V4L/DVB (13329): s5h1409: provide HVR-1600 specific optimizations

Perform some optimization of the register configuration based on a trace
of the HVR-1600 Windows i2c traffic (and consultation with Steven Toth).
Note that some of these values may be able to be moved into the common driver,
but I am holding off on that until they can be tested with other boards.

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/dvb/frontends/s5h1409.c b/drivers/media/dvb/frontends/s5h1409.c
index fb30115..85fba58 100644
--- a/drivers/media/dvb/frontends/s5h1409.c
+++ b/drivers/media/dvb/frontends/s5h1409.c
@@ -614,6 +614,21 @@
 	/* The datasheet says that after initialisation, VSB is default */
 	state->current_modulation = VSB_8;
 
+	/* Optimize for the HVR-1600 if appropriate.  Note that some of these
+	   may get folded into the generic case after testing with other
+	   devices */
+	if (state->config->hvr1600_opt == S5H1409_HVR1600_OPTIMIZE) {
+		/* VSB AGC REF */
+		s5h1409_writereg(state, 0x09, 0x0050);
+
+		/* Unknown but Windows driver does it... */
+		s5h1409_writereg(state, 0x21, 0x0001);
+		s5h1409_writereg(state, 0x50, 0x030e);
+
+		/* QAM AGC REF */
+		s5h1409_writereg(state, 0x82, 0x0800);
+	}
+
 	if (state->config->output_mode == S5H1409_SERIAL_OUTPUT)
 		s5h1409_writereg(state, 0xab,
 			s5h1409_readreg(state, 0xab) | 0x100); /* Serial */