1 files changed, 30 insertions, 1 deletions

diff --git a/drivers/media/dvb/frontends/s5h1411.c b/drivers/media/dvb/frontends/s5h1411.c
index d8adf1e32019..5fca113a2013 100644
--- a/drivers/media/dvb/frontends/s5h1411.c
+++ b/drivers/media/dvb/frontends/s5h1411.c
@@ -794,7 +794,36 @@ static int s5h1411_read_snr(struct dvb_frontend *fe, u16 *snr)
 static int s5h1411_read_signal_strength(struct dvb_frontend *fe,
         u16 *signal_strength)
 {
-        return s5h1411_read_snr(fe, signal_strength);
+        /* borrowed from lgdt330x.c
+         *
+         * Calculate strength from SNR up to 35dB
+         * Even though the SNR can go higher than 35dB,
+         * there is some comfort factor in having a range of
+         * strong signals that can show at 100%
+         */
+        u16 snr;
+        u32 tmp;
+        int ret = s5h1411_read_snr(fe, &snr);
+
+        *signal_strength = 0;
+
+        if (0 == ret) {
+                /* The following calculation method was chosen
+                 * purely for the sake of code re-use from the
+                 * other demod drivers that use this method */
+
+                /* Convert from SNR in dB * 10 to 8.24 fixed-point */
+                tmp = (snr * ((1 << 24) / 10));
+
+                /* Convert from 8.24 fixed-point to
+                 * scale the range 0 - 35*2^24 into 0 - 65535*/
+                if (tmp >= 8960 * 0x10000)
+                        *signal_strength = 0xffff;
+                else
+                        *signal_strength = tmp / 8960;
+        }
+
+        return ret;
 }
 
 static int s5h1411_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)