xref: /openbmc/linux/drivers/net/wireless/ti/wl1251/tx.h (revision 9cfc5c90)
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
232