[PATCH v6 23/24] rtw89: add SAR files

[Ping-Ke Shih <pkshih@realtek.com>]

SAR stands for specific absorption rate. Driver controls TX power to follow
the regulation of SAR.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtw89/sar.c | 190 +++++++++++++++++++++++
 drivers/net/wireless/realtek/rtw89/sar.h |  26 ++++
 2 files changed, 216 insertions(+)
 create mode 100644 drivers/net/wireless/realtek/rtw89/sar.c
 create mode 100644 drivers/net/wireless/realtek/rtw89/sar.h

diff --git a/drivers/net/wireless/realtek/rtw89/sar.c b/drivers/net/wireless/realtek/rtw89/sar.c
new file mode 100644
index 000000000000..097c87899cea
--- /dev/null
+++ b/drivers/net/wireless/realtek/rtw89/sar.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/* Copyright(c) 2019-2020  Realtek Corporation
+ */
+
+#include "debug.h"
+#include "sar.h"
+
+static int rtw89_query_sar_config_common(struct rtw89_dev *rtwdev, s32 *cfg)
+{
+	struct rtw89_sar_cfg_common *rtwsar = &rtwdev->sar.cfg_common;
+	enum rtw89_subband subband = rtwdev->hal.current_subband;
+
+	if (!rtwsar->set[subband])
+		return -ENODATA;
+
+	*cfg = rtwsar->cfg[subband];
+	return 0;
+}
+
+static const
+struct rtw89_sar_handler rtw89_sar_handlers[RTW89_SAR_SOURCE_NR] = {
+	[RTW89_SAR_SOURCE_COMMON] = {
+		.descr_sar_source = "RTW89_SAR_SOURCE_COMMON",
+		.txpwr_factor_sar = 2,
+		.query_sar_config = rtw89_query_sar_config_common,
+	},
+};
+
+#define rtw89_sar_set_src(_dev, _src, _cfg_name, _cfg_data)		\
+	do {								\
+		typeof(_src) _s = (_src);				\
+		typeof(_dev) _d = (_dev);				\
+		BUILD_BUG_ON(!rtw89_sar_handlers[_s].descr_sar_source);	\
+		BUILD_BUG_ON(!rtw89_sar_handlers[_s].query_sar_config);	\
+		lockdep_assert_held(&_d->mutex);			\
+		_d->sar._cfg_name = *(_cfg_data);			\
+		_d->sar.src = _s;					\
+	} while (0)
+
+static s8 rtw89_txpwr_sar_to_mac(struct rtw89_dev *rtwdev, u8 fct, s32 cfg)
+{
+	const u8 fct_mac = rtwdev->chip->txpwr_factor_mac;
+	s32 cfg_mac;
+
+	cfg_mac = fct > fct_mac ?
+		  cfg >> (fct - fct_mac) : cfg << (fct_mac - fct);
+
+	return (s8)clamp_t(s32, cfg_mac,
+			   RTW89_SAR_TXPWR_MAC_MIN,
+			   RTW89_SAR_TXPWR_MAC_MAX);
+}
+
+s8 rtw89_query_sar(struct rtw89_dev *rtwdev)
+{
+	const enum rtw89_sar_sources src = rtwdev->sar.src;
+	/* its members are protected by rtw89_sar_set_src() */
+	const struct rtw89_sar_handler *sar_hdl = &rtw89_sar_handlers[src];
+	int ret;
+	s32 cfg;
+	u8 fct;
+
+	lockdep_assert_held(&rtwdev->mutex);
+
+	if (src == RTW89_SAR_SOURCE_NONE)
+		return RTW89_SAR_TXPWR_MAC_MAX;
+
+	ret = sar_hdl->query_sar_config(rtwdev, &cfg);
+	if (ret)
+		return RTW89_SAR_TXPWR_MAC_MAX;
+
+	fct = sar_hdl->txpwr_factor_sar;
+
+	return rtw89_txpwr_sar_to_mac(rtwdev, fct, cfg);
+}
+
+void rtw89_print_sar(struct seq_file *m, struct rtw89_dev *rtwdev)
+{
+	const enum rtw89_sar_sources src = rtwdev->sar.src;
+	/* its members are protected by rtw89_sar_set_src() */
+	const struct rtw89_sar_handler *sar_hdl = &rtw89_sar_handlers[src];
+	const u8 fct_mac = rtwdev->chip->txpwr_factor_mac;
+	int ret;
+	s32 cfg;
+	u8 fct;
+
+	lockdep_assert_held(&rtwdev->mutex);
+
+	if (src == RTW89_SAR_SOURCE_NONE) {
+		seq_puts(m, "no SAR is applied\n");
+		return;
+	}
+
+	seq_printf(m, "source: %d (%s)\n", src, sar_hdl->descr_sar_source);
+
+	ret = sar_hdl->query_sar_config(rtwdev, &cfg);
+	if (ret) {
+		seq_printf(m, "config: return code: %d\n", ret);
+		seq_printf(m, "assign: max setting: %d (unit: 1/%lu dBm)\n",
+			   RTW89_SAR_TXPWR_MAC_MAX, BIT(fct_mac));
+		return;
+	}
+
+	fct = sar_hdl->txpwr_factor_sar;
+
+	seq_printf(m, "config: %d (unit: 1/%lu dBm)\n", cfg, BIT(fct));
+}
+
+static int rtw89_apply_sar_common(struct rtw89_dev *rtwdev,
+				  const struct rtw89_sar_cfg_common *sar)
+{
+	enum rtw89_sar_sources src;
+	int ret = 0;
+
+	mutex_lock(&rtwdev->mutex);
+
+	src = rtwdev->sar.src;
+	if (src != RTW89_SAR_SOURCE_NONE && src != RTW89_SAR_SOURCE_COMMON) {
+		rtw89_warn(rtwdev, "SAR source: %d is in use", src);
+		ret = -EBUSY;
+		goto exit;
+	}
+
+	rtw89_sar_set_src(rtwdev, RTW89_SAR_SOURCE_COMMON, cfg_common, sar);
+	rtw89_chip_set_txpwr(rtwdev);
+
+exit:
+	mutex_unlock(&rtwdev->mutex);
+	return ret;
+}
+
+static const u8 rtw89_common_sar_subband_map[] = {
+	RTW89_CH_2G,
+	RTW89_CH_5G_BAND_1,
+	RTW89_CH_5G_BAND_3,
+	RTW89_CH_5G_BAND_4,
+};
+
+static const struct cfg80211_sar_freq_ranges rtw89_common_sar_freq_ranges[] = {
+	{ .start_freq = 2412, .end_freq = 2484, },
+	{ .start_freq = 5180, .end_freq = 5320, },
+	{ .start_freq = 5500, .end_freq = 5720, },
+	{ .start_freq = 5745, .end_freq = 5825, },
+};
+
+static_assert(ARRAY_SIZE(rtw89_common_sar_subband_map) ==
+	      ARRAY_SIZE(rtw89_common_sar_freq_ranges));
+
+const struct cfg80211_sar_capa rtw89_sar_capa = {
+	.type = NL80211_SAR_TYPE_POWER,
+	.num_freq_ranges = ARRAY_SIZE(rtw89_common_sar_freq_ranges),
+	.freq_ranges = rtw89_common_sar_freq_ranges,
+};
+
+int rtw89_ops_set_sar_specs(struct ieee80211_hw *hw,
+			    const struct cfg80211_sar_specs *sar)
+{
+	struct rtw89_dev *rtwdev = hw->priv;
+	struct rtw89_sar_cfg_common sar_common = {0};
+	u8 fct;
+	u32 freq_start;
+	u32 freq_end;
+	u32 band;
+	s32 power;
+	u32 i, idx;
+
+	if (sar->type != NL80211_SAR_TYPE_POWER)
+		return -EINVAL;
+
+	fct = rtw89_sar_handlers[RTW89_SAR_SOURCE_COMMON].txpwr_factor_sar;
+
+	for (i = 0; i < sar->num_sub_specs; i++) {
+		idx = sar->sub_specs[i].freq_range_index;
+		if (idx >= ARRAY_SIZE(rtw89_common_sar_freq_ranges))
+			return -EINVAL;
+
+		freq_start = rtw89_common_sar_freq_ranges[idx].start_freq;
+		freq_end = rtw89_common_sar_freq_ranges[idx].end_freq;
+		band = rtw89_common_sar_subband_map[idx];
+		power = sar->sub_specs[i].power;
+
+		rtw89_info(rtwdev, "On freq %u to %u, ", freq_start, freq_end);
+		rtw89_info(rtwdev, "set SAR power limit %d (unit: 1/%lu dBm)\n",
+			   power, BIT(fct));
+
+		sar_common.set[band] = true;
+		sar_common.cfg[band] = power;
+	}
+
+	return rtw89_apply_sar_common(rtwdev, &sar_common);
+}
diff --git a/drivers/net/wireless/realtek/rtw89/sar.h b/drivers/net/wireless/realtek/rtw89/sar.h
new file mode 100644
index 000000000000..7b5484c84eb1
--- /dev/null
+++ b/drivers/net/wireless/realtek/rtw89/sar.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/* Copyright(c) 2019-2020  Realtek Corporation
+ */
+
+#ifndef __RTW89_SAR_H__
+#define __RTW89_SAR_H__
+
+#include "core.h"
+
+#define RTW89_SAR_TXPWR_MAC_MAX S8_MAX
+#define RTW89_SAR_TXPWR_MAC_MIN S8_MIN
+
+struct rtw89_sar_handler {
+	const char *descr_sar_source;
+	u8 txpwr_factor_sar;
+	int (*query_sar_config)(struct rtw89_dev *rtwdev, s32 *cfg);
+};
+
+extern const struct cfg80211_sar_capa rtw89_sar_capa;
+
+s8 rtw89_query_sar(struct rtw89_dev *rtwdev);
+void rtw89_print_sar(struct seq_file *m, struct rtw89_dev *rtwdev);
+int rtw89_ops_set_sar_specs(struct ieee80211_hw *hw,
+			    const struct cfg80211_sar_specs *sar);
+
+#endif
-- 
2.25.1