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 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * version 2 as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, but 12 * WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 19 * 02110-1301 USA 20 * 21 */ 22 23 #include <linux/skbuff.h> 24 #include <linux/gfp.h> 25 #include <net/mac80211.h> 26 27 #include "wl1251.h" 28 #include "reg.h" 29 #include "io.h" 30 #include "rx.h" 31 #include "cmd.h" 32 #include "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_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 = NL80211_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 75 /* 76 * FIXME: guessing that snr needs to be divided by two, otherwise 77 * the values don't make any sense 78 */ 79 wl->noise = desc->rssi - desc->snr / 2; 80 81 status->freq = ieee80211_channel_to_frequency(desc->channel, 82 status->band); 83 84 status->flag |= RX_FLAG_MACTIME_START; 85 86 if (!wl->monitor_present && (desc->flags & RX_DESC_ENCRYPTION_MASK)) { 87 status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED; 88 89 if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL))) 90 status->flag |= RX_FLAG_DECRYPTED; 91 92 if (unlikely(desc->flags & RX_DESC_MIC_FAIL)) 93 status->flag |= RX_FLAG_MMIC_ERROR; 94 } 95 96 if (unlikely(!(desc->flags & RX_DESC_VALID_FCS))) 97 status->flag |= RX_FLAG_FAILED_FCS_CRC; 98 99 switch (desc->rate) { 100 /* skip 1 and 12 Mbps because they have same value 0x0a */ 101 case RATE_2MBPS: 102 status->rate_idx = 1; 103 break; 104 case RATE_5_5MBPS: 105 status->rate_idx = 2; 106 break; 107 case RATE_11MBPS: 108 status->rate_idx = 3; 109 break; 110 case RATE_6MBPS: 111 status->rate_idx = 4; 112 break; 113 case RATE_9MBPS: 114 status->rate_idx = 5; 115 break; 116 case RATE_18MBPS: 117 status->rate_idx = 7; 118 break; 119 case RATE_24MBPS: 120 status->rate_idx = 8; 121 break; 122 case RATE_36MBPS: 123 status->rate_idx = 9; 124 break; 125 case RATE_48MBPS: 126 status->rate_idx = 10; 127 break; 128 case RATE_54MBPS: 129 status->rate_idx = 11; 130 break; 131 } 132 133 /* for 1 and 12 Mbps we have to check the modulation */ 134 if (desc->rate == RATE_1MBPS) { 135 if (!(desc->mod_pre & OFDM_RATE_BIT)) 136 /* CCK -> RATE_1MBPS */ 137 status->rate_idx = 0; 138 else 139 /* OFDM -> RATE_12MBPS */ 140 status->rate_idx = 6; 141 } 142 143 if (desc->mod_pre & SHORT_PREAMBLE_BIT) 144 status->enc_flags |= RX_ENC_FLAG_SHORTPRE; 145 } 146 147 static void wl1251_rx_body(struct wl1251 *wl, 148 struct wl1251_rx_descriptor *desc) 149 { 150 struct sk_buff *skb; 151 struct ieee80211_rx_status status; 152 u8 *rx_buffer, beacon = 0; 153 u16 length, *fc; 154 u32 curr_id, last_id_inc, rx_packet_ring_addr; 155 156 length = WL1251_RX_ALIGN(desc->length - PLCP_HEADER_LENGTH); 157 curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT; 158 last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1); 159 160 if (last_id_inc != curr_id) { 161 wl1251_warning("curr ID:%d, last ID inc:%d", 162 curr_id, last_id_inc); 163 wl->rx_last_id = curr_id; 164 } else { 165 wl->rx_last_id = last_id_inc; 166 } 167 168 rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr + 169 sizeof(struct wl1251_rx_descriptor) + 20; 170 if (wl->rx_current_buffer) 171 rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size; 172 173 skb = __dev_alloc_skb(length, GFP_KERNEL); 174 if (!skb) { 175 wl1251_error("Couldn't allocate RX frame"); 176 return; 177 } 178 179 rx_buffer = skb_put(skb, length); 180 wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length); 181 182 /* The actual length doesn't include the target's alignment */ 183 skb_trim(skb, desc->length - PLCP_HEADER_LENGTH); 184 185 fc = (u16 *)skb->data; 186 187 if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON) 188 beacon = 1; 189 190 wl1251_rx_status(wl, desc, &status, beacon); 191 192 wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len, 193 beacon ? "beacon" : ""); 194 195 memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status)); 196 ieee80211_rx_ni(wl->hw, skb); 197 } 198 199 static void wl1251_rx_ack(struct wl1251 *wl) 200 { 201 u32 data, addr; 202 203 if (wl->rx_current_buffer) { 204 addr = ACX_REG_INTERRUPT_TRIG_H; 205 data = INTR_TRIG_RX_PROC1; 206 } else { 207 addr = ACX_REG_INTERRUPT_TRIG; 208 data = INTR_TRIG_RX_PROC0; 209 } 210 211 wl1251_reg_write32(wl, addr, data); 212 213 /* Toggle buffer ring */ 214 wl->rx_current_buffer = !wl->rx_current_buffer; 215 } 216 217 218 void wl1251_rx(struct wl1251 *wl) 219 { 220 struct wl1251_rx_descriptor *rx_desc; 221 222 if (wl->state != WL1251_STATE_ON) 223 return; 224 225 rx_desc = wl->rx_descriptor; 226 227 /* We first read the frame's header */ 228 wl1251_rx_header(wl, rx_desc); 229 230 /* Now we can read the body */ 231 wl1251_rx_body(wl, rx_desc); 232 233 /* Finally, we need to ACK the RX */ 234 wl1251_rx_ack(wl); 235 } 236