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,
  43                             sizeof(struct wl12xx_rx_descriptor));
  44 }
  45
  46 static void wl12xx_rx_status(struct wl12xx *wl,
  47                              struct wl12xx_rx_descriptor *desc,
  48                              struct ieee80211_rx_status *status,
  49                              u8 beacon)
  50 {
  51         memset(status, 0, sizeof(struct ieee80211_rx_status));
  52
  53         status->band = IEEE80211_BAND_2GHZ;
  54         status->mactime = desc->timestamp;
  55
  56         /*
  57          * The rx status timestamp is a 32 bits value while the TSF is a
  58          * 64 bits one.
  59          * For IBSS merging, TSF is mandatory, so we have to get it
  60          * somehow, so we ask for ACX_TSF_INFO.
  61          * That could be moved to the get_tsf() hook, but unfortunately,
  62          * this one must be atomic, while our SPI routines can sleep.
  63          */
  64         if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
  65                 u64 mactime;
  66                 int ret;
  67                 struct wl12xx_command cmd;
  68                 struct acx_tsf_info *tsf_info;
  69
  70                 memset(&cmd, 0, sizeof(cmd));
  71
  72                 ret = wl12xx_cmd_interrogate(wl, ACX_TSF_INFO,
  73                                              sizeof(struct acx_tsf_info),
  74                                              &cmd);
  75                 if (ret < 0) {
  76                         wl12xx_warning("ACX_FW_REV interrogate failed");
  77                         return;
  78                 }
  79
  80                 tsf_info = (struct acx_tsf_info *)&(cmd.parameters);
  81
  82                 mactime = tsf_info->current_tsf_lsb |
  83                         (tsf_info->current_tsf_msb << 31);
  84
  85                 status->mactime = mactime;
  86         }
  87
  88         status->signal = desc->rssi;
  89         status->qual = (desc->rssi - WL12XX_RX_MIN_RSSI) * 100 /
  90                 (WL12XX_RX_MAX_RSSI - WL12XX_RX_MIN_RSSI);
  91         status->qual = min(status->qual, 100);
  92         status->qual = max(status->qual, 0);
  93
  94         /*
  95          * FIXME: guessing that snr needs to be divided by two, otherwise
  96          * the values don't make any sense
  97          */
  98         status->noise = desc->rssi - desc->snr / 2;
  99
 100         status->freq = ieee80211_channel_to_frequency(desc->channel);
 101
 102         status->flag |= RX_FLAG_TSFT;
 103
 104         if (desc->flags & RX_DESC_ENCRYPTION_MASK) {
 105                 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
 106
 107                 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
 108                         status->flag |= RX_FLAG_DECRYPTED;
 109
 110                 if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
 111                         status->flag |= RX_FLAG_MMIC_ERROR;
 112         }
 113
 114         if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
 115                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
 116
 117
 118         /* FIXME: set status->rate_idx */
 119 }
 120
 121 static void wl12xx_rx_body(struct wl12xx *wl,
 122                            struct wl12xx_rx_descriptor *desc)
 123 {
 124         struct sk_buff *skb;
 125         struct ieee80211_rx_status status;
 126         u8 *rx_buffer, beacon = 0;
 127         u16 length, *fc;
 128         u32 curr_id, last_id_inc, rx_packet_ring_addr;
 129
 130         length = WL12XX_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
 131         curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
 132         last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
 133
 134         if (last_id_inc != curr_id) {
 135                 wl12xx_warning("curr ID:%d, last ID inc:%d",
 136                                curr_id, last_id_inc);
 137                 wl->rx_last_id = curr_id;
 138         } else {
 139                 wl->rx_last_id = last_id_inc;
 140         }
 141
 142         rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
 143                 sizeof(struct wl12xx_rx_descriptor) + 20;
 144         if (wl->rx_current_buffer)
 145                 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 146
 147         skb = dev_alloc_skb(length);
 148         if (!skb) {
 149                 wl12xx_error("Couldn't allocate RX frame");
 150                 return;
 151         }
 152
 153         rx_buffer = skb_put(skb, length);
 154         wl12xx_spi_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 155
 156         /* The actual lenght doesn't include the target's alignment */
 157         skb->len = desc->length  - PLCP_HEADER_LENGTH;
 158
 159         fc = (u16 *)skb->data;
 160
 161         if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 162                 beacon = 1;
 163
 164         wl12xx_rx_status(wl, desc, &status, beacon);
 165
 166         wl12xx_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 167                      beacon ? "beacon" : "");
 168
 169         ieee80211_rx(wl->hw, skb, &status);
 170 }
 171
 172 static void wl12xx_rx_ack(struct wl12xx *wl)
 173 {
 174         u32 data, addr;
 175
 176         if (wl->rx_current_buffer) {
 177                 addr = ACX_REG_INTERRUPT_TRIG_H;
 178                 data = INTR_TRIG_RX_PROC1;
 179         } else {
 180                 addr = ACX_REG_INTERRUPT_TRIG;
 181                 data = INTR_TRIG_RX_PROC0;
 182         }
 183
 184         wl12xx_reg_write32(wl, addr, data);
 185
 186         /* Toggle buffer ring */
 187         wl->rx_current_buffer = !wl->rx_current_buffer;
 188 }
 189
 190
 191 void wl12xx_rx(struct wl12xx *wl)
 192 {
 193         struct wl12xx_rx_descriptor rx_desc;
 194
 195         if (wl->state != WL12XX_STATE_ON)
 196                 return;
 197
 198         /* We first read the frame's header */
 199         wl12xx_rx_header(wl, &rx_desc);
 200
 201         /* Now we can read the body */
 202         wl12xx_rx_body(wl, &rx_desc);
 203
 204         /* Finally, we need to ACK the RX */
 205         wl12xx_rx_ack(wl);
 206
 207         return;
 208 }