iguanair.c

Go to the documentation of this file.

/*
 * IguanaWorks USB IR Transceiver support
 *
 * Copyright (C) 2012 Sean Young <[email protected]>
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/input.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <media/rc-core.h>

#define DRIVER_NAME "iguanair"
#define BUF_SIZE 152

struct iguanair {
    struct rc_dev *rc;

    struct device *dev;
    struct usb_device *udev;

    uint16_t version;
    uint8_t bufsize;
    uint8_t cycle_overhead;

    struct mutex lock;

    /* receiver support */
    bool receiver_on;
    dma_addr_t dma_in, dma_out;
    uint8_t *buf_in;
    struct urb *urb_in, *urb_out;
    struct completion completion;

    /* transmit support */
    bool tx_overflow;
    uint32_t carrier;
    struct send_packet *packet;

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

#define CMD_GET_VERSION     0x01
#define CMD_GET_BUFSIZE     0x11
#define CMD_GET_FEATURES    0x10
#define CMD_SEND        0x15
#define CMD_EXECUTE     0x1f
#define CMD_RX_OVERFLOW     0x31
#define CMD_TX_OVERFLOW     0x32
#define CMD_RECEIVER_ON     0x12
#define CMD_RECEIVER_OFF    0x14

#define DIR_IN          0xdc
#define DIR_OUT         0xcd

#define MAX_IN_PACKET       8u
#define MAX_OUT_PACKET      (sizeof(struct send_packet) + BUF_SIZE)
#define TIMEOUT         1000
#define RX_RESOLUTION       21333

struct packet {
    uint16_t start;
    uint8_t direction;
    uint8_t cmd;
};

struct send_packet {
    struct packet header;
    uint8_t length;
    uint8_t channels;
    uint8_t busy7;
    uint8_t busy4;
    uint8_t payload[0];
};

static void process_ir_data(struct iguanair *ir, unsigned len)
{
    if (len >= 4 && ir->buf_in[0] == 0 && ir->buf_in[1] == 0) {
        switch (ir->buf_in[3]) {
        case CMD_GET_VERSION:
            if (len == 6) {
                ir->version = (ir->buf_in[5] << 8) |
                            ir->buf_in[4];
                complete(&ir->completion);
            }
            break;
        case CMD_GET_BUFSIZE:
            if (len >= 5) {
                ir->bufsize = ir->buf_in[4];
                complete(&ir->completion);
            }
            break;
        case CMD_GET_FEATURES:
            if (len > 5) {
                ir->cycle_overhead = ir->buf_in[5];
                complete(&ir->completion);
            }
            break;
        case CMD_TX_OVERFLOW:
            ir->tx_overflow = true;
        case CMD_RECEIVER_OFF:
        case CMD_RECEIVER_ON:
        case CMD_SEND:
            complete(&ir->completion);
            break;
        case CMD_RX_OVERFLOW:
            dev_warn(ir->dev, "receive overflow\n");
            ir_raw_event_reset(ir->rc);
            break;
        default:
            dev_warn(ir->dev, "control code %02x received\n",
                            ir->buf_in[3]);
            break;
        }
    } else if (len >= 7) {
        DEFINE_IR_RAW_EVENT(rawir);
        unsigned i;
        bool event = false;

        init_ir_raw_event(&rawir);

        for (i = 0; i < 7; i++) {
            if (ir->buf_in[i] == 0x80) {
                rawir.pulse = false;
                rawir.duration = US_TO_NS(21845);
            } else {
                rawir.pulse = (ir->buf_in[i] & 0x80) == 0;
                rawir.duration = ((ir->buf_in[i] & 0x7f) + 1) *
                                 RX_RESOLUTION;
            }

            if (ir_raw_event_store_with_filter(ir->rc, &rawir))
                event = true;
        }

        if (event)
            ir_raw_event_handle(ir->rc);
    }
}

static void iguanair_rx(struct urb *urb)
{
    struct iguanair *ir;
    int rc;

    if (!urb)
        return;

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

    switch (urb->status) {
    case 0:
        process_ir_data(ir, urb->actual_length);
        break;
    case -ECONNRESET:
    case -ENOENT:
    case -ESHUTDOWN:
        usb_unlink_urb(urb);
        return;
    case -EPIPE:
    default:
        dev_dbg(ir->dev, "Error: urb status = %d\n", urb->status);
        break;
    }

    rc = usb_submit_urb(urb, GFP_ATOMIC);
    if (rc && rc != -ENODEV)
        dev_warn(ir->dev, "failed to resubmit urb: %d\n", rc);
}

static void iguanair_irq_out(struct urb *urb)
{
    struct iguanair *ir = urb->context;

    if (urb->status)
        dev_dbg(ir->dev, "Error: out urb status = %d\n", urb->status);
}

static int iguanair_send(struct iguanair *ir, unsigned size)
{
    int rc;

    INIT_COMPLETION(ir->completion);

    ir->urb_out->transfer_buffer_length = size;
    rc = usb_submit_urb(ir->urb_out, GFP_KERNEL);
    if (rc)
        return rc;

    if (wait_for_completion_timeout(&ir->completion, TIMEOUT) == 0)
        return -ETIMEDOUT;

    return rc;
}

static int iguanair_get_features(struct iguanair *ir)
{
    int rc;

    ir->packet->header.start = 0;
    ir->packet->header.direction = DIR_OUT;
    ir->packet->header.cmd = CMD_GET_VERSION;

    rc = iguanair_send(ir, sizeof(ir->packet->header));
    if (rc) {
        dev_info(ir->dev, "failed to get version\n");
        goto out;
    }

    if (ir->version < 0x205) {
        dev_err(ir->dev, "firmware 0x%04x is too old\n", ir->version);
        rc = -ENODEV;
        goto out;
    }

    ir->bufsize = 150;
    ir->cycle_overhead = 65;

    ir->packet->header.cmd = CMD_GET_BUFSIZE;

    rc = iguanair_send(ir, sizeof(ir->packet->header));
    if (rc) {
        dev_info(ir->dev, "failed to get buffer size\n");
        goto out;
    }

    if (ir->bufsize > BUF_SIZE) {
        dev_info(ir->dev, "buffer size %u larger than expected\n",
                                ir->bufsize);
        ir->bufsize = BUF_SIZE;
    }

    ir->packet->header.cmd = CMD_GET_FEATURES;

    rc = iguanair_send(ir, sizeof(ir->packet->header));
    if (rc) {
        dev_info(ir->dev, "failed to get features\n");
        goto out;
    }

out:
    return rc;
}

static int iguanair_receiver(struct iguanair *ir, bool enable)
{
    int rc;

    ir->packet->header.start = 0;
    ir->packet->header.direction = DIR_OUT;
    ir->packet->header.cmd = enable ? CMD_RECEIVER_ON : CMD_RECEIVER_OFF;

    if (enable)
        ir_raw_event_reset(ir->rc);

    rc = iguanair_send(ir, sizeof(ir->packet->header));

    return rc;
}

/*
 * The iguana ir creates the carrier by busy spinning after each pulse or
 * space. This is counted in CPU cycles, with the CPU running at 24MHz. It is
 * broken down into 7-cycles and 4-cyles delays, with a preference for
 * 4-cycle delays.
 */
static int iguanair_set_tx_carrier(struct rc_dev *dev, uint32_t carrier)
{
    struct iguanair *ir = dev->priv;

    if (carrier < 25000 || carrier > 150000)
        return -EINVAL;

    mutex_lock(&ir->lock);

    if (carrier != ir->carrier) {
        uint32_t cycles, fours, sevens;

        ir->carrier = carrier;

        cycles = DIV_ROUND_CLOSEST(24000000, carrier * 2) -
                            ir->cycle_overhead;

        /*  make up the the remainer of 4-cycle blocks */
        switch (cycles & 3) {
        case 0:
            sevens = 0;
            break;
        case 1:
            sevens = 3;
            break;
        case 2:
            sevens = 2;
            break;
        case 3:
            sevens = 1;
            break;
        }

        fours = (cycles - sevens * 7) / 4;

        /* magic happens here */
        ir->packet->busy7 = (4 - sevens) * 2;
        ir->packet->busy4 = 110 - fours;
    }

    mutex_unlock(&ir->lock);

    return carrier;
}

static int iguanair_set_tx_mask(struct rc_dev *dev, uint32_t mask)
{
    struct iguanair *ir = dev->priv;

    if (mask > 15)
        return 4;

    mutex_lock(&ir->lock);
    ir->packet->channels = mask << 4;
    mutex_unlock(&ir->lock);

    return 0;
}

static int iguanair_tx(struct rc_dev *dev, unsigned *txbuf, unsigned count)
{
    struct iguanair *ir = dev->priv;
    uint8_t space;
    unsigned i, size, periods, bytes;
    int rc;

    mutex_lock(&ir->lock);

    /* convert from us to carrier periods */
    for (i = space = size = 0; i < count; i++) {
        periods = DIV_ROUND_CLOSEST(txbuf[i] * ir->carrier, 1000000);
        bytes = DIV_ROUND_UP(periods, 127);
        if (size + bytes > ir->bufsize) {
            count = i;
            break;
        }
        while (periods > 127) {
            ir->packet->payload[size++] = 127 | space;
            periods -= 127;
        }

        ir->packet->payload[size++] = periods | space;
        space ^= 0x80;
    }

    if (count == 0) {
        rc = -EINVAL;
        goto out;
    }

    ir->packet->header.start = 0;
    ir->packet->header.direction = DIR_OUT;
    ir->packet->header.cmd = CMD_SEND;
    ir->packet->length = size;

    ir->tx_overflow = false;

    rc = iguanair_send(ir, sizeof(*ir->packet) + size);

    if (rc == 0 && ir->tx_overflow)
        rc = -EOVERFLOW;

out:
    mutex_unlock(&ir->lock);

    return rc ? rc : count;
}

static int iguanair_open(struct rc_dev *rdev)
{
    struct iguanair *ir = rdev->priv;
    int rc;

    mutex_lock(&ir->lock);

    rc = iguanair_receiver(ir, true);
    if (rc == 0)
        ir->receiver_on = true;

    mutex_unlock(&ir->lock);

    return rc;
}

static void iguanair_close(struct rc_dev *rdev)
{
    struct iguanair *ir = rdev->priv;
    int rc;

    mutex_lock(&ir->lock);

    rc = iguanair_receiver(ir, false);
    ir->receiver_on = false;
    if (rc && rc != -ENODEV)
        dev_warn(ir->dev, "failed to disable receiver: %d\n", rc);

    mutex_unlock(&ir->lock);
}

static int __devinit iguanair_probe(struct usb_interface *intf,
                        const struct usb_device_id *id)
{
    struct usb_device *udev = interface_to_usbdev(intf);
    struct iguanair *ir;
    struct rc_dev *rc;
    int ret, pipein, pipeout;
    struct usb_host_interface *idesc;

    ir = kzalloc(sizeof(*ir), GFP_KERNEL);
    rc = rc_allocate_device();
    if (!ir || !rc) {
        ret = -ENOMEM;
        goto out;
    }

    ir->buf_in = usb_alloc_coherent(udev, MAX_IN_PACKET, GFP_KERNEL,
                                &ir->dma_in);
    ir->packet = usb_alloc_coherent(udev, MAX_OUT_PACKET, GFP_KERNEL,
                                &ir->dma_out);
    ir->urb_in = usb_alloc_urb(0, GFP_KERNEL);
    ir->urb_out = usb_alloc_urb(0, GFP_KERNEL);

    if (!ir->buf_in || !ir->packet || !ir->urb_in || !ir->urb_out) {
        ret = -ENOMEM;
        goto out;
    }

    idesc = intf->altsetting;

    if (idesc->desc.bNumEndpoints < 2) {
        ret = -ENODEV;
        goto out;
    }

    ir->rc = rc;
    ir->dev = &intf->dev;
    ir->udev = udev;
    mutex_init(&ir->lock);

    init_completion(&ir->completion);
    pipeout = usb_sndintpipe(udev,
                idesc->endpoint[1].desc.bEndpointAddress);
    usb_fill_int_urb(ir->urb_out, udev, pipeout, ir->packet, MAX_OUT_PACKET,
                        iguanair_irq_out, ir, 1);
    ir->urb_out->transfer_dma = ir->dma_out;
    ir->urb_out->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

    pipein = usb_rcvintpipe(udev, idesc->endpoint[0].desc.bEndpointAddress);
    usb_fill_int_urb(ir->urb_in, udev, pipein, ir->buf_in, MAX_IN_PACKET,
                             iguanair_rx, ir, 1);
    ir->urb_in->transfer_dma = ir->dma_in;
    ir->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

    ret = usb_submit_urb(ir->urb_in, GFP_KERNEL);
    if (ret) {
        dev_warn(&intf->dev, "failed to submit urb: %d\n", ret);
        goto out;
    }

    ret = iguanair_get_features(ir);
    if (ret)
        goto out2;

    snprintf(ir->name, sizeof(ir->name),
        "IguanaWorks USB IR Transceiver version 0x%04x", ir->version);

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

    rc->input_name = ir->name;
    rc->input_phys = ir->phys;
    usb_to_input_id(ir->udev, &rc->input_id);
    rc->dev.parent = &intf->dev;
    rc->driver_type = RC_DRIVER_IR_RAW;
    rc->allowed_protos = RC_TYPE_ALL;
    rc->priv = ir;
    rc->open = iguanair_open;
    rc->close = iguanair_close;
    rc->s_tx_mask = iguanair_set_tx_mask;
    rc->s_tx_carrier = iguanair_set_tx_carrier;
    rc->tx_ir = iguanair_tx;
    rc->driver_name = DRIVER_NAME;
    rc->map_name = RC_MAP_RC6_MCE;
    rc->timeout = MS_TO_NS(100);
    rc->rx_resolution = RX_RESOLUTION;

    iguanair_set_tx_carrier(rc, 38000);

    ret = rc_register_device(rc);
    if (ret < 0) {
        dev_err(&intf->dev, "failed to register rc device %d", ret);
        goto out2;
    }

    usb_set_intfdata(intf, ir);

    return 0;
out2:
    usb_kill_urb(ir->urb_in);
    usb_kill_urb(ir->urb_out);
out:
    if (ir) {
        usb_free_urb(ir->urb_in);
        usb_free_urb(ir->urb_out);
        usb_free_coherent(udev, MAX_IN_PACKET, ir->buf_in, ir->dma_in);
        usb_free_coherent(udev, MAX_OUT_PACKET, ir->packet,
                                ir->dma_out);
    }
    rc_free_device(rc);
    kfree(ir);
    return ret;
}

static void __devexit iguanair_disconnect(struct usb_interface *intf)
{
    struct iguanair *ir = usb_get_intfdata(intf);

    rc_unregister_device(ir->rc);
    usb_set_intfdata(intf, NULL);
    usb_kill_urb(ir->urb_in);
    usb_kill_urb(ir->urb_out);
    usb_free_urb(ir->urb_in);
    usb_free_urb(ir->urb_out);
    usb_free_coherent(ir->udev, MAX_IN_PACKET, ir->buf_in, ir->dma_in);
    usb_free_coherent(ir->udev, MAX_OUT_PACKET, ir->packet, ir->dma_out);
    kfree(ir);
}

static int iguanair_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct iguanair *ir = usb_get_intfdata(intf);
    int rc = 0;

    mutex_lock(&ir->lock);

    if (ir->receiver_on) {
        rc = iguanair_receiver(ir, false);
        if (rc)
            dev_warn(ir->dev, "failed to disable receiver for suspend\n");
    }

    usb_kill_urb(ir->urb_in);
    usb_kill_urb(ir->urb_out);

    mutex_unlock(&ir->lock);

    return rc;
}

static int iguanair_resume(struct usb_interface *intf)
{
    struct iguanair *ir = usb_get_intfdata(intf);
    int rc = 0;

    mutex_lock(&ir->lock);

    rc = usb_submit_urb(ir->urb_in, GFP_KERNEL);
    if (rc)
        dev_warn(&intf->dev, "failed to submit urb: %d\n", rc);

    if (ir->receiver_on) {
        rc = iguanair_receiver(ir, true);
        if (rc)
            dev_warn(ir->dev, "failed to enable receiver after resume\n");
    }

    mutex_unlock(&ir->lock);

    return rc;
}

static const struct usb_device_id iguanair_table[] = {
    { USB_DEVICE(0x1781, 0x0938) },
    { }
};

static struct usb_driver iguanair_driver = {
    .name = DRIVER_NAME,
    .probe = iguanair_probe,
    .disconnect = __devexit_p(iguanair_disconnect),
    .suspend = iguanair_suspend,
    .resume = iguanair_resume,
    .reset_resume = iguanair_resume,
    .id_table = iguanair_table,
    .soft_unbind = 1    /* we want to disable receiver on unbind */
};

module_usb_driver(iguanair_driver);

MODULE_DESCRIPTION("IguanaWorks USB IR Transceiver");
MODULE_AUTHOR("Sean Young <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, iguanair_table);