drivers/net/wireless/wl12xx/wl1251_rx.c

   1 /*
   2  * This file is part of wl1251
   3  *
   4  * Copyright (c) 1998-2007 Texas Instruments Incorporated
   5  * Copyright (C) 2008 Nokia Corporation
   6  *
   7  * Contact: Kalle Valo <kalle.valo@nokia.com>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * version 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  *
  23  */
  24
  25 #include <linux/skbuff.h>
  26 #include <linux/gfp.h>
  27 #include <net/mac80211.h>
  28
  29 #include "wl1251.h"
  30 #include "wl1251_reg.h"
  31 #include "wl1251_io.h"
  32 #include "wl1251_rx.h"
  33 #include "wl1251_cmd.h"
  34 #include "wl1251_acx.h"
  35
  36 static void wl1251_rx_header(struct wl1251 *wl,
  37                              struct wl1251_rx_descriptor *desc)
  38 {
  39         u32 rx_packet_ring_addr;
  40
  41         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
  42         if (wl->rx_current_buffer)
  43                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
  44
  45         wl1251_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
  46 }
  47
  48 static void wl1251_rx_status(struct wl1251 *wl,
  49                              struct wl1251_rx_descriptor *desc,
  50                              struct ieee80211_rx_status *status,
  51                              u8 beacon)
  52 {
  53         u64 mactime;
  54         int ret;
  55
  56         memset(status, 0, sizeof(struct ieee80211_rx_status));
  57
  58         status->band = IEEE80211_BAND_2GHZ;
  59         status->mactime = desc->timestamp;
  60
  61         /*
  62          * The rx status timestamp is a 32 bits value while the TSF is a
  63          * 64 bits one.
  64          * For IBSS merging, TSF is mandatory, so we have to get it
  65          * somehow, so we ask for ACX_TSF_INFO.
  66          * That could be moved to the get_tsf() hook, but unfortunately,
  67          * this one must be atomic, while our SPI routines can sleep.
  68          */
  69         if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
  70                 ret = wl1251_acx_tsf_info(wl, &mactime);
  71                 if (ret == 0)
  72                         status->mactime = mactime;
  73         }
  74
  75         status->signal = desc->rssi;
  76
  77         /*
  78          * FIXME: guessing that snr needs to be divided by two, otherwise
  79          * the values don't make any sense
  80          */
  81         wl->noise = desc->rssi - desc->snr / 2;
  82
  83         status->freq = ieee80211_channel_to_frequency(desc->channel);
  84
  85         status->flag |= RX_FLAG_TSFT;
  86
  87         if (desc->flags & RX_DESC_ENCRYPTION_MASK) {
  88                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  89
  90                 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
  91                         status->flag |= RX_FLAG_DECRYPTED;
  92
  93                 if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
  94                         status->flag |= RX_FLAG_MMIC_ERROR;
  95         }
  96
  97         if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
  98                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
  99
 100
 101         /* FIXME: set status->rate_idx */
 102 }
 103
 104 static void wl1251_rx_body(struct wl1251 *wl,
 105                            struct wl1251_rx_descriptor *desc)
 106 {
 107         struct sk_buff *skb;
 108         struct ieee80211_rx_status status;
 109         u8 *rx_buffer, beacon = 0;
 110         u16 length, *fc;
 111         u32 curr_id, last_id_inc, rx_packet_ring_addr;
 112
 113         length = WL1251_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
 114         curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
 115         last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
 116
 117         if (last_id_inc != curr_id) {
 118                 wl1251_warning("curr ID:%d, last ID inc:%d",
 119                                curr_id, last_id_inc);
 120                 wl->rx_last_id = curr_id;
 121         } else {
 122                 wl->rx_last_id = last_id_inc;
 123         }
 124
 125         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
 126                 sizeof(struct wl1251_rx_descriptor) + 20;
 127         if (wl->rx_current_buffer)
 128                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 129
 130         skb = __dev_alloc_skb(length, GFP_KERNEL);
 131         if (!skb) {
 132                 wl1251_error("Couldn't allocate RX frame");
 133                 return;
 134         }
 135
 136         rx_buffer = skb_put(skb, length);
 137         wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 138
 139         /* The actual lenght doesn't include the target's alignment */
 140         skb->len = desc->length  - PLCP_HEADER_LENGTH;
 141
 142         fc = (u16 *)skb->data;
 143
 144         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 145                 beacon = 1;
 146
 147         wl1251_rx_status(wl, desc, &status, beacon);
 148
 149         wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 150                      beacon ? "beacon" : "");
 151
 152         memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
 153         ieee80211_rx_ni(wl->hw, skb);
 154 }
 155
 156 static void wl1251_rx_ack(struct wl1251 *wl)
 157 {
 158         u32 data, addr;
 159
 160         if (wl->rx_current_buffer) {
 161                 addr = ACX_REG_INTERRUPT_TRIG_H;
 162                 data = INTR_TRIG_RX_PROC1;
 163         } else {
 164                 addr = ACX_REG_INTERRUPT_TRIG;
 165                 data = INTR_TRIG_RX_PROC0;
 166         }
 167
 168         wl1251_reg_write32(wl, addr, data);
 169
 170         /* Toggle buffer ring */
 171         wl->rx_current_buffer = !wl->rx_current_buffer;
 172 }
 173
 174
 175 void wl1251_rx(struct wl1251 *wl)
 176 {
 177         struct wl1251_rx_descriptor *rx_desc;
 178
 179         if (wl->state != WL1251_STATE_ON)
 180                 return;
 181
 182         rx_desc = wl->rx_descriptor;
 183
 184         /* We first read the frame's header */
 185         wl1251_rx_header(wl, rx_desc);
 186
 187         /* Now we can read the body */
 188         wl1251_rx_body(wl, rx_desc);
 189
 190         /* Finally, we need to ACK the RX */
 191         wl1251_rx_ack(wl);
 192 }