[media] dib7090p: improve the support of the dib7090 and dib7790

The intend of this patch is to improve the support of the dib7090 and
dib7790. The AGC1 min value is set to 32768 by default. The actual AGC1 min
and the external attenuation are controled depending on the received RF
level.
Signed-off-by: Olivier Grenie <olivier.grenie@parrot.com>
Signed-off-by: Patrick Boettcher <patrick.boettcher@parrot.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/dvb-usb/dib0700_devices.c

@@ -2541,7 +2541,7 @@ static struct dibx000_agc_config dib7090_agc_config[2] = {
 		.wbd_alpha      = 5,
 
 		.agc1_max       = 65535,
-		.agc1_min       = 0,
+		.agc1_min       = 32768,
 
 		.agc2_max       = 65535,
 		.agc2_min       = 0,
@@ -2618,7 +2618,7 @@ static struct dib7000p_config nim7090_dib7000p_config = {
 	.output_mpeg2_in_188_bytes  = 1,
 	.hostbus_diversity			= 1,
 	.tuner_is_baseband			= 1,
-	.update_lna					= NULL,
+	.update_lna					= tfe7790p_update_lna, /* GPIO used is the same as TFE7790 */
 
 	.agc_config_count			= 2,
 	.agc						= dib7090_agc_config,
@@ -2642,12 +2642,26 @@ static struct dib7000p_config nim7090_dib7000p_config = {
 	.enMpegOutput				= 1,
 };
 
+static int tfe7090p_pvr_update_lna(struct dvb_frontend *fe, u16 agc_global)
+{
+	deb_info("TFE7090P-PVR update LNA: agc global=%i", agc_global);
+	if (agc_global < 25000) {
+		dib7000p_set_gpio(fe, 5, 0, 0);
+		dib7000p_set_agc1_min(fe, 0);
+	} else {
+		dib7000p_set_gpio(fe, 5, 0, 1);
+		dib7000p_set_agc1_min(fe, 32768);
+	}
+
+	return 0;
+}
+
 static struct dib7000p_config tfe7090pvr_dib7000p_config[2] = {
 	{
 		.output_mpeg2_in_188_bytes  = 1,
 		.hostbus_diversity			= 1,
 		.tuner_is_baseband			= 1,
-		.update_lna					= NULL,
+		.update_lna					= tfe7090p_pvr_update_lna,
 
 		.agc_config_count			= 2,
 		.agc						= dib7090_agc_config,
@@ -2674,7 +2688,7 @@ static struct dib7000p_config tfe7090pvr_dib7000p_config[2] = {
 		.output_mpeg2_in_188_bytes  = 1,
 		.hostbus_diversity			= 1,
 		.tuner_is_baseband			= 1,
-		.update_lna					= NULL,
+		.update_lna					= tfe7090p_pvr_update_lna,
 
 		.agc_config_count			= 2,
 		.agc						= dib7090_agc_config,