[media] rtl2832: implement DVBv5 signal strength statistics

Estimate signal strength from IF digital AGC.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index 90d4f45d9958..6aaaec2a40c2 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -474,6 +474,8 @@ static int rtl2832_init(struct dvb_frontend *fe)
                 goto err;
 #endif
         /* init stats here in order signal app which stats are supported */
+        c->strength.len = 1;
+        c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
         c->cnr.len = 1;
         c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
         c->post_bit_error.len = 1;
@@ -823,6 +825,24 @@ static void rtl2832_stat_work(struct work_struct *work)
 
         dev_dbg(&client->dev, "\n");
 
+        /* signal strength */
+        if (dev->fe_status & FE_HAS_SIGNAL) {
+                /* read digital AGC */
+                ret = rtl2832_bulk_read(client, 0x305, &u8tmp, 1);
+                if (ret)
+                        goto err;
+
+                dev_dbg(&client->dev, "digital agc=%02x", u8tmp);
+
+                u8tmp = ~u8tmp;
+                u16tmp = u8tmp << 8 | u8tmp << 0;
+
+                c->strength.stat[0].scale = FE_SCALE_RELATIVE;
+                c->strength.stat[0].uvalue = u16tmp;
+        } else {
+                c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+        }
+
         /* CNR */
         if (dev->fe_status & FE_HAS_VITERBI) {
                 unsigned hierarchy, constellation;