V4L/DVB (13331): mxl5005s: provide ability to override QAM gain for HVR-1600
The HVR-1600 doesn't use the standard mechanism for computing the gain when
in QAM mode, instead always forcing it to be 0x02. Provide the ability to
override the algorithm on a per-board basis.
This change results in an improvement of 0.4-0.6 dB for QAM tuning.
This work was sponsored by ONELAN Limited.
Cc: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/common/tuners/mxl5005s.c b/drivers/media/common/tuners/mxl5005s.c
index 0803dab..605e28b 100644
--- a/drivers/media/common/tuners/mxl5005s.c
+++ b/drivers/media/common/tuners/mxl5005s.c
@@ -2789,7 +2789,10 @@
/* add for 2.6.5 Special setting for QAM */
if (state->Mod_Type == MXL_QAM) {
- if (state->RF_IN < 680000000)
+ if (state->config->qam_gain != 0)
+ status += MXL_ControlWrite(fe, RFSYN_CHP_GAIN,
+ state->config->qam_gain);
+ else if (state->RF_IN < 680000000)
status += MXL_ControlWrite(fe, RFSYN_CHP_GAIN, 3);
else
status += MXL_ControlWrite(fe, RFSYN_CHP_GAIN, 2);
diff --git a/drivers/media/common/tuners/mxl5005s.h b/drivers/media/common/tuners/mxl5005s.h
index 7ac6815..fc8a1ff 100644
--- a/drivers/media/common/tuners/mxl5005s.h
+++ b/drivers/media/common/tuners/mxl5005s.h
@@ -108,6 +108,10 @@
#define MXL_LOW_IF 1
u8 if_mode;
+ /* Some boards need to override the built-in logic for determining
+ the gain when in QAM mode (the HVR-1600 is one such case) */
+ u8 qam_gain;
+
/* Stuff I don't know what to do with */
u8 AgcMasterByte;
};
diff --git a/drivers/media/video/cx18/cx18-dvb.c b/drivers/media/video/cx18/cx18-dvb.c
index f402e79..54a6fd3 100644
--- a/drivers/media/video/cx18/cx18-dvb.c
+++ b/drivers/media/video/cx18/cx18-dvb.c
@@ -61,6 +61,7 @@
.top = MXL5005S_TOP_25P2,
.mod_mode = MXL_DIGITAL_MODE,
.if_mode = MXL_ZERO_IF,
+ .qam_gain = 0x02,
.AgcMasterByte = 0x00,
};