media: si2157: add support for 1.7MHz and 6.1 MHz

Some tuners allow setting the bandwidth filter to 1.7MHz and
6.1 MHz. Add support for it upstream, as the narrower is the
bandwidth filter, the better.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/tuners/si2157.c

@@ -458,8 +458,12 @@ static int si2157_set_params(struct dvb_frontend *fe)
 		goto err;
 	}
 
+	if (SUPPORTS_1700KHz(dev) && c->bandwidth_hz <= 1700000)
+		bandwidth = 0x09;
 	if (c->bandwidth_hz <= 6000000)
 		bandwidth = 0x06;
+	if (SUPPORTS_1700KHz(dev) && c->bandwidth_hz <= 6100000)
+		bandwidth = 0x10;
 	else if (c->bandwidth_hz <= 7000000)
 		bandwidth = 0x07;
 	else if (c->bandwidth_hz <= 8000000)

drivers/media/tuners/si2157_priv.h

@@ -66,6 +66,11 @@ struct si2157_cmd {
 	unsigned rlen;
 };
 
+#define SUPPORTS_1700KHz(dev) (((dev)->part_id == SI2141) || \
+			       ((dev)->part_id == SI2147) || \
+			       ((dev)->part_id == SI2157) || \
+			       ((dev)->part_id == SI2177))
+
 /* Old firmware namespace */
 #define SI2158_A20_FIRMWARE "dvb-tuner-si2158-a20-01.fw"
 #define SI2141_A10_FIRMWARE "dvb-tuner-si2141-a10-01.fw"