[media] si2157: Set delivery system and bandwidth before tuning

This change “[media] si2157: Set delivery system and bandwidth before tuning” (commit a1dad50) in Linux kernel is authored by Olli Salonen <olli.salonen [at] iki.fi> on Sun Jul 13 10:52:21 2014 -0300.

Description of "[media] si2157: Set delivery system and bandwidth before tuning"

The change “[media] si2157: Set delivery system and bandwidth before tuning” introduces changes as follows.

[media] si2157: Set delivery system and bandwidth before tuning

Tell used TV standard and bandwidth for tuner firmware.

Signed-off-by: Olli Salonen <olli.salonen@iki.fi>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

Linux kernel releases containing commit a1dad50

The Linux kernel releases containing this commit are as follows.

Linux kernel code changes from "[media] si2157: Set delivery system and bandwidth before tuning"

There are 31 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 drivers/media/tuners/si2157.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 
diff --git a/drivers/media/tuners/si2157.c b/drivers/media/tuners/si2157.c
index 58c5ef586383..b656f9b72e84 100644
--- a/drivers/media/tuners/si2157.c
+++ b/drivers/media/tuners/si2157.c
@@ -209,6 +209,7 @@ static int si2157_set_params(struct dvb_frontend *fe)
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
 	int ret;
 	struct si2157_cmd cmd;
+	u8 bandwidth, delivery_system;
 
 	dev_dbg(&s->client->dev,
 			"%s: delivery_system=%d frequency=%u bandwidth_hz=%u\n",
@@ -220,6 +221,36 @@ static int si2157_set_params(struct dvb_frontend *fe)
 		goto err;
 	}
 
+	if (c->bandwidth_hz <= 6000000)
+		bandwidth = 0x06;
+	else if (c->bandwidth_hz <= 7000000)
+		bandwidth = 0x07;
+	else if (c->bandwidth_hz <= 8000000)
+		bandwidth = 0x08;
+	else
+		bandwidth = 0x0f;
+
+	switch (c->delivery_system) {
+	case SYS_DVBT:
+	case SYS_DVBT2: /* it seems DVB-T and DVB-T2 both are 0x20 here */
+			delivery_system = 0x20;
+			break;
+	case SYS_DVBC_ANNEX_A:
+			delivery_system = 0x30;
+			break;
+	default:
+			ret = -EINVAL;
+			goto err;
+	}
+
+	memcpy(cmd.args, "\x14\x00\x03\x07\x00\x00", 6);
+	cmd.args[4] = delivery_system | bandwidth;
+	cmd.wlen = 6;
+	cmd.rlen = 1;
+	ret = si2157_cmd_execute(s, &cmd);
+	if (ret)
+		goto err;
+
 	/* set frequency */
 	memcpy(cmd.args, "\x41\x00\x00\x00\x00\x00\x00\x00", 8);
 	cmd.args[4] = (c->frequency >>  0) & 0xff;

The commit for this change in Linux stable tree is a1dad50 (patch).

Last modified: 2020/02/10