/*
 * USB RedRat3 IR Transceiver rc-core driver
 *
 * Copyright (c) 2011 by Jarod Wilson <jarod@redhat.com>
 *  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 <asm/unaligned.h>
#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_AUTHOR "Jarod Wilson <jarod@redhat.com>"
#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

/* Size of the fixed-length portion of the signal */
#define RR3_DRIVER_MAXLENS      128
#define RR3_MAX_SIG_SIZE        512
#define RR3_TIME_UNIT           50
#define RR3_END_OF_SIGNAL       0x7f
#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

struct redrat3_header {
        __be16 length;
        __be16 transfer_type;
} __packed;

/* sending and receiving irdata */
struct redrat3_irdata {
        struct redrat3_header header;
        __be32 pause;
        __be16 mod_freq_count;
        __be16 num_periods;
        __u8 max_lengths;
        __u8 no_lengths;
        __be16 max_sig_size;
        __be16 sig_size;
        __u8 no_repeats;
        __be16 lens[RR3_DRIVER_MAXLENS]; /* not aligned */
        __u8 sigdata[RR3_MAX_SIG_SIZE];
} __packed;

/* firmware errors */
struct redrat3_error {
        struct redrat3_header header;
        __be16 fw_error;
} __packed;

/* 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 */
        void *bulk_in_buf;
        /* urb used to read ir data */
        struct urb *read_urb;

        /* the send endpoint */
        struct usb_endpoint_descriptor *ep_out;

        /* usb dma */
        dma_addr_t dma_in;

        /* 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 */
        struct redrat3_irdata irdata;
        u16 bytes_read;

        u32 carrier;

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

/*
 * 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__);

        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_irdata *irdata)
{
        u32 mod_freq = 0;
        u16 mod_freq_count = be16_to_cpu(irdata->mod_freq_count);

        if (mod_freq_count != 0)
                mod_freq = (RR3_CLK * be16_to_cpu(irdata->num_periods)) /
                        (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 device *dev;
        unsigned i, trailer = 0;
        unsigned sig_size, single_len, offset, val;
        unsigned long delay;
        u32 mod_freq;

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

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

        dev = rr3->dev;

        /* 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);

        mod_freq = redrat3_val_to_mod_freq(&rr3->irdata);
        rr3_dbg(dev, "Got mod_freq of %u\n", mod_freq);

        /* process each rr3 encoded byte into an int */
        sig_size = be16_to_cpu(rr3->irdata.sig_size);
        for (i = 0; i < sig_size; i++) {
                offset = rr3->irdata.sigdata[i];
                val = get_unaligned_be16(&rr3->irdata.lens[offset]);
                single_len = redrat3_len_to_us(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);
}

/* 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 = 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_free_urb(rr3->read_urb);

        usb_free_coherent(udev, le16_to_cpu(rr3->ep_in->wMaxPacketSize),
                          rr3->bulk_in_buf, rr3->dma_in);

        kfree(rr3);
}

static u32 redrat3_get_timeout(struct redrat3_dev *rr3)
{
        __be32 *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");
        else {
                timeout = redrat3_len_to_us(be32_to_cpup(tmp));

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

        kfree(tmp);

        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 = kmalloc(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, unsigned len)
{
        struct redrat3_header *header = rr3->bulk_in_buf;
        unsigned pktlen, pkttype;

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

        /* grab the Length and type of transfer */
        pktlen = be16_to_cpu(header->length);
        pkttype = be16_to_cpu(header->transfer_type);

        if (pktlen > sizeof(rr3->irdata)) {
                dev_warn(rr3->dev, "packet length %u too large\n", pktlen);
                return;
        }

        switch (pkttype) {
        case RR3_ERROR:
                if (len >= sizeof(struct redrat3_error)) {
                        struct redrat3_error *error = rr3->bulk_in_buf;
                        unsigned fw_error = be16_to_cpu(error->fw_error);
                        redrat3_dump_fw_error(rr3, fw_error);
                }
                break;

        case RR3_MOD_SIGNAL_IN:
                memcpy(&rr3->irdata, rr3->bulk_in_buf, len);
                rr3->bytes_read = len;
                rr3_dbg(rr3->dev, "bytes_read %d, pktlen %d\n",
                        rr3->bytes_read, pktlen);
                break;

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

static void redrat3_read_packet_continue(struct redrat3_dev *rr3, unsigned len)
{
        void *irdata = &rr3->irdata;

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

        if (len + rr3->bytes_read > sizeof(rr3->irdata)) {
                dev_warn(rr3->dev, "too much data for packet\n");
                rr3->bytes_read = 0;
                return;
        }

        memcpy(irdata + rr3->bytes_read, rr3->bulk_in_buf, len);

        rr3->bytes_read += len;
        rr3_dbg(rr3->dev, "bytes_read %d, pktlen %d\n", rr3->bytes_read,
                                 be16_to_cpu(rr3->irdata.header.length));
}

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

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

        if (rr3->bytes_read == 0 && len >= sizeof(struct redrat3_header)) {
                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 < be16_to_cpu(rr3->irdata.header.length))
                /* we're still accumulating data */
                return 0;

        /* if we get here, we've got IR data to decode */
        pkttype = be16_to_cpu(rr3->irdata.header.transfer_type);
        if (pkttype == RR3_MOD_SIGNAL_IN)
                redrat3_process_ir_data(rr3);
        else
                rr3_dbg(dev, "discarding non-signal data packet (type 0x%02x)\n",
                                                                pkttype);

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

/* callback function from USB when async USB request has completed */
static void redrat3_handle_async(struct urb *urb)
{
        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;
                break;
        }
}

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

        /* Clk used in mod. freq. generation is CLK24/4. */
        return 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_irdata *irdata = NULL;
        int ret, ret_len;
        int lencheck, cur_sample_len, pipe;
        int *sample_lens = NULL;
        u8 curlencheck = 0;
        unsigned i, sendbuf_len;

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

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

        count = min_t(unsigned, count, RR3_MAX_SIG_SIZE - RR3_TX_TRAILER_LEN);

        /* 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;
        }

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

        for (i = 0; i < count; i++) {
                cur_sample_len = redrat3_us_to_len(txbuf[i]);
                if (cur_sample_len > 0xffff) {
                        dev_warn(dev, "transmit period of %uus truncated to %uus\n",
                                        txbuf[i], redrat3_len_to_us(0xffff));
                        cur_sample_len = 0xffff;
                }
                for (lencheck = 0; lencheck < curlencheck; lencheck++) {
                        if (sample_lens[lencheck] == cur_sample_len)
                                break;
                }
                if (lencheck == curlencheck) {
                        rr3_dbg(dev, "txbuf[%d]=%u, pos %d, enc %u\n",
                                i, txbuf[i], curlencheck, cur_sample_len);
                        if (curlencheck < RR3_DRIVER_MAXLENS) {
                                /* now convert the value to a proper
                                 * rr3 value.. */
                                sample_lens[curlencheck] = cur_sample_len;
                                put_unaligned_be16(cur_sample_len,
                                                &irdata->lens[curlencheck]);
                                curlencheck++;
                        } else {
                                count = i - 1;
                                break;
                        }
                }
                irdata->sigdata[i] = lencheck;
        }

        irdata->sigdata[count] = RR3_END_OF_SIGNAL;
        irdata->sigdata[count + 1] = RR3_END_OF_SIGNAL;

        sendbuf_len = offsetof(struct redrat3_irdata,
                                        sigdata[count + RR3_TX_TRAILER_LEN]);
        /* fill in our packet header */
        irdata->header.length = cpu_to_be16(sendbuf_len -
                                                sizeof(struct redrat3_header));
        irdata->header.transfer_type = cpu_to_be16(RR3_MOD_SIGNAL_OUT);
        irdata->pause = cpu_to_be32(redrat3_len_to_us(100));
        irdata->mod_freq_count = cpu_to_be16(mod_freq_to_val(rr3->carrier));
        irdata->no_lengths = curlencheck;
        irdata->sig_size = cpu_to_be16(count + RR3_TX_TRAILER_LEN);

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

        /* 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, irdata, 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(irdata);

        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_BIT_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->rx_resolution = US_TO_NS(2);
        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 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,
                le16_to_cpu(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,
                le16_to_cpu(ep_in->wMaxPacketSize), redrat3_handle_async, rr3);

        rr3->ep_out = ep_out;
        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 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     = 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).");