1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /* Copyright(c) 2019-2020  Realtek Corporation
3  */
4 
5 #include "debug.h"
6 #include "sar.h"
7 
8 static enum rtw89_sar_subband rtw89_sar_get_subband(struct rtw89_dev *rtwdev,
9 						    u32 center_freq)
10 {
11 	switch (center_freq) {
12 	default:
13 		rtw89_debug(rtwdev, RTW89_DBG_SAR,
14 			    "center freq: %u to SAR subband is unhandled\n",
15 			    center_freq);
16 		fallthrough;
17 	case 2412 ... 2484:
18 		return RTW89_SAR_2GHZ_SUBBAND;
19 	case 5180 ... 5320:
20 		return RTW89_SAR_5GHZ_SUBBAND_1_2;
21 	case 5500 ... 5720:
22 		return RTW89_SAR_5GHZ_SUBBAND_2_E;
23 	case 5745 ... 5825:
24 		return RTW89_SAR_5GHZ_SUBBAND_3;
25 	case 5955 ... 6155:
26 		return RTW89_SAR_6GHZ_SUBBAND_5_L;
27 	case 6175 ... 6415:
28 		return RTW89_SAR_6GHZ_SUBBAND_5_H;
29 	case 6435 ... 6515:
30 		return RTW89_SAR_6GHZ_SUBBAND_6;
31 	case 6535 ... 6695:
32 		return RTW89_SAR_6GHZ_SUBBAND_7_L;
33 	case 6715 ... 6855:
34 		return RTW89_SAR_6GHZ_SUBBAND_7_H;
35 
36 	/* freq 6875 (ch 185, 20MHz) spans RTW89_SAR_6GHZ_SUBBAND_7_H
37 	 * and RTW89_SAR_6GHZ_SUBBAND_8, so directly describe it with
38 	 * struct rtw89_sar_span in the following.
39 	 */
40 
41 	case 6895 ... 7115:
42 		return RTW89_SAR_6GHZ_SUBBAND_8;
43 	}
44 }
45 
46 struct rtw89_sar_span {
47 	enum rtw89_sar_subband subband_low;
48 	enum rtw89_sar_subband subband_high;
49 };
50 
51 #define RTW89_SAR_SPAN_VALID(span) ((span)->subband_high)
52 
53 #define RTW89_SAR_6GHZ_SPAN_HEAD 6145
54 #define RTW89_SAR_6GHZ_SPAN_IDX(center_freq) \
55 	((((int)(center_freq) - RTW89_SAR_6GHZ_SPAN_HEAD) / 5) / 2)
56 
57 #define RTW89_DECL_SAR_6GHZ_SPAN(center_freq, subband_l, subband_h) \
58 	[RTW89_SAR_6GHZ_SPAN_IDX(center_freq)] = { \
59 		.subband_low = RTW89_SAR_6GHZ_ ## subband_l, \
60 		.subband_high = RTW89_SAR_6GHZ_ ## subband_h, \
61 	}
62 
63 /* Since 6GHz SAR subbands are not edge aligned, some cases span two SAR
64  * subbands. In the following, we describe each of them with rtw89_sar_span.
65  */
66 static const struct rtw89_sar_span rtw89_sar_overlapping_6ghz[] = {
67 	RTW89_DECL_SAR_6GHZ_SPAN(6145, SUBBAND_5_L, SUBBAND_5_H),
68 	RTW89_DECL_SAR_6GHZ_SPAN(6165, SUBBAND_5_L, SUBBAND_5_H),
69 	RTW89_DECL_SAR_6GHZ_SPAN(6185, SUBBAND_5_L, SUBBAND_5_H),
70 	RTW89_DECL_SAR_6GHZ_SPAN(6505, SUBBAND_6, SUBBAND_7_L),
71 	RTW89_DECL_SAR_6GHZ_SPAN(6525, SUBBAND_6, SUBBAND_7_L),
72 	RTW89_DECL_SAR_6GHZ_SPAN(6545, SUBBAND_6, SUBBAND_7_L),
73 	RTW89_DECL_SAR_6GHZ_SPAN(6665, SUBBAND_7_L, SUBBAND_7_H),
74 	RTW89_DECL_SAR_6GHZ_SPAN(6705, SUBBAND_7_L, SUBBAND_7_H),
75 	RTW89_DECL_SAR_6GHZ_SPAN(6825, SUBBAND_7_H, SUBBAND_8),
76 	RTW89_DECL_SAR_6GHZ_SPAN(6865, SUBBAND_7_H, SUBBAND_8),
77 	RTW89_DECL_SAR_6GHZ_SPAN(6875, SUBBAND_7_H, SUBBAND_8),
78 	RTW89_DECL_SAR_6GHZ_SPAN(6885, SUBBAND_7_H, SUBBAND_8),
79 };
80 
81 static int rtw89_query_sar_config_common(struct rtw89_dev *rtwdev, s32 *cfg)
82 {
83 	struct rtw89_sar_cfg_common *rtwsar = &rtwdev->sar.cfg_common;
84 	struct rtw89_hal *hal = &rtwdev->hal;
85 	enum rtw89_band band = hal->current_band_type;
86 	u32 center_freq = hal->current_freq;
87 	const struct rtw89_sar_span *span = NULL;
88 	enum rtw89_sar_subband subband_l, subband_h;
89 	int idx;
90 
91 	if (band == RTW89_BAND_6G) {
92 		idx = RTW89_SAR_6GHZ_SPAN_IDX(center_freq);
93 		/* To decrease size of rtw89_sar_overlapping_6ghz[],
94 		 * RTW89_SAR_6GHZ_SPAN_IDX() truncates the leading NULLs
95 		 * to make first span as index 0 of the table. So, if center
96 		 * frequency is less than the first one, it will get netative.
97 		 */
98 		if (idx >= 0 && idx < ARRAY_SIZE(rtw89_sar_overlapping_6ghz))
99 			span = &rtw89_sar_overlapping_6ghz[idx];
100 	}
101 
102 	if (span && RTW89_SAR_SPAN_VALID(span)) {
103 		subband_l = span->subband_low;
104 		subband_h = span->subband_high;
105 	} else {
106 		subband_l = rtw89_sar_get_subband(rtwdev, center_freq);
107 		subband_h = subband_l;
108 	}
109 
110 	rtw89_debug(rtwdev, RTW89_DBG_SAR,
111 		    "for {band %u, center_freq %u}, SAR subband: {%u, %u}\n",
112 		    band, center_freq, subband_l, subband_h);
113 
114 	if (!rtwsar->set[subband_l] && !rtwsar->set[subband_h])
115 		return -ENODATA;
116 
117 	if (!rtwsar->set[subband_l])
118 		*cfg = rtwsar->cfg[subband_h];
119 	else if (!rtwsar->set[subband_h])
120 		*cfg = rtwsar->cfg[subband_l];
121 	else
122 		*cfg = min(rtwsar->cfg[subband_l], rtwsar->cfg[subband_h]);
123 
124 	return 0;
125 }
126 
127 static const
128 struct rtw89_sar_handler rtw89_sar_handlers[RTW89_SAR_SOURCE_NR] = {
129 	[RTW89_SAR_SOURCE_COMMON] = {
130 		.descr_sar_source = "RTW89_SAR_SOURCE_COMMON",
131 		.txpwr_factor_sar = 2,
132 		.query_sar_config = rtw89_query_sar_config_common,
133 	},
134 };
135 
136 #define rtw89_sar_set_src(_dev, _src, _cfg_name, _cfg_data)		\
137 	do {								\
138 		typeof(_src) _s = (_src);				\
139 		typeof(_dev) _d = (_dev);				\
140 		BUILD_BUG_ON(!rtw89_sar_handlers[_s].descr_sar_source);	\
141 		BUILD_BUG_ON(!rtw89_sar_handlers[_s].query_sar_config);	\
142 		lockdep_assert_held(&_d->mutex);			\
143 		_d->sar._cfg_name = *(_cfg_data);			\
144 		_d->sar.src = _s;					\
145 	} while (0)
146 
147 static s8 rtw89_txpwr_sar_to_mac(struct rtw89_dev *rtwdev, u8 fct, s32 cfg)
148 {
149 	const u8 fct_mac = rtwdev->chip->txpwr_factor_mac;
150 	s32 cfg_mac;
151 
152 	cfg_mac = fct > fct_mac ?
153 		  cfg >> (fct - fct_mac) : cfg << (fct_mac - fct);
154 
155 	return (s8)clamp_t(s32, cfg_mac,
156 			   RTW89_SAR_TXPWR_MAC_MIN,
157 			   RTW89_SAR_TXPWR_MAC_MAX);
158 }
159 
160 s8 rtw89_query_sar(struct rtw89_dev *rtwdev)
161 {
162 	const enum rtw89_sar_sources src = rtwdev->sar.src;
163 	/* its members are protected by rtw89_sar_set_src() */
164 	const struct rtw89_sar_handler *sar_hdl = &rtw89_sar_handlers[src];
165 	int ret;
166 	s32 cfg;
167 	u8 fct;
168 
169 	lockdep_assert_held(&rtwdev->mutex);
170 
171 	if (src == RTW89_SAR_SOURCE_NONE)
172 		return RTW89_SAR_TXPWR_MAC_MAX;
173 
174 	ret = sar_hdl->query_sar_config(rtwdev, &cfg);
175 	if (ret)
176 		return RTW89_SAR_TXPWR_MAC_MAX;
177 
178 	fct = sar_hdl->txpwr_factor_sar;
179 
180 	return rtw89_txpwr_sar_to_mac(rtwdev, fct, cfg);
181 }
182 
183 void rtw89_print_sar(struct seq_file *m, struct rtw89_dev *rtwdev)
184 {
185 	const enum rtw89_sar_sources src = rtwdev->sar.src;
186 	/* its members are protected by rtw89_sar_set_src() */
187 	const struct rtw89_sar_handler *sar_hdl = &rtw89_sar_handlers[src];
188 	const u8 fct_mac = rtwdev->chip->txpwr_factor_mac;
189 	int ret;
190 	s32 cfg;
191 	u8 fct;
192 
193 	lockdep_assert_held(&rtwdev->mutex);
194 
195 	if (src == RTW89_SAR_SOURCE_NONE) {
196 		seq_puts(m, "no SAR is applied\n");
197 		return;
198 	}
199 
200 	seq_printf(m, "source: %d (%s)\n", src, sar_hdl->descr_sar_source);
201 
202 	ret = sar_hdl->query_sar_config(rtwdev, &cfg);
203 	if (ret) {
204 		seq_printf(m, "config: return code: %d\n", ret);
205 		seq_printf(m, "assign: max setting: %d (unit: 1/%lu dBm)\n",
206 			   RTW89_SAR_TXPWR_MAC_MAX, BIT(fct_mac));
207 		return;
208 	}
209 
210 	fct = sar_hdl->txpwr_factor_sar;
211 
212 	seq_printf(m, "config: %d (unit: 1/%lu dBm)\n", cfg, BIT(fct));
213 }
214 
215 static int rtw89_apply_sar_common(struct rtw89_dev *rtwdev,
216 				  const struct rtw89_sar_cfg_common *sar)
217 {
218 	enum rtw89_sar_sources src;
219 	int ret = 0;
220 
221 	mutex_lock(&rtwdev->mutex);
222 
223 	src = rtwdev->sar.src;
224 	if (src != RTW89_SAR_SOURCE_NONE && src != RTW89_SAR_SOURCE_COMMON) {
225 		rtw89_warn(rtwdev, "SAR source: %d is in use", src);
226 		ret = -EBUSY;
227 		goto exit;
228 	}
229 
230 	rtw89_sar_set_src(rtwdev, RTW89_SAR_SOURCE_COMMON, cfg_common, sar);
231 	rtw89_chip_set_txpwr(rtwdev);
232 
233 exit:
234 	mutex_unlock(&rtwdev->mutex);
235 	return ret;
236 }
237 
238 static const struct cfg80211_sar_freq_ranges rtw89_common_sar_freq_ranges[] = {
239 	{ .start_freq = 2412, .end_freq = 2484, },
240 	{ .start_freq = 5180, .end_freq = 5320, },
241 	{ .start_freq = 5500, .end_freq = 5720, },
242 	{ .start_freq = 5745, .end_freq = 5825, },
243 	{ .start_freq = 5955, .end_freq = 6155, },
244 	{ .start_freq = 6175, .end_freq = 6415, },
245 	{ .start_freq = 6435, .end_freq = 6515, },
246 	{ .start_freq = 6535, .end_freq = 6695, },
247 	{ .start_freq = 6715, .end_freq = 6875, },
248 	{ .start_freq = 6875, .end_freq = 7115, },
249 };
250 
251 static_assert(RTW89_SAR_SUBBAND_NR ==
252 	      ARRAY_SIZE(rtw89_common_sar_freq_ranges));
253 
254 const struct cfg80211_sar_capa rtw89_sar_capa = {
255 	.type = NL80211_SAR_TYPE_POWER,
256 	.num_freq_ranges = ARRAY_SIZE(rtw89_common_sar_freq_ranges),
257 	.freq_ranges = rtw89_common_sar_freq_ranges,
258 };
259 
260 int rtw89_ops_set_sar_specs(struct ieee80211_hw *hw,
261 			    const struct cfg80211_sar_specs *sar)
262 {
263 	struct rtw89_dev *rtwdev = hw->priv;
264 	struct rtw89_sar_cfg_common sar_common = {0};
265 	u8 fct;
266 	u32 freq_start;
267 	u32 freq_end;
268 	s32 power;
269 	u32 i, idx;
270 
271 	if (sar->type != NL80211_SAR_TYPE_POWER)
272 		return -EINVAL;
273 
274 	fct = rtw89_sar_handlers[RTW89_SAR_SOURCE_COMMON].txpwr_factor_sar;
275 
276 	for (i = 0; i < sar->num_sub_specs; i++) {
277 		idx = sar->sub_specs[i].freq_range_index;
278 		if (idx >= ARRAY_SIZE(rtw89_common_sar_freq_ranges))
279 			return -EINVAL;
280 
281 		freq_start = rtw89_common_sar_freq_ranges[idx].start_freq;
282 		freq_end = rtw89_common_sar_freq_ranges[idx].end_freq;
283 		power = sar->sub_specs[i].power;
284 
285 		rtw89_debug(rtwdev, RTW89_DBG_SAR,
286 			    "On freq %u to %u, set SAR limit %d (unit: 1/%lu dBm)\n",
287 			    freq_start, freq_end, power, BIT(fct));
288 
289 		sar_common.set[idx] = true;
290 		sar_common.cfg[idx] = power;
291 	}
292 
293 	return rtw89_apply_sar_common(rtwdev, &sar_common);
294 }
295