summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/ti/wl1251/rx.c
blob: 123c4bb50e0a0c2eff220c4509c2ece5aab7b365 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/*
 * This file is part of wl1251
 *
 * Copyright (c) 1998-2007 Texas Instruments Incorporated
 * Copyright (C) 2008 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/skbuff.h>
#include <linux/gfp.h>
#include <net/mac80211.h>

#include "wl1251.h"
#include "reg.h"
#include "io.h"
#include "rx.h"
#include "cmd.h"
#include "acx.h"

static void wl1251_rx_header(struct wl1251 *wl,
			     struct wl1251_rx_descriptor *desc)
{
	u32 rx_packet_ring_addr;

	rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
	if (wl->rx_current_buffer)
		rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;

	wl1251_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
}

static void wl1251_rx_status(struct wl1251 *wl,
			     struct wl1251_rx_descriptor *desc,
			     struct ieee80211_rx_status *status,
			     u8 beacon)
{
	u64 mactime;
	int ret;

	memset(status, 0, sizeof(struct ieee80211_rx_status));

	status->band = IEEE80211_BAND_2GHZ;
	status->mactime = desc->timestamp;

	/*
	 * The rx status timestamp is a 32 bits value while the TSF is a
	 * 64 bits one.
	 * For IBSS merging, TSF is mandatory, so we have to get it
	 * somehow, so we ask for ACX_TSF_INFO.
	 * That could be moved to the get_tsf() hook, but unfortunately,
	 * this one must be atomic, while our SPI routines can sleep.
	 */
	if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
		ret = wl1251_acx_tsf_info(wl, &mactime);
		if (ret == 0)
			status->mactime = mactime;
	}

	status->signal = desc->rssi;

	/*
	 * FIXME: guessing that snr needs to be divided by two, otherwise
	 * the values don't make any sense
	 */
	wl->noise = desc->rssi - desc->snr / 2;

	status->freq = ieee80211_channel_to_frequency(desc->channel,
						      status->band);

	status->flag |= RX_FLAG_MACTIME_START;

	if (!wl->monitor_present && (desc->flags & RX_DESC_ENCRYPTION_MASK)) {
		status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;

		if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
			status->flag |= RX_FLAG_DECRYPTED;

		if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
			status->flag |= RX_FLAG_MMIC_ERROR;
	}

	if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
		status->flag |= RX_FLAG_FAILED_FCS_CRC;

	switch (desc->rate) {
		/* skip 1 and 12 Mbps because they have same value 0x0a */
	case RATE_2MBPS:
		status->rate_idx = 1;
		break;
	case RATE_5_5MBPS:
		status->rate_idx = 2;
		break;
	case RATE_11MBPS:
		status->rate_idx = 3;
		break;
	case RATE_6MBPS:
		status->rate_idx = 4;
		break;
	case RATE_9MBPS:
		status->rate_idx = 5;
		break;
	case RATE_18MBPS:
		status->rate_idx = 7;
		break;
	case RATE_24MBPS:
		status->rate_idx = 8;
		break;
	case RATE_36MBPS:
		status->rate_idx = 9;
		break;
	case RATE_48MBPS:
		status->rate_idx = 10;
		break;
	case RATE_54MBPS:
		status->rate_idx = 11;
		break;
	}

	/* for 1 and 12 Mbps we have to check the modulation */
	if (desc->rate == RATE_1MBPS) {
		if (!(desc->mod_pre & OFDM_RATE_BIT))
			/* CCK -> RATE_1MBPS */
			status->rate_idx = 0;
		else
			/* OFDM -> RATE_12MBPS */
			status->rate_idx = 6;
	}

	if (desc->mod_pre & SHORT_PREAMBLE_BIT)
		status->flag |= RX_FLAG_SHORTPRE;
}

static void wl1251_rx_body(struct wl1251 *wl,
			   struct wl1251_rx_descriptor *desc)
{
	struct sk_buff *skb;
	struct ieee80211_rx_status status;
	u8 *rx_buffer, beacon = 0;
	u16 length, *fc;
	u32 curr_id, last_id_inc, rx_packet_ring_addr;

	length = WL1251_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
	curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
	last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);

	if (last_id_inc != curr_id) {
		wl1251_warning("curr ID:%d, last ID inc:%d",
			       curr_id, last_id_inc);
		wl->rx_last_id = curr_id;
	} else {
		wl->rx_last_id = last_id_inc;
	}

	rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
		sizeof(struct wl1251_rx_descriptor) + 20;
	if (wl->rx_current_buffer)
		rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;

	skb = __dev_alloc_skb(length, GFP_KERNEL);
	if (!skb) {
		wl1251_error("Couldn't allocate RX frame");
		return;
	}

	rx_buffer = skb_put(skb, length);
	wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);

	/* The actual length doesn't include the target's alignment */
	skb->len = desc->length  - PLCP_HEADER_LENGTH;

	fc = (u16 *)skb->data;

	if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
		beacon = 1;

	wl1251_rx_status(wl, desc, &status, beacon);

	wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
		     beacon ? "beacon" : "");

	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
	ieee80211_rx_ni(wl->hw, skb);
}

static void wl1251_rx_ack(struct wl1251 *wl)
{
	u32 data, addr;

	if (wl->rx_current_buffer) {
		addr = ACX_REG_INTERRUPT_TRIG_H;
		data = INTR_TRIG_RX_PROC1;
	} else {
		addr = ACX_REG_INTERRUPT_TRIG;
		data = INTR_TRIG_RX_PROC0;
	}

	wl1251_reg_write32(wl, addr, data);

	/* Toggle buffer ring */
	wl->rx_current_buffer = !wl->rx_current_buffer;
}


void wl1251_rx(struct wl1251 *wl)
{
	struct wl1251_rx_descriptor *rx_desc;

	if (wl->state != WL1251_STATE_ON)
		return;

	rx_desc = wl->rx_descriptor;

	/* We first read the frame's header */
	wl1251_rx_header(wl, rx_desc);

	/* Now we can read the body */
	wl1251_rx_body(wl, rx_desc);

	/* Finally, we need to ACK the RX */
	wl1251_rx_ack(wl);
}