/*
 * This file is part of wl1271
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <luciano.coelho@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/gfp.h>

#include "wl12xx.h"
#include "acx.h"
#include "reg.h"
#include "rx.h"
#include "io.h"

static u8 wl1271_rx_get_mem_block(struct wl1271_fw_common_status *status,
                                  u32 drv_rx_counter)
{
        return le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]) &
                RX_MEM_BLOCK_MASK;
}

static u32 wl1271_rx_get_buf_size(struct wl1271_fw_common_status *status,
                                 u32 drv_rx_counter)
{
        return (le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]) &
                RX_BUF_SIZE_MASK) >> RX_BUF_SIZE_SHIFT_DIV;
}

static void wl1271_rx_status(struct wl1271 *wl,
                             struct wl1271_rx_descriptor *desc,
                             struct ieee80211_rx_status *status,
                             u8 beacon)
{
        memset(status, 0, sizeof(struct ieee80211_rx_status));

        if ((desc->flags & WL1271_RX_DESC_BAND_MASK) == WL1271_RX_DESC_BAND_BG)
                status->band = IEEE80211_BAND_2GHZ;
        else
                status->band = IEEE80211_BAND_5GHZ;

        status->rate_idx = wl1271_rate_to_idx(desc->rate, status->band);

#ifdef CONFIG_WL12XX_HT
        /* 11n support */
        if (desc->rate <= CONF_HW_RXTX_RATE_MCS0)
                status->flag |= RX_FLAG_HT;
#endif

        status->signal = desc->rssi;

        /*
         * FIXME: In wl1251, the SNR should be divided by two.  In wl1271 we
         * need to divide by two for now, but TI has been discussing about
         * changing it.  This needs to be rechecked.
         */
        wl->noise = desc->rssi - (desc->snr >> 1);

        status->freq = ieee80211_channel_to_frequency(desc->channel,
                                                      status->band);

        if (desc->flags & WL1271_RX_DESC_ENCRYPT_MASK) {
                u8 desc_err_code = desc->status & WL1271_RX_DESC_STATUS_MASK;

                status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED |
                                RX_FLAG_DECRYPTED;

                if (unlikely(desc_err_code == WL1271_RX_DESC_MIC_FAIL)) {
                        status->flag |= RX_FLAG_MMIC_ERROR;
                        wl1271_warning("Michael MIC error");
                }
        }
}

static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length)
{
        struct wl1271_rx_descriptor *desc;
        struct sk_buff *skb;
        struct ieee80211_hdr *hdr;
        u8 *buf;
        u8 beacon = 0;

        /*
         * In PLT mode we seem to get frames and mac80211 warns about them,
         * workaround this by not retrieving them at all.
         */
        if (unlikely(wl->state == WL1271_STATE_PLT))
                return -EINVAL;

        /* the data read starts with the descriptor */
        desc = (struct wl1271_rx_descriptor *) data;

        switch (desc->status & WL1271_RX_DESC_STATUS_MASK) {
        /* discard corrupted packets */
        case WL1271_RX_DESC_DRIVER_RX_Q_FAIL:
        case WL1271_RX_DESC_DECRYPT_FAIL:
                wl1271_warning("corrupted packet in RX with status: 0x%x",
                               desc->status & WL1271_RX_DESC_STATUS_MASK);
                return -EINVAL;
        case WL1271_RX_DESC_SUCCESS:
        case WL1271_RX_DESC_MIC_FAIL:
                break;
        default:
                wl1271_error("invalid RX descriptor status: 0x%x",
                             desc->status & WL1271_RX_DESC_STATUS_MASK);
                return -EINVAL;
        }

        skb = __dev_alloc_skb(length, GFP_KERNEL);
        if (!skb) {
                wl1271_error("Couldn't allocate RX frame");
                return -ENOMEM;
        }

        buf = skb_put(skb, length);
        memcpy(buf, data, length);

        /* now we pull the descriptor out of the buffer */
        skb_pull(skb, sizeof(*desc));

        hdr = (struct ieee80211_hdr *)skb->data;
        if (ieee80211_is_beacon(hdr->frame_control))
                beacon = 1;

        wl1271_rx_status(wl, desc, IEEE80211_SKB_RXCB(skb), beacon);

        wl1271_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb,
                     skb->len - desc->pad_len,
                     beacon ? "beacon" : "");

        skb_trim(skb, skb->len - desc->pad_len);

        skb_queue_tail(&wl->deferred_rx_queue, skb);
        ieee80211_queue_work(wl->hw, &wl->netstack_work);

        return 0;
}

void wl1271_rx(struct wl1271 *wl, struct wl1271_fw_common_status *status)
{
        struct wl1271_acx_mem_map *wl_mem_map = wl->target_mem_map;
        u32 buf_size;
        u32 fw_rx_counter  = status->fw_rx_counter & NUM_RX_PKT_DESC_MOD_MASK;
        u32 drv_rx_counter = wl->rx_counter & NUM_RX_PKT_DESC_MOD_MASK;
        u32 rx_counter;
        u32 mem_block;
        u32 pkt_length;
        u32 pkt_offset;

        while (drv_rx_counter != fw_rx_counter) {
                buf_size = 0;
                rx_counter = drv_rx_counter;
                while (rx_counter != fw_rx_counter) {
                        pkt_length = wl1271_rx_get_buf_size(status, rx_counter);
                        if (buf_size + pkt_length > WL1271_AGGR_BUFFER_SIZE)
                                break;
                        buf_size += pkt_length;
                        rx_counter++;
                        rx_counter &= NUM_RX_PKT_DESC_MOD_MASK;
                }

                if (buf_size == 0) {
                        wl1271_warning("received empty data");
                        break;
                }

                if (wl->chip.id != CHIP_ID_1283_PG20) {
                        /*
                         * Choose the block we want to read
                         * For aggregated packets, only the first memory block
                         * should be retrieved. The FW takes care of the rest.
                         */
                        mem_block = wl1271_rx_get_mem_block(status,
                                                            drv_rx_counter);

                        wl->rx_mem_pool_addr.addr = (mem_block << 8) +
                           le32_to_cpu(wl_mem_map->packet_memory_pool_start);

                        wl->rx_mem_pool_addr.addr_extra =
                                wl->rx_mem_pool_addr.addr + 4;

                        wl1271_write(wl, WL1271_SLV_REG_DATA,
                                     &wl->rx_mem_pool_addr,
                                     sizeof(wl->rx_mem_pool_addr), false);
                }

                /* Read all available packets at once */
                wl1271_read(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
                                buf_size, true);

                /* Split data into separate packets */
                pkt_offset = 0;
                while (pkt_offset < buf_size) {
                        pkt_length = wl1271_rx_get_buf_size(status,
                                        drv_rx_counter);
                        /*
                         * the handle data call can only fail in memory-outage
                         * conditions, in that case the received frame will just
                         * be dropped.
                         */
                        wl1271_rx_handle_data(wl,
                                              wl->aggr_buf + pkt_offset,
                                              pkt_length);
                        wl->rx_counter++;
                        drv_rx_counter++;
                        drv_rx_counter &= NUM_RX_PKT_DESC_MOD_MASK;
                        pkt_offset += pkt_length;
                }
        }

        /*
         * Write the driver's packet counter to the FW. This is only required
         * for older hardware revisions
         */
        if (wl->quirks & WL12XX_QUIRK_END_OF_TRANSACTION)
                wl1271_write32(wl, RX_DRIVER_COUNTER_ADDRESS, wl->rx_counter);
}

void wl1271_set_default_filters(struct wl1271 *wl)
{
        if (wl->bss_type == BSS_TYPE_AP_BSS) {
                wl->rx_config = WL1271_DEFAULT_AP_RX_CONFIG;
                wl->rx_filter = WL1271_DEFAULT_AP_RX_FILTER;
        } else {
                wl->rx_config = WL1271_DEFAULT_STA_RX_CONFIG;
                wl->rx_filter = WL1271_DEFAULT_STA_RX_FILTER;
        }
}