Insufficient memory available for bulk "
            "transfer structure\n");
        break;

    /*
     * Other error codes... These are primarily errors that can occur in
     * the control messages sent to the redrat
     */
    case 0x40:
        if (!rr3->transmitting)
            pr_cont("Signal capture has been terminated\n");
        break;
    case 0x41:
        pr_cont("Attempt to set/get and unknown signal I/O "
            "algorithm parameter\n");
        break;
    case 0x42:
        pr_cont("Signal capture already started\n");
        break;

    default:
        pr_cont("Unknown Error\n");
        break;
    }
}

static u32 redrat3_val_to_mod_freq(struct redrat3_signal_header *ph)
{
    u32 mod_freq = 0;

    if (ph->mod_freq_count != 0)
        mod_freq = (RR3_CLK * ph->no_periods) /
                (ph->mod_freq_count * RR3_CLK_PER_COUNT);

    return mod_freq;
}

/* this function scales down the figures for the same result... */
static u32 redrat3_len_to_us(u32 length)
{
    u32 biglen = length * 1000;
    u32 divisor = (RR3_CLK_CONV_FACTOR) / 1000;
    u32 result = (u32) (biglen / divisor);

    /* don't allow zero lengths to go back, breaks lirc */
    return result ? result : 1;
}

/*
 * convert us back into redrat3 lengths
 *
 * length * 1000   length * 1000000
 * ------------- = ---------------- = micro
 * rr3clk / 1000       rr3clk

 * 6 * 2       4 * 3        micro * rr3clk          micro * rr3clk / 1000
 * ----- = 4   ----- = 6    -------------- = len    ---------------------
 *   3           2             1000000                    1000
 */
static u32 redrat3_us_to_len(u32 microsec)
{
    u32 result;
    u32 divisor;

    microsec &= IR_MAX_DURATION;
    divisor = (RR3_CLK_CONV_FACTOR / 1000);
    result = (u32)(microsec * divisor) / 1000;

    /* don't allow zero lengths to go back, breaks lirc */
    return result ? result : 1;

}

/* timer callback to send reset event */
static void redrat3_rx_timeout(unsigned long data)
{
    struct redrat3_dev *rr3 = (struct redrat3_dev *)data;

    rr3_dbg(rr3->dev, "calling ir_raw_event_reset\n");
    ir_raw_event_reset(rr3->rc);
}

static void redrat3_process_ir_data(struct redrat3_dev *rr3)
{
    DEFINE_IR_RAW_EVENT(rawir);
    struct redrat3_signal_header header;
    struct device *dev;
    int i, trailer = 0;
    unsigned long delay;
    u32 mod_freq, single_len;
    u16 *len_vals;
    u8 *data_vals;
    u32 tmp32;
    u16 tmp16;
    char *sig_data;

    if (!rr3) {
        pr_err("%s called with no context!\n", __func__);
        return;
    }

    rr3_ftr(rr3->dev, "Entered %s\n", __func__);

    dev = rr3->dev;
    sig_data = rr3->pbuf;

    header.length = rr3->pktlen;
    header.transfer_type = rr3->pkttype;

    /* Sanity check */
    if (!(header.length >= RR3_HEADER_LENGTH))
        dev_warn(dev, "read returned less than rr3 header len\n");

    /* Make sure we reset the IR kfifo after a bit of inactivity */
    delay = usecs_to_jiffies(rr3->hw_timeout);
    mod_timer(&rr3->rx_timeout, jiffies + delay);

    memcpy(&tmp32, sig_data + RR3_PAUSE_OFFSET, sizeof(tmp32));
    header.pause = be32_to_cpu(tmp32);

    memcpy(&tmp16, sig_data + RR3_FREQ_COUNT_OFFSET, sizeof(tmp16));
    header.mod_freq_count = be16_to_cpu(tmp16);

    memcpy(&tmp16, sig_data + RR3_NUM_PERIOD_OFFSET, sizeof(tmp16));
    header.no_periods = be16_to_cpu(tmp16);

    header.max_lengths = sig_data[RR3_MAX_LENGTHS_OFFSET];
    header.no_lengths = sig_data[RR3_NUM_LENGTHS_OFFSET];

    memcpy(&tmp16, sig_data + RR3_MAX_SIGS_OFFSET, sizeof(tmp16));
    header.max_sig_size = be16_to_cpu(tmp16);

    memcpy(&tmp16, sig_data + RR3_NUM_SIGS_OFFSET, sizeof(tmp16));
    header.sig_size = be16_to_cpu(tmp16);

    header.no_repeats= sig_data[RR3_REPEATS_OFFSET];

    if (debug) {
        redrat3_dump_signal_header(&header);
        redrat3_dump_signal_data(sig_data, header.sig_size);
    }

    mod_freq = redrat3_val_to_mod_freq(&header);
    rr3_dbg(dev, "Got mod_freq of %u\n", mod_freq);

    /* Here we pull out the 'length' values from the signal */
    len_vals = (u16 *)(sig_data + RR3_HEADER_LENGTH);

    data_vals = sig_data + RR3_HEADER_LENGTH +
            (header.max_lengths * sizeof(u16));

    /* process each rr3 encoded byte into an int */
    for (i = 0; i < header.sig_size; i++) {
        u16 val = len_vals[data_vals[i]];
        single_len = redrat3_len_to_us((u32)be16_to_cpu(val));

        /* we should always get pulse/space/pulse/space samples */
        if (i % 2)
            rawir.pulse = false;
        else
            rawir.pulse = true;

        rawir.duration = US_TO_NS(single_len);
        /* Save initial pulse length to fudge trailer */
        if (i == 0)
            trailer = rawir.duration;
        /* cap the value to IR_MAX_DURATION */
        rawir.duration &= IR_MAX_DURATION;

        rr3_dbg(dev, "storing %s with duration %d (i: %d)\n",
            rawir.pulse ? "pulse" : "space", rawir.duration, i);
        ir_raw_event_store_with_filter(rr3->rc, &rawir);
    }

    /* add a trailing space, if need be */
    if (i % 2) {
        rawir.pulse = false;
        /* this duration is made up, and may not be ideal... */
        if (trailer < US_TO_NS(1000))
            rawir.duration = US_TO_NS(2800);
        else
            rawir.duration = trailer;
        rr3_dbg(dev, "storing trailing space with duration %d\n",
            rawir.duration);
        ir_raw_event_store_with_filter(rr3->rc, &rawir);
    }

    rr3_dbg(dev, "calling ir_raw_event_handle\n");
    ir_raw_event_handle(rr3->rc);

    return;
}

/* Util fn to send rr3 cmds */
static u8 redrat3_send_cmd(int cmd, struct redrat3_dev *rr3)
{
    struct usb_device *udev;
    u8 *data;
    int res;

    data = kzalloc(sizeof(u8), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    udev = rr3->udev;
    res = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), cmd,
                  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                  0x0000, 0x0000, data, sizeof(u8), HZ * 10);

    if (res < 0) {
        dev_err(rr3->dev, "%s: Error sending rr3 cmd res %d, data %d",
            __func__, res, *data);
        res = -EIO;
    } else
        res = (u8)data[0];

    kfree(data);

    return res;
}

/* Enables the long range detector and starts async receive */
static int redrat3_enable_detector(struct redrat3_dev *rr3)
{
    struct device *dev = rr3->dev;
    u8 ret;

    rr3_ftr(dev, "Entering %s\n", __func__);

    ret = redrat3_send_cmd(RR3_RC_DET_ENABLE, rr3);
    if (ret != 0)
        dev_dbg(dev, "%s: unexpected ret of %d\n",
            __func__, ret);

    ret = redrat3_send_cmd(RR3_RC_DET_STATUS, rr3);
    if (ret != 1) {
        dev_err(dev, "%s: detector status: %d, should be 1\n",
            __func__, ret);
        return -EIO;
    }

    rr3->det_enabled = true;
    redrat3_issue_async(rr3);

    return 0;
}

/* Disables the rr3 long range detector */
static void redrat3_disable_detector(struct redrat3_dev *rr3)
{
    struct device *dev = rr3->dev;
    u8 ret;

    rr3_ftr(dev, "Entering %s\n", __func__);

    ret = redrat3_send_cmd(RR3_RC_DET_DISABLE, rr3);
    if (ret != 0)
        dev_err(dev, "%s: failure!\n", __func__);

    ret = redrat3_send_cmd(RR3_RC_DET_STATUS, rr3);
    if (ret != 0)
        dev_warn(dev, "%s: detector status: %d, should be 0\n",
             __func__, ret);

    rr3->det_enabled = false;
}

static inline void redrat3_delete(struct redrat3_dev *rr3,
                  struct usb_device *udev)
{
    rr3_ftr(rr3->dev, "%s cleaning up\n", __func__);
    usb_kill_urb(rr3->read_urb);
    usb_kill_urb(rr3->write_urb);

    usb_free_urb(rr3->read_urb);
    usb_free_urb(rr3->write_urb);

    usb_free_coherent(udev, rr3->ep_in->wMaxPacketSize,
              rr3->bulk_in_buf, rr3->dma_in);
    usb_free_coherent(udev, rr3->ep_out->wMaxPacketSize,
              rr3->bulk_out_buf, rr3->dma_out);

    kfree(rr3);
}

static u32 redrat3_get_timeout(struct redrat3_dev *rr3)
{
    u32 *tmp;
    u32 timeout = MS_TO_US(150); /* a sane default, if things go haywire */
    int len, ret, pipe;

    len = sizeof(*tmp);
    tmp = kzalloc(len, GFP_KERNEL);
    if (!tmp) {
        dev_warn(rr3->dev, "Memory allocation faillure\n");
        return timeout;
    }

    pipe = usb_rcvctrlpipe(rr3->udev, 0);
    ret = usb_control_msg(rr3->udev, pipe, RR3_GET_IR_PARAM,
                  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                  RR3_IR_IO_SIG_TIMEOUT, 0, tmp, len, HZ * 5);
    if (ret != len) {
        dev_warn(rr3->dev, "Failed to read timeout from hardware\n");
        return timeout;
    }

    timeout = redrat3_len_to_us(be32_to_cpu(*tmp));

    rr3_dbg(rr3->dev, "Got timeout of %d ms\n", timeout / 1000);
    return timeout;
}

static void redrat3_reset(struct redrat3_dev *rr3)
{
    struct usb_device *udev = rr3->udev;
    struct device *dev = rr3->dev;
    int rc, rxpipe, txpipe;
    u8 *val;
    int len = sizeof(u8);

    rr3_ftr(dev, "Entering %s\n", __func__);

    rxpipe = usb_rcvctrlpipe(udev, 0);
    txpipe = usb_sndctrlpipe(udev, 0);

    val = kzalloc(len, GFP_KERNEL);
    if (!val) {
        dev_err(dev, "Memory allocation failure\n");
        return;
    }

    *val = 0x01;
    rc = usb_control_msg(udev, rxpipe, RR3_RESET,
                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                 RR3_CPUCS_REG_ADDR, 0, val, len, HZ * 25);
    rr3_dbg(dev, "reset returned 0x%02x\n", rc);

    *val = 5;
    rc = usb_control_msg(udev, txpipe, RR3_SET_IR_PARAM,
                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
                 RR3_IR_IO_LENGTH_FUZZ, 0, val, len, HZ * 25);
    rr3_dbg(dev, "set ir parm len fuzz %d rc 0x%02x\n", *val, rc);

    *val = RR3_DRIVER_MAXLENS;
    rc = usb_control_msg(udev, txpipe, RR3_SET_IR_PARAM,
                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
                 RR3_IR_IO_MAX_LENGTHS, 0, val, len, HZ * 25);
    rr3_dbg(dev, "set ir parm max lens %d rc 0x%02x\n", *val, rc);

    kfree(val);
}

static void redrat3_get_firmware_rev(struct redrat3_dev *rr3)
{
    int rc = 0;
    char *buffer;

    rr3_ftr(rr3->dev, "Entering %s\n", __func__);

    buffer = kzalloc(sizeof(char) * (RR3_FW_VERSION_LEN + 1), GFP_KERNEL);
    if (!buffer) {
        dev_err(rr3->dev, "Memory allocation failure\n");
        return;
    }

    rc = usb_control_msg(rr3->udev, usb_rcvctrlpipe(rr3->udev, 0),
                 RR3_FW_VERSION,
                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                 0, 0, buffer, RR3_FW_VERSION_LEN, HZ * 5);

    if (rc >= 0)
        dev_info(rr3->dev, "Firmware rev: %s", buffer);
    else
        dev_err(rr3->dev, "Problem fetching firmware ID\n");

    kfree(buffer);
    rr3_ftr(rr3->dev, "Exiting %s\n", __func__);
}

static void redrat3_read_packet_start(struct redrat3_dev *rr3, int len)
{
    u16 tx_error;
    u16 hdrlen;

    rr3_ftr(rr3->dev, "Entering %s\n", __func__);

    /* grab the Length and type of transfer */
    memcpy(&(rr3->pktlen), (unsigned char *) rr3->bulk_in_buf,
           sizeof(rr3->pktlen));
    memcpy(&(rr3->pkttype), ((unsigned char *) rr3->bulk_in_buf +
        sizeof(rr3->pktlen)),
           sizeof(rr3->pkttype));

    /*data needs conversion to know what its real values are*/
    rr3->pktlen = be16_to_cpu(rr3->pktlen);
    rr3->pkttype = be16_to_cpu(rr3->pkttype);

    switch (rr3->pkttype) {
    case RR3_ERROR:
        memcpy(&tx_error, ((unsigned char *)rr3->bulk_in_buf
            + (sizeof(rr3->pktlen) + sizeof(rr3->pkttype))),
               sizeof(tx_error));
        tx_error = be16_to_cpu(tx_error);
        redrat3_dump_fw_error(rr3, tx_error);
        break;

    case RR3_MOD_SIGNAL_IN:
        hdrlen = sizeof(rr3->pktlen) + sizeof(rr3->pkttype);
        rr3->bytes_read = len;
        rr3->bytes_read -= hdrlen;
        rr3->datap = &(rr3->pbuf[0]);

        memcpy(rr3->datap, ((unsigned char *)rr3->bulk_in_buf + hdrlen),
               rr3->bytes_read);
        rr3->datap += rr3->bytes_read;
        rr3_dbg(rr3->dev, "bytes_read %d, pktlen %d\n",
            rr3->bytes_read, rr3->pktlen);
        break;

    default:
        rr3_dbg(rr3->dev, "ignoring packet with type 0x%02x, "
            "len of %d, 0x%02x\n", rr3->pkttype, len, rr3->pktlen);
        break;
    }
}

static void redrat3_read_packet_continue(struct redrat3_dev *rr3, int len)
{

    rr3_ftr(rr3->dev, "Entering %s\n", __func__);

    memcpy(rr3->datap, (unsigned char *)rr3->bulk_in_buf, len);
    rr3->datap += len;

    rr3->bytes_read += len;
    rr3_dbg(rr3->dev, "bytes_read %d, pktlen %d\n",
        rr3->bytes_read, rr3->pktlen);
}

/* gather IR data from incoming urb, process it when we have enough */
static int redrat3_get_ir_data(struct redrat3_dev *rr3, int len)
{
    struct device *dev = rr3->dev;
    int ret = 0;

    rr3_ftr(dev, "Entering %s\n", __func__);

    if (rr3->pktlen > RR3_MAX_BUF_SIZE) {
        dev_err(rr3->dev, "error: packet larger than buffer\n");
        ret = -EINVAL;
        goto out;
    }

    if ((rr3->bytes_read == 0) &&
        (len >= (sizeof(rr3->pkttype) + sizeof(rr3->pktlen)))) {
        redrat3_read_packet_start(rr3, len);
    } else if (rr3->bytes_read != 0) {
        redrat3_read_packet_continue(rr3, len);
    } else if (rr3->bytes_read == 0) {
        dev_err(dev, "error: no packet data read\n");
        ret = -ENODATA;
        goto out;
    }

    if (rr3->bytes_read > rr3->pktlen) {
        dev_err(dev, "bytes_read (%d) greater than pktlen (%d)\n",
            rr3->bytes_read, rr3->pktlen);
        ret = -EINVAL;
        goto out;
    } else if (rr3->bytes_read < rr3->pktlen)
        /* we're still accumulating data */
        return 0;

    /* if we get here, we've got IR data to decode */
    if (rr3->pkttype == RR3_MOD_SIGNAL_IN)
        redrat3_process_ir_data(rr3);
    else
        rr3_dbg(dev, "discarding non-signal data packet "
            "(type 0x%02x)\n", rr3->pkttype);

out:
    rr3->bytes_read = 0;
    rr3->pktlen = 0;
    rr3->pkttype = 0;
    return ret;
}

/* callback function from USB when async USB request has completed */
static void redrat3_handle_async(struct urb *urb, struct pt_regs *regs)
{
    struct redrat3_dev *rr3;
    int ret;

    if (!urb)
        return;

    rr3 = urb->context;
    if (!rr3) {
        pr_err("%s called with invalid context!\n", __func__);
        usb_unlink_urb(urb);
        return;
    }

    rr3_ftr(rr3->dev, "Entering %s\n", __func__);

    switch (urb->status) {
    case 0:
        ret = redrat3_get_ir_data(rr3, urb->actual_length);
        if (!ret) {
            /* no error, prepare to read more */
            redrat3_issue_async(rr3);
        }
        break;

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

    case -EPIPE:
    default:
        dev_warn(rr3->dev, "Error: urb status = %d\n", urb->status);
        rr3->bytes_read = 0;
        rr3->pktlen = 0;
        rr3->pkttype = 0;
        break;
    }
}

static void redrat3_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
{
    struct redrat3_dev *rr3;
    int len;

    if (!urb)
        return;

    rr3 = urb->context;
    if (rr3) {
        len = urb->actual_length;
        rr3_ftr(rr3->dev, "%s: called (status=%d len=%d)\n",
            __func__, urb->status, len);
    }
}

static u16 mod_freq_to_val(unsigned int mod_freq)
{
    int mult = 6000000;

    /* Clk used in mod. freq. generation is CLK24/4. */
    return (u16)(65536 - (mult / mod_freq));
}

static int redrat3_set_tx_carrier(struct rc_dev *rcdev, u32 carrier)
{
    struct redrat3_dev *rr3 = rcdev->priv;
    struct device *dev = rr3->dev;

    rr3_dbg(dev, "Setting modulation frequency to %u", carrier);
    if (carrier == 0)
        return -EINVAL;

    rr3->carrier = carrier;

    return carrier;
}

static int redrat3_transmit_ir(struct rc_dev *rcdev, unsigned *txbuf,
                unsigned count)
{
    struct redrat3_dev *rr3 = rcdev->priv;
    struct device *dev = rr3->dev;
    struct redrat3_signal_header header;
    int i, j, ret, ret_len, offset;
    int lencheck, cur_sample_len, pipe;
    char *buffer = NULL, *sigdata = NULL;
    int *sample_lens = NULL;
    u32 tmpi;
    u16 tmps;
    u8 *datap;
    u8 curlencheck = 0;
    u16 *lengths_ptr;
    int sendbuf_len;

    rr3_ftr(dev, "Entering %s\n", __func__);

    if (rr3->transmitting) {
        dev_warn(dev, "%s: transmitter already in use\n", __func__);
        return -EAGAIN;
    }

    if (count > (RR3_DRIVER_MAXLENS * 2))
        return -EINVAL;

    /* rr3 will disable rc detector on transmit */
    rr3->det_enabled = false;
    rr3->transmitting = true;

    sample_lens = kzalloc(sizeof(int) * RR3_DRIVER_MAXLENS, GFP_KERNEL);
    if (!sample_lens) {
        ret = -ENOMEM;
        goto out;
    }

    for (i = 0; i < count; i++) {
        for (lencheck = 0; lencheck < curlencheck; lencheck++) {
            cur_sample_len = redrat3_us_to_len(txbuf[i]);
            if (sample_lens[lencheck] == cur_sample_len)
                break;
        }
        if (lencheck == curlencheck) {
            cur_sample_len = redrat3_us_to_len(txbuf[i]);
            rr3_dbg(dev, "txbuf[%d]=%u, pos %d, enc %u\n",
                i, txbuf[i], curlencheck, cur_sample_len);
            if (curlencheck < 255) {
                /* now convert the value to a proper
                 * rr3 value.. */
                sample_lens[curlencheck] = cur_sample_len;
                curlencheck++;
            } else {
                dev_err(dev, "signal too long\n");
                ret = -EINVAL;
                goto out;
            }
        }
    }

    sigdata = kzalloc((count + RR3_TX_TRAILER_LEN), GFP_KERNEL);
    if (!sigdata) {
        ret = -ENOMEM;
        goto out;
    }

    sigdata[count] = RR3_END_OF_SIGNAL;
    sigdata[count + 1] = RR3_END_OF_SIGNAL;
    for (i = 0; i < count; i++) {
        for (j = 0; j < curlencheck; j++) {
            if (sample_lens[j] == redrat3_us_to_len(txbuf[i]))
                sigdata[i] = j;
        }
    }

    offset = RR3_TX_HEADER_OFFSET;
    sendbuf_len = RR3_HEADER_LENGTH + (sizeof(u16) * RR3_DRIVER_MAXLENS)
            + count + RR3_TX_TRAILER_LEN + offset;

    buffer = kzalloc(sendbuf_len, GFP_KERNEL);
    if (!buffer) {
        ret = -ENOMEM;
        goto out;
    }

    /* fill in our packet header */
    header.length = sendbuf_len - offset;
    header.transfer_type = RR3_MOD_SIGNAL_OUT;
    header.pause = redrat3_len_to_us(100);
    header.mod_freq_count = mod_freq_to_val(rr3->carrier);
    header.no_periods = 0; /* n/a to transmit */
    header.max_lengths = RR3_DRIVER_MAXLENS;
    header.no_lengths = curlencheck;
    header.max_sig_size = RR3_MAX_SIG_SIZE;
    header.sig_size = count + RR3_TX_TRAILER_LEN;
    /* we currently rely on repeat handling in the IR encoding source */
    header.no_repeats = 0;

    tmps = cpu_to_be16(header.length);
    memcpy(buffer, &tmps, 2);

    tmps = cpu_to_be16(header.transfer_type);
    memcpy(buffer + 2, &tmps, 2);

    tmpi = cpu_to_be32(header.pause);
    memcpy(buffer + offset, &tmpi, sizeof(tmpi));

    tmps = cpu_to_be16(header.mod_freq_count);
    memcpy(buffer + offset + RR3_FREQ_COUNT_OFFSET, &tmps, 2);

    buffer[offset + RR3_NUM_LENGTHS_OFFSET] = header.no_lengths;

    tmps = cpu_to_be16(header.sig_size);
    memcpy(buffer + offset + RR3_NUM_SIGS_OFFSET, &tmps, 2);

    buffer[offset + RR3_REPEATS_OFFSET] = header.no_repeats;

    lengths_ptr = (u16 *)(buffer + offset + RR3_HEADER_LENGTH);
    for (i = 0; i < curlencheck; ++i)
        lengths_ptr[i] = cpu_to_be16(sample_lens[i]);

    datap = (u8 *)(buffer + offset + RR3_HEADER_LENGTH +
                (sizeof(u16) * RR3_DRIVER_MAXLENS));
    memcpy(datap, sigdata, (count + RR3_TX_TRAILER_LEN));

    if (debug) {
        redrat3_dump_signal_header(&header);
        redrat3_dump_signal_data(buffer, header.sig_size);
    }

    pipe = usb_sndbulkpipe(rr3->udev, rr3->ep_out->bEndpointAddress);
    tmps = usb_bulk_msg(rr3->udev, pipe, buffer,
                sendbuf_len, &ret_len, 10 * HZ);
    rr3_dbg(dev, "sent %d bytes, (ret %d)\n", ret_len, tmps);

    /* now tell the hardware to transmit what we sent it */
    pipe = usb_rcvctrlpipe(rr3->udev, 0);
    ret = usb_control_msg(rr3->udev, pipe, RR3_TX_SEND_SIGNAL,
                  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                  0, 0, buffer, 2, HZ * 10);

    if (ret < 0)
        dev_err(dev, "Error: control msg send failed, rc %d\n", ret);
    else
        ret = count;

out:
    kfree(sample_lens);
    kfree(buffer);
    kfree(sigdata);

    rr3->transmitting = false;
    /* rr3 re-enables rc detector because it was enabled before */
    rr3->det_enabled = true;

    return ret;
}

static struct rc_dev *redrat3_init_rc_dev(struct redrat3_dev *rr3)
{
    struct device *dev = rr3->dev;
    struct rc_dev *rc;
    int ret = -ENODEV;
    u16 prod = le16_to_cpu(rr3->udev->descriptor.idProduct);

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

    snprintf(rr3->name, sizeof(rr3->name), "RedRat3%s "
         "Infrared Remote Transceiver (%04x:%04x)",
         prod == USB_RR3IIUSB_PRODUCT_ID ? "-II" : "",
         le16_to_cpu(rr3->udev->descriptor.idVendor), prod);

    usb_make_path(rr3->udev, rr3->phys, sizeof(rr3->phys));

    rc->input_name = rr3->name;
    rc->input_phys = rr3->phys;
    usb_to_input_id(rr3->udev, &rc->input_id);
    rc->dev.parent = dev;
    rc->priv = rr3;
    rc->driver_type = RC_DRIVER_IR_RAW;
    rc->allowed_protos = RC_TYPE_ALL;
    rc->timeout = US_TO_NS(2750);
    rc->tx_ir = redrat3_transmit_ir;
    rc->s_tx_carrier = redrat3_set_tx_carrier;
    rc->driver_name = DRIVER_NAME;
    rc->map_name = RC_MAP_HAUPPAUGE;

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

    return rc;

out:
    rc_free_device(rc);
    return NULL;
}

static int __devinit redrat3_dev_probe(struct usb_interface *intf,
                       const struct usb_device_id *id)
{
    struct usb_device *udev = interface_to_usbdev(intf);
    struct device *dev = &intf->dev;
    struct usb_host_interface *uhi;
    struct redrat3_dev *rr3;
    struct usb_endpoint_descriptor *ep;
    struct usb_endpoint_descriptor *ep_in = NULL;
    struct usb_endpoint_descriptor *ep_out = NULL;
    u8 addr, attrs;
    int pipe, i;
    int retval = -ENOMEM;

    rr3_ftr(dev, "%s called\n", __func__);

    uhi = intf->cur_altsetting;

    /* find our bulk-in and bulk-out endpoints */
    for (i = 0; i < uhi->desc.bNumEndpoints; ++i) {
        ep = &uhi->endpoint[i].desc;
        addr = ep->bEndpointAddress;
        attrs = ep->bmAttributes;

        if ((ep_in == NULL) &&
            ((addr & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) &&
            ((attrs & USB_ENDPOINT_XFERTYPE_MASK) ==
             USB_ENDPOINT_XFER_BULK)) {
            rr3_dbg(dev, "found bulk-in endpoint at 0x%02x\n",
                ep->bEndpointAddress);
            /* data comes in on 0x82, 0x81 is for other data... */
            if (ep->bEndpointAddress == RR3_BULK_IN_EP_ADDR)
                ep_in = ep;
        }

        if ((ep_out == NULL) &&
            ((addr & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) &&
            ((attrs & USB_ENDPOINT_XFERTYPE_MASK) ==
             USB_ENDPOINT_XFER_BULK)) {
            rr3_dbg(dev, "found bulk-out endpoint at 0x%02x\n",
                ep->bEndpointAddress);
            ep_out = ep;
        }
    }

    if (!ep_in || !ep_out) {
        dev_err(dev, "Couldn't find both in and out endpoints\n");
        retval = -ENODEV;
        goto no_endpoints;
    }

    /* allocate memory for our device state and initialize it */
    rr3 = kzalloc(sizeof(*rr3), GFP_KERNEL);
    if (rr3 == NULL) {
        dev_err(dev, "Memory allocation failure\n");
        goto no_endpoints;
    }

    rr3->dev = &intf->dev;

    /* set up bulk-in endpoint */
    rr3->read_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!rr3->read_urb) {
        dev_err(dev, "Read urb allocation failure\n");
        goto error;
    }

    rr3->ep_in = ep_in;
    rr3->bulk_in_buf = usb_alloc_coherent(udev, ep_in->wMaxPacketSize,
                          GFP_ATOMIC, &rr3->dma_in);
    if (!rr3->bulk_in_buf) {
        dev_err(dev, "Read buffer allocation failure\n");
        goto error;
    }

    pipe = usb_rcvbulkpipe(udev, ep_in->bEndpointAddress);
    usb_fill_bulk_urb(rr3->read_urb, udev, pipe,
              rr3->bulk_in_buf, ep_in->wMaxPacketSize,
              (usb_complete_t)redrat3_handle_async, rr3);

    /* set up bulk-out endpoint*/
    rr3->write_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!rr3->write_urb) {
        dev_err(dev, "Write urb allocation failure\n");
        goto error;
    }

    rr3->ep_out = ep_out;
    rr3->bulk_out_buf = usb_alloc_coherent(udev, ep_out->wMaxPacketSize,
                           GFP_ATOMIC, &rr3->dma_out);
    if (!rr3->bulk_out_buf) {
        dev_err(dev, "Write buffer allocation failure\n");
        goto error;
    }

    pipe = usb_sndbulkpipe(udev, ep_out->bEndpointAddress);
    usb_fill_bulk_urb(rr3->write_urb, udev, pipe,
              rr3->bulk_out_buf, ep_out->wMaxPacketSize,
              (usb_complete_t)redrat3_write_bulk_callback, rr3);

    mutex_init(&rr3->lock);
    rr3->udev = udev;

    redrat3_reset(rr3);
    redrat3_get_firmware_rev(rr3);

    /* might be all we need to do? */
    retval = redrat3_enable_detector(rr3);
    if (retval < 0)
        goto error;

    /* store current hardware timeout, in us, will use for kfifo resets */
    rr3->hw_timeout = redrat3_get_timeout(rr3);

    /* default.. will get overridden by any sends with a freq defined */
    rr3->carrier = 38000;

    rr3->rc = redrat3_init_rc_dev(rr3);
    if (!rr3->rc) {
        retval = -ENOMEM;
        goto error;
    }
    setup_timer(&rr3->rx_timeout, redrat3_rx_timeout, (unsigned long)rr3);

    /* we can register the device now, as it is ready */
    usb_set_intfdata(intf, rr3);

    rr3_ftr(dev, "Exiting %s\n", __func__);
    return 0;

error:
    redrat3_delete(rr3, rr3->udev);

no_endpoints:
    dev_err(dev, "%s: retval = %x", __func__, retval);

    return retval;
}

static void __devexit redrat3_dev_disconnect(struct usb_interface *intf)
{
    struct usb_device *udev = interface_to_usbdev(intf);
    struct redrat3_dev *rr3 = usb_get_intfdata(intf);

    rr3_ftr(&intf->dev, "Entering %s\n", __func__);

    if (!rr3)
        return;

    redrat3_disable_detector(rr3);

    usb_set_intfdata(intf, NULL);
    rc_unregister_device(rr3->rc);
    del_timer_sync(&rr3->rx_timeout);
    redrat3_delete(rr3, udev);

    rr3_ftr(&intf->dev, "RedRat3 IR Transceiver now disconnected\n");
}

static int redrat3_dev_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct redrat3_dev *rr3 = usb_get_intfdata(intf);
    rr3_ftr(rr3->dev, "suspend\n");
    usb_kill_urb(rr3->read_urb);
    return 0;
}

static int redrat3_dev_resume(struct usb_interface *intf)
{
    struct redrat3_dev *rr3 = usb_get_intfdata(intf);
    rr3_ftr(rr3->dev, "resume\n");
    if (usb_submit_urb(rr3->read_urb, GFP_ATOMIC))
        return -EIO;
    return 0;
}

static struct usb_driver redrat3_dev_driver = {
    .name       = DRIVER_NAME,
    .probe      = redrat3_dev_probe,
    .disconnect = __devexit_p(redrat3_dev_disconnect),
    .suspend    = redrat3_dev_suspend,
    .resume     = redrat3_dev_resume,
    .reset_resume   = redrat3_dev_resume,
    .id_table   = redrat3_dev_table
};

module_usb_driver(redrat3_dev_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_AUTHOR(DRIVER_AUTHOR2);
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, redrat3_dev_table);

module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable module debug spew. 0 = no debugging (default) "
         "0x1 = standard debug messages, 0x2 = function tracing debug. "
         "Flag bits are addative (i.e., 0x3 for both debug types).");