drivers/net/wireless/wl1251/tx.h

   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 #ifndef __WL1251_TX_H__
  24 #define __WL1251_TX_H__
  25
  26 #include <linux/bitops.h>
  27 #include "acx.h"
  28
  29 /*
  30  *
  31  * TX PATH
  32  *
  33  * The Tx path uses a double buffer and a tx_control structure, each located
  34  * at a fixed address in the device's memory. On startup, the host retrieves
  35  * the pointers to these addresses. A double buffer allows for continuous data
  36  * flow towards the device. The host keeps track of which buffer is available
  37  * and alternates between these two buffers on a per packet basis.
  38  *
  39  * The size of each of the two buffers is large enough to hold the longest
  40  * 802.3 packet - maximum size Ethernet packet + header + descriptor.
  41  * TX complete indication will be received a-synchronously in a TX done cyclic
  42  * buffer which is composed of 16 tx_result descriptors structures and is used
  43  * in a cyclic manner.
  44  *
  45  * The TX (HOST) procedure is as follows:
  46  * 1. Read the Tx path status, that will give the data_out_count.
  47  * 2. goto 1, if not possible.
  48  *    i.e. if data_in_count - data_out_count >= HwBuffer size (2 for double
  49  *    buffer).
  50  * 3. Copy the packet (preceded by double_buffer_desc), if possible.
  51  *    i.e. if data_in_count - data_out_count < HwBuffer size (2 for double
  52  *    buffer).
  53  * 4. increment data_in_count.
  54  * 5. Inform the firmware by generating a firmware internal interrupt.
  55  * 6. FW will increment data_out_count after it reads the buffer.
  56  *
  57  * The TX Complete procedure:
  58  * 1. To get a TX complete indication the host enables the tx_complete flag in
  59  *    the TX descriptor Structure.
  60  * 2. For each packet with a Tx Complete field set, the firmware adds the
  61  *    transmit results to the cyclic buffer (txDoneRing) and sets both done_1
  62  *    and done_2 to 1 to indicate driver ownership.
  63  * 3. The firmware sends a Tx Complete interrupt to the host to trigger the
  64  *    host to process the new data. Note: interrupt will be send per packet if
  65  *    TX complete indication was requested in tx_control or per crossing
  66  *    aggregation threshold.
  67  * 4. After receiving the Tx Complete interrupt, the host reads the
  68  *    TxDescriptorDone information in a cyclic manner and clears both done_1
  69  *    and done_2 fields.
  70  *
  71  */
  72
  73 #define TX_COMPLETE_REQUIRED_BIT        0x80
  74 #define TX_STATUS_DATA_OUT_COUNT_MASK   0xf
  75
  76 #define WL1251_TX_ALIGN_TO 4
  77 #define WL1251_TX_ALIGN(len) (((len) + WL1251_TX_ALIGN_TO - 1) & \
  78                              ~(WL1251_TX_ALIGN_TO - 1))
  79 #define WL1251_TKIP_IV_SPACE 4
  80
  81 struct tx_control {
  82         /* Rate Policy (class) index */
  83         unsigned rate_policy:3;
  84
  85         /* When set, no ack policy is expected */
  86         unsigned ack_policy:1;
  87
  88         /*
  89          * Packet type:
  90          * 0 -> 802.11
  91          * 1 -> 802.3
  92          * 2 -> IP
  93          * 3 -> raw codec
  94          */
  95         unsigned packet_type:2;
  96
  97         /* If set, this is a QoS-Null or QoS-Data frame */
  98         unsigned qos:1;
  99
 100         /*
 101          * If set, the target triggers the tx complete INT
 102          * upon frame sending completion.
 103          */
 104         unsigned tx_complete:1;
 105
 106         /* 2 bytes padding before packet header */
 107         unsigned xfer_pad:1;
 108
 109         unsigned reserved:7;
 110 } __packed;
 111
 112
 113 struct tx_double_buffer_desc {
 114         /* Length of payload, including headers. */
 115         __le16 length;
 116
 117         /*
 118          * A bit mask that specifies the initial rate to be used
 119          * Possible values are:
 120          * 0x0001 - 1Mbits
 121          * 0x0002 - 2Mbits
 122          * 0x0004 - 5.5Mbits
 123          * 0x0008 - 6Mbits
 124          * 0x0010 - 9Mbits
 125          * 0x0020 - 11Mbits
 126          * 0x0040 - 12Mbits
 127          * 0x0080 - 18Mbits
 128          * 0x0100 - 22Mbits
 129          * 0x0200 - 24Mbits
 130          * 0x0400 - 36Mbits
 131          * 0x0800 - 48Mbits
 132          * 0x1000 - 54Mbits
 133          */
 134         __le16 rate;
 135
 136         /* Time in us that a packet can spend in the target */
 137         __le32 expiry_time;
 138
 139         /* index of the TX queue used for this packet */
 140         u8 xmit_queue;
 141
 142         /* Used to identify a packet */
 143         u8 id;
 144
 145         struct tx_control control;
 146
 147         /*
 148          * The FW should cut the packet into fragments
 149          * of this size.
 150          */
 151         __le16 frag_threshold;
 152
 153         /* Numbers of HW queue blocks to be allocated */
 154         u8 num_mem_blocks;
 155
 156         u8 reserved;
 157 } __packed;
 158
 159 enum {
 160         TX_SUCCESS              = 0,
 161         TX_DMA_ERROR            = BIT(7),
 162         TX_DISABLED             = BIT(6),
 163         TX_RETRY_EXCEEDED       = BIT(5),
 164         TX_TIMEOUT              = BIT(4),
 165         TX_KEY_NOT_FOUND        = BIT(3),
 166         TX_ENCRYPT_FAIL         = BIT(2),
 167         TX_UNAVAILABLE_PRIORITY = BIT(1),
 168 };
 169
 170 struct tx_result {
 171         /*
 172          * Ownership synchronization between the host and
 173          * the firmware. If done_1 and done_2 are cleared,
 174          * owned by the FW (no info ready).
 175          */
 176         u8 done_1;
 177
 178         /* same as double_buffer_desc->id */
 179         u8 id;
 180
 181         /*
 182          * Total air access duration consumed by this
 183          * packet, including all retries and overheads.
 184          */
 185         u16 medium_usage;
 186
 187         /* Total media delay (from 1st EDCA AIFS counter until TX Complete). */
 188         u32 medium_delay;
 189
 190         /* Time between host xfer and tx complete */
 191         u32 fw_hnadling_time;
 192
 193         /* The LS-byte of the last TKIP sequence number. */
 194         u8 lsb_seq_num;
 195
 196         /* Retry count */
 197         u8 ack_failures;
 198
 199         /* At which rate we got a ACK */
 200         u16 rate;
 201
 202         u16 reserved;
 203
 204         /* TX_* */
 205         u8 status;
 206
 207         /* See done_1 */
 208         u8 done_2;
 209 } __packed;
 210
 211 static inline int wl1251_tx_get_queue(int queue)
 212 {
 213         switch (queue) {
 214         case 0:
 215                 return QOS_AC_VO;
 216         case 1:
 217                 return QOS_AC_VI;
 218         case 2:
 219                 return QOS_AC_BE;
 220         case 3:
 221                 return QOS_AC_BK;
 222         default:
 223                 return QOS_AC_BE;
 224         }
 225 }
 226
 227 void wl1251_tx_work(struct work_struct *work);
 228 void wl1251_tx_complete(struct wl1251 *wl);
 229 void wl1251_tx_flush(struct wl1251 *wl);
 230
 231 #endif