/*
 * This file contains the handling of TX in wlan driver.
 */
#include <linux/hardirq.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/sched.h>
#include <linux/export.h>
#include <net/cfg80211.h>

#include "host.h"
#include "radiotap.h"
#include "decl.h"
#include "defs.h"
#include "dev.h"
#include "mesh.h"

/**
 * convert_radiotap_rate_to_mv - converts Tx/Rx rates from IEEE80211_RADIOTAP_RATE
 * units (500 Kb/s) into Marvell WLAN format (see Table 8 in Section 3.2.1)
 *
 * @rate:       Input rate
 * returns:     Output Rate (0 if invalid)
 */
static u32 convert_radiotap_rate_to_mv(u8 rate)
{
        switch (rate) {
        case 2:         /*   1 Mbps */
                return 0 | (1 << 4);
        case 4:         /*   2 Mbps */
                return 1 | (1 << 4);
        case 11:                /* 5.5 Mbps */
                return 2 | (1 << 4);
        case 22:                /*  11 Mbps */
                return 3 | (1 << 4);
        case 12:                /*   6 Mbps */
                return 4 | (1 << 4);
        case 18:                /*   9 Mbps */
                return 5 | (1 << 4);
        case 24:                /*  12 Mbps */
                return 6 | (1 << 4);
        case 36:                /*  18 Mbps */
                return 7 | (1 << 4);
        case 48:                /*  24 Mbps */
                return 8 | (1 << 4);
        case 72:                /*  36 Mbps */
                return 9 | (1 << 4);
        case 96:                /*  48 Mbps */
                return 10 | (1 << 4);
        case 108:               /*  54 Mbps */
                return 11 | (1 << 4);
        }
        return 0;
}

/**
 * lbs_hard_start_xmit - checks the conditions and sends packet to IF
 * layer if everything is ok
 *
 * @skb:        A pointer to skb which includes TX packet
 * @dev:        A pointer to the &struct net_device
 * returns:     0 or -1
 */
netdev_tx_t lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        unsigned long flags;
        struct lbs_private *priv = dev->ml_priv;
        struct txpd *txpd;
        char *p802x_hdr;
        uint16_t pkt_len;
        netdev_tx_t ret = NETDEV_TX_OK;

        lbs_deb_enter(LBS_DEB_TX);

        /* We need to protect against the queues being restarted before
           we get round to stopping them */
        spin_lock_irqsave(&priv->driver_lock, flags);

        if (priv->surpriseremoved)
                goto free;

        if (!skb->len || (skb->len > MRVDRV_ETH_TX_PACKET_BUFFER_SIZE)) {
                lbs_deb_tx("tx err: skb length %d 0 or > %zd\n",
                       skb->len, MRVDRV_ETH_TX_PACKET_BUFFER_SIZE);
                /* We'll never manage to send this one; drop it and return 'OK' */

                dev->stats.tx_dropped++;
                dev->stats.tx_errors++;
                goto free;
        }


        netif_stop_queue(priv->dev);
        if (priv->mesh_dev)
                netif_stop_queue(priv->mesh_dev);

        if (priv->tx_pending_len) {
                /* This can happen if packets come in on the mesh and eth
                   device simultaneously -- there's no mutual exclusion on
                   hard_start_xmit() calls between devices. */
                lbs_deb_tx("Packet on %s while busy\n", dev->name);
                ret = NETDEV_TX_BUSY;
                goto unlock;
        }

        priv->tx_pending_len = -1;
        spin_unlock_irqrestore(&priv->driver_lock, flags);

        lbs_deb_hex(LBS_DEB_TX, "TX Data", skb->data, min_t(unsigned int, skb->len, 100));

        txpd = (void *)priv->tx_pending_buf;
        memset(txpd, 0, sizeof(struct txpd));

        p802x_hdr = skb->data;
        pkt_len = skb->len;

        if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
                struct tx_radiotap_hdr *rtap_hdr = (void *)skb->data;

                /* set txpd fields from the radiotap header */
                txpd->tx_control = cpu_to_le32(convert_radiotap_rate_to_mv(rtap_hdr->rate));

                /* skip the radiotap header */
                p802x_hdr += sizeof(*rtap_hdr);
                pkt_len -= sizeof(*rtap_hdr);

                /* copy destination address from 802.11 header */
                memcpy(txpd->tx_dest_addr_high, p802x_hdr + 4, ETH_ALEN);
        } else {
                /* copy destination address from 802.3 header */
                memcpy(txpd->tx_dest_addr_high, p802x_hdr, ETH_ALEN);
        }

        txpd->tx_packet_length = cpu_to_le16(pkt_len);
        txpd->tx_packet_location = cpu_to_le32(sizeof(struct txpd));

        lbs_mesh_set_txpd(priv, dev, txpd);

        lbs_deb_hex(LBS_DEB_TX, "txpd", (u8 *) &txpd, sizeof(struct txpd));

        lbs_deb_hex(LBS_DEB_TX, "Tx Data", (u8 *) p802x_hdr, le16_to_cpu(txpd->tx_packet_length));

        memcpy(&txpd[1], p802x_hdr, le16_to_cpu(txpd->tx_packet_length));

        spin_lock_irqsave(&priv->driver_lock, flags);
        priv->tx_pending_len = pkt_len + sizeof(struct txpd);

        lbs_deb_tx("%s lined up packet\n", __func__);

        dev->stats.tx_packets++;
        dev->stats.tx_bytes += skb->len;

        if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
                /* Keep the skb to echo it back once Tx feedback is
                   received from FW */
                skb_orphan(skb);

                /* Keep the skb around for when we get feedback */
                priv->currenttxskb = skb;
        } else {
 free:
                dev_kfree_skb_any(skb);
        }

 unlock:
        spin_unlock_irqrestore(&priv->driver_lock, flags);
        wake_up(&priv->waitq);

        lbs_deb_leave_args(LBS_DEB_TX, "ret %d", ret);
        return ret;
}

/**
 * lbs_send_tx_feedback - sends to the host the last transmitted packet,
 * filling the radiotap headers with transmission information.
 *
 * @priv:       A pointer to &struct lbs_private structure
 * @try_count:  A 32-bit value containing transmission retry status.
 *
 * returns:     void
 */
void lbs_send_tx_feedback(struct lbs_private *priv, u32 try_count)
{
        struct tx_radiotap_hdr *radiotap_hdr;

        if (priv->wdev->iftype != NL80211_IFTYPE_MONITOR ||
            priv->currenttxskb == NULL)
                return;

        radiotap_hdr = (struct tx_radiotap_hdr *)priv->currenttxskb->data;

        radiotap_hdr->data_retries = try_count ?
                (1 + priv->txretrycount - try_count) : 0;

        priv->currenttxskb->protocol = eth_type_trans(priv->currenttxskb,
                                                      priv->dev);
        netif_rx(priv->currenttxskb);

        priv->currenttxskb = NULL;

        if (priv->connect_status == LBS_CONNECTED)
                netif_wake_queue(priv->dev);

        if (priv->mesh_dev && netif_running(priv->mesh_dev))
                netif_wake_queue(priv->mesh_dev);
}
EXPORT_SYMBOL_GPL(lbs_send_tx_feedback);