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 "wl1251_reg.h"
  30 #include "wl1251_io.h"
  31 #include "wl1251_rx.h"
  32 #include "wl1251_cmd.h"
  33 #include "wl1251_acx.h"
  34
  35 static void wl1251_rx_header(struct wl1251 *wl,
  36                              struct wl1251_rx_descriptor *desc)
  37 {
  38         u32 rx_packet_ring_addr;
  39
  40         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
  41         if (wl->rx_current_buffer)
  42                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
  43
  44         wl1251_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
  45 }
  46
  47 static void wl1251_rx_status(struct wl1251 *wl,
  48                              struct wl1251_rx_descriptor *desc,
  49                              struct ieee80211_rx_status *status,
  50                              u8 beacon)
  51 {
  52         u64 mactime;
  53         int ret;
  54
  55         memset(status, 0, sizeof(struct ieee80211_rx_status));
  56
  57         status->band = IEEE80211_BAND_2GHZ;
  58         status->mactime = desc->timestamp;
  59
  60         /*
  61          * The rx status timestamp is a 32 bits value while the TSF is a
  62          * 64 bits one.
  63          * For IBSS merging, TSF is mandatory, so we have to get it
  64          * somehow, so we ask for ACX_TSF_INFO.
  65          * That could be moved to the get_tsf() hook, but unfortunately,
  66          * this one must be atomic, while our SPI routines can sleep.
  67          */
  68         if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
  69                 ret = wl1251_acx_tsf_info(wl, &mactime);
  70                 if (ret == 0)
  71                         status->mactime = mactime;
  72         }
  73
  74         status->signal = desc->rssi;
  75         status->qual = (desc->rssi - WL1251_RX_MIN_RSSI) * 100 /
  76                 (WL1251_RX_MAX_RSSI - WL1251_RX_MIN_RSSI);
  77         status->qual = min(status->qual, 100);
  78         status->qual = max(status->qual, 0);
  79
  80         /*
  81          * FIXME: guessing that snr needs to be divided by two, otherwise
  82          * the values don't make any sense
  83          */
  84         status->noise = desc->rssi - desc->snr / 2;
  85
  86         status->freq = ieee80211_channel_to_frequency(desc->channel);
  87
  88         status->flag |= RX_FLAG_TSFT;
  89
  90         if (desc->flags & RX_DESC_ENCRYPTION_MASK) {
  91                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  92
  93                 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
  94                         status->flag |= RX_FLAG_DECRYPTED;
  95
  96                 if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
  97                         status->flag |= RX_FLAG_MMIC_ERROR;
  98         }
  99
 100         if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
 101                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
 102
 103
 104         /* FIXME: set status->rate_idx */
 105 }
 106
 107 static void wl1251_rx_body(struct wl1251 *wl,
 108                            struct wl1251_rx_descriptor *desc)
 109 {
 110         struct sk_buff *skb;
 111         struct ieee80211_rx_status status;
 112         u8 *rx_buffer, beacon = 0;
 113         u16 length, *fc;
 114         u32 curr_id, last_id_inc, rx_packet_ring_addr;
 115
 116         length = WL1251_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
 117         curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
 118         last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
 119
 120         if (last_id_inc != curr_id) {
 121                 wl1251_warning("curr ID:%d, last ID inc:%d",
 122                                curr_id, last_id_inc);
 123                 wl->rx_last_id = curr_id;
 124         } else {
 125                 wl->rx_last_id = last_id_inc;
 126         }
 127
 128         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
 129                 sizeof(struct wl1251_rx_descriptor) + 20;
 130         if (wl->rx_current_buffer)
 131                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 132
 133         skb = dev_alloc_skb(length);
 134         if (!skb) {
 135                 wl1251_error("Couldn't allocate RX frame");
 136                 return;
 137         }
 138
 139         rx_buffer = skb_put(skb, length);
 140         wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 141
 142         /* The actual lenght doesn't include the target's alignment */
 143         skb->len = desc->length  - PLCP_HEADER_LENGTH;
 144
 145         fc = (u16 *)skb->data;
 146
 147         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 148                 beacon = 1;
 149
 150         wl1251_rx_status(wl, desc, &status, beacon);
 151
 152         wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 153                      beacon ? "beacon" : "");
 154
 155         memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
 156         ieee80211_rx(wl->hw, skb);
 157 }
 158
 159 static void wl1251_rx_ack(struct wl1251 *wl)
 160 {
 161         u32 data, addr;
 162
 163         if (wl->rx_current_buffer) {
 164                 addr = ACX_REG_INTERRUPT_TRIG_H;
 165                 data = INTR_TRIG_RX_PROC1;
 166         } else {
 167                 addr = ACX_REG_INTERRUPT_TRIG;
 168                 data = INTR_TRIG_RX_PROC0;
 169         }
 170
 171         wl1251_reg_write32(wl, addr, data);
 172
 173         /* Toggle buffer ring */
 174         wl->rx_current_buffer = !wl->rx_current_buffer;
 175 }
 176
 177
 178 void wl1251_rx(struct wl1251 *wl)
 179 {
 180         struct wl1251_rx_descriptor *rx_desc;
 181
 182         if (wl->state != WL1251_STATE_ON)
 183                 return;
 184
 185         rx_desc = wl->rx_descriptor;
 186
 187         /* We first read the frame's header */
 188         wl1251_rx_header(wl, rx_desc);
 189
 190         /* Now we can read the body */
 191         wl1251_rx_body(wl, rx_desc);
 192
 193         /* Finally, we need to ACK the RX */
 194         wl1251_rx_ack(wl);
 195
 196         return;
 197 }