1/******************************************************************************
2 *
3 * Copyright(c) 2009-2012  Realtek Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2 of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
17 *
18 * The full GNU General Public License is included in this distribution in the
19 * file called LICENSE.
20 *
21 * Contact Information:
22 * wlanfae <wlanfae@realtek.com>
23 * Realtek Corporation, No. 2, Innovation Road II, Hsinchu Science Park,
24 * Hsinchu 300, Taiwan.
25 *
26 * Larry Finger <Larry.Finger@lwfinger.net>
27 *
28 *****************************************************************************/
29
30#include "wifi.h"
31#include "base.h"
32#include "rc.h"
33
34/*
35 *Finds the highest rate index we can use
36 *if skb is special data like DHCP/EAPOL, we set should
37 *it to lowest rate CCK_1M, otherwise we set rate to
38 *CCK11M or OFDM_54M based on wireless mode.
39 */
40static u8 _rtl_rc_get_highest_rix(struct rtl_priv *rtlpriv,
41				  struct ieee80211_sta *sta,
42				  struct sk_buff *skb, bool not_data)
43{
44	struct rtl_mac *rtlmac = rtl_mac(rtlpriv);
45	struct rtl_hal *rtlhal = rtl_hal(rtlpriv);
46	struct rtl_phy *rtlphy = &(rtlpriv->phy);
47	struct rtl_sta_info *sta_entry = NULL;
48	u8 wireless_mode = 0;
49
50	/*
51	 *this rate is no use for true rate, firmware
52	 *will control rate at all it just used for
53	 *1.show in iwconfig in B/G mode
54	 *2.in rtl_get_tcb_desc when we check rate is
55	 *      1M we will not use FW rate but user rate.
56	 */
57	if (rtlmac->opmode == NL80211_IFTYPE_AP ||
58		rtlmac->opmode == NL80211_IFTYPE_ADHOC) {
59		if (sta) {
60			sta_entry = (struct rtl_sta_info *) sta->drv_priv;
61			wireless_mode = sta_entry->wireless_mode;
62		} else {
63			return 0;
64		}
65	} else {
66		wireless_mode = rtlmac->mode;
67	}
68
69	if (rtl_is_special_data(rtlpriv->mac80211.hw, skb, true) ||
70			not_data) {
71		return 0;
72	} else {
73		if (rtlhal->current_bandtype == BAND_ON_2_4G) {
74			if (wireless_mode == WIRELESS_MODE_B) {
75				return B_MODE_MAX_RIX;
76			} else if (wireless_mode == WIRELESS_MODE_G) {
77				return G_MODE_MAX_RIX;
78			} else {
79				if (get_rf_type(rtlphy) != RF_2T2R)
80					return N_MODE_MCS7_RIX;
81				else
82					return N_MODE_MCS15_RIX;
83			}
84		} else {
85			if (wireless_mode == WIRELESS_MODE_A) {
86				return A_MODE_MAX_RIX;
87			} else {
88				if (get_rf_type(rtlphy) != RF_2T2R)
89					return N_MODE_MCS7_RIX;
90				else
91					return N_MODE_MCS15_RIX;
92			}
93		}
94	}
95}
96
97static void _rtl_rc_rate_set_series(struct rtl_priv *rtlpriv,
98				    struct ieee80211_sta *sta,
99				    struct ieee80211_tx_rate *rate,
100				    struct ieee80211_tx_rate_control *txrc,
101				    u8 tries, char rix, int rtsctsenable,
102				    bool not_data)
103{
104	struct rtl_mac *mac = rtl_mac(rtlpriv);
105	u8 sgi_20 = 0, sgi_40 = 0;
106
107	if (sta) {
108		sgi_20 = sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_20;
109		sgi_40 = sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_40;
110	}
111	rate->count = tries;
112	rate->idx = rix >= 0x00 ? rix : 0x00;
113
114	if (!not_data) {
115		if (txrc->short_preamble)
116			rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
117		if (mac->opmode == NL80211_IFTYPE_AP ||
118			mac->opmode == NL80211_IFTYPE_ADHOC) {
119			if (sta && (sta->ht_cap.cap &
120			    IEEE80211_HT_CAP_SUP_WIDTH_20_40))
121				rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
122		} else {
123			if (mac->bw_40)
124				rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
125		}
126		if (sgi_20 || sgi_40)
127			rate->flags |= IEEE80211_TX_RC_SHORT_GI;
128		if (sta && sta->ht_cap.ht_supported)
129			rate->flags |= IEEE80211_TX_RC_MCS;
130	}
131}
132
133static void rtl_get_rate(void *ppriv, struct ieee80211_sta *sta,
134			 void *priv_sta, struct ieee80211_tx_rate_control *txrc)
135{
136	struct rtl_priv *rtlpriv = ppriv;
137	struct sk_buff *skb = txrc->skb;
138	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
139	struct ieee80211_tx_rate *rates = tx_info->control.rates;
140	__le16 fc = rtl_get_fc(skb);
141	u8 try_per_rate, i, rix;
142	bool not_data = !ieee80211_is_data(fc);
143
144	if (rate_control_send_low(sta, priv_sta, txrc))
145		return;
146
147	rix = _rtl_rc_get_highest_rix(rtlpriv, sta, skb, not_data);
148	try_per_rate = 1;
149	_rtl_rc_rate_set_series(rtlpriv, sta, &rates[0], txrc,
150				try_per_rate, rix, 1, not_data);
151
152	if (!not_data) {
153		for (i = 1; i < 4; i++)
154			_rtl_rc_rate_set_series(rtlpriv, sta, &rates[i],
155						txrc, i, (rix - i), 1,
156						not_data);
157	}
158}
159
160static bool _rtl_tx_aggr_check(struct rtl_priv *rtlpriv,
161		struct rtl_sta_info *sta_entry, u16 tid)
162{
163	struct rtl_mac *mac = rtl_mac(rtlpriv);
164
165	if (mac->act_scanning)
166		return false;
167
168	if (mac->opmode == NL80211_IFTYPE_STATION &&
169		mac->cnt_after_linked < 3)
170		return false;
171
172	if (sta_entry->tids[tid].agg.agg_state == RTL_AGG_STOP)
173		return true;
174
175	return false;
176}
177
178/*mac80211 Rate Control callbacks*/
179static void rtl_tx_status(void *ppriv,
180			  struct ieee80211_supported_band *sband,
181			  struct ieee80211_sta *sta, void *priv_sta,
182			  struct sk_buff *skb)
183{
184	struct rtl_priv *rtlpriv = ppriv;
185	struct rtl_mac *mac = rtl_mac(rtlpriv);
186	struct ieee80211_hdr *hdr = rtl_get_hdr(skb);
187	__le16 fc = rtl_get_fc(skb);
188	struct rtl_sta_info *sta_entry;
189
190	if (!priv_sta || !ieee80211_is_data(fc))
191		return;
192
193	if (rtl_is_special_data(mac->hw, skb, true))
194		return;
195
196	if (is_multicast_ether_addr(ieee80211_get_DA(hdr))
197	    || is_broadcast_ether_addr(ieee80211_get_DA(hdr)))
198		return;
199
200	if (sta) {
201		/* Check if aggregation has to be enabled for this tid */
202		sta_entry = (struct rtl_sta_info *) sta->drv_priv;
203		if ((sta->ht_cap.ht_supported) &&
204				!(skb->protocol == cpu_to_be16(ETH_P_PAE))) {
205			if (ieee80211_is_data_qos(fc)) {
206				u8 tid = rtl_get_tid(skb);
207				if (_rtl_tx_aggr_check(rtlpriv, sta_entry,
208				    tid)) {
209					sta_entry->tids[tid].agg.agg_state =
210							 RTL_AGG_PROGRESS;
211					ieee80211_start_tx_ba_session(sta,
212								 tid, 5000);
213				}
214			}
215		}
216	}
217}
218
219static void rtl_rate_init(void *ppriv,
220			  struct ieee80211_supported_band *sband,
221			  struct ieee80211_sta *sta, void *priv_sta)
222{
223}
224
225static void rtl_rate_update(void *ppriv,
226			    struct ieee80211_supported_band *sband,
227			    struct ieee80211_sta *sta, void *priv_sta,
228			    u32 changed,
229			    enum nl80211_channel_type oper_chan_type)
230{
231}
232
233static void *rtl_rate_alloc(struct ieee80211_hw *hw,
234		struct dentry *debugfsdir)
235{
236	struct rtl_priv *rtlpriv = rtl_priv(hw);
237	return rtlpriv;
238}
239
240static void rtl_rate_free(void *rtlpriv)
241{
242	return;
243}
244
245static void *rtl_rate_alloc_sta(void *ppriv,
246				struct ieee80211_sta *sta, gfp_t gfp)
247{
248	struct rtl_priv *rtlpriv = ppriv;
249	struct rtl_rate_priv *rate_priv;
250
251	rate_priv = kzalloc(sizeof(struct rtl_rate_priv), gfp);
252	if (!rate_priv) {
253		RT_TRACE(rtlpriv, COMP_ERR, DBG_EMERG,
254			 "Unable to allocate private rc structure\n");
255		return NULL;
256	}
257
258	rtlpriv->rate_priv = rate_priv;
259
260	return rate_priv;
261}
262
263static void rtl_rate_free_sta(void *rtlpriv,
264			      struct ieee80211_sta *sta, void *priv_sta)
265{
266	struct rtl_rate_priv *rate_priv = priv_sta;
267	kfree(rate_priv);
268}
269
270static struct rate_control_ops rtl_rate_ops = {
271	.module = NULL,
272	.name = "rtl_rc",
273	.alloc = rtl_rate_alloc,
274	.free = rtl_rate_free,
275	.alloc_sta = rtl_rate_alloc_sta,
276	.free_sta = rtl_rate_free_sta,
277	.rate_init = rtl_rate_init,
278	.rate_update = rtl_rate_update,
279	.tx_status = rtl_tx_status,
280	.get_rate = rtl_get_rate,
281};
282
283int rtl_rate_control_register(void)
284{
285	return ieee80211_rate_control_register(&rtl_rate_ops);
286}
287
288void rtl_rate_control_unregister(void)
289{
290	ieee80211_rate_control_unregister(&rtl_rate_ops);
291}
292