/*
 * Abilis Systems Single DVB-T Receiver
 * Copyright (C) 2008 Pierrick Hascoet <pierrick.hascoet@abilis.com>
 * Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
 *
 * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/usb.h>

#include "as102_drv.h"
#include "as102_usb_drv.h"
#include "as102_fw.h"

static void as102_usb_disconnect(struct usb_interface *interface);
static int as102_usb_probe(struct usb_interface *interface,
                           const struct usb_device_id *id);

static int as102_usb_start_stream(struct as102_dev_t *dev);
static void as102_usb_stop_stream(struct as102_dev_t *dev);

static int as102_open(struct inode *inode, struct file *file);
static int as102_release(struct inode *inode, struct file *file);

static struct usb_device_id as102_usb_id_table[] = {
        { USB_DEVICE(AS102_USB_DEVICE_VENDOR_ID, AS102_USB_DEVICE_PID_0001) },
        { USB_DEVICE(PCTV_74E_USB_VID, PCTV_74E_USB_PID) },
        { USB_DEVICE(ELGATO_EYETV_DTT_USB_VID, ELGATO_EYETV_DTT_USB_PID) },
        { USB_DEVICE(NBOX_DVBT_DONGLE_USB_VID, NBOX_DVBT_DONGLE_USB_PID) },
        { USB_DEVICE(SKY_IT_DIGITAL_KEY_USB_VID, SKY_IT_DIGITAL_KEY_USB_PID) },
        { } /* Terminating entry */
};

/* Note that this table must always have the same number of entries as the
   as102_usb_id_table struct */
static const char * const as102_device_names[] = {
        AS102_REFERENCE_DESIGN,
        AS102_PCTV_74E,
        AS102_ELGATO_EYETV_DTT_NAME,
        AS102_NBOX_DVBT_DONGLE_NAME,
        AS102_SKY_IT_DIGITAL_KEY_NAME,
        NULL /* Terminating entry */
};

/* eLNA configuration: devices built on the reference design work best
   with 0xA0, while custom designs seem to require 0xC0 */
static uint8_t const as102_elna_cfg[] = {
        0xA0,
        0xC0,
        0xC0,
        0xA0,
        0xA0,
        0x00 /* Terminating entry */
};

struct usb_driver as102_usb_driver = {
        .name           = DRIVER_FULL_NAME,
        .probe          = as102_usb_probe,
        .disconnect     = as102_usb_disconnect,
        .id_table       = as102_usb_id_table
};

static const struct file_operations as102_dev_fops = {
        .owner          = THIS_MODULE,
        .open           = as102_open,
        .release        = as102_release,
};

static struct usb_class_driver as102_usb_class_driver = {
        .name           = "aton2-%d",
        .fops           = &as102_dev_fops,
        .minor_base     = AS102_DEVICE_MAJOR,
};

static int as102_usb_xfer_cmd(struct as10x_bus_adapter_t *bus_adap,
                              unsigned char *send_buf, int send_buf_len,
                              unsigned char *recv_buf, int recv_buf_len)
{
        int ret = 0;
        ENTER();

        if (send_buf != NULL) {
                ret = usb_control_msg(bus_adap->usb_dev,
                                      usb_sndctrlpipe(bus_adap->usb_dev, 0),
                                      AS102_USB_DEVICE_TX_CTRL_CMD,
                                      USB_DIR_OUT | USB_TYPE_VENDOR |
                                      USB_RECIP_DEVICE,
                                      bus_adap->cmd_xid, /* value */
                                      0, /* index */
                                      send_buf, send_buf_len,
                                      USB_CTRL_SET_TIMEOUT /* 200 */);
                if (ret < 0) {
                        dprintk(debug, "usb_control_msg(send) failed, err %i\n",
                                        ret);
                        return ret;
                }

                if (ret != send_buf_len) {
                        dprintk(debug, "only wrote %d of %d bytes\n",
                                        ret, send_buf_len);
                        return -1;
                }
        }

        if (recv_buf != NULL) {
#ifdef TRACE
                dprintk(debug, "want to read: %d bytes\n", recv_buf_len);
#endif
                ret = usb_control_msg(bus_adap->usb_dev,
                                      usb_rcvctrlpipe(bus_adap->usb_dev, 0),
                                      AS102_USB_DEVICE_RX_CTRL_CMD,
                                      USB_DIR_IN | USB_TYPE_VENDOR |
                                      USB_RECIP_DEVICE,
                                      bus_adap->cmd_xid, /* value */
                                      0, /* index */
                                      recv_buf, recv_buf_len,
                                      USB_CTRL_GET_TIMEOUT /* 200 */);
                if (ret < 0) {
                        dprintk(debug, "usb_control_msg(recv) failed, err %i\n",
                                        ret);
                        return ret;
                }
#ifdef TRACE
                dprintk(debug, "read %d bytes\n", recv_buf_len);
#endif
        }

        LEAVE();
        return ret;
}

static int as102_send_ep1(struct as10x_bus_adapter_t *bus_adap,
                          unsigned char *send_buf,
                          int send_buf_len,
                          int swap32)
{
        int ret = 0, actual_len;

        ret = usb_bulk_msg(bus_adap->usb_dev,
                           usb_sndbulkpipe(bus_adap->usb_dev, 1),
                           send_buf, send_buf_len, &actual_len, 200);
        if (ret) {
                dprintk(debug, "usb_bulk_msg(send) failed, err %i\n", ret);
                return ret;
        }

        if (actual_len != send_buf_len) {
                dprintk(debug, "only wrote %d of %d bytes\n",
                                actual_len, send_buf_len);
                return -1;
        }
        return ret ? ret : actual_len;
}

static int as102_read_ep2(struct as10x_bus_adapter_t *bus_adap,
                   unsigned char *recv_buf, int recv_buf_len)
{
        int ret = 0, actual_len;

        if (recv_buf == NULL)
                return -EINVAL;

        ret = usb_bulk_msg(bus_adap->usb_dev,
                           usb_rcvbulkpipe(bus_adap->usb_dev, 2),
                           recv_buf, recv_buf_len, &actual_len, 200);
        if (ret) {
                dprintk(debug, "usb_bulk_msg(recv) failed, err %i\n", ret);
                return ret;
        }

        if (actual_len != recv_buf_len) {
                dprintk(debug, "only read %d of %d bytes\n",
                                actual_len, recv_buf_len);
                return -1;
        }
        return ret ? ret : actual_len;
}

struct as102_priv_ops_t as102_priv_ops = {
        .upload_fw_pkt  = as102_send_ep1,
        .xfer_cmd       = as102_usb_xfer_cmd,
        .as102_read_ep2 = as102_read_ep2,
        .start_stream   = as102_usb_start_stream,
        .stop_stream    = as102_usb_stop_stream,
};

static int as102_submit_urb_stream(struct as102_dev_t *dev, struct urb *urb)
{
        int err;

        usb_fill_bulk_urb(urb,
                          dev->bus_adap.usb_dev,
                          usb_rcvbulkpipe(dev->bus_adap.usb_dev, 0x2),
                          urb->transfer_buffer,
                          AS102_USB_BUF_SIZE,
                          as102_urb_stream_irq,
                          dev);

        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (err)
                dprintk(debug, "%s: usb_submit_urb failed\n", __func__);

        return err;
}

void as102_urb_stream_irq(struct urb *urb)
{
        struct as102_dev_t *as102_dev = urb->context;

        if (urb->actual_length > 0) {
                dvb_dmx_swfilter(&as102_dev->dvb_dmx,
                                 urb->transfer_buffer,
                                 urb->actual_length);
        } else {
                if (urb->actual_length == 0)
                        memset(urb->transfer_buffer, 0, AS102_USB_BUF_SIZE);
        }

        /* is not stopped, re-submit urb */
        if (as102_dev->streaming)
                as102_submit_urb_stream(as102_dev, urb);
}

static void as102_free_usb_stream_buffer(struct as102_dev_t *dev)
{
        int i;

        ENTER();

        for (i = 0; i < MAX_STREAM_URB; i++)
                usb_free_urb(dev->stream_urb[i]);

        usb_free_coherent(dev->bus_adap.usb_dev,
                        MAX_STREAM_URB * AS102_USB_BUF_SIZE,
                        dev->stream,
                        dev->dma_addr);
        LEAVE();
}

static int as102_alloc_usb_stream_buffer(struct as102_dev_t *dev)
{
        int i, ret = 0;

        ENTER();

        dev->stream = usb_alloc_coherent(dev->bus_adap.usb_dev,
                                       MAX_STREAM_URB * AS102_USB_BUF_SIZE,
                                       GFP_KERNEL,
                                       &dev->dma_addr);
        if (!dev->stream) {
                dprintk(debug, "%s: usb_buffer_alloc failed\n", __func__);
                return -ENOMEM;
        }

        memset(dev->stream, 0, MAX_STREAM_URB * AS102_USB_BUF_SIZE);

        /* init urb buffers */
        for (i = 0; i < MAX_STREAM_URB; i++) {
                struct urb *urb;

                urb = usb_alloc_urb(0, GFP_ATOMIC);
                if (urb == NULL) {
                        dprintk(debug, "%s: usb_alloc_urb failed\n", __func__);
                        as102_free_usb_stream_buffer(dev);
                        return -ENOMEM;
                }

                urb->transfer_buffer = dev->stream + (i * AS102_USB_BUF_SIZE);
                urb->transfer_dma = dev->dma_addr + (i * AS102_USB_BUF_SIZE);
                urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
                urb->transfer_buffer_length = AS102_USB_BUF_SIZE;

                dev->stream_urb[i] = urb;
        }
        LEAVE();
        return ret;
}

static void as102_usb_stop_stream(struct as102_dev_t *dev)
{
        int i;

        for (i = 0; i < MAX_STREAM_URB; i++)
                usb_kill_urb(dev->stream_urb[i]);
}

static int as102_usb_start_stream(struct as102_dev_t *dev)
{
        int i, ret = 0;

        for (i = 0; i < MAX_STREAM_URB; i++) {
                ret = as102_submit_urb_stream(dev, dev->stream_urb[i]);
                if (ret) {
                        as102_usb_stop_stream(dev);
                        return ret;
                }
        }

        return 0;
}

static void as102_usb_release(struct kref *kref)
{
        struct as102_dev_t *as102_dev;

        ENTER();

        as102_dev = container_of(kref, struct as102_dev_t, kref);
        if (as102_dev != NULL) {
                usb_put_dev(as102_dev->bus_adap.usb_dev);
                kfree(as102_dev);
        }

        LEAVE();
}

static void as102_usb_disconnect(struct usb_interface *intf)
{
        struct as102_dev_t *as102_dev;

        ENTER();

        /* extract as102_dev_t from usb_device private data */
        as102_dev = usb_get_intfdata(intf);

        /* unregister dvb layer */
        as102_dvb_unregister(as102_dev);

        /* free usb buffers */
        as102_free_usb_stream_buffer(as102_dev);

        usb_set_intfdata(intf, NULL);

        /* usb unregister device */
        usb_deregister_dev(intf, &as102_usb_class_driver);

        /* decrement usage counter */
        kref_put(&as102_dev->kref, as102_usb_release);

        pr_info("%s: device has been disconnected\n", DRIVER_NAME);

        LEAVE();
}

static int as102_usb_probe(struct usb_interface *intf,
                           const struct usb_device_id *id)
{
        int ret;
        struct as102_dev_t *as102_dev;
        int i;

        ENTER();

        /* This should never actually happen */
        if (ARRAY_SIZE(as102_usb_id_table) !=
            (sizeof(as102_device_names) / sizeof(const char *))) {
                pr_err("Device names table invalid size");
                return -EINVAL;
        }

        as102_dev = kzalloc(sizeof(struct as102_dev_t), GFP_KERNEL);
        if (as102_dev == NULL)
                return -ENOMEM;

        /* Assign the user-friendly device name */
        for (i = 0; i < ARRAY_SIZE(as102_usb_id_table); i++) {
                if (id == &as102_usb_id_table[i]) {
                        as102_dev->name = as102_device_names[i];
                        as102_dev->elna_cfg = as102_elna_cfg[i];
                }
        }

        if (as102_dev->name == NULL)
                as102_dev->name = "Unknown AS102 device";

        /* set private callback functions */
        as102_dev->bus_adap.ops = &as102_priv_ops;

        /* init cmd token for usb bus */
        as102_dev->bus_adap.cmd = &as102_dev->bus_adap.token.usb.c;
        as102_dev->bus_adap.rsp = &as102_dev->bus_adap.token.usb.r;

        /* init kernel device reference */
        kref_init(&as102_dev->kref);

        /* store as102 device to usb_device private data */
        usb_set_intfdata(intf, (void *) as102_dev);

        /* store in as102 device the usb_device pointer */
        as102_dev->bus_adap.usb_dev = usb_get_dev(interface_to_usbdev(intf));

        /* we can register the device now, as it is ready */
        ret = usb_register_dev(intf, &as102_usb_class_driver);
        if (ret < 0) {
                /* something prevented us from registering this driver */
                dev_err(&intf->dev,
                        "%s: usb_register_dev() failed (errno = %d)\n",
                        __func__, ret);
                goto failed;
        }

        pr_info("%s: device has been detected\n", DRIVER_NAME);

        /* request buffer allocation for streaming */
        ret = as102_alloc_usb_stream_buffer(as102_dev);
        if (ret != 0)
                goto failed;

        /* register dvb layer */
        ret = as102_dvb_register(as102_dev);

        LEAVE();
        return ret;

failed:
        usb_set_intfdata(intf, NULL);
        kfree(as102_dev);
        return ret;
}

static int as102_open(struct inode *inode, struct file *file)
{
        int ret = 0, minor = 0;
        struct usb_interface *intf = NULL;
        struct as102_dev_t *dev = NULL;

        ENTER();

        /* read minor from inode */
        minor = iminor(inode);

        /* fetch device from usb interface */
        intf = usb_find_interface(&as102_usb_driver, minor);
        if (intf == NULL) {
                pr_err("%s: can't find device for minor %d\n",
                       __func__, minor);
                ret = -ENODEV;
                goto exit;
        }

        /* get our device */
        dev = usb_get_intfdata(intf);
        if (dev == NULL) {
                ret = -EFAULT;
                goto exit;
        }

        /* save our device object in the file's private structure */
        file->private_data = dev;

        /* increment our usage count for the device */
        kref_get(&dev->kref);

exit:
        LEAVE();
        return ret;
}

static int as102_release(struct inode *inode, struct file *file)
{
        int ret = 0;
        struct as102_dev_t *dev = NULL;

        ENTER();

        dev = file->private_data;
        if (dev != NULL) {
                /* decrement the count on our device */
                kref_put(&dev->kref, as102_usb_release);
        }

        LEAVE();
        return ret;
}

MODULE_DEVICE_TABLE(usb, as102_usb_id_table);