[PATCH 6/6] b43: add RF power offset for N-PHY r8 + radio 2057 r8

[Alessio Ferri <alessio.ferri@mythread.it>]

Add the 2.4 GHz RF power offset table for N-PHY rev 8 paired with
radio 2057 rev 8 and wire it to the existing dispatcher.

b43_ntab_get_rf_pwr_offset_table() currently dispatches on phy->rev
== 17 (radio_rev 14) and phy->rev == 16 (radio_rev 9) for 2.4 GHz.
phy->rev == 8 falls through and the function logs:

    b43-phyX ERROR: No 2GHz RF power table available for this device

Add a phy->rev == 8 / radio_rev == 8 case returning the new table.

The values are sourced from the proprietary Broadcom wl driver's
nphy_papd_padgain_dlt_2g_2057rev5 array. Reusing the rev 5 values
is structurally appropriate: the IPA TX gain table added by the
preceding patch in this series shares the low 24 bits of every
entry with rev 5 - same gain step amplitudes, only the PAD-gain
selector byte differs. b43's pad_gain extraction in
b43_nphy_tx_pwr_ctl_init() reads bits 19..23 of the gain entry,
which sit in the shared low-24-bit range; the same gain index
therefore maps to the same physical PAD gain code on both
revisions and warrants the same per-index dB offset.

Note that b43_nphy_tx_gain_table_upload() currently has a "TODO:
Enable this once we have gains configured" early-return for
phy->rev >= 7. With that early-return in place, this table is
fetched (silencing the b43err that would otherwise abort PHY
init) but its values are not yet written to MMIO. Resolving the
TODO is a separate investigation outside the scope of this
series; the values supplied here are documented now so that, once
the upload path is enabled, the correct rev 8 offsets are
already in tree.

Signed-off-by: Alessio Ferri <alessio.ferri@mythread.it>
---
 .../net/wireless/broadcom/b43/tables_nphy.c   | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/net/wireless/broadcom/b43/tables_nphy.c b/drivers/net/wireless/broadcom/b43/tables_nphy.c
index 84e8d718d..ecd660b9c 100644
--- a/drivers/net/wireless/broadcom/b43/tables_nphy.c
+++ b/drivers/net/wireless/broadcom/b43/tables_nphy.c
@@ -2923,6 +2923,21 @@ static const s16 b43_ntab_rf_pwr_offset_2057_rev9_5g[] = {
 	0,
 };
 
+/* Sourced from the rev 5 sibling: the rev 8 IPA TX gain table
+ * shares the low 24 bits of every entry with rev 5 (only the
+ * PAD-gain selector byte differs), so the same gain index maps to
+ * the same physical PAD gain code on both revisions.
+ */
+static const s16 b43_ntab_rf_pwr_offset_2057_rev8_2g[] = {
+	-109, -109, -82, -68, -58,
+	-50,  -44, -39, -35, -31,
+	-28,  -26, -23, -21, -19,
+	-17,  -16, -14, -13, -11,
+	-10,   -9,  -8,  -7,  -5,
+	 -5,   -4,  -3,  -2,  -1,
+	 -1,    0,
+};
+
 /* Extracted from MMIO dump of 6.30.223.248
  * Entries: 0, 26, 28, 29, 30, 31 were guessed
  */
@@ -3782,6 +3797,10 @@ const s16 *b43_ntab_get_rf_pwr_offset_table(struct b43_wldev *dev)
 			if (phy->radio_rev == 9)
 				return b43_ntab_rf_pwr_offset_2057_rev9_2g;
 			break;
+		case 8:
+			if (phy->radio_rev == 8)
+				return b43_ntab_rf_pwr_offset_2057_rev8_2g;
+			break;
 		}
 
 		b43err(dev->wl,
-- 
2.43.0