drivers/net/wireless/wl12xx/rx.c

   1 /*
   2  * This file is part of wl12xx
   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 "wl12xx.h"
  29 #include "reg.h"
  30 #include "spi.h"
  31 #include "rx.h"
  32
  33 static void wl12xx_rx_header(struct wl12xx *wl,
  34                              struct wl12xx_rx_descriptor *desc)
  35 {
  36         u32 rx_packet_ring_addr;
  37
  38         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
  39         if (wl->rx_current_buffer)
  40                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
  41
  42         wl12xx_spi_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
  43 }
  44
  45 static void wl12xx_rx_status(struct wl12xx *wl,
  46                              struct wl12xx_rx_descriptor *desc,
  47                              struct ieee80211_rx_status *status,
  48                              u8 beacon)
  49 {
  50         u64 mactime;
  51         int ret;
  52
  53         memset(status, 0, sizeof(struct ieee80211_rx_status));
  54
  55         status->band = IEEE80211_BAND_2GHZ;
  56         status->mactime = desc->timestamp;
  57
  58         /*
  59          * The rx status timestamp is a 32 bits value while the TSF is a
  60          * 64 bits one.
  61          * For IBSS merging, TSF is mandatory, so we have to get it
  62          * somehow, so we ask for ACX_TSF_INFO.
  63          * That could be moved to the get_tsf() hook, but unfortunately,
  64          * this one must be atomic, while our SPI routines can sleep.
  65          */
  66         if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
  67                 ret = wl12xx_acx_tsf_info(wl, &mactime);
  68                 if (ret == 0)
  69                         status->mactime = mactime;
  70         }
  71
  72         status->signal = desc->rssi;
  73         status->qual = (desc->rssi - WL12XX_RX_MIN_RSSI) * 100 /
  74                 (WL12XX_RX_MAX_RSSI - WL12XX_RX_MIN_RSSI);
  75         status->qual = min(status->qual, 100);
  76         status->qual = max(status->qual, 0);
  77
  78         /*
  79          * FIXME: guessing that snr needs to be divided by two, otherwise
  80          * the values don't make any sense
  81          */
  82         status->noise = desc->rssi - desc->snr / 2;
  83
  84         status->freq = ieee80211_channel_to_frequency(desc->channel);
  85
  86         status->flag |= RX_FLAG_TSFT;
  87
  88         if (desc->flags & RX_DESC_ENCRYPTION_MASK) {
  89                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
  90
  91                 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
  92                         status->flag |= RX_FLAG_DECRYPTED;
  93
  94                 if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
  95                         status->flag |= RX_FLAG_MMIC_ERROR;
  96         }
  97
  98         if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
  99                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
 100
 101
 102         /* FIXME: set status->rate_idx */
 103 }
 104
 105 static void wl12xx_rx_body(struct wl12xx *wl,
 106                            struct wl12xx_rx_descriptor *desc)
 107 {
 108         struct sk_buff *skb;
 109         struct ieee80211_rx_status status;
 110         u8 *rx_buffer, beacon = 0;
 111         u16 length, *fc;
 112         u32 curr_id, last_id_inc, rx_packet_ring_addr;
 113
 114         length = WL12XX_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
 115         curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
 116         last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
 117
 118         if (last_id_inc != curr_id) {
 119                 wl12xx_warning("curr ID:%d, last ID inc:%d",
 120                                curr_id, last_id_inc);
 121                 wl->rx_last_id = curr_id;
 122         } else {
 123                 wl->rx_last_id = last_id_inc;
 124         }
 125
 126         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
 127                 sizeof(struct wl12xx_rx_descriptor) + 20;
 128         if (wl->rx_current_buffer)
 129                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 130
 131         skb = dev_alloc_skb(length);
 132         if (!skb) {
 133                 wl12xx_error("Couldn't allocate RX frame");
 134                 return;
 135         }
 136
 137         rx_buffer = skb_put(skb, length);
 138         wl12xx_spi_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 139
 140         /* The actual lenght doesn't include the target's alignment */
 141         skb->len = desc->length  - PLCP_HEADER_LENGTH;
 142
 143         fc = (u16 *)skb->data;
 144
 145         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 146                 beacon = 1;
 147
 148         wl12xx_rx_status(wl, desc, &status, beacon);
 149
 150         wl12xx_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 151                      beacon ? "beacon" : "");
 152
 153         ieee80211_rx(wl->hw, skb, &status);
 154 }
 155
 156 static void wl12xx_rx_ack(struct wl12xx *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         wl12xx_reg_write32(wl, addr, data);
 169
 170         /* Toggle buffer ring */
 171         wl->rx_current_buffer = !wl->rx_current_buffer;
 172 }
 173
 174
 175 void wl12xx_rx(struct wl12xx *wl)
 176 {
 177         struct wl12xx_rx_descriptor *rx_desc;
 178
 179         if (wl->state != WL12XX_STATE_ON)
 180                 return;
 181
 182         rx_desc = wl->rx_descriptor;
 183
 184         /* We first read the frame's header */
 185         wl12xx_rx_header(wl, rx_desc);
 186
 187         /* Now we can read the body */
 188         wl12xx_rx_body(wl, rx_desc);
 189
 190         /* Finally, we need to ACK the RX */
 191         wl12xx_rx_ack(wl);
 192
 193         return;
 194 }