keyspan_remote.c

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/*
 * keyspan_remote: USB driver for the Keyspan DMR
 *
 * Copyright (C) 2005 Zymeta Corporation - Michael Downey ([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, version 2.
 *
 * This driver has been put together with the support of Innosys, Inc.
 * and Keyspan, Inc the manufacturers of the Keyspan USB DMR product.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb/input.h>

#define DRIVER_VERSION  "v0.1"
#define DRIVER_AUTHOR   "Michael Downey <[email protected]>"
#define DRIVER_DESC "Driver for the USB Keyspan remote control."
#define DRIVER_LICENSE  "GPL"

/* Parameters that can be passed to the driver. */
static int debug;
module_param(debug, int, 0444);
MODULE_PARM_DESC(debug, "Enable extra debug messages and information");

/* Vendor and product ids */
#define USB_KEYSPAN_VENDOR_ID       0x06CD
#define USB_KEYSPAN_PRODUCT_UIA11   0x0202

/* Defines for converting the data from the remote. */
#define ZERO        0x18
#define ZERO_MASK   0x1F    /* 5 bits for a 0 */
#define ONE     0x3C
#define ONE_MASK    0x3F    /* 6 bits for a 1 */
#define SYNC        0x3F80
#define SYNC_MASK   0x3FFF  /* 14 bits for a SYNC sequence */
#define STOP        0x00
#define STOP_MASK   0x1F    /* 5 bits for the STOP sequence */
#define GAP     0xFF

#define RECV_SIZE   8   /* The UIA-11 type have a 8 byte limit. */

/*
 * Table that maps the 31 possible keycodes to input keys.
 * Currently there are 15 and 17 button models so RESERVED codes
 * are blank areas in the mapping.
 */
static const unsigned short keyspan_key_table[] = {
    KEY_RESERVED,       /* 0 is just a place holder. */
    KEY_RESERVED,
    KEY_STOP,
    KEY_PLAYCD,
    KEY_RESERVED,
    KEY_PREVIOUSSONG,
    KEY_REWIND,
    KEY_FORWARD,
    KEY_NEXTSONG,
    KEY_RESERVED,
    KEY_RESERVED,
    KEY_RESERVED,
    KEY_PAUSE,
    KEY_VOLUMEUP,
    KEY_RESERVED,
    KEY_RESERVED,
    KEY_RESERVED,
    KEY_VOLUMEDOWN,
    KEY_RESERVED,
    KEY_UP,
    KEY_RESERVED,
    KEY_MUTE,
    KEY_LEFT,
    KEY_ENTER,
    KEY_RIGHT,
    KEY_RESERVED,
    KEY_RESERVED,
    KEY_DOWN,
    KEY_RESERVED,
    KEY_KPASTERISK,
    KEY_RESERVED,
    KEY_MENU
};

/* table of devices that work with this driver */
static struct usb_device_id keyspan_table[] = {
    { USB_DEVICE(USB_KEYSPAN_VENDOR_ID, USB_KEYSPAN_PRODUCT_UIA11) },
    { }                 /* Terminating entry */
};

/* Structure to store all the real stuff that a remote sends to us. */
struct keyspan_message {
    u16 system;
    u8  button;
    u8  toggle;
};

/* Structure used for all the bit testing magic needed to be done. */
struct bit_tester {
    u32 tester;
    int len;
    int pos;
    int bits_left;
    u8  buffer[32];
};

/* Structure to hold all of our driver specific stuff */
struct usb_keyspan {
    char                name[128];
    char                phys[64];
    unsigned short          keymap[ARRAY_SIZE(keyspan_key_table)];
    struct usb_device       *udev;
    struct input_dev        *input;
    struct usb_interface        *interface;
    struct usb_endpoint_descriptor  *in_endpoint;
    struct urb*         irq_urb;
    int             open;
    dma_addr_t          in_dma;
    unsigned char           *in_buffer;

    /* variables used to parse messages from remote. */
    struct bit_tester       data;
    int             stage;
    int             toggle;
};

static struct usb_driver keyspan_driver;

/*
 * Debug routine that prints out what we've received from the remote.
 */
static void keyspan_print(struct usb_keyspan* dev) /*unsigned char* data)*/
{
    char codes[4 * RECV_SIZE];
    int i;

    for (i = 0; i < RECV_SIZE; i++)
        snprintf(codes + i * 3, 4, "%02x ", dev->in_buffer[i]);

    dev_info(&dev->udev->dev, "%s\n", codes);
}

/*
 * Routine that manages the bit_tester structure.  It makes sure that there are
 * at least bits_needed bits loaded into the tester.
 */
static int keyspan_load_tester(struct usb_keyspan* dev, int bits_needed)
{
    if (dev->data.bits_left >= bits_needed)
        return 0;

    /*
     * Somehow we've missed the last message. The message will be repeated
     * though so it's not too big a deal
     */
    if (dev->data.pos >= dev->data.len) {
        dev_dbg(&dev->interface->dev,
            "%s - Error ran out of data. pos: %d, len: %d\n",
            __func__, dev->data.pos, dev->data.len);
        return -1;
    }

    /* Load as much as we can into the tester. */
    while ((dev->data.bits_left + 7 < (sizeof(dev->data.tester) * 8)) &&
           (dev->data.pos < dev->data.len)) {
        dev->data.tester += (dev->data.buffer[dev->data.pos++] << dev->data.bits_left);
        dev->data.bits_left += 8;
    }

    return 0;
}

static void keyspan_report_button(struct usb_keyspan *remote, int button, int press)
{
    struct input_dev *input = remote->input;

    input_event(input, EV_MSC, MSC_SCAN, button);
    input_report_key(input, remote->keymap[button], press);
    input_sync(input);
}

/*
 * Routine that handles all the logic needed to parse out the message from the remote.
 */
static void keyspan_check_data(struct usb_keyspan *remote)
{
    int i;
    int found = 0;
    struct keyspan_message message;

    switch(remote->stage) {
    case 0:
        /*
         * In stage 0 we want to find the start of a message.  The remote sends a 0xFF as filler.
         * So the first byte that isn't a FF should be the start of a new message.
         */
        for (i = 0; i < RECV_SIZE && remote->in_buffer[i] == GAP; ++i);

        if (i < RECV_SIZE) {
            memcpy(remote->data.buffer, remote->in_buffer, RECV_SIZE);
            remote->data.len = RECV_SIZE;
            remote->data.pos = 0;
            remote->data.tester = 0;
            remote->data.bits_left = 0;
            remote->stage = 1;
        }
        break;

    case 1:
        /*
         * Stage 1 we should have 16 bytes and should be able to detect a
         * SYNC.  The SYNC is 14 bits, 7 0's and then 7 1's.
         */
        memcpy(remote->data.buffer + remote->data.len, remote->in_buffer, RECV_SIZE);
        remote->data.len += RECV_SIZE;

        found = 0;
        while ((remote->data.bits_left >= 14 || remote->data.pos < remote->data.len) && !found) {
            for (i = 0; i < 8; ++i) {
                if (keyspan_load_tester(remote, 14) != 0) {
                    remote->stage = 0;
                    return;
                }

                if ((remote->data.tester & SYNC_MASK) == SYNC) {
                    remote->data.tester = remote->data.tester >> 14;
                    remote->data.bits_left -= 14;
                    found = 1;
                    break;
                } else {
                    remote->data.tester = remote->data.tester >> 1;
                    --remote->data.bits_left;
                }
            }
        }

        if (!found) {
            remote->stage = 0;
            remote->data.len = 0;
        } else {
            remote->stage = 2;
        }
        break;

    case 2:
        /*
         * Stage 2 we should have 24 bytes which will be enough for a full
         * message.  We need to parse out the system code, button code,
         * toggle code, and stop.
         */
        memcpy(remote->data.buffer + remote->data.len, remote->in_buffer, RECV_SIZE);
        remote->data.len += RECV_SIZE;

        message.system = 0;
        for (i = 0; i < 9; i++) {
            keyspan_load_tester(remote, 6);

            if ((remote->data.tester & ZERO_MASK) == ZERO) {
                message.system = message.system << 1;
                remote->data.tester = remote->data.tester >> 5;
                remote->data.bits_left -= 5;
            } else if ((remote->data.tester & ONE_MASK) == ONE) {
                message.system = (message.system << 1) + 1;
                remote->data.tester = remote->data.tester >> 6;
                remote->data.bits_left -= 6;
            } else {
                dev_err(&remote->interface->dev,
                    "%s - Unknown sequence found in system data.\n",
                    __func__);
                remote->stage = 0;
                return;
            }
        }

        message.button = 0;
        for (i = 0; i < 5; i++) {
            keyspan_load_tester(remote, 6);

            if ((remote->data.tester & ZERO_MASK) == ZERO) {
                message.button = message.button << 1;
                remote->data.tester = remote->data.tester >> 5;
                remote->data.bits_left -= 5;
            } else if ((remote->data.tester & ONE_MASK) == ONE) {
                message.button = (message.button << 1) + 1;
                remote->data.tester = remote->data.tester >> 6;
                remote->data.bits_left -= 6;
            } else {
                dev_err(&remote->interface->dev,
                    "%s - Unknown sequence found in button data.\n",
                    __func__);
                remote->stage = 0;
                return;
            }
        }

        keyspan_load_tester(remote, 6);
        if ((remote->data.tester & ZERO_MASK) == ZERO) {
            message.toggle = 0;
            remote->data.tester = remote->data.tester >> 5;
            remote->data.bits_left -= 5;
        } else if ((remote->data.tester & ONE_MASK) == ONE) {
            message.toggle = 1;
            remote->data.tester = remote->data.tester >> 6;
            remote->data.bits_left -= 6;
        } else {
            dev_err(&remote->interface->dev,
                "%s - Error in message, invalid toggle.\n",
                __func__);
            remote->stage = 0;
            return;
        }

        keyspan_load_tester(remote, 5);
        if ((remote->data.tester & STOP_MASK) == STOP) {
            remote->data.tester = remote->data.tester >> 5;
            remote->data.bits_left -= 5;
        } else {
            dev_err(&remote->interface->dev,
                "Bad message received, no stop bit found.\n");
        }

        dev_dbg(&remote->interface->dev,
            "%s found valid message: system: %d, button: %d, toggle: %d\n",
            __func__, message.system, message.button, message.toggle);

        if (message.toggle != remote->toggle) {
            keyspan_report_button(remote, message.button, 1);
            keyspan_report_button(remote, message.button, 0);
            remote->toggle = message.toggle;
        }

        remote->stage = 0;
        break;
    }
}

/*
 * Routine for sending all the initialization messages to the remote.
 */
static int keyspan_setup(struct usb_device* dev)
{
    int retval = 0;

    retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                 0x11, 0x40, 0x5601, 0x0, NULL, 0, 0);
    if (retval) {
        dev_dbg(&dev->dev, "%s - failed to set bit rate due to error: %d\n",
            __func__, retval);
        return(retval);
    }

    retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                 0x44, 0x40, 0x0, 0x0, NULL, 0, 0);
    if (retval) {
        dev_dbg(&dev->dev, "%s - failed to set resume sensitivity due to error: %d\n",
            __func__, retval);
        return(retval);
    }

    retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                 0x22, 0x40, 0x0, 0x0, NULL, 0, 0);
    if (retval) {
        dev_dbg(&dev->dev, "%s - failed to turn receive on due to error: %d\n",
            __func__, retval);
        return(retval);
    }

    dev_dbg(&dev->dev, "%s - Setup complete.\n", __func__);
    return(retval);
}

/*
 * Routine used to handle a new message that has come in.
 */
static void keyspan_irq_recv(struct urb *urb)
{
    struct usb_keyspan *dev = urb->context;
    int retval;

    /* Check our status in case we need to bail out early. */
    switch (urb->status) {
    case 0:
        break;

    /* Device went away so don't keep trying to read from it. */
    case -ECONNRESET:
    case -ENOENT:
    case -ESHUTDOWN:
        return;

    default:
        goto resubmit;
        break;
    }

    if (debug)
        keyspan_print(dev);

    keyspan_check_data(dev);

resubmit:
    retval = usb_submit_urb(urb, GFP_ATOMIC);
    if (retval)
        dev_err(&dev->interface->dev,
            "%s - usb_submit_urb failed with result: %d\n",
            __func__, retval);
}

static int keyspan_open(struct input_dev *dev)
{
    struct usb_keyspan *remote = input_get_drvdata(dev);

    remote->irq_urb->dev = remote->udev;
    if (usb_submit_urb(remote->irq_urb, GFP_KERNEL))
        return -EIO;

    return 0;
}

static void keyspan_close(struct input_dev *dev)
{
    struct usb_keyspan *remote = input_get_drvdata(dev);

    usb_kill_urb(remote->irq_urb);
}

static struct usb_endpoint_descriptor *keyspan_get_in_endpoint(struct usb_host_interface *iface)
{

    struct usb_endpoint_descriptor *endpoint;
    int i;

    for (i = 0; i < iface->desc.bNumEndpoints; ++i) {
        endpoint = &iface->endpoint[i].desc;

        if (usb_endpoint_is_int_in(endpoint)) {
            /* we found our interrupt in endpoint */
            return endpoint;
        }
    }

    return NULL;
}

/*
 * Routine that sets up the driver to handle a specific USB device detected on the bus.
 */
static int keyspan_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
    struct usb_device *udev = interface_to_usbdev(interface);
    struct usb_endpoint_descriptor *endpoint;
    struct usb_keyspan *remote;
    struct input_dev *input_dev;
    int i, error;

    endpoint = keyspan_get_in_endpoint(interface->cur_altsetting);
    if (!endpoint)
        return -ENODEV;

    remote = kzalloc(sizeof(*remote), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!remote || !input_dev) {
        error = -ENOMEM;
        goto fail1;
    }

    remote->udev = udev;
    remote->input = input_dev;
    remote->interface = interface;
    remote->in_endpoint = endpoint;
    remote->toggle = -1;    /* Set to -1 so we will always not match the toggle from the first remote message. */

    remote->in_buffer = usb_alloc_coherent(udev, RECV_SIZE, GFP_ATOMIC, &remote->in_dma);
    if (!remote->in_buffer) {
        error = -ENOMEM;
        goto fail1;
    }

    remote->irq_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!remote->irq_urb) {
        error = -ENOMEM;
        goto fail2;
    }

    error = keyspan_setup(udev);
    if (error) {
        error = -ENODEV;
        goto fail3;
    }

    if (udev->manufacturer)
        strlcpy(remote->name, udev->manufacturer, sizeof(remote->name));

    if (udev->product) {
        if (udev->manufacturer)
            strlcat(remote->name, " ", sizeof(remote->name));
        strlcat(remote->name, udev->product, sizeof(remote->name));
    }

    if (!strlen(remote->name))
        snprintf(remote->name, sizeof(remote->name),
             "USB Keyspan Remote %04x:%04x",
             le16_to_cpu(udev->descriptor.idVendor),
             le16_to_cpu(udev->descriptor.idProduct));

    usb_make_path(udev, remote->phys, sizeof(remote->phys));
    strlcat(remote->phys, "/input0", sizeof(remote->phys));
    memcpy(remote->keymap, keyspan_key_table, sizeof(remote->keymap));

    input_dev->name = remote->name;
    input_dev->phys = remote->phys;
    usb_to_input_id(udev, &input_dev->id);
    input_dev->dev.parent = &interface->dev;
    input_dev->keycode = remote->keymap;
    input_dev->keycodesize = sizeof(unsigned short);
    input_dev->keycodemax = ARRAY_SIZE(remote->keymap);

    input_set_capability(input_dev, EV_MSC, MSC_SCAN);
    __set_bit(EV_KEY, input_dev->evbit);
    for (i = 0; i < ARRAY_SIZE(keyspan_key_table); i++)
        __set_bit(keyspan_key_table[i], input_dev->keybit);
    __clear_bit(KEY_RESERVED, input_dev->keybit);

    input_set_drvdata(input_dev, remote);

    input_dev->open = keyspan_open;
    input_dev->close = keyspan_close;

    /*
     * Initialize the URB to access the device.
     * The urb gets sent to the device in keyspan_open()
     */
    usb_fill_int_urb(remote->irq_urb,
             remote->udev,
             usb_rcvintpipe(remote->udev, endpoint->bEndpointAddress),
             remote->in_buffer, RECV_SIZE, keyspan_irq_recv, remote,
             endpoint->bInterval);
    remote->irq_urb->transfer_dma = remote->in_dma;
    remote->irq_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

    /* we can register the device now, as it is ready */
    error = input_register_device(remote->input);
    if (error)
        goto fail3;

    /* save our data pointer in this interface device */
    usb_set_intfdata(interface, remote);

    return 0;

 fail3: usb_free_urb(remote->irq_urb);
 fail2: usb_free_coherent(udev, RECV_SIZE, remote->in_buffer, remote->in_dma);
 fail1: kfree(remote);
    input_free_device(input_dev);

    return error;
}

/*
 * Routine called when a device is disconnected from the USB.
 */
static void keyspan_disconnect(struct usb_interface *interface)
{
    struct usb_keyspan *remote;

    remote = usb_get_intfdata(interface);
    usb_set_intfdata(interface, NULL);

    if (remote) {   /* We have a valid driver structure so clean up everything we allocated. */
        input_unregister_device(remote->input);
        usb_kill_urb(remote->irq_urb);
        usb_free_urb(remote->irq_urb);
        usb_free_coherent(remote->udev, RECV_SIZE, remote->in_buffer, remote->in_dma);
        kfree(remote);
    }
}

/*
 * Standard driver set up sections
 */
static struct usb_driver keyspan_driver =
{
    .name =     "keyspan_remote",
    .probe =    keyspan_probe,
    .disconnect =   keyspan_disconnect,
    .id_table = keyspan_table
};

module_usb_driver(keyspan_driver);

MODULE_DEVICE_TABLE(usb, keyspan_table);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE(DRIVER_LICENSE);