V4L/DVB (4477): Improve hardware algorithm by setting the appropriate registers
Hardware algorithm needs to be configured to:
1) Increase timeout constants, to detect weaker signals;
2) do a wider zigzag search.
Acked-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/cx24123.c b/drivers/media/dvb/frontends/cx24123.c
index 6fd44a1..f77b2d5 100644
--- a/drivers/media/dvb/frontends/cx24123.c
+++ b/drivers/media/dvb/frontends/cx24123.c
@@ -191,7 +191,7 @@
{0x06, 0x31}, /* MPEG (default) */
{0x0b, 0x00}, /* Freq search start point (default) */
{0x0c, 0x00}, /* Demodulator sample gain (default) */
- {0x0d, 0x02}, /* Frequency search range = Fsymbol / 4 (default) */
+ {0x0d, 0x7f}, /* Force driver to shift until the maximum (+-10 MHz) */
{0x0e, 0x03}, /* Default non-inverted, FEC 3/4 (default) */
{0x0f, 0xfe}, /* FEC search mask (all supported codes) */
{0x10, 0x01}, /* Default search inversion, no repeat (default) */
@@ -222,6 +222,7 @@
{0x46, 0x0d}, /* Symbol rate estimator on (default) */
{0x56, 0xc1}, /* Error Counter = Viterbi BER */
{0x57, 0xff}, /* Error Counter Window (default) */
+ {0x5c, 0x20}, /* Acquisition AFC Expiration window (default is 0x10) */
{0x67, 0x83}, /* Non-DCII symbol clock */
};
@@ -779,13 +780,15 @@
if (lock & 0x01)
*status |= FE_HAS_SIGNAL;
if (sync & 0x02)
- *status |= FE_HAS_CARRIER;
+ *status |= FE_HAS_CARRIER; /* Phase locked */
if (sync & 0x04)
*status |= FE_HAS_VITERBI;
+
+ /* Reed-Solomon Status */
if (sync & 0x08)
*status |= FE_HAS_SYNC;
if (sync & 0x80)
- *status |= FE_HAS_LOCK;
+ *status |= FE_HAS_LOCK; /*Full Sync */
return 0;
}
@@ -812,6 +815,7 @@
static int cx24123_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
{
struct cx24123_state *state = fe->demodulator_priv;
+
*signal_strength = cx24123_readreg(state, 0x3b) << 8; /* larger = better */
dprintk("%s: Signal strength = %d\n",__FUNCTION__,*signal_strength);