This subnode can be used to set per-rate tx power limits either per
country code / regdomain or globally.
These limits are typically provided by the device manufacturers and are
used to limit sideband emissions and stay within regulatory limits
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/eeprom.c | 203 ++++++++++++++++++++
drivers/net/wireless/mediatek/mt76/mt76.h | 13 ++
2 files changed, 216 insertions(+)
diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
index c236e303ccfd..334606b07693 100644
--- a/drivers/net/wireless/mediatek/mt76/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
@@ -104,6 +104,209 @@ mt76_eeprom_override(struct mt76_dev *dev)
}
EXPORT_SYMBOL_GPL(mt76_eeprom_override);
+static bool mt76_string_prop_find(struct property *prop, const char *str)
+{
+ const char *cp = NULL;
+
+ if (!prop || !str || !str[0])
+ return false;
+
+ while ((cp = of_prop_next_string(prop, cp)) != NULL)
+ if (!strcasecmp(cp, str))
+ return true;
+
+ return false;
+}
+
+static struct device_node *
+mt76_find_power_limits_node(struct mt76_dev *dev)
+{
+ struct device_node *np = dev->dev->of_node;
+ const char *const region_names[] = {
+ [NL80211_DFS_ETSI] = "etsi",
+ [NL80211_DFS_FCC] = "fcc",
+ [NL80211_DFS_JP] = "jp",
+ };
+ struct device_node *cur, *fallback = NULL;
+ const char *region_name = NULL;
+
+ if (dev->region < ARRAY_SIZE(region_names))
+ region_name = region_names[dev->region];
+
+ np = of_get_child_by_name(np, "power-limits");
+ if (!np)
+ return NULL;
+
+ for_each_child_of_node(np, cur) {
+ struct property *country = of_find_property(cur, "country", NULL);
+ struct property *regd = of_find_property(cur, "regdomain", NULL);
+
+ if (!country && !regd) {
+ fallback = cur;
+ continue;
+ }
+
+ if (mt76_string_prop_find(country, dev->alpha2) ||
+ mt76_string_prop_find(regd, region_name))
+ return cur;
+ }
+
+ return fallback;
+}
+
+static const __be32 *
+mt76_get_of_array(struct device_node *np, char *name, size_t *len, int min)
+{
+ struct property *prop = of_find_property(np, name, NULL);
+
+ if (!prop || !prop->value || prop->length < min * 4)
+ return NULL;
+
+ *len = prop->length;
+
+ return prop->value;
+}
+
+static struct device_node *
+mt76_find_channel_node(struct device_node *np, struct ieee80211_channel *chan)
+{
+ struct device_node *cur;
+ const __be32 *val;
+ size_t len;
+
+ for_each_child_of_node(np, cur) {
+ val = mt76_get_of_array(cur, "channels", &len, 2);
+ if (!val)
+ continue;
+
+ while (len >= 2 * sizeof(*val)) {
+ if (chan->hw_value >= be32_to_cpu(val[0]) &&
+ chan->hw_value <= be32_to_cpu(val[1]))
+ return cur;
+
+ val += 2;
+ len -= 2 * sizeof(*val);
+ }
+ }
+
+ return NULL;
+}
+
+static s8
+mt76_get_txs_delta(struct device_node *np, u8 nss)
+{
+ const __be32 *val;
+ size_t len;
+
+ if (nss >= 4)
+ return 0;
+
+ val = mt76_get_of_array(np, "txs_delta", &len, 3);
+ return be32_to_cpu(val[3 - nss]);
+}
+
+static void
+mt76_apply_array_limit(s8 *pwr, size_t pwr_len, const __be32 *data,
+ s8 target_power, s8 nss_delta, s8 *max_power)
+{
+ int i;
+
+ if (!data)
+ return;
+
+ for (i = 0; i < pwr_len; i++) {
+ pwr[i] = min_t(s8, target_power,
+ be32_to_cpu(data[i]) + nss_delta);
+ *max_power = max(*max_power, pwr[i]);
+ }
+}
+
+s8 mt76_get_rate_power_limits(struct mt76_phy *phy,
+ struct ieee80211_channel *chan,
+ struct mt76_power_limits *dest,
+ s8 target_power)
+{
+ struct mt76_dev *dev = phy->dev;
+ struct device_node *np;
+ const __be32 *val;
+ char name[16];
+ u32 mcs_rates = dev->drv->mcs_rates;
+ char band;
+ size_t len;
+ int i, cur;
+ s8 max_power = 0;
+ s8 txs_delta;
+
+ if (!mcs_rates)
+ mcs_rates = 10;
+
+ memset(dest, target_power, sizeof(*dest));
+
+ if (!IS_ENABLED(CONFIG_OF))
+ return target_power;
+
+ np = mt76_find_power_limits_node(dev);
+ if (!np)
+ return target_power;
+
+ switch (chan->band) {
+ case NL80211_BAND_2GHZ:
+ band = '2';
+ break;
+ case NL80211_BAND_5GHZ:
+ band = '5';
+ break;
+ default:
+ return target_power;
+ }
+
+ snprintf(name, sizeof(name), "txpower-%cg", band);
+ np = of_get_child_by_name(np, name);
+ if (!np)
+ return target_power;
+
+ np = mt76_find_channel_node(np, chan);
+ if (!np)
+ return target_power;
+
+ txs_delta = mt76_get_txs_delta(np, hweight8(phy->antenna_mask));
+
+ val = mt76_get_of_array(np, "cck", &len, ARRAY_SIZE(dest->cck));
+ mt76_apply_array_limit(dest->cck, ARRAY_SIZE(dest->cck), val,
+ target_power, txs_delta, &max_power);
+
+ val = mt76_get_of_array(np, "ofdm", &len, ARRAY_SIZE(dest->ofdm));
+ mt76_apply_array_limit(dest->ofdm, ARRAY_SIZE(dest->ofdm), val,
+ target_power, txs_delta, &max_power);
+
+ val = mt76_get_of_array(np, "mcs", &len, mcs_rates + 1);
+ if (!val)
+ return max_power;
+
+ len /= 4;
+ cur = be32_to_cpu(val[0]);
+ for (i = 0; i < ARRAY_SIZE(dest->mcs); i++) {
+ if (len < mcs_rates + 1)
+ break;
+
+ mt76_apply_array_limit(dest->mcs[i], ARRAY_SIZE(dest->mcs[i]),
+ val + 1, target_power, txs_delta,
+ &max_power);
+ if (--cur > 0)
+ continue;
+
+ val += mcs_rates + 1;
+ len -= mcs_rates + 1;
+ if (!len)
+ break;
+
+ cur = be32_to_cpu(val[0]);
+ }
+
+ return max_power;
+}
+EXPORT_SYMBOL_GPL(mt76_get_rate_power_limits);
+
int
mt76_eeprom_init(struct mt76_dev *dev, int len)
{
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index dfe625a53c63..64cafc0caa33 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -306,6 +306,7 @@ struct mt76_driver_ops {
u32 drv_flags;
u32 survey_flags;
u16 txwi_size;
+ u8 mcs_rates;
void (*update_survey)(struct mt76_dev *dev);
@@ -558,6 +559,7 @@ struct mt76_dev {
struct mt76_rate_power rate_power;
+ char alpha2[3];
enum nl80211_dfs_regions region;
u32 debugfs_reg;
@@ -577,6 +579,12 @@ struct mt76_dev {
};
};
+struct mt76_power_limits {
+ s8 cck[4];
+ s8 ofdm[8];
+ s8 mcs[4][10];
+};
+
enum mt76_phy_type {
MT_PHY_TYPE_CCK,
MT_PHY_TYPE_OFDM,
@@ -959,4 +967,9 @@ struct sk_buff *mt76_mcu_get_response(struct mt76_dev *dev,
void mt76_set_irq_mask(struct mt76_dev *dev, u32 addr, u32 clear, u32 set);
+s8 mt76_get_rate_power_limits(struct mt76_phy *phy,
+ struct ieee80211_channel *chan,
+ struct mt76_power_limits *dest,
+ s8 target_power);
+
#endif
--
2.24.0
