[media] tda10023: Don't use a magic numbers for QAM modulation (37c52abd) · Commits · 戴 / test

drivers/media/dvb/frontends/tda10023.c

+43 −23

Original line number	Diff line number	Diff line
		@@ -298,25 +298,43 @@ static int tda10023_init (struct dvb_frontend *fe)
		return 0;
		}

		struct qam_params {
		u8 qam, lockthr, mseth, aref, agcrefnyq, eragnyq_thd;
		};

		static int tda10023_set_parameters (struct dvb_frontend *fe,
		struct dvb_frontend_parameters *p)
		{
		struct tda10023_state* state = fe->demodulator_priv;

		static int qamvals[6][6] = {
		// QAM LOCKTHR MSETH AREF AGCREFNYQ ERAGCNYQ_THD
		{ (5<<2), 0x78, 0x8c, 0x96, 0x78, 0x4c }, // 4 QAM
		{ (0<<2), 0x87, 0xa2, 0x91, 0x8c, 0x57 }, // 16 QAM
		{ (1<<2), 0x64, 0x74, 0x96, 0x8c, 0x57 }, // 32 QAM
		{ (2<<2), 0x46, 0x43, 0x6a, 0x6a, 0x44 }, // 64 QAM
		{ (3<<2), 0x36, 0x34, 0x7e, 0x78, 0x4c }, // 128 QAM
		{ (4<<2), 0x26, 0x23, 0x6c, 0x5c, 0x3c }, // 256 QAM
		static const struct qam_params qam_params[] = {
		/* Modulation QAM LOCKTHR MSETH AREF AGCREFNYQ ERAGCNYQ_THD */
		[QPSK] = { (5<<2), 0x78, 0x8c, 0x96, 0x78, 0x4c },
		[QAM_16] = { (0<<2), 0x87, 0xa2, 0x91, 0x8c, 0x57 },
		[QAM_32] = { (1<<2), 0x64, 0x74, 0x96, 0x8c, 0x57 },
		[QAM_64] = { (2<<2), 0x46, 0x43, 0x6a, 0x6a, 0x44 },
		[QAM_128] = { (3<<2), 0x36, 0x34, 0x7e, 0x78, 0x4c },
		[QAM_256] = { (4<<2), 0x26, 0x23, 0x6c, 0x5c, 0x3c },
		};
		unsigned qam = p->u.qam.modulation;

		int qam = p->u.qam.modulation;

		if (qam < 0 \|\| qam > 5)
		/*
		* gcc optimizes the code bellow the same way as it would code:
		* "if (qam > 5) return -EINVAL;"
		* Yet, the code is clearer, as it shows what QAM standards are
		* supported by the driver, and avoids the usage of magic numbers on
		* it.
		*/
		switch (qam) {
		case QPSK:
		case QAM_16:
		case QAM_32:
		case QAM_64:
		case QAM_128:
		case QAM_256:
		break;
		default:
		return -EINVAL;
		}

		if (fe->ops.tuner_ops.set_params) {
		fe->ops.tuner_ops.set_params(fe, p);
		@@ -324,16 +342,18 @@ static int tda10023_set_parameters (struct dvb_frontend *fe,
		}

		tda10023_set_symbolrate (state, p->u.qam.symbol_rate);
		tda10023_writereg (state, 0x05, qamvals[qam][1]);
		tda10023_writereg (state, 0x08, qamvals[qam][2]);
		tda10023_writereg (state, 0x09, qamvals[qam][3]);
		tda10023_writereg (state, 0xb4, qamvals[qam][4]);
		tda10023_writereg (state, 0xb6, qamvals[qam][5]);

		// tda10023_writereg (state, 0x04, (p->inversion?0x12:0x32));
		// tda10023_writebit (state, 0x04, 0x60, (p->inversion?0:0x20));
		tda10023_writereg(state, 0x05, qam_params[qam].lockthr);
		tda10023_writereg(state, 0x08, qam_params[qam].mseth);
		tda10023_writereg(state, 0x09, qam_params[qam].aref);
		tda10023_writereg(state, 0xb4, qam_params[qam].agcrefnyq);
		tda10023_writereg(state, 0xb6, qam_params[qam].eragnyq_thd);

		#if 0
		tda10023_writereg(state, 0x04, (p->inversion ? 0x12 : 0x32));
		tda10023_writebit(state, 0x04, 0x60, (p->inversion ? 0 : 0x20));
		#endif
		tda10023_writebit(state, 0x04, 0x40, 0x40);
		tda10023_setup_reg0 (state, qamvals[qam][0]);
		tda10023_setup_reg0(state, qam_params[qam].qam);

		return 0;
		}

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