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Commit 34a56f2c authored by Rafał Miłecki's avatar Rafał Miłecki Committed by John W. Linville
Browse files

b43: N-PHY: implement calculating RX IQ comp 



Signed-off-by: default avatarRafał Miłecki <zajec5@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 2faa6b83

drivers/net/wireless/b43/phy_n.c

+99 −0
Original line number Diff line number Diff line
@@ -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)

{