xref: /openbmc/linux/drivers/net/wireless/ti/wl1251/rx.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file is part of wl1251
4  *
5  * Copyright (c) 1998-2007 Texas Instruments Incorporated
6  * Copyright (C) 2008 Nokia Corporation
7  */
8 
9 #include <linux/skbuff.h>
10 #include <linux/gfp.h>
11 #include <net/mac80211.h>
12 
13 #include "wl1251.h"
14 #include "reg.h"
15 #include "io.h"
16 #include "rx.h"
17 #include "cmd.h"
18 #include "acx.h"
19 
20 static void wl1251_rx_header(struct wl1251 *wl,
21 			     struct wl1251_rx_descriptor *desc)
22 {
23 	u32 rx_packet_ring_addr;
24 
25 	rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr;
26 	if (wl->rx_current_buffer)
27 		rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
28 
29 	wl1251_mem_read(wl, rx_packet_ring_addr, desc, sizeof(*desc));
30 }
31 
32 static void wl1251_rx_status(struct wl1251 *wl,
33 			     struct wl1251_rx_descriptor *desc,
34 			     struct ieee80211_rx_status *status,
35 			     u8 beacon)
36 {
37 	u64 mactime;
38 	int ret;
39 
40 	memset(status, 0, sizeof(struct ieee80211_rx_status));
41 
42 	status->band = NL80211_BAND_2GHZ;
43 	status->mactime = desc->timestamp;
44 
45 	/*
46 	 * The rx status timestamp is a 32 bits value while the TSF is a
47 	 * 64 bits one.
48 	 * For IBSS merging, TSF is mandatory, so we have to get it
49 	 * somehow, so we ask for ACX_TSF_INFO.
50 	 * That could be moved to the get_tsf() hook, but unfortunately,
51 	 * this one must be atomic, while our SPI routines can sleep.
52 	 */
53 	if ((wl->bss_type == BSS_TYPE_IBSS) && beacon) {
54 		ret = wl1251_acx_tsf_info(wl, &mactime);
55 		if (ret == 0)
56 			status->mactime = mactime;
57 	}
58 
59 	status->signal = desc->rssi;
60 
61 	/*
62 	 * FIXME: guessing that snr needs to be divided by two, otherwise
63 	 * the values don't make any sense
64 	 */
65 	wl->noise = desc->rssi - desc->snr / 2;
66 
67 	status->freq = ieee80211_channel_to_frequency(desc->channel,
68 						      status->band);
69 
70 	status->flag |= RX_FLAG_MACTIME_START;
71 
72 	if (!wl->monitor_present && (desc->flags & RX_DESC_ENCRYPTION_MASK)) {
73 		status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
74 
75 		if (likely(!(desc->flags & RX_DESC_DECRYPT_FAIL)))
76 			status->flag |= RX_FLAG_DECRYPTED;
77 
78 		if (unlikely(desc->flags & RX_DESC_MIC_FAIL))
79 			status->flag |= RX_FLAG_MMIC_ERROR;
80 	}
81 
82 	if (unlikely(!(desc->flags & RX_DESC_VALID_FCS)))
83 		status->flag |= RX_FLAG_FAILED_FCS_CRC;
84 
85 	switch (desc->rate) {
86 		/* skip 1 and 12 Mbps because they have same value 0x0a */
87 	case RATE_2MBPS:
88 		status->rate_idx = 1;
89 		break;
90 	case RATE_5_5MBPS:
91 		status->rate_idx = 2;
92 		break;
93 	case RATE_11MBPS:
94 		status->rate_idx = 3;
95 		break;
96 	case RATE_6MBPS:
97 		status->rate_idx = 4;
98 		break;
99 	case RATE_9MBPS:
100 		status->rate_idx = 5;
101 		break;
102 	case RATE_18MBPS:
103 		status->rate_idx = 7;
104 		break;
105 	case RATE_24MBPS:
106 		status->rate_idx = 8;
107 		break;
108 	case RATE_36MBPS:
109 		status->rate_idx = 9;
110 		break;
111 	case RATE_48MBPS:
112 		status->rate_idx = 10;
113 		break;
114 	case RATE_54MBPS:
115 		status->rate_idx = 11;
116 		break;
117 	}
118 
119 	/* for 1 and 12 Mbps we have to check the modulation */
120 	if (desc->rate == RATE_1MBPS) {
121 		if (!(desc->mod_pre & OFDM_RATE_BIT))
122 			/* CCK -> RATE_1MBPS */
123 			status->rate_idx = 0;
124 		else
125 			/* OFDM -> RATE_12MBPS */
126 			status->rate_idx = 6;
127 	}
128 
129 	if (desc->mod_pre & SHORT_PREAMBLE_BIT)
130 		status->enc_flags |= RX_ENC_FLAG_SHORTPRE;
131 }
132 
133 static void wl1251_rx_body(struct wl1251 *wl,
134 			   struct wl1251_rx_descriptor *desc)
135 {
136 	struct sk_buff *skb;
137 	struct ieee80211_rx_status status;
138 	u8 *rx_buffer, beacon = 0;
139 	u16 length, *fc;
140 	u32 curr_id, last_id_inc, rx_packet_ring_addr;
141 
142 	length = WL1251_RX_ALIGN(desc->length  - PLCP_HEADER_LENGTH);
143 	curr_id = (desc->flags & RX_DESC_SEQNUM_MASK) >> RX_DESC_PACKETID_SHIFT;
144 	last_id_inc = (wl->rx_last_id + 1) % (RX_MAX_PACKET_ID + 1);
145 
146 	if (last_id_inc != curr_id) {
147 		wl1251_warning("curr ID:%d, last ID inc:%d",
148 			       curr_id, last_id_inc);
149 		wl->rx_last_id = curr_id;
150 	} else {
151 		wl->rx_last_id = last_id_inc;
152 	}
153 
154 	rx_packet_ring_addr = wl->data_path->rx_packet_ring_addr +
155 		sizeof(struct wl1251_rx_descriptor) + 20;
156 	if (wl->rx_current_buffer)
157 		rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
158 
159 	skb = __dev_alloc_skb(length, GFP_KERNEL);
160 	if (!skb) {
161 		wl1251_error("Couldn't allocate RX frame");
162 		return;
163 	}
164 
165 	rx_buffer = skb_put(skb, length);
166 	wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
167 
168 	/* The actual length doesn't include the target's alignment */
169 	skb_trim(skb, desc->length - PLCP_HEADER_LENGTH);
170 
171 	fc = (u16 *)skb->data;
172 
173 	if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
174 		beacon = 1;
175 
176 	wl1251_rx_status(wl, desc, &status, beacon);
177 
178 	wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
179 		     beacon ? "beacon" : "");
180 
181 	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
182 	ieee80211_rx_ni(wl->hw, skb);
183 }
184 
185 static void wl1251_rx_ack(struct wl1251 *wl)
186 {
187 	u32 data, addr;
188 
189 	if (wl->rx_current_buffer) {
190 		addr = ACX_REG_INTERRUPT_TRIG_H;
191 		data = INTR_TRIG_RX_PROC1;
192 	} else {
193 		addr = ACX_REG_INTERRUPT_TRIG;
194 		data = INTR_TRIG_RX_PROC0;
195 	}
196 
197 	wl1251_reg_write32(wl, addr, data);
198 
199 	/* Toggle buffer ring */
200 	wl->rx_current_buffer = !wl->rx_current_buffer;
201 }
202 
203 
204 void wl1251_rx(struct wl1251 *wl)
205 {
206 	struct wl1251_rx_descriptor *rx_desc;
207 
208 	if (wl->state != WL1251_STATE_ON)
209 		return;
210 
211 	rx_desc = wl->rx_descriptor;
212 
213 	/* We first read the frame's header */
214 	wl1251_rx_header(wl, rx_desc);
215 
216 	/* Now we can read the body */
217 	wl1251_rx_body(wl, rx_desc);
218 
219 	/* Finally, we need to ACK the RX */
220 	wl1251_rx_ack(wl);
221 }
222