/*
 *  Driver for the Auvitek USB bridge
 *
 *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
 *
 *  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.
 */

#include "au0828.h"
#include "au8522.h"

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <media/v4l2-common.h>
#include <linux/mutex.h>

/* Due to enum tuner_pad_index */
#include <media/tuner.h>

/*
 * 1 = General debug messages
 * 2 = USB handling
 * 4 = I2C related
 * 8 = Bridge related
 * 16 = IR related
 */
int au0828_debug;
module_param_named(debug, au0828_debug, int, 0644);
MODULE_PARM_DESC(debug,
                 "set debug bitmask: 1=general, 2=USB, 4=I2C, 8=bridge, 16=IR");

static unsigned int disable_usb_speed_check;
module_param(disable_usb_speed_check, int, 0444);
MODULE_PARM_DESC(disable_usb_speed_check,
                 "override min bandwidth requirement of 480M bps");

#define _AU0828_BULKPIPE 0x03
#define _BULKPIPESIZE 0xffff

static int send_control_msg(struct au0828_dev *dev, u16 request, u32 value,
                            u16 index);
static int recv_control_msg(struct au0828_dev *dev, u16 request, u32 value,
        u16 index, unsigned char *cp, u16 size);

/* USB Direction */
#define CMD_REQUEST_IN          0x00
#define CMD_REQUEST_OUT         0x01

u32 au0828_readreg(struct au0828_dev *dev, u16 reg)
{
        u8 result = 0;

        recv_control_msg(dev, CMD_REQUEST_IN, 0, reg, &result, 1);
        dprintk(8, "%s(0x%04x) = 0x%02x\n", __func__, reg, result);

        return result;
}

u32 au0828_writereg(struct au0828_dev *dev, u16 reg, u32 val)
{
        dprintk(8, "%s(0x%04x, 0x%02x)\n", __func__, reg, val);
        return send_control_msg(dev, CMD_REQUEST_OUT, val, reg);
}

static int send_control_msg(struct au0828_dev *dev, u16 request, u32 value,
        u16 index)
{
        int status = -ENODEV;

        if (dev->usbdev) {

                /* cp must be memory that has been allocated by kmalloc */
                status = usb_control_msg(dev->usbdev,
                                usb_sndctrlpipe(dev->usbdev, 0),
                                request,
                                USB_DIR_OUT | USB_TYPE_VENDOR |
                                        USB_RECIP_DEVICE,
                                value, index, NULL, 0, 1000);

                status = min(status, 0);

                if (status < 0) {
                        pr_err("%s() Failed sending control message, error %d.\n",
                                __func__, status);
                }

        }

        return status;
}

static int recv_control_msg(struct au0828_dev *dev, u16 request, u32 value,
        u16 index, unsigned char *cp, u16 size)
{
        int status = -ENODEV;
        mutex_lock(&dev->mutex);
        if (dev->usbdev) {
                status = usb_control_msg(dev->usbdev,
                                usb_rcvctrlpipe(dev->usbdev, 0),
                                request,
                                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                value, index,
                                dev->ctrlmsg, size, 1000);

                status = min(status, 0);

                if (status < 0) {
                        pr_err("%s() Failed receiving control message, error %d.\n",
                                __func__, status);
                }

                /* the host controller requires heap allocated memory, which
                   is why we didn't just pass "cp" into usb_control_msg */
                memcpy(cp, dev->ctrlmsg, size);
        }
        mutex_unlock(&dev->mutex);
        return status;
}

#ifdef CONFIG_MEDIA_CONTROLLER
static void au0828_media_graph_notify(struct media_entity *new,
                                      void *notify_data);
#endif

static void au0828_unregister_media_device(struct au0828_dev *dev)
{
#ifdef CONFIG_MEDIA_CONTROLLER
        struct media_device *mdev = dev->media_dev;
        struct media_entity_notify *notify, *nextp;

        if (!mdev || !media_devnode_is_registered(mdev->devnode))
                return;

        /* Remove au0828 entity_notify callbacks */
        list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list) {
                if (notify->notify != au0828_media_graph_notify)
                        continue;
                media_device_unregister_entity_notify(mdev, notify);
        }

        /* clear enable_source, disable_source */
        mutex_lock(&mdev->graph_mutex);
        dev->media_dev->source_priv = NULL;
        dev->media_dev->enable_source = NULL;
        dev->media_dev->disable_source = NULL;
        mutex_unlock(&mdev->graph_mutex);

        media_device_unregister(dev->media_dev);
        media_device_cleanup(dev->media_dev);
        kfree(dev->media_dev);
        dev->media_dev = NULL;
#endif
}

void au0828_usb_release(struct au0828_dev *dev)
{
        au0828_unregister_media_device(dev);

        /* I2C */
        au0828_i2c_unregister(dev);

        kfree(dev);
}

static void au0828_usb_disconnect(struct usb_interface *interface)
{
        struct au0828_dev *dev = usb_get_intfdata(interface);

        dprintk(1, "%s()\n", __func__);

        /* there is a small window after disconnect, before
           dev->usbdev is NULL, for poll (e.g: IR) try to access
           the device and fill the dmesg with error messages.
           Set the status so poll routines can check and avoid
           access after disconnect.
        */
        set_bit(DEV_DISCONNECTED, &dev->dev_state);

        au0828_rc_unregister(dev);
        /* Digital TV */
        au0828_dvb_unregister(dev);

        usb_set_intfdata(interface, NULL);
        mutex_lock(&dev->mutex);
        dev->usbdev = NULL;
        mutex_unlock(&dev->mutex);
        if (au0828_analog_unregister(dev)) {
                /*
                 * No need to call au0828_usb_release() if V4L2 is enabled,
                 * as this is already called via au0828_usb_v4l2_release()
                 */
                return;
        }
        au0828_usb_release(dev);
}

static int au0828_media_device_init(struct au0828_dev *dev,
                                    struct usb_device *udev)
{
#ifdef CONFIG_MEDIA_CONTROLLER
        struct media_device *mdev;

        mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
        if (!mdev)
                return -ENOMEM;

        /* check if media device is already initialized */
        if (!mdev->dev)
                media_device_usb_init(mdev, udev, udev->product);

        dev->media_dev = mdev;
#endif
        return 0;
}

#ifdef CONFIG_MEDIA_CONTROLLER
static void au0828_media_graph_notify(struct media_entity *new,
                                      void *notify_data)
{
        struct au0828_dev *dev = (struct au0828_dev *) notify_data;
        int ret;
        struct media_entity *entity, *mixer = NULL, *decoder = NULL;

        if (!new) {
                /*
                 * Called during au0828 probe time to connect
                 * entites that were created prior to registering
                 * the notify handler. Find mixer and decoder.
                */
                media_device_for_each_entity(entity, dev->media_dev) {
                        if (entity->function == MEDIA_ENT_F_AUDIO_MIXER)
                                mixer = entity;
                        else if (entity->function == MEDIA_ENT_F_ATV_DECODER)
                                decoder = entity;
                }
                goto create_link;
        }

        switch (new->function) {
        case MEDIA_ENT_F_AUDIO_MIXER:
                mixer = new;
                if (dev->decoder)
                        decoder = dev->decoder;
                break;
        case MEDIA_ENT_F_ATV_DECODER:
                /* In case, Mixer is added first, find mixer and create link */
                media_device_for_each_entity(entity, dev->media_dev) {
                        if (entity->function == MEDIA_ENT_F_AUDIO_MIXER)
                                mixer = entity;
                }
                decoder = new;
                break;
        default:
                break;
        }

create_link:
        if (decoder && mixer) {
                ret = media_create_pad_link(decoder,
                                            DEMOD_PAD_AUDIO_OUT,
                                            mixer, 0,
                                            MEDIA_LNK_FL_ENABLED);
                if (ret)
                        dev_err(&dev->usbdev->dev,
                                "Mixer Pad Link Create Error: %d\n", ret);
        }
}

/* Callers should hold graph_mutex */
static int au0828_enable_source(struct media_entity *entity,
                                struct media_pipeline *pipe)
{
        struct media_entity  *source, *find_source;
        struct media_entity *sink;
        struct media_link *link, *found_link = NULL;
        int ret = 0;
        struct media_device *mdev = entity->graph_obj.mdev;
        struct au0828_dev *dev;

        if (!mdev)
                return -ENODEV;

        dev = mdev->source_priv;

        /*
         * For Audio and V4L2 entity, find the link to which decoder
         * is the sink. Look for an active link between decoder and
         * source (tuner/s-video/Composite), if one exists, nothing
         * to do. If not, look for any  active links between source
         * and any other entity. If one exists, source is busy. If
         * source is free, setup link and start pipeline from source.
         * For DVB FE entity, the source for the link is the tuner.
         * Check if tuner is available and setup link and start
         * pipeline.
        */
        if (entity->function == MEDIA_ENT_F_DTV_DEMOD) {
                sink = entity;
                find_source = dev->tuner;
        } else {
                /* Analog isn't configured or register failed */
                if (!dev->decoder) {
                        ret = -ENODEV;
                        goto end;
                }

                sink = dev->decoder;

                /*
                 * Default input is tuner and default input_type
                 * is AU0828_VMUX_TELEVISION.
                 * FIXME:
                 * There is a problem when s_input is called to
                 * change the default input. s_input will try to
                 * enable_source before attempting to change the
                 * input on the device, and will end up enabling
                 * default source which is tuner.
                 *
                 * Additional logic is necessary in au0828
                 * to detect that the input has changed and
                 * enable the right source.
                */

                if (dev->input_type == AU0828_VMUX_TELEVISION)
                        find_source = dev->tuner;
                else if (dev->input_type == AU0828_VMUX_SVIDEO ||
                         dev->input_type == AU0828_VMUX_COMPOSITE)
                        find_source = &dev->input_ent[dev->input_type];
                else {
                        /* unknown input - let user select input */
                        ret = 0;
                        goto end;
                }
        }

        /* Is an active link between sink and source */
        if (dev->active_link) {
                /*
                 * If DVB is using the tuner and calling entity is
                 * audio/video, the following check will be false,
                 * since sink is different. Result is Busy.
                 */
                if (dev->active_link->sink->entity == sink &&
                    dev->active_link->source->entity == find_source) {
                        /*
                         * Either ALSA or Video own tuner. sink is
                         * the same for both. Prevent Video stepping
                         * on ALSA when ALSA owns the source.
                        */
                        if (dev->active_link_owner != entity &&
                            dev->active_link_owner->function ==
                                                MEDIA_ENT_F_AUDIO_CAPTURE) {
                                pr_debug("ALSA has the tuner\n");
                                ret = -EBUSY;
                                goto end;
                        }
                        ret = 0;
                        goto end;
                } else {
                        ret = -EBUSY;
                        goto end;
                }
        }

        list_for_each_entry(link, &sink->links, list) {
                /* Check sink, and source */
                if (link->sink->entity == sink &&
                    link->source->entity == find_source) {
                        found_link = link;
                        break;
                }
        }

        if (!found_link) {
                ret = -ENODEV;
                goto end;
        }

        /* activate link between source and sink and start pipeline */
        source = found_link->source->entity;
        ret = __media_entity_setup_link(found_link, MEDIA_LNK_FL_ENABLED);
        if (ret) {
                pr_err("Activate tuner link %s->%s. Error %d\n",
                        source->name, sink->name, ret);
                goto end;
        }

        ret = __media_pipeline_start(entity, pipe);
        if (ret) {
                pr_err("Start Pipeline: %s->%s Error %d\n",
                        source->name, entity->name, ret);
                ret = __media_entity_setup_link(found_link, 0);
                pr_err("Deactivate link Error %d\n", ret);
                goto end;
        }
        /*
         * save active link and active link owner to avoid audio
         * deactivating video owned link from disable_source and
         * vice versa
        */
        dev->active_link = found_link;
        dev->active_link_owner = entity;
        dev->active_source = source;
        dev->active_sink = sink;

        pr_debug("Enabled Source: %s->%s->%s Ret %d\n",
                 dev->active_source->name, dev->active_sink->name,
                 dev->active_link_owner->name, ret);
end:
        pr_debug("au0828_enable_source() end %s %d %d\n",
                 entity->name, entity->function, ret);
        return ret;
}

/* Callers should hold graph_mutex */
static void au0828_disable_source(struct media_entity *entity)
{
        int ret = 0;
        struct media_device *mdev = entity->graph_obj.mdev;
        struct au0828_dev *dev;

        if (!mdev)
                return;

        dev = mdev->source_priv;

        if (!dev->active_link)
                return;

        /* link is active - stop pipeline from source (tuner) */
        if (dev->active_link->sink->entity == dev->active_sink &&
            dev->active_link->source->entity == dev->active_source) {
                /*
                 * prevent video from deactivating link when audio
                 * has active pipeline
                */
                if (dev->active_link_owner != entity)
                        return;
                __media_pipeline_stop(entity);
                ret = __media_entity_setup_link(dev->active_link, 0);
                if (ret)
                        pr_err("Deactivate link Error %d\n", ret);

                pr_debug("Disabled Source: %s->%s->%s Ret %d\n",
                         dev->active_source->name, dev->active_sink->name,
                         dev->active_link_owner->name, ret);

                dev->active_link = NULL;
                dev->active_link_owner = NULL;
                dev->active_source = NULL;
                dev->active_sink = NULL;
        }
}
#endif

static int au0828_media_device_register(struct au0828_dev *dev,
                                        struct usb_device *udev)
{
#ifdef CONFIG_MEDIA_CONTROLLER
        int ret;
        struct media_entity *entity, *demod = NULL;
        struct media_link *link;

        if (!dev->media_dev)
                return 0;

        if (!media_devnode_is_registered(dev->media_dev->devnode)) {

                /* register media device */
                ret = media_device_register(dev->media_dev);
                if (ret) {
                        dev_err(&udev->dev,
                                "Media Device Register Error: %d\n", ret);
                        return ret;
                }
        } else {
                /*
                 * Call au0828_media_graph_notify() to connect
                 * audio graph to our graph. In this case, audio
                 * driver registered the device and there is no
                 * entity_notify to be called when new entities
                 * are added. Invoke it now.
                */
                au0828_media_graph_notify(NULL, (void *) dev);
        }

        /*
         * Find tuner, decoder and demod.
         *
         * The tuner and decoder should be cached, as they'll be used by
         *      au0828_enable_source.
         *
         * It also needs to disable the link between tuner and
         * decoder/demod, to avoid disable step when tuner is requested
         * by video or audio. Note that this step can't be done until dvb
         * graph is created during dvb register.
        */
        media_device_for_each_entity(entity, dev->media_dev) {
                switch (entity->function) {
                case MEDIA_ENT_F_TUNER:
                        dev->tuner = entity;
                        break;
                case MEDIA_ENT_F_ATV_DECODER:
                        dev->decoder = entity;
                        break;
                case MEDIA_ENT_F_DTV_DEMOD:
                        demod = entity;
                        break;
                }
        }

        /* Disable link between tuner->demod and/or tuner->decoder */
        if (dev->tuner) {
                list_for_each_entry(link, &dev->tuner->links, list) {
                        if (demod && link->sink->entity == demod)
                                media_entity_setup_link(link, 0);
                        if (dev->decoder && link->sink->entity == dev->decoder)
                                media_entity_setup_link(link, 0);
                }
        }

        /* register entity_notify callback */
        dev->entity_notify.notify_data = (void *) dev;
        dev->entity_notify.notify = (void *) au0828_media_graph_notify;
        ret = media_device_register_entity_notify(dev->media_dev,
                                                  &dev->entity_notify);
        if (ret) {
                dev_err(&udev->dev,
                        "Media Device register entity_notify Error: %d\n",
                        ret);
                return ret;
        }
        /* set enable_source */
        mutex_lock(&dev->media_dev->graph_mutex);
        dev->media_dev->source_priv = (void *) dev;
        dev->media_dev->enable_source = au0828_enable_source;
        dev->media_dev->disable_source = au0828_disable_source;
        mutex_unlock(&dev->media_dev->graph_mutex);
#endif
        return 0;
}

static int au0828_usb_probe(struct usb_interface *interface,
        const struct usb_device_id *id)
{
        int ifnum;
        int retval = 0;

        struct au0828_dev *dev;
        struct usb_device *usbdev = interface_to_usbdev(interface);

        ifnum = interface->altsetting->desc.bInterfaceNumber;

        if (ifnum != 0)
                return -ENODEV;

        dprintk(1, "%s() vendor id 0x%x device id 0x%x ifnum:%d\n", __func__,
                le16_to_cpu(usbdev->descriptor.idVendor),
                le16_to_cpu(usbdev->descriptor.idProduct),
                ifnum);

        /*
         * Make sure we have 480 Mbps of bandwidth, otherwise things like
         * video stream wouldn't likely work, since 12 Mbps is generally
         * not enough even for most Digital TV streams.
         */
        if (usbdev->speed != USB_SPEED_HIGH && disable_usb_speed_check == 0) {
                pr_err("au0828: Device initialization failed.\n");
                pr_err("au0828: Device must be connected to a high-speed USB 2.0 port.\n");
                return -ENODEV;
        }

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (dev == NULL) {
                pr_err("%s() Unable to allocate memory\n", __func__);
                return -ENOMEM;
        }

        mutex_init(&dev->lock);
        mutex_lock(&dev->lock);
        mutex_init(&dev->mutex);
        mutex_init(&dev->dvb.lock);
        dev->usbdev = usbdev;
        dev->boardnr = id->driver_info;
        dev->board = au0828_boards[dev->boardnr];

        /* Initialize the media controller */
        retval = au0828_media_device_init(dev, usbdev);
        if (retval) {
                pr_err("%s() au0828_media_device_init failed\n",
                       __func__);
                mutex_unlock(&dev->lock);
                kfree(dev);
                return retval;
        }

        retval = au0828_v4l2_device_register(interface, dev);
        if (retval) {
                au0828_usb_v4l2_media_release(dev);
                mutex_unlock(&dev->lock);
                kfree(dev);
                return retval;
        }

        /* Power Up the bridge */
        au0828_write(dev, REG_600, 1 << 4);

        /* Bring up the GPIO's and supporting devices */
        au0828_gpio_setup(dev);

        /* I2C */
        au0828_i2c_register(dev);

        /* Setup */
        au0828_card_setup(dev);

        /* Analog TV */
        retval = au0828_analog_register(dev, interface);
        if (retval) {
                pr_err("%s() au0282_dev_register failed to register on V4L2\n",
                        __func__);
                mutex_unlock(&dev->lock);
                kfree(dev);
                goto done;
        }

        /* Digital TV */
        retval = au0828_dvb_register(dev);
        if (retval)
                pr_err("%s() au0282_dev_register failed\n",
                       __func__);

        /* Remote controller */
        au0828_rc_register(dev);

        /*
         * Store the pointer to the au0828_dev so it can be accessed in
         * au0828_usb_disconnect
         */
        usb_set_intfdata(interface, dev);

        pr_info("Registered device AU0828 [%s]\n",
                dev->board.name == NULL ? "Unset" : dev->board.name);

        mutex_unlock(&dev->lock);

        retval = au0828_media_device_register(dev, usbdev);

done:
        if (retval < 0)
                au0828_usb_disconnect(interface);

        return retval;
}

static int au0828_suspend(struct usb_interface *interface,
                                pm_message_t message)
{
        struct au0828_dev *dev = usb_get_intfdata(interface);

        if (!dev)
                return 0;

        pr_info("Suspend\n");

        au0828_rc_suspend(dev);
        au0828_v4l2_suspend(dev);
        au0828_dvb_suspend(dev);

        /* FIXME: should suspend also ATV/DTV */

        return 0;
}

static int au0828_resume(struct usb_interface *interface)
{
        struct au0828_dev *dev = usb_get_intfdata(interface);
        if (!dev)
                return 0;

        pr_info("Resume\n");

        /* Power Up the bridge */
        au0828_write(dev, REG_600, 1 << 4);

        /* Bring up the GPIO's and supporting devices */
        au0828_gpio_setup(dev);

        au0828_rc_resume(dev);
        au0828_v4l2_resume(dev);
        au0828_dvb_resume(dev);

        /* FIXME: should resume also ATV/DTV */

        return 0;
}

static struct usb_driver au0828_usb_driver = {
        .name           = KBUILD_MODNAME,
        .probe          = au0828_usb_probe,
        .disconnect     = au0828_usb_disconnect,
        .id_table       = au0828_usb_id_table,
        .suspend        = au0828_suspend,
        .resume         = au0828_resume,
        .reset_resume   = au0828_resume,
};

static int __init au0828_init(void)
{
        int ret;

        if (au0828_debug & 1)
                pr_info("%s() Debugging is enabled\n", __func__);

        if (au0828_debug & 2)
                pr_info("%s() USB Debugging is enabled\n", __func__);

        if (au0828_debug & 4)
                pr_info("%s() I2C Debugging is enabled\n", __func__);

        if (au0828_debug & 8)
                pr_info("%s() Bridge Debugging is enabled\n",
                       __func__);

        if (au0828_debug & 16)
                pr_info("%s() IR Debugging is enabled\n",
                       __func__);

        pr_info("au0828 driver loaded\n");

        ret = usb_register(&au0828_usb_driver);
        if (ret)
                pr_err("usb_register failed, error = %d\n", ret);

        return ret;
}

static void __exit au0828_exit(void)
{
        usb_deregister(&au0828_usb_driver);
}

module_init(au0828_init);
module_exit(au0828_exit);

MODULE_DESCRIPTION("Driver for Auvitek AU0828 based products");
MODULE_AUTHOR("Steven Toth <stoth@linuxtv.org>");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.0.3");