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 <net/mac80211.h>
  27
  28 #include "wl1251.h"
  29 #include "reg.h"
  30 #include "wl1251_spi.h"
  31 #include "wl1251_rx.h"
  32 #include "wl1251_acx.h"
  33
  34 static void wl1251_rx_header(struct wl1251 *wl,
  35                              struct wl1251_rx_descriptor *desc)
  36 {
  37         u32 rx_packet_ring_addr;
  38
  39         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
  40         if (wl->rx_current_buffer)
  41                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
  42
  43         wl1251_spi_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
  44 }
  45
  46 static void wl1251_rx_status(struct wl1251 *wl,
  47                              struct wl1251_rx_descriptor *desc,
  48                              struct ieee80211_rx_status *status,
  49                              u8 beacon)
  50 {
  51         u64 mactime;
  52         int ret;
  53
  54         memset(status, 0, sizeof(struct ieee80211_rx_status));
  55
  56         status->band = IEEE80211_BAND_2GHZ;
  57         status->mactime = desc->timestamp;
  58
  59         /*
  60          * The rx status timestamp is a 32 bits value while the TSF is a
  61          * 64 bits one.
  62          * For IBSS merging, TSF is mandatory, so we have to get it
  63          * somehow, so we ask for ACX_TSF_INFO.
  64          * That could be moved to the get_tsf() hook, but unfortunately,
  65          * this one must be atomic, while our SPI routines can sleep.
  66          */
  67         if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
  68                 ret = wl1251_acx_tsf_info(wl, &mactime);
  69                 if (ret == 0)
  70                         status->mactime = mactime;
  71         }
  72
  73         status->signal = desc->rssi;
  74         status->qual = (desc->rssi - WL1251_RX_MIN_RSSI) * 100 /
  75                 (WL1251_RX_MAX_RSSI - WL1251_RX_MIN_RSSI);
  76         status->qual = min(status->qual, 100);
  77         status->qual = max(status->qual, 0);
  78
  79         /*
  80          * FIXME: guessing that snr needs to be divided by two, otherwise
  81          * the values don't make any sense
  82          */
  83         status->noise = desc->rssi - desc->snr / 2;
  84
  85         status->freq = ieee80211_channel_to_frequency(desc->channel);
  86
  87         status->flag |= RX_FLAG_TSFT;
  88
  89         if (desc->flags & RX_DESC_ENCRYPTION_MASK) {
  90                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  91
  92                 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
  93                         status->flag |= RX_FLAG_DECRYPTED;
  94
  95                 if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
  96                         status->flag |= RX_FLAG_MMIC_ERROR;
  97         }
  98
  99         if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
 100                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
 101
 102
 103         /* FIXME: set status->rate_idx */
 104 }
 105
 106 static void wl1251_rx_body(struct wl1251 *wl,
 107                            struct wl1251_rx_descriptor *desc)
 108 {
 109         struct sk_buff *skb;
 110         struct ieee80211_rx_status status;
 111         u8 *rx_buffer, beacon = 0;
 112         u16 length, *fc;
 113         u32 curr_id, last_id_inc, rx_packet_ring_addr;
 114
 115         length = WL1251_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
 116         curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
 117         last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
 118
 119         if (last_id_inc != curr_id) {
 120                 wl1251_warning("curr ID:%d, last ID inc:%d",
 121                                curr_id, last_id_inc);
 122                 wl->rx_last_id = curr_id;
 123         } else {
 124                 wl->rx_last_id = last_id_inc;
 125         }
 126
 127         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
 128                 sizeof(struct wl1251_rx_descriptor) + 20;
 129         if (wl->rx_current_buffer)
 130                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 131
 132         skb = dev_alloc_skb(length);
 133         if (!skb) {
 134                 wl1251_error("Couldn't allocate RX frame");
 135                 return;
 136         }
 137
 138         rx_buffer = skb_put(skb, length);
 139         wl1251_spi_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 140
 141         /* The actual lenght doesn't include the target's alignment */
 142         skb->len = desc->length  - PLCP_HEADER_LENGTH;
 143
 144         fc = (u16 *)skb->data;
 145
 146         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 147                 beacon = 1;
 148
 149         wl1251_rx_status(wl, desc, &status, beacon);
 150
 151         wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 152                      beacon ? "beacon" : "");
 153
 154         memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
 155         ieee80211_rx(wl->hw, skb);
 156 }
 157
 158 static void wl1251_rx_ack(struct wl1251 *wl)
 159 {
 160         u32 data, addr;
 161
 162         if (wl->rx_current_buffer) {
 163                 addr = ACX_REG_INTERRUPT_TRIG_H;
 164                 data = INTR_TRIG_RX_PROC1;
 165         } else {
 166                 addr = ACX_REG_INTERRUPT_TRIG;
 167                 data = INTR_TRIG_RX_PROC0;
 168         }
 169
 170         wl1251_reg_write32(wl, addr, data);
 171
 172         /* Toggle buffer ring */
 173         wl->rx_current_buffer = !wl->rx_current_buffer;
 174 }
 175
 176
 177 void wl1251_rx(struct wl1251 *wl)
 178 {
 179         struct wl1251_rx_descriptor *rx_desc;
 180
 181         if (wl->state != WL1251_STATE_ON)
 182                 return;
 183
 184         rx_desc = wl->rx_descriptor;
 185
 186         /* We first read the frame's header */
 187         wl1251_rx_header(wl, rx_desc);
 188
 189         /* Now we can read the body */
 190         wl1251_rx_body(wl, rx_desc);
 191
 192         /* Finally, we need to ACK the RX */
 193         wl1251_rx_ack(wl);
 194
 195         return;
 196 }