Commit f8fde0e0 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] r820t: Give a better estimation of the signal strength 



Instead of a binary signal strength measure, use the tuner gain
to obtain a better estimation of the signal strength.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: default avatarAntti Palosaari <crope@iki.fi>
parent 6889ab2a

drivers/media/tuners/r820t.c

+27 −3
Original line number Diff line number Diff line
@@ -1082,6 +1082,18 @@ static int r820t_set_tv_standard(struct r820t_priv *priv, 
	return 0;

}



static int r820t_read_gain(struct r820t_priv *priv)

{

	u8 data[4];

	int rc;



	rc = r820_read(priv, 0x00, data, sizeof(data));

	if (rc < 0)

		return rc;



	return ((data[3] & 0x0f) << 1) + ((data[3] & 0xf0) >> 4);

}



static int generic_set_freq(struct dvb_frontend *fe,

			    u32 freq /* in HZ */,

			    unsigned bw,
@@ -1353,11 +1365,23 @@ static int r820t_set_params(struct dvb_frontend *fe) 
static int r820t_signal(struct dvb_frontend *fe, u16 *strength)

{

	struct r820t_priv *priv = fe->tuner_priv;

	int rc = 0;



	if (priv->has_lock)

		*strength = 0xffff;

	else

	if (priv->has_lock) {

		rc = r820t_read_gain(priv);

		if (rc < 0)

			return rc;



		/* A higher gain at LNA means a lower signal strength */

		*strength = (45 - rc) << 4 | 0xff;

	} else {

		*strength = 0;

	}



	tuner_dbg("%s: %s, gain=%d strength=%d\n",

		  __func__,

		  priv->has_lock ? "PLL locked" : "no signal",

		  rc, *strength);



	return 0;

}