V4L/DVB (6501): stv0297: Signal strength fixes
Fixes the signal strength value (higher value = higher signal strength)
and scales the value to the range of 0..ffff. The characteristic itself
is wrong. To get proper values on a TT-C2300 in the range of 40..60%
real signal strength, the values from the patch should be divide by two.
The attached patch doesn't fix the characteristic.
Signed-off-by: Hartmut Birr <e9hack@googlemail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/stv0297.c b/drivers/media/dvb/frontends/stv0297.c
index 17e5cb5..7c23775 100644
--- a/drivers/media/dvb/frontends/stv0297.c
+++ b/drivers/media/dvb/frontends/stv0297.c
@@ -358,11 +358,23 @@
static int stv0297_read_signal_strength(struct dvb_frontend *fe, u16 * strength)
{
struct stv0297_state *state = fe->demodulator_priv;
- u8 STRENGTH[2];
+ u8 STRENGTH[3];
+ u16 tmp;
- stv0297_readregs(state, 0x41, STRENGTH, 2);
- *strength = (STRENGTH[1] & 0x03) << 8 | STRENGTH[0];
-
+ stv0297_readregs(state, 0x41, STRENGTH, 3);
+ tmp = (STRENGTH[1] & 0x03) << 8 | STRENGTH[0];
+ if (STRENGTH[2] & 0x20) {
+ if (tmp < 0x200)
+ tmp = 0;
+ else
+ tmp = tmp - 0x200;
+ } else {
+ if (tmp > 0x1ff)
+ tmp = 0;
+ else
+ tmp = 0x1ff - tmp;
+ }
+ *strength = (tmp << 7) | (tmp >> 2);
return 0;
}