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Commit 3366cd5d authored by David Howells's avatar David Howells Committed by Mauro Carvalho Chehab
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[media] ts2020: Provide DVBv5 API signal strength 



Provide a DVBv5 API signal strength.  This is in units of 0.001 dBm rather
than a percentage.

>From Antti Palosaari's testing with a signal generator, it appears that the
gain calculated according to Montage's specification if negated is a
reasonable representation of the signal strength of the generator.

To this end:

 (1) Polled statistic gathering needed to be implemented in the TS2020 driver.
     This is done in the ts2020_stat_work() function.

 (2) The calculated gain is placed as the signal strength in the
     dtv_property_cache associated with the front end with the scale set to
     FE_SCALE_DECIBEL.

 (3) The DVBv3 format signal strength then needed to be calculated from the
     signal strength stored in the dtv_property_cache rather than accessing
     the value when ts2020_read_signal_strength() is called.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAntti Palosaari <crope@iki.fi>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 0f91c9d6

drivers/media/dvb-frontends/ts2020.c

+53 −9
Original line number Diff line number Diff line
@@ -32,10 +32,11 @@ struct ts2020_priv { 
	struct regmap_config regmap_config;

	struct regmap *regmap;

	struct dvb_frontend *fe;

	struct delayed_work stat_work;

	int (*get_agc_pwm)(struct dvb_frontend *fe, u8 *_agc_pwm);

	/* i2c details */

	int i2c_address;

	struct i2c_adapter *i2c;

	int i2c_address;

	u8 clk_out:2;

	u8 clk_out_div:5;

	u32 frequency_div; /* LO output divider switch frequency */
@@ -65,6 +66,7 @@ static int ts2020_release(struct dvb_frontend *fe) 
static int ts2020_sleep(struct dvb_frontend *fe)

{

	struct ts2020_priv *priv = fe->tuner_priv;

	int ret;

	u8 u8tmp;



	if (priv->tuner == TS2020_M88TS2020)
@@ -72,11 +74,18 @@ static int ts2020_sleep(struct dvb_frontend *fe) 
	else

		u8tmp = 0x00;



	return regmap_write(priv->regmap, u8tmp, 0x00);

	ret = regmap_write(priv->regmap, u8tmp, 0x00);

	if (ret < 0)

		return ret;



	/* stop statistics polling */

	cancel_delayed_work_sync(&priv->stat_work);

	return 0;

}



static int ts2020_init(struct dvb_frontend *fe)

{

	struct dtv_frontend_properties *c = &fe->dtv_property_cache;

	struct ts2020_priv *priv = fe->tuner_priv;

	int i;

	u8 u8tmp;
@@ -138,6 +147,13 @@ static int ts2020_init(struct dvb_frontend *fe) 
				     reg_vals[i].val);

	}



	/* Initialise v5 stats here */

	c->strength.len = 1;

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

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



	/* Start statistics polling */

	schedule_delayed_work(&priv->stat_work, 0);

	return 0;

}
@@ -410,20 +426,47 @@ static int ts2020_get_tuner_gain(struct dvb_frontend *fe, __s64 *_gain) 
	return ts2020_read_tuner_gain(fe, v_agc, _gain);

}



/*

 * Gather statistics on a regular basis

 */

static void ts2020_stat_work(struct work_struct *work)

{

	struct ts2020_priv *priv = container_of(work, struct ts2020_priv,

					       stat_work.work);

	struct i2c_client *client = priv->client;

	struct dtv_frontend_properties *c = &priv->fe->dtv_property_cache;

	int ret;



	dev_dbg(&client->dev, "\n");



	ret = ts2020_get_tuner_gain(priv->fe, &c->strength.stat[0].svalue);

	if (ret < 0)

		goto err;



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



	schedule_delayed_work(&priv->stat_work, msecs_to_jiffies(2000));

	return;

err:

	dev_dbg(&client->dev, "failed=%d\n", ret);

}



/*

 * Read TS2020 signal strength in v3 format.

 */

static int ts2020_read_signal_strength(struct dvb_frontend *fe,

						u16 *signal_strength)

				       u16 *_signal_strength)

{

	struct dtv_frontend_properties *c = &fe->dtv_property_cache;

	unsigned strength;

	__s64 gain;

	int ret;



	/* Determine the total gain of the tuner */

	ret = ts2020_get_tuner_gain(fe, &gain);

	if (ret < 0)

		return ret;

	if (c->strength.stat[0].scale == FE_SCALE_NOT_AVAILABLE) {

		*_signal_strength = 0;

		return 0;

	}



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



	/* Calculate the signal strength based on the total gain of the tuner */

	if (gain < -85000)
@@ -439,7 +482,7 @@ static int ts2020_read_signal_strength(struct dvb_frontend *fe, 
		/* 90% - 99%: strong signal */

		strength = 90 + (45000 + gain) / 5000;



	*signal_strength = strength * 65535 / 100;

	*_signal_strength = strength * 65535 / 100;

	return 0;

}
@@ -546,6 +589,7 @@ static int ts2020_probe(struct i2c_client *client, 
	dev->get_agc_pwm = pdata->get_agc_pwm;

	fe->tuner_priv = dev;

	dev->client = client;

	INIT_DELAYED_WORK(&dev->stat_work, ts2020_stat_work);



	/* check if the tuner is there */

	ret = regmap_read(dev->regmap, 0x00, &utmp);