diff options
| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2013-04-07 18:12:56 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2013-04-16 21:20:12 -0300 |
| commit | f8fde0e045aeac4417b09bef01b3ada74a4cbc80 (patch) | |
| tree | 20421fa889615a116ad574585707b40733a63107 /drivers/media/tuners | |
| parent | 6889ab2a25cf39a048edc69b4d61884b8b4da6b0 (diff) | |
[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: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
Diffstat (limited to 'drivers/media/tuners')
| -rw-r--r-- | drivers/media/tuners/r820t.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/drivers/media/tuners/r820t.c b/drivers/media/tuners/r820t.c index 7e02920f385a..ed9cd6569548 100644 --- a/drivers/media/tuners/r820t.c +++ b/drivers/media/tuners/r820t.c @@ -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; } |