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Commit c19314b0 authored by Antti Palosaari's avatar Antti Palosaari Committed by Mauro Carvalho Chehab
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[media] m88ts2022: reimplement synthesizer calculations 



Used synthesizer is very typical integer-N PLL, with configurable
reference frequency divider, output frequency divider and of
course N itself. Most common method to calculate values is first
select output divider, then calculate VCO frequency and finally
calculate PLL N from VCO frequency. Do it that way.

Also make some cleanups for filter logic and signal strength.

Signed-off-by: default avatarAntti Palosaari <crope@iki.fi>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 92676ac9

drivers/media/tuners/m88ts2022.c

+53 −68
Original line number Diff line number Diff line
@@ -175,27 +175,33 @@ static int m88ts2022_set_params(struct dvb_frontend *fe) 
{

	struct m88ts2022_priv *priv = fe->tuner_priv;

	struct dtv_frontend_properties *c = &fe->dtv_property_cache;

	int ret = 0, div;

	u8 buf[3], u8tmp, cap_code, lpf_mxdiv, div_max, div_min;

	u16 N_reg, N, K;

	u32 lpf_gm, lpf_coeff, gdiv28, frequency_khz, frequency_offset;

	u32 freq_3db;

	int ret;

	unsigned int frequency_khz, frequency_offset_khz, f_3db_hz;

	unsigned int f_ref_khz, f_vco_khz, div_ref, div_out, pll_n, gdiv28;

	u8 buf[3], u8tmp, cap_code, lpf_gm, lpf_mxdiv, div_max, div_min;

	u16 u16tmp;

	dev_dbg(&priv->i2c->dev,

			"%s: frequency=%d symbol_rate=%d rolloff=%d\n",

			__func__, c->frequency, c->symbol_rate, c->rolloff);

	/*

	 * Integer-N PLL synthesizer

	 * kHz is used for all calculations to keep calculations within 32-bit

	 */

	f_ref_khz = DIV_ROUND_CLOSEST(priv->cfg->clock, 1000);

	div_ref = DIV_ROUND_CLOSEST(f_ref_khz, 2000);



	if (c->symbol_rate < 5000000)

		frequency_offset = 3000000; /* 3 MHz */

		frequency_offset_khz = 3000; /* 3 MHz */

	else

		frequency_offset = 0;

		frequency_offset_khz = 0;



	frequency_khz = c->frequency + (frequency_offset / 1000);

	frequency_khz = c->frequency + frequency_offset_khz;



	if (frequency_khz < 1103000) {

		div = 2;

		div_out = 4;

		u8tmp = 0x1b;

	} else {

		div = 1;

		div_out = 2;

		u8tmp = 0x0b;

	}
@@ -205,30 +211,30 @@ static int m88ts2022_set_params(struct dvb_frontend *fe) 
	if (ret)

		goto err;



	K = DIV_ROUND_CLOSEST((priv->cfg->clock / 2), 1000000);

	N = 1ul * frequency_khz * K * div * 2 / (priv->cfg->clock / 1000);

	N += N % 2;

	f_vco_khz = frequency_khz * div_out;

	pll_n = f_vco_khz * div_ref / f_ref_khz;

	pll_n += pll_n % 2;

	priv->frequency_khz = pll_n * f_ref_khz / div_ref / div_out;



	if (N < 4095)

		N_reg = N - 1024;

	else if (N < 6143)

		N_reg = N + 1024;

	if (pll_n < 4095)

		u16tmp = pll_n - 1024;

	else if (pll_n < 6143)

		u16tmp = pll_n + 1024;

	else

		N_reg = N + 3072;

		u16tmp = pll_n + 3072;



	buf[0] = (N_reg >> 8) & 0x3f;

	buf[1] = (N_reg >> 0) & 0xff;

	buf[2] = K - 8;

	buf[0] = (u16tmp >> 8) & 0x3f;

	buf[1] = (u16tmp >> 0) & 0xff;

	buf[2] = div_ref - 8;

	ret = m88ts2022_wr_regs(priv, 0x01, buf, 3);

	if (ret)

		goto err;



	priv->frequency_khz = 1ul * N * (priv->cfg->clock / 1000) / K / div / 2;



	dev_dbg(&priv->i2c->dev,

			"%s: frequency=%d offset=%d K=%d N=%d div=%d\n",

			"%s: frequency=%u offset=%d f_vco_khz=%u pll_n=%u div_ref=%u div_out=%u\n",

			__func__, priv->frequency_khz,

			priv->frequency_khz - c->frequency, K, N, div);

			priv->frequency_khz - c->frequency, f_vco_khz, pll_n,

			div_ref, div_out);



	ret = m88ts2022_cmd(fe, 0x10, 5, 0x15, 0x40, 0x00, NULL);

	if (ret)
@@ -284,7 +290,8 @@ static int m88ts2022_set_params(struct dvb_frontend *fe) 
	if (ret)

		goto err;



	gdiv28 = DIV_ROUND_CLOSEST(priv->cfg->clock / 1000000 * 1694, 1000);

	/* filters */

	gdiv28 = DIV_ROUND_CLOSEST(f_ref_khz * 1694U, 1000000U);



	ret = m88ts2022_wr_reg(priv, 0x04, gdiv28);

	if (ret)
@@ -309,35 +316,20 @@ static int m88ts2022_set_params(struct dvb_frontend *fe) 
	gdiv28 = gdiv28 * 207 / (cap_code * 2 + 151);

	div_max = gdiv28 * 135 / 100;

	div_min = gdiv28 * 78 / 100;

	if (div_max > 63)

		div_max = 63;



	freq_3db = 1ul * c->symbol_rate * 135 / 200 + 2000000;

	freq_3db += frequency_offset;

	if (freq_3db < 7000000)

		freq_3db = 7000000;

	if (freq_3db > 40000000)

		freq_3db = 40000000;



	lpf_coeff = 3200;

	lpf_gm = DIV_ROUND_CLOSEST(freq_3db * gdiv28, lpf_coeff *

			(priv->cfg->clock / 1000));

	if (lpf_gm > 23)

		lpf_gm = 23;

	if (lpf_gm < 1)

		lpf_gm = 1;



	lpf_mxdiv = DIV_ROUND_CLOSEST(lpf_gm * lpf_coeff *

			(priv->cfg->clock / 1000), freq_3db);



	if (lpf_mxdiv < div_min) {

		lpf_gm++;

		lpf_mxdiv = DIV_ROUND_CLOSEST(lpf_gm * lpf_coeff *

				(priv->cfg->clock / 1000), freq_3db);

	}

	div_max = clamp_val(div_max, 0U, 63U);



	if (lpf_mxdiv > div_max)

		lpf_mxdiv = div_max;

	f_3db_hz = c->symbol_rate * 135UL / 200UL;

	f_3db_hz +=  2000000U + (frequency_offset_khz * 1000U);

	f_3db_hz = clamp(f_3db_hz, 7000000U, 40000000U);



#define LPF_COEFF 3200U

	lpf_gm = DIV_ROUND_CLOSEST(f_3db_hz * gdiv28, LPF_COEFF * f_ref_khz);

	lpf_gm = clamp_val(lpf_gm, 1U, 23U);



	lpf_mxdiv = DIV_ROUND_CLOSEST(lpf_gm * LPF_COEFF * f_ref_khz, f_3db_hz);

	if (lpf_mxdiv < div_min)

		lpf_mxdiv = DIV_ROUND_CLOSEST(++lpf_gm * LPF_COEFF * f_ref_khz, f_3db_hz);

	lpf_mxdiv = clamp_val(lpf_mxdiv, 0U, div_max);



	ret = m88ts2022_wr_reg(priv, 0x04, lpf_mxdiv);

	if (ret)
@@ -492,44 +484,37 @@ static int m88ts2022_get_if_frequency(struct dvb_frontend *fe, u32 *frequency) 
static int m88ts2022_get_rf_strength(struct dvb_frontend *fe, u16 *strength)

{

	struct m88ts2022_priv *priv = fe->tuner_priv;

	u8  u8tmp, gain1, gain2, gain3;

	u16 gain, u16tmp;

	int ret;

	u8 u8tmp;

	u16 gain, u16tmp;

	unsigned int gain1, gain2, gain3;



	ret = m88ts2022_rd_reg(priv, 0x3d, &u8tmp);

	if (ret)

		goto err;



	gain1 = (u8tmp >> 0) & 0x1f;

	if (gain1 > 15)

		gain1 = 15;

	gain1 = clamp(gain1, 0U, 15U);



	ret = m88ts2022_rd_reg(priv, 0x21, &u8tmp);

	if (ret)

		goto err;



	gain2 = (u8tmp >> 0) & 0x1f;

	if (gain2 < 2)

		gain2 = 2;

	if (gain2 > 16)

		gain2 = 16;

	gain2 = clamp(gain2, 2U, 16U);



	ret = m88ts2022_rd_reg(priv, 0x66, &u8tmp);

	if (ret)

		goto err;



	gain3 = (u8tmp >> 3) & 0x07;

	if (gain3 > 6)

		gain3 = 6;

	gain3 = clamp(gain3, 0U, 6U);



	gain = gain1 * 265 + gain2 * 338 + gain3 * 285;



	/* scale value to 0x0000-0xffff */

	u16tmp = (0xffff - gain);

	if (u16tmp < 59000)

		u16tmp = 59000;

	else if (u16tmp > 61500)

		u16tmp = 61500;

	u16tmp = clamp_val(u16tmp, 59000U, 61500U);



	*strength = (u16tmp - 59000) * 0xffff / (61500 - 59000);

err: