/*
 * 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 <linux/sched.h>

#include "wlcore.h"
#include "debug.h"
#include "acx.h"
#include "rx.h"
#include "tx.h"
#include "io.h"
#include "hw_ops.h"

/*
 * TODO: this is here just for now, it must be removed when the data
 * operations are in place.
 */
#include "../wl12xx/reg.h"

static u32 wlcore_rx_get_buf_size(struct wl1271 *wl,
                                  u32 rx_pkt_desc)
{
        if (wl->quirks & WLCORE_QUIRK_RX_BLOCKSIZE_ALIGN)
                return (rx_pkt_desc & ALIGNED_RX_BUF_SIZE_MASK) >>
                       ALIGNED_RX_BUF_SIZE_SHIFT;

        return (rx_pkt_desc & RX_BUF_SIZE_MASK) >> RX_BUF_SIZE_SHIFT_DIV;
}

static u32 wlcore_rx_get_align_buf_size(struct wl1271 *wl, u32 pkt_len)
{
        if (wl->quirks & WLCORE_QUIRK_RX_BLOCKSIZE_ALIGN)
                return ALIGN(pkt_len, WL12XX_BUS_BLOCK_SIZE);

        return pkt_len;
}

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 = wlcore_rate_to_idx(wl, desc->rate, status->band);

        /* 11n support */
        if (desc->rate <= wl->hw_min_ht_rate)
                status->flag |= RX_FLAG_HT;

        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. Desc: 0x%x",
                                       desc_err_code);
                }
        }

        if (beacon)
                wlcore_set_pending_regdomain_ch(wl, (u16)desc->channel,
                                                status->band);
}

static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length,
                                 enum wl_rx_buf_align rx_align, u8 *hlid)
{
        struct wl1271_rx_descriptor *desc;
        struct sk_buff *skb;
        struct ieee80211_hdr *hdr;
        u8 *buf;
        u8 beacon = 0;
        u8 is_data = 0;
        u8 reserved = 0, offset_to_data = 0;
        u16 seq_num;
        u32 pkt_data_len;

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

        pkt_data_len = wlcore_hw_get_rx_packet_len(wl, data, length);
        if (!pkt_data_len) {
                wl1271_error("Invalid packet arrived from HW. length %d",
                             length);
                return -EINVAL;
        }

        if (rx_align == WLCORE_RX_BUF_UNALIGNED)
                reserved = RX_BUF_ALIGN;
        else if (rx_align == WLCORE_RX_BUF_PADDED)
                offset_to_data = RX_BUF_ALIGN;

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

        if (desc->packet_class == WL12XX_RX_CLASS_LOGGER) {
                size_t len = length - sizeof(*desc);
                wl12xx_copy_fwlog(wl, data + sizeof(*desc), len);
                wake_up_interruptible(&wl->fwlog_waitq);
                return 0;
        }

        /* discard corrupted packets */
        if (desc->status & WL1271_RX_DESC_DECRYPT_FAIL) {
                hdr = (void *)(data + sizeof(*desc) + offset_to_data);
                wl1271_warning("corrupted packet in RX: status: 0x%x len: %d",
                               desc->status & WL1271_RX_DESC_STATUS_MASK,
                               pkt_data_len);
                wl1271_dump((DEBUG_RX|DEBUG_CMD), "PKT: ", data + sizeof(*desc),
                            min(pkt_data_len,
                                ieee80211_hdrlen(hdr->frame_control)));
                return -EINVAL;
        }

        /* skb length not including rx descriptor */
        skb = __dev_alloc_skb(pkt_data_len + reserved, GFP_KERNEL);
        if (!skb) {
                wl1271_error("Couldn't allocate RX frame");
                return -ENOMEM;
        }

        /* reserve the unaligned payload(if any) */
        skb_reserve(skb, reserved);

        buf = skb_put(skb, pkt_data_len);

        /*
         * Copy packets from aggregation buffer to the skbs without rx
         * descriptor and with packet payload aligned care. In case of unaligned
         * packets copy the packets in offset of 2 bytes guarantee IP header
         * payload aligned to 4 bytes.
         */
        memcpy(buf, data + sizeof(*desc), pkt_data_len);
        if (rx_align == WLCORE_RX_BUF_PADDED)
                skb_pull(skb, RX_BUF_ALIGN);

        *hlid = desc->hlid;

        hdr = (struct ieee80211_hdr *)skb->data;
        if (ieee80211_is_beacon(hdr->frame_control))
                beacon = 1;
        if (ieee80211_is_data_present(hdr->frame_control))
                is_data = 1;

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

        seq_num = (le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ) >> 4;
        wl1271_debug(DEBUG_RX, "rx skb 0x%p: %d B %s seq %d hlid %d", skb,
                     skb->len - desc->pad_len,
                     beacon ? "beacon" : "",
                     seq_num, *hlid);

        skb_queue_tail(&wl->deferred_rx_queue, skb);
        queue_work(wl->freezable_wq, &wl->netstack_work);

        return is_data;
}

int wlcore_rx(struct wl1271 *wl, struct wl_fw_status_1 *status)
{
        unsigned long active_hlids[BITS_TO_LONGS(WL12XX_MAX_LINKS)] = {0};
        u32 buf_size;
        u32 fw_rx_counter = status->fw_rx_counter % wl->num_rx_desc;
        u32 drv_rx_counter = wl->rx_counter % wl->num_rx_desc;
        u32 rx_counter;
        u32 pkt_len, align_pkt_len;
        u32 pkt_offset, des;
        u8 hlid;
        enum wl_rx_buf_align rx_align;
        int ret = 0;

        while (drv_rx_counter != fw_rx_counter) {
                buf_size = 0;
                rx_counter = drv_rx_counter;
                while (rx_counter != fw_rx_counter) {
                        des = le32_to_cpu(status->rx_pkt_descs[rx_counter]);
                        pkt_len = wlcore_rx_get_buf_size(wl, des);
                        align_pkt_len = wlcore_rx_get_align_buf_size(wl,
                                                                     pkt_len);
                        if (buf_size + align_pkt_len > wl->aggr_buf_size)
                                break;
                        buf_size += align_pkt_len;
                        rx_counter++;
                        rx_counter %= wl->num_rx_desc;
                }

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

                /* Read all available packets at once */
                des = le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]);
                ret = wlcore_hw_prepare_read(wl, des, buf_size);
                if (ret < 0)
                        goto out;

                ret = wlcore_read_data(wl, REG_SLV_MEM_DATA, wl->aggr_buf,
                                       buf_size, true);
                if (ret < 0)
                        goto out;

                /* Split data into separate packets */
                pkt_offset = 0;
                while (pkt_offset < buf_size) {
                        des = le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]);
                        pkt_len = wlcore_rx_get_buf_size(wl, des);
                        rx_align = wlcore_hw_get_rx_buf_align(wl, des);

                        /*
                         * the handle data call can only fail in memory-outage
                         * conditions, in that case the received frame will just
                         * be dropped.
                         */
                        if (wl1271_rx_handle_data(wl,
                                                  wl->aggr_buf + pkt_offset,
                                                  pkt_len, rx_align,
                                                  &hlid) == 1) {
                                if (hlid < WL12XX_MAX_LINKS)
                                        __set_bit(hlid, active_hlids);
                                else
                                        WARN(1,
                                             "hlid exceeded WL12XX_MAX_LINKS "
                                             "(%d)\n", hlid);
                        }

                        wl->rx_counter++;
                        drv_rx_counter++;
                        drv_rx_counter %= wl->num_rx_desc;
                        pkt_offset += wlcore_rx_get_align_buf_size(wl, pkt_len);
                }
        }

        /*
         * Write the driver's packet counter to the FW. This is only required
         * for older hardware revisions
         */
        if (wl->quirks & WLCORE_QUIRK_END_OF_TRANSACTION) {
                ret = wlcore_write32(wl, WL12XX_REG_RX_DRIVER_COUNTER,
                                     wl->rx_counter);
                if (ret < 0)
                        goto out;
        }

        wl12xx_rearm_rx_streaming(wl, active_hlids);

out:
        return ret;
}

#ifdef CONFIG_PM
int wl1271_rx_filter_enable(struct wl1271 *wl,
                            int index, bool enable,
                            struct wl12xx_rx_filter *filter)
{
        int ret;

        if (wl->rx_filter_enabled[index] == enable) {
                wl1271_warning("Request to enable an already "
                             "enabled rx filter %d", index);
                return 0;
        }

        ret = wl1271_acx_set_rx_filter(wl, index, enable, filter);

        if (ret) {
                wl1271_error("Failed to %s rx data filter %d (err=%d)",
                             enable ? "enable" : "disable", index, ret);
                return ret;
        }

        wl->rx_filter_enabled[index] = enable;

        return 0;
}

int wl1271_rx_filter_clear_all(struct wl1271 *wl)
{
        int i, ret = 0;

        for (i = 0; i < WL1271_MAX_RX_FILTERS; i++) {
                if (!wl->rx_filter_enabled[i])
                        continue;
                ret = wl1271_rx_filter_enable(wl, i, 0, NULL);
                if (ret)
                        goto out;
        }

out:
        return ret;
}
#endif /* CONFIG_PM */