2020-05-29 16:21:56

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH 1/3] dt-bindings: net: wireless: mt76: add power-limits node

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 <[email protected]>
---
.../bindings/net/wireless/mediatek,mt76.txt | 47 +++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt b/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt
index ab7e7a00e534..9d9ace0cfbf9 100644
--- a/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt
+++ b/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt
@@ -36,6 +36,7 @@ Optional nodes:
- led: Properties for a connected LED
Optional properties:
- led-sources: See Documentation/devicetree/bindings/leds/common.txt
+- power-limits: contains per-regdomain/channel rate power limit subnodes

&pcie {
pcie0 {
@@ -76,3 +77,49 @@ wmac: wmac@18000000 {

power-domains = <&scpsys MT7622_POWER_DOMAIN_WB>;
};
+
+
+Subnodes of power-limits:
+
+Properties:
+- country: One or more country codes, as used by the cfg80211 regdomain code
+- regdomain: "FCC", "ETSI" or "JP"
+
+If neither country, nor regdomain is specified, the power limits node is used
+as a fallback when no other subnode matches.
+
+Subnodes txpower-2g, txpower-5g:
+
+Properties:
+- channels: pairs of first and last channel number
+- cck: 4 half-dBm per-rate power limit values
+- ofdm: 8 half-dBm per-rate power limit values
+- mcs:
+ sets of per-rate power limit values for 802.11n/802.11ac rates for
+ multiple channel bandwidth settings.
+ Each set starts with the number of channel bandwidth settings for
+ which the rate set applies, followed by either 8 (MT7603/MT7628) or
+ 10 (all other chips) power limit values.
+ The order of the channel bandwidth settings is: 20, 40, 80, 160 MHz.
+
+
+power-limit example:
+
+power-limits {
+ r0 {
+ regdomain = "FCC";
+ txpower-5g {
+ r1 {
+ channels = <36 48>;
+ ofdm = <23 23 23 23 23 23 23 23>;
+ mcs = <1 23 23 23 23 23 23 23 23 23 23>,
+ <3 22 22 22 22 22 22 22 22 22 22>;
+ };
+ r2 {
+ channels = <100 181>;
+ ofdm = <14 14 14 14 14 14 14 14>;
+ mcs = <4 14 14 14 14 14 14 14 14 14 14>;
+ };
+ };
+ };
+};
--
2.24.0


2020-05-29 16:22:52

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH 3/3] mt76: mt7615: implement support for using DT rate power limits

Limits are used to update the channel max_power settings and also passed
to the firmware on channel changes

Signed-off-by: Felix Fietkau <[email protected]>
---
.../net/wireless/mediatek/mt76/mt7615/init.c | 11 +++-
.../net/wireless/mediatek/mt76/mt7615/mcu.c | 61 ++++++++++++++++++-
2 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/init.c b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
index e2d80518e5af..04a32123e7fe 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
@@ -234,6 +234,7 @@ void mt7615_init_txpower(struct mt7615_dev *dev,
int delta_idx, delta = mt76_tx_power_nss_delta(n_chains);
u8 *eep = (u8 *)dev->mt76.eeprom.data;
enum nl80211_band band = sband->band;
+ struct mt76_power_limits limits;
u8 rate_val;

delta_idx = mt7615_eeprom_get_power_delta_index(dev, band);
@@ -262,7 +263,11 @@ void mt7615_init_txpower(struct mt7615_dev *dev,
target_power = max(target_power, eep[index]);
}

- target_power = DIV_ROUND_UP(target_power + delta, 2);
+ target_power += delta;
+ target_power = mt76_get_rate_power_limits(&dev->mphy, chan,
+ &limits,
+ target_power);
+ target_power = DIV_ROUND_UP(target_power, 2);
chan->max_power = min_t(int, chan->max_reg_power,
target_power);
chan->orig_mpwr = target_power;
@@ -280,8 +285,12 @@ mt7615_regd_notifier(struct wiphy *wiphy,
struct mt7615_phy *phy = mphy->priv;
struct cfg80211_chan_def *chandef = &mphy->chandef;

+ memcpy(dev->mt76.alpha2, request->alpha2, sizeof(dev->mt76.alpha2));
dev->mt76.region = request->dfs_region;

+ mt7615_init_txpower(dev, &mphy->sband_2g.sband);
+ mt7615_init_txpower(dev, &mphy->sband_5g.sband);
+
if (!(chandef->chan->flags & IEEE80211_CHAN_RADAR))
return;

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
index 6e869b8c5e26..0b1933111004 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
@@ -2654,16 +2654,75 @@ static void mt7615_mcu_set_txpower_sku(struct mt7615_phy *phy, u8 *sku)
{
struct mt76_phy *mphy = phy->mt76;
struct ieee80211_hw *hw = mphy->hw;
+ struct mt76_power_limits limits;
+ s8 *limits_array = (s8 *)&limits;
int n_chains = hweight8(mphy->antenna_mask);
int tx_power;
int i;
+ static const u8 sku_mapping[] = {
+#define SKU_FIELD(_type, _field) \
+ [MT_SKU_##_type] = offsetof(struct mt76_power_limits, _field)
+ SKU_FIELD(CCK_1_2, cck[0]),
+ SKU_FIELD(CCK_55_11, cck[2]),
+ SKU_FIELD(OFDM_6_9, ofdm[0]),
+ SKU_FIELD(OFDM_12_18, ofdm[2]),
+ SKU_FIELD(OFDM_24_36, ofdm[4]),
+ SKU_FIELD(OFDM_48, ofdm[6]),
+ SKU_FIELD(OFDM_54, ofdm[7]),
+ SKU_FIELD(HT20_0_8, mcs[0][0]),
+ SKU_FIELD(HT20_32, ofdm[0]),
+ SKU_FIELD(HT20_1_2_9_10, mcs[0][1]),
+ SKU_FIELD(HT20_3_4_11_12, mcs[0][3]),
+ SKU_FIELD(HT20_5_13, mcs[0][5]),
+ SKU_FIELD(HT20_6_14, mcs[0][6]),
+ SKU_FIELD(HT20_7_15, mcs[0][7]),
+ SKU_FIELD(HT40_0_8, mcs[1][0]),
+ SKU_FIELD(HT40_32, ofdm[0]),
+ SKU_FIELD(HT40_1_2_9_10, mcs[1][1]),
+ SKU_FIELD(HT40_3_4_11_12, mcs[1][3]),
+ SKU_FIELD(HT40_5_13, mcs[1][5]),
+ SKU_FIELD(HT40_6_14, mcs[1][6]),
+ SKU_FIELD(HT40_7_15, mcs[1][7]),
+ SKU_FIELD(VHT20_0, mcs[0][0]),
+ SKU_FIELD(VHT20_1_2, mcs[0][1]),
+ SKU_FIELD(VHT20_3_4, mcs[0][3]),
+ SKU_FIELD(VHT20_5_6, mcs[0][5]),
+ SKU_FIELD(VHT20_7, mcs[0][7]),
+ SKU_FIELD(VHT20_8, mcs[0][8]),
+ SKU_FIELD(VHT20_9, mcs[0][9]),
+ SKU_FIELD(VHT40_0, mcs[1][0]),
+ SKU_FIELD(VHT40_1_2, mcs[1][1]),
+ SKU_FIELD(VHT40_3_4, mcs[1][3]),
+ SKU_FIELD(VHT40_5_6, mcs[1][5]),
+ SKU_FIELD(VHT40_7, mcs[1][7]),
+ SKU_FIELD(VHT40_8, mcs[1][8]),
+ SKU_FIELD(VHT40_9, mcs[1][9]),
+ SKU_FIELD(VHT80_0, mcs[2][0]),
+ SKU_FIELD(VHT80_1_2, mcs[2][1]),
+ SKU_FIELD(VHT80_3_4, mcs[2][3]),
+ SKU_FIELD(VHT80_5_6, mcs[2][5]),
+ SKU_FIELD(VHT80_7, mcs[2][7]),
+ SKU_FIELD(VHT80_8, mcs[2][8]),
+ SKU_FIELD(VHT80_9, mcs[2][9]),
+ SKU_FIELD(VHT160_0, mcs[3][0]),
+ SKU_FIELD(VHT160_1_2, mcs[3][1]),
+ SKU_FIELD(VHT160_3_4, mcs[3][3]),
+ SKU_FIELD(VHT160_5_6, mcs[3][5]),
+ SKU_FIELD(VHT160_7, mcs[3][7]),
+ SKU_FIELD(VHT160_8, mcs[3][8]),
+ SKU_FIELD(VHT160_9, mcs[3][9]),
+#undef SKU_FIELD
+ };

tx_power = hw->conf.power_level * 2 -
mt76_tx_power_nss_delta(n_chains);
+
+ tx_power = mt76_get_rate_power_limits(mphy, mphy->chandef.chan,
+ &limits, tx_power);
mphy->txpower_cur = tx_power;

for (i = 0; i < MT_SKU_1SS_DELTA; i++)
- sku[i] = tx_power;
+ sku[i] = limits_array[sku_mapping[i]];

for (i = 0; i < 4; i++) {
int delta = 0;
--
2.24.0

2020-05-29 21:27:26

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 1/3] dt-bindings: net: wireless: mt76: add power-limits node

On Fri, May 29, 2020 at 06:19:27PM +0200, Felix Fietkau wrote:
> 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

How do other WiFi chips handle this? If this is added to DT, then it
should be common for all WiFi h/w.

> Signed-off-by: Felix Fietkau <[email protected]>
> ---
> .../bindings/net/wireless/mediatek,mt76.txt | 47 +++++++++++++++++++
> 1 file changed, 47 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt b/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt
> index ab7e7a00e534..9d9ace0cfbf9 100644
> --- a/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt
> +++ b/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt
> @@ -36,6 +36,7 @@ Optional nodes:
> - led: Properties for a connected LED
> Optional properties:
> - led-sources: See Documentation/devicetree/bindings/leds/common.txt
> +- power-limits: contains per-regdomain/channel rate power limit subnodes
>
> &pcie {
> pcie0 {
> @@ -76,3 +77,49 @@ wmac: wmac@18000000 {
>
> power-domains = <&scpsys MT7622_POWER_DOMAIN_WB>;
> };
> +
> +
> +Subnodes of power-limits:
> +
> +Properties:
> +- country: One or more country codes, as used by the cfg80211 regdomain code
> +- regdomain: "FCC", "ETSI" or "JP"
> +
> +If neither country, nor regdomain is specified, the power limits node is used
> +as a fallback when no other subnode matches.
> +
> +Subnodes txpower-2g, txpower-5g:
> +
> +Properties:
> +- channels: pairs of first and last channel number
> +- cck: 4 half-dBm per-rate power limit values
> +- ofdm: 8 half-dBm per-rate power limit values
> +- mcs:
> + sets of per-rate power limit values for 802.11n/802.11ac rates for
> + multiple channel bandwidth settings.
> + Each set starts with the number of channel bandwidth settings for
> + which the rate set applies, followed by either 8 (MT7603/MT7628) or
> + 10 (all other chips) power limit values.
> + The order of the channel bandwidth settings is: 20, 40, 80, 160 MHz.
> +
> +
> +power-limit example:
> +
> +power-limits {
> + r0 {
> + regdomain = "FCC";
> + txpower-5g {
> + r1 {
> + channels = <36 48>;
> + ofdm = <23 23 23 23 23 23 23 23>;
> + mcs = <1 23 23 23 23 23 23 23 23 23 23>,
> + <3 22 22 22 22 22 22 22 22 22 22>;
> + };
> + r2 {
> + channels = <100 181>;
> + ofdm = <14 14 14 14 14 14 14 14>;
> + mcs = <4 14 14 14 14 14 14 14 14 14 14>;
> + };
> + };
> + };
> +};
> --
> 2.24.0
>

2020-05-30 07:09:32

by Felix Fietkau

[permalink] [raw]
Subject: Re: [PATCH 1/3] dt-bindings: net: wireless: mt76: add power-limits node

On 2020-05-29 23:26, Rob Herring wrote:
> On Fri, May 29, 2020 at 06:19:27PM +0200, Felix Fietkau wrote:
>> 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
>
> How do other WiFi chips handle this? If this is added to DT, then it
> should be common for all WiFi h/w.
Most devices store this data in EEPROM, and the way it's handled also
varies across different chips. QCA has EEPROM data that only provides
limits for edge channels (called "conformance test limits")
The only other example I could find of a driver that stores it in DT is
mwifiex, which uses an opaque short array of bytes that is passed to the
firmware directly.
So I don't think it makes sense to put this in the common bindings.
On the other hand, I did try to keep the format as generic and
extensible as possible, so we could always move it over from mt76 to the
common binding once we encounter another driver that needs something
like this.

- Felix