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Commit f14bfe94 authored by Manu Abraham's avatar Manu Abraham Committed by Mauro Carvalho Chehab
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[media] stb6100: Improve tuner performance 



- Reduce the amount of white noise present, which causes the
  demodulator a significant time to acquire a frontend lock
  on a whole. Frontend shows a large significant improvement in
  performance.

Thanks to Peter Nayler for helping to identify the potential
hotspots and fixing them.

Signed-off-by: default avatarManu Abraham <manu@linuxtv.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 3037fd14

drivers/media/dvb/frontends/stb6100.c

+127 −66
Original line number Diff line number Diff line
@@ -157,13 +157,25 @@ static int stb6100_read_reg(struct stb6100_state *state, u8 reg) 
	u8 regs[STB6100_NUMREGS];

	int rc;



	struct i2c_msg msg = {

		.addr	= state->config->tuner_address + reg,

		.flags	= I2C_M_RD,

		.buf	= regs,

		.len	= 1

	};



	rc = i2c_transfer(state->i2c, &msg, 1);



	if (unlikely(reg >= STB6100_NUMREGS)) {

		dprintk(verbose, FE_ERROR, 1, "Invalid register offset 0x%x", reg);

		return -EINVAL;

	}

	if ((rc = stb6100_read_regs(state, regs)) < 0)

		return rc;

	return (unsigned int)regs[reg];

	if (unlikely(verbose > FE_DEBUG)) {

		dprintk(verbose, FE_DEBUG, 1, "    Read from 0x%02x", state->config->tuner_address);

		dprintk(verbose, FE_DEBUG, 1, "        %s: 0x%02x", stb6100_regnames[reg], regs[0]);

	}



	return (unsigned int)regs[0];

}



static int stb6100_write_reg_range(struct stb6100_state *state, u8 buf[], int start, int len)
@@ -211,20 +223,17 @@ static int stb6100_write_reg(struct stb6100_state *state, u8 reg, u8 data) 
	return stb6100_write_reg_range(state, &data, reg, 1);

}



static int stb6100_write_regs(struct stb6100_state *state, u8 regs[])

{

	stb6100_normalise_regs(regs);

	return stb6100_write_reg_range(state, &regs[1], 1, STB6100_NUMREGS - 1);

}



static int stb6100_get_status(struct dvb_frontend *fe, u32 *status)

{

	int rc;

	struct stb6100_state *state = fe->tuner_priv;



	if ((rc = stb6100_read_reg(state, STB6100_LD)) < 0)

	rc = stb6100_read_reg(state, STB6100_LD);

	if (rc < 0) {

		dprintk(verbose, FE_ERROR, 1, "%s failed", __func__);

		return rc;



	}

	return (rc & STB6100_LD_LOCK) ? TUNER_STATUS_LOCKED : 0;

}
@@ -234,7 +243,8 @@ static int stb6100_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth) 
	u8 f;

	struct stb6100_state *state = fe->tuner_priv;



	if ((rc = stb6100_read_reg(state, STB6100_F)) < 0)

	rc = stb6100_read_reg(state, STB6100_F);

	if (rc < 0)

		return rc;

	f = rc & STB6100_F_F;
@@ -265,14 +275,21 @@ static int stb6100_set_bandwidth(struct dvb_frontend *fe, u32 bandwidth) 
	/* Turn on LPF bandwidth setting clock control,

	 * set bandwidth, wait 10ms, turn off.

	 */

	if ((rc = stb6100_write_reg(state, STB6100_FCCK, 0x0d | STB6100_FCCK_FCCK)) < 0)

	rc = stb6100_write_reg(state, STB6100_FCCK, 0x0d | STB6100_FCCK_FCCK);

	if (rc < 0)

		return rc;

	if ((rc = stb6100_write_reg(state, STB6100_F, 0xc0 | tmp)) < 0)

	rc = stb6100_write_reg(state, STB6100_F, 0xc0 | tmp);

	if (rc < 0)

		return rc;

	msleep(1);

	if ((rc = stb6100_write_reg(state, STB6100_FCCK, 0x0d)) < 0)



	msleep(5);  /*  This is dangerous as another (related) thread may start */



	rc = stb6100_write_reg(state, STB6100_FCCK, 0x0d);

	if (rc < 0)

		return rc;



	msleep(10);  /*  This is dangerous as another (related) thread may start */



	return 0;

}
@@ -284,7 +301,8 @@ static int stb6100_get_frequency(struct dvb_frontend *fe, u32 *frequency) 
	struct stb6100_state *state = fe->tuner_priv;

	u8 regs[STB6100_NUMREGS];



	if ((rc = stb6100_read_regs(state, regs)) < 0)

	rc = stb6100_read_regs(state, regs);

	if (rc < 0)

		return rc;



	odiv = (regs[STB6100_VCO] & STB6100_VCO_ODIV) >> STB6100_VCO_ODIV_SHIFT;
@@ -312,8 +330,7 @@ static int stb6100_set_frequency(struct dvb_frontend *fe, u32 frequency) 
	u8 regs[STB6100_NUMREGS];

	u8 g, psd2, odiv;



	if ((rc = stb6100_read_regs(state, regs)) < 0)

		return rc;

	dprintk(verbose, FE_DEBUG, 1, "Version 2010-8-14 13:51");



	if (fe->ops.get_frontend) {

		dprintk(verbose, FE_DEBUG, 1, "Get frontend parameters");
@@ -321,96 +338,140 @@ static int stb6100_set_frequency(struct dvb_frontend *fe, u32 frequency) 
	}

	srate = p.u.qpsk.symbol_rate;



	regs[STB6100_DLB] = 0xdc;

	/* Disable LPEN */

	regs[STB6100_LPEN] &= ~STB6100_LPEN_LPEN; /* PLL Loop disabled */

	/* Set up tuner cleanly, LPF calibration on */

	rc = stb6100_write_reg(state, STB6100_FCCK, 0x4d | STB6100_FCCK_FCCK);

	if (rc < 0)

		return rc;  /* allow LPF calibration */



	if ((rc = stb6100_write_regs(state, regs)) < 0)

	/* PLL Loop disabled, bias on, VCO on, synth on */

	regs[STB6100_LPEN] = 0xeb;

	rc = stb6100_write_reg(state, STB6100_LPEN, regs[STB6100_LPEN]);

	if (rc < 0)

		return rc;



	/* Baseband gain.	*/

	if (srate >= 15000000)

		g = 9;  //  +4 dB

	else if (srate >= 5000000)

		g = 11; //  +8 dB

	else

		g = 14; // +14 dB



	regs[STB6100_G] = (regs[STB6100_G] & ~STB6100_G_G) | g;

	regs[STB6100_G] &= ~STB6100_G_GCT; /* mask GCT */

	regs[STB6100_G] |= (1 << 5); /* 2Vp-p Mode */

	/* Program the registers with their data values */



	/* VCO divide ratio (LO divide ratio, VCO prescaler enable).	*/

	if (frequency <= 1075000)

		odiv = 1;

	else

		odiv = 0;

	regs[STB6100_VCO] = (regs[STB6100_VCO] & ~STB6100_VCO_ODIV) | (odiv << STB6100_VCO_ODIV_SHIFT);



	if ((frequency > 1075000) && (frequency <= 1325000))

		psd2 = 0;

	else

		psd2 = 1;

	regs[STB6100_K] = (regs[STB6100_K] & ~STB6100_K_PSD2) | (psd2 << STB6100_K_PSD2_SHIFT);

	/* VCO enabled, seach clock off as per LL3.7, 3.4.1 */

	regs[STB6100_VCO] = 0xe0 | (odiv << STB6100_VCO_ODIV_SHIFT);



	/* OSM	*/

	for (ptr = lkup;

	     (ptr->val_high != 0) && !CHKRANGE(frequency, ptr->val_low, ptr->val_high);

	     ptr++);



	if (ptr->val_high == 0) {

		printk(KERN_ERR "%s: frequency out of range: %u kHz\n", __func__, frequency);

		return -EINVAL;

	}

	regs[STB6100_VCO] = (regs[STB6100_VCO] & ~STB6100_VCO_OSM) | ptr->reg;

	rc = stb6100_write_reg(state, STB6100_VCO, regs[STB6100_VCO]);

	if (rc < 0)

		return rc;



	if ((frequency > 1075000) && (frequency <= 1325000))

		psd2 = 0;

	else

		psd2 = 1;

	/* F(VCO) = F(LO) * (ODIV == 0 ? 2 : 4)			*/

	fvco = frequency << (1 + odiv);

	/* N(I) = floor(f(VCO) / (f(XTAL) * (PSD2 ? 2 : 1)))	*/

	nint = fvco / (state->reference << psd2);

	/* N(F) = round(f(VCO) / f(XTAL) * (PSD2 ? 2 : 1) - N(I)) * 2 ^ 9	*/

	nfrac = DIV_ROUND_CLOSEST((fvco - (nint * state->reference << psd2))

					 << (9 - psd2),

				  state->reference);

					 << (9 - psd2), state->reference);



	/* NI */

	regs[STB6100_NI] = nint;

	rc = stb6100_write_reg(state, STB6100_NI, regs[STB6100_NI]);

	if (rc < 0)

		return rc;



	/* NF */

	regs[STB6100_NF_LSB] = nfrac;

	rc = stb6100_write_reg(state, STB6100_NF_LSB, regs[STB6100_NF_LSB]);

	if (rc < 0)

		return rc;



	/* K */

	regs[STB6100_K] = (0x38 & ~STB6100_K_PSD2) | (psd2 << STB6100_K_PSD2_SHIFT);

	regs[STB6100_K] = (regs[STB6100_K] & ~STB6100_K_NF_MSB) | ((nfrac >> 8) & STB6100_K_NF_MSB);

	rc = stb6100_write_reg(state, STB6100_K, regs[STB6100_K]);

	if (rc < 0)

		return rc;



	/* G Baseband gain. */

	if (srate >= 15000000)

		g = 9;  /*  +4 dB */

	else if (srate >= 5000000)

		g = 11; /*  +8 dB */

	else

		g = 14; /* +14 dB */



	regs[STB6100_G] = (0x10 & ~STB6100_G_G) | g;

	regs[STB6100_G] &= ~STB6100_G_GCT; /* mask GCT */

	regs[STB6100_G] |= (1 << 5); /* 2Vp-p Mode */

	rc = stb6100_write_reg(state, STB6100_G, regs[STB6100_G]);

	if (rc < 0)

		return rc;



	/* F we don't write as it is set up in BW set */



	/* DLB set DC servo loop BW to 160Hz (LLA 3.8 / 2.1) */

	regs[STB6100_DLB] = 0xcc;

	rc = stb6100_write_reg(state, STB6100_DLB, regs[STB6100_DLB]);

	if (rc < 0)

		return rc;



	dprintk(verbose, FE_DEBUG, 1,

		"frequency = %u, srate = %u, g = %u, odiv = %u, psd2 = %u, fxtal = %u, osm = %u, fvco = %u, N(I) = %u, N(F) = %u",

		frequency, srate, (unsigned int)g, (unsigned int)odiv,

		(unsigned int)psd2, state->reference,

		ptr->reg, fvco, nint, nfrac);

	regs[STB6100_NI] = nint;

	regs[STB6100_NF_LSB] = nfrac;

	regs[STB6100_K] = (regs[STB6100_K] & ~STB6100_K_NF_MSB) | ((nfrac >> 8) & STB6100_K_NF_MSB);

	regs[STB6100_VCO] |= STB6100_VCO_OSCH;		/* VCO search enabled		*/

	regs[STB6100_VCO] |= STB6100_VCO_OCK;		/* VCO search clock off		*/

	regs[STB6100_FCCK] |= STB6100_FCCK_FCCK;	/* LPF BW setting clock enabled	*/

	regs[STB6100_LPEN] &= ~STB6100_LPEN_LPEN;	/* PLL loop disabled		*/

	/* Power up. */

	regs[STB6100_LPEN] |= STB6100_LPEN_SYNP	| STB6100_LPEN_OSCP | STB6100_LPEN_BEN;



	msleep(2);

	if ((rc = stb6100_write_regs(state, regs)) < 0)

	/* Set up the test registers */

	regs[STB6100_TEST1] = 0x8f;

	rc = stb6100_write_reg(state, STB6100_TEST1, regs[STB6100_TEST1]);

	if (rc < 0)

		return rc;

	regs[STB6100_TEST3] = 0xde;

	rc = stb6100_write_reg(state, STB6100_TEST3, regs[STB6100_TEST3]);

	if (rc < 0)

		return rc;



	msleep(2);

	regs[STB6100_LPEN] |= STB6100_LPEN_LPEN;	/* PLL loop enabled		*/

	if ((rc = stb6100_write_reg(state, STB6100_LPEN, regs[STB6100_LPEN])) < 0)

	/* Bring up tuner according to LLA 3.7 3.4.1, step 2 */

	regs[STB6100_LPEN] = 0xfb; /* PLL Loop enabled, bias on, VCO on, synth on */

	rc = stb6100_write_reg(state, STB6100_LPEN, regs[STB6100_LPEN]);

	if (rc < 0)

		return rc;



	msleep(2);



	/* Bring up tuner according to LLA 3.7 3.4.1, step 3 */

	regs[STB6100_VCO] &= ~STB6100_VCO_OCK;		/* VCO fast search		*/

	if ((rc = stb6100_write_reg(state, STB6100_VCO, regs[STB6100_VCO])) < 0)

	rc = stb6100_write_reg(state, STB6100_VCO, regs[STB6100_VCO]);

	if (rc < 0)

		return rc;



	msleep(10);					/* wait for LO to lock		*/

	msleep(10);  /*  This is dangerous as another (related) thread may start */ /* wait for LO to lock */



	regs[STB6100_VCO] &= ~STB6100_VCO_OSCH;		/* vco search disabled		*/

	regs[STB6100_VCO] |= STB6100_VCO_OCK;		/* search clock off		*/

	if ((rc = stb6100_write_reg(state, STB6100_VCO, regs[STB6100_VCO])) < 0)

		return rc;

	regs[STB6100_FCCK] &= ~STB6100_FCCK_FCCK;       /* LPF BW clock disabled	*/

	stb6100_normalise_regs(regs);

	if ((rc = stb6100_write_reg_range(state, &regs[1], 1, STB6100_NUMREGS - 3)) < 0)

	rc = stb6100_write_reg(state, STB6100_VCO, regs[STB6100_VCO]);

	if (rc < 0)

		return rc;



	msleep(100);

	rc = stb6100_write_reg(state, STB6100_FCCK, 0x0d);

	if (rc < 0)

		return rc;  /* Stop LPF calibration */



	msleep(10);  /*  This is dangerous as another (related) thread may start */

		     /* wait for stabilisation, (should not be necessary)		*/

	return 0;

}
@@ -433,8 +494,8 @@ static int stb6100_init(struct dvb_frontend *fe) 
	state->bandwidth	= status->bandwidth * 1000;	/* Hz	*/

	state->reference	= status->refclock / 1000;	/* kHz	*/



	/* Set default bandwidth.	*/

	return stb6100_set_bandwidth(fe, state->bandwidth);

	/* Set default bandwidth. Modified, PN 13-May-10	*/

	return 0;

}



static int stb6100_get_state(struct dvb_frontend *fe,