When chip's temperature is changed, RF characters are changed. To keep the
characters to be consistent, 8723d uses thermal meter to assist in
calibrating LCK, IQK, crystal and TX power.

A base thermal value is programmed in efuse, all calibration data in
MP process is based on this thermal value. So we calucate the delta of
thermal value between the base value, and use this delta to reference XTAL
and TX power offset tables to know how much we need to adjust.

For IQK and LCK, driver checks if delta of thermal value is over 8, then
they are triggered.

For crystal adjustment, when delta of thermal value is changed, we check
XTAL tables to get offset of XTAL value. If thermal value is larger than
base value, positive table (_p as suffix) is used. Otherwise, we use
negative table (_n as suffix). Then, we add offset to XTAL default value
programmed in efuse, and write sum value to register.

To compensate TX power, there are two hierarchical tables. First level use
delta of thermal value to access eight tables to yield delta of TX power
index. Then, plus base TX power index to get index of BB swing table
(second level tables) where register value is induced.

BB swing table can't deal with all cases, if index of BB swing table is
over the size of the table. In this case, TX AGC is used to compensate the
remnant part. Assume 'upper' is the upper bound of BB swing table, and
'target' is the desired index. Then, we can illustrate them as

  compensation method    BB swing        TX AGC
  -------------------    --------    --------------
  target > upper         upper       target - upper
  target < 0             0           target
  otherwise              target      0

For debug purpose, add a column 'rem' to tx_pwr_tbl entry, and it looks
like

  path rate       pwr       base      (byr  lmt ) rem
    A  CCK_1M     32(0x20)   34   -2 (   0   -2)    0
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200512102621.5148-4-yhchuang@realtek.com