mac80211: add TPC support in control path

Transmit power control (TPC) per packet hence per station can be used to
manage interference and increase overall spatial reuse and therefore
increases sum throughput in WiFi networks with multiple APs and STAs.
Although several of today's wifi chips, e.g., from QCA and from Mediatek
support fine-grained TPC per packet, the Linux mac80211 layer does not
provide support this annotation nor control yet.

This series proposes several changes to introduce TPC support in
mac80211, in particular to annotate tx-power per packet/per mrr stage in
the Tx control path.
The patches include new nembers in the Tx control path structs, a
modified tx-power level support annotation, hardware flags and an
utility function for the convenient use of struct ieee80211_rate_status
(introduced by 44fa75f207d8a106bc75e6230db61e961fdbf8a8) for tx-power
status report in drivers.

Compile-Tested: current wireless-next tree with all flags on
Tested-on PCEngines APU with ath9k WiFi device on OpenWrt Linux
        Kernel 5.10.137
I tested the tx-power annotation with an implementation of TPC in ath9k
(not included in this RFC) and small changes in minstrel_ht for debugfs
access. Tx-power status report in ath9k required the proposed utility
function in mac80211.

Signed-off-by: Thomas Huehn <thomas.huehn@hs-nordhausen.de>
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>

Jonas Jelonek (4):
  mac80211: modify tx-power level annotation
  mac80211: add tx-power annotation in control path
  mac80211: add hardware flags for TPC support
  mac80211: add utility function for tx_rate - rate_info conversion

 include/net/mac80211.h | 60 +++++++++++++++++++++++++++++++++++-------
 net/mac80211/debugfs.c |  2 ++
 net/mac80211/util.c    | 35 ++++++++++++++++++++++++
 3 files changed, 87 insertions(+), 10 deletions(-)

-- 
2.30.2