From 34a56f2cae865224829d3fa7b8d7ddeee139191f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Fri, 15 Jan 2010 15:29:05 +0100 Subject: [PATCH] b43: N-PHY: implement calculating RX IQ comp MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Rafał Miłecki Signed-off-by: John W. Linville --- drivers/net/wireless/b43/phy_n.c | 99 ++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) diff --git a/drivers/net/wireless/b43/phy_n.c b/drivers/net/wireless/b43/phy_n.c index 776d0082ef1c..d08feffdce68 100644 --- a/drivers/net/wireless/b43/phy_n.c +++ b/drivers/net/wireless/b43/phy_n.c @@ -464,6 +464,105 @@ static void b43_nphy_rx_iq_coeffs(struct b43_wldev *dev, bool write, } } +/* http://bcm-v4.sipsolutions.net/802.11/PHY/N/CalcRxIqComp */ +static void b43_nphy_calc_rx_iq_comp(struct b43_wldev *dev, u8 mask) +{ + int i; + s32 iq; + u32 ii; + u32 qq; + int iq_nbits, qq_nbits; + int arsh, brsh; + u16 tmp, a, b; + + struct nphy_iq_est est; + struct b43_phy_n_iq_comp old; + struct b43_phy_n_iq_comp new = { }; + bool error = false; + + if (mask == 0) + return; + + b43_nphy_rx_iq_coeffs(dev, false, &old); + b43_nphy_rx_iq_coeffs(dev, true, &new); + b43_nphy_rx_iq_est(dev, &est, 0x4000, 32, false); + new = old; + + for (i = 0; i < 2; i++) { + if (i == 0 && (mask & 1)) { + iq = est.iq0_prod; + ii = est.i0_pwr; + qq = est.q0_pwr; + } else if (i == 1 && (mask & 2)) { + iq = est.iq1_prod; + ii = est.i1_pwr; + qq = est.q1_pwr; + } else { + B43_WARN_ON(1); + continue; + } + + if (ii + qq < 2) { + error = true; + break; + } + + iq_nbits = fls(abs(iq)); + qq_nbits = fls(qq); + + arsh = iq_nbits - 20; + if (arsh >= 0) { + a = -((iq << (30 - iq_nbits)) + (ii >> (1 + arsh))); + tmp = ii >> arsh; + } else { + a = -((iq << (30 - iq_nbits)) + (ii << (-1 - arsh))); + tmp = ii << -arsh; + } + if (tmp == 0) { + error = true; + break; + } + a /= tmp; + + brsh = qq_nbits - 11; + if (brsh >= 0) { + b = (qq << (31 - qq_nbits)); + tmp = ii >> brsh; + } else { + b = (qq << (31 - qq_nbits)); + tmp = ii << -brsh; + } + if (tmp == 0) { + error = true; + break; + } + b = int_sqrt(b / tmp - a * a) - (1 << 10); + + if (i == 0 && (mask & 0x1)) { + if (dev->phy.rev >= 3) { + new.a0 = a & 0x3FF; + new.b0 = b & 0x3FF; + } else { + new.a0 = b & 0x3FF; + new.b0 = a & 0x3FF; + } + } else if (i == 1 && (mask & 0x2)) { + if (dev->phy.rev >= 3) { + new.a1 = a & 0x3FF; + new.b1 = b & 0x3FF; + } else { + new.a1 = b & 0x3FF; + new.b1 = a & 0x3FF; + } + } + } + + if (error) + new = old; + + b43_nphy_rx_iq_coeffs(dev, true, &new); +} + /* http://bcm-v4.sipsolutions.net/802.11/PHY/N/TxIqWar */ static void b43_nphy_tx_iq_workaround(struct b43_wldev *dev) { -- 2.20.1