Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 59a7a23c authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] drxk: use a better calculus for RF strength 



The AZ6007 driver released by Terratec has a better way to
estimate the signal strength, at CtrlSigStrength(). Port it
to the driver.
It should be noticed that there are two parameters there that
are tuner-specific.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 8f3741e0

drivers/media/dvb-frontends/drxk_hard.c

+109 −17
Original line number Diff line number Diff line
@@ -6390,6 +6390,107 @@ static int drxk_set_parameters(struct dvb_frontend *fe) 
	return 0;

}



static int get_strength(struct drxk_state *state, u64 *strength)

{

	int status;

	struct SCfgAgc   rfAgc, ifAgc;

	u32          totalGain  = 0;

	u32          atten      = 0;

	u32          agcRange   = 0;

	u16            scu_lvl  = 0;

	u16            scu_coc  = 0;

	/* FIXME: those are part of the tuner presets */

	u16 tunerRfGain         = 50; /* Default value on az6007 driver */

	u16 tunerIfGain         = 40; /* Default value on az6007 driver */



	*strength = 0;



	if (IsDVBT(state)) {

		rfAgc = state->m_dvbtRfAgcCfg;

		ifAgc = state->m_dvbtIfAgcCfg;

	} else if (IsQAM(state)) {

		rfAgc = state->m_qamRfAgcCfg;

		ifAgc = state->m_qamIfAgcCfg;

	} else {

		rfAgc = state->m_atvRfAgcCfg;

		ifAgc = state->m_atvIfAgcCfg;

	}



	if (rfAgc.ctrlMode == DRXK_AGC_CTRL_AUTO) {

		/* SCU outputLevel */

		status = read16(state, SCU_RAM_AGC_RF_IACCU_HI__A, &scu_lvl);

		if (status < 0)

			return status;



		/* SCU c.o.c. */

		read16(state, SCU_RAM_AGC_RF_IACCU_HI_CO__A, &scu_coc);

		if (status < 0)

			return status;



		if (((u32) scu_lvl + (u32) scu_coc) < 0xffff)

			rfAgc.outputLevel = scu_lvl + scu_coc;

		else

			rfAgc.outputLevel = 0xffff;



		/* Take RF gain into account */

		totalGain += tunerRfGain;



		/* clip output value */

		if (rfAgc.outputLevel < rfAgc.minOutputLevel)

			rfAgc.outputLevel = rfAgc.minOutputLevel;

		if (rfAgc.outputLevel > rfAgc.maxOutputLevel)

			rfAgc.outputLevel = rfAgc.maxOutputLevel;



		agcRange = (u32) (rfAgc.maxOutputLevel - rfAgc.minOutputLevel);

		if (agcRange > 0) {

			atten += 100UL *

				((u32)(tunerRfGain)) *

				((u32)(rfAgc.outputLevel - rfAgc.minOutputLevel))

				/ agcRange;

		}

	}



	if (ifAgc.ctrlMode == DRXK_AGC_CTRL_AUTO) {

		status = read16(state, SCU_RAM_AGC_IF_IACCU_HI__A,

				&ifAgc.outputLevel);

		if (status < 0)

			return status;



		status = read16(state, SCU_RAM_AGC_INGAIN_TGT_MIN__A,

				&ifAgc.top);

		if (status < 0)

			return status;



		/* Take IF gain into account */

		totalGain += (u32) tunerIfGain;



		/* clip output value */

		if (ifAgc.outputLevel < ifAgc.minOutputLevel)

			ifAgc.outputLevel = ifAgc.minOutputLevel;

		if (ifAgc.outputLevel > ifAgc.maxOutputLevel)

			ifAgc.outputLevel = ifAgc.maxOutputLevel;



		agcRange  = (u32) (ifAgc.maxOutputLevel - ifAgc.minOutputLevel);

		if (agcRange > 0) {

			atten += 100UL *

				((u32)(tunerIfGain)) *

				((u32)(ifAgc.outputLevel - ifAgc.minOutputLevel))

				/ agcRange;

		}

	}



	/*

	 * Convert to 0..65535 scale.

	 * If it can't be measured (AGC is disabled), just show 100%.

	 */

	if (totalGain > 0)

		*strength = (65535UL * atten / totalGain);

	else

		*strength = 65535;



	return 0;

}



static int drxk_get_stats(struct dvb_frontend *fe)

{

	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
@@ -6404,7 +6505,7 @@ static int drxk_get_stats(struct dvb_frontend *fe) 
	u32 pre_bit_count;

	u32 pkt_count;

	u32 pkt_error_count;

	s32 cnr, gain;

	s32 cnr;



	if (state->m_DrxkState == DRXK_NO_DEV)

		return -ENODEV;
@@ -6421,6 +6522,13 @@ static int drxk_get_stats(struct dvb_frontend *fe) 
	if (stat == DEMOD_LOCK)

		state->fe_status |= 0x07;



	/*

	 * Estimate signal strength from AGC

	 */

	get_strength(state, &c->strength.stat[0].uvalue);

	c->strength.stat[0].scale = FE_SCALE_RELATIVE;





	if (stat >= DEMOD_LOCK) {

		GetSignalToNoise(state, &cnr);

		c->cnr.stat[0].svalue = cnr * 100;
@@ -6500,22 +6608,6 @@ static int drxk_get_stats(struct dvb_frontend *fe) 
	c->post_bit_count.stat[0].scale = FE_SCALE_COUNTER;

	c->post_bit_count.stat[0].uvalue += post_bit_count;



	/*

	 * Read AGC gain

	 *

	 * IFgain = (IQM_AF_AGC_IF__A * 26.75) (nA)

	 */

	status = read16(state, IQM_AF_AGC_IF__A, &reg16);

	if (status < 0) {

		printk(KERN_ERR "drxk: Error %d on %s\n", status, __func__);

		return status;

	}

	gain = 2675 * (reg16 - DRXK_AGC_DAC_OFFSET) / 100;



	/* FIXME: it makes sense to fix the scale here to dBm */

	c->strength.stat[0].scale = FE_SCALE_RELATIVE;

	c->strength.stat[0].uvalue = gain;



error:

	return status;

}