1 files changed, 48 insertions, 1 deletions

diff --git a/drivers/media/dvb/pt1/va1j5jf8007t.c b/drivers/media/dvb/pt1/va1j5jf8007t.c
index 71117f4ca7e6..3db4f3e34e8f 100644
--- a/drivers/media/dvb/pt1/va1j5jf8007t.c
+++ b/drivers/media/dvb/pt1/va1j5jf8007t.c
@@ -46,6 +46,52 @@ struct va1j5jf8007t_state {
 	enum va1j5jf8007t_tune_state tune_state;
 };
 
+static int va1j5jf8007t_read_snr(struct dvb_frontend *fe, u16 *snr)
+{
+	struct va1j5jf8007t_state *state;
+	u8 addr;
+	int i;
+	u8 write_buf[1], read_buf[1];
+	struct i2c_msg msgs[2];
+	s32 word, x, y;
+
+	state = fe->demodulator_priv;
+	addr = state->config->demod_address;
+
+	word = 0;
+	for (i = 0; i < 3; i++) {
+		write_buf[0] = 0x8b + i;
+
+		msgs[0].addr = addr;
+		msgs[0].flags = 0;
+		msgs[0].len = sizeof(write_buf);
+		msgs[0].buf = write_buf;
+
+		msgs[1].addr = addr;
+		msgs[1].flags = I2C_M_RD;
+		msgs[1].len = sizeof(read_buf);
+		msgs[1].buf = read_buf;
+
+		if (i2c_transfer(state->adap, msgs, 2) != 2)
+			return -EREMOTEIO;
+
+		word <<= 8;
+		word |= read_buf[0];
+	}
+
+	if (!word)
+		return -EIO;
+
+	x = 10 * (intlog10(0x540000 * 100 / word) - (2 << 24));
+	y = (24ll << 46) / 1000000;
+	y = ((s64)y * x >> 30) - (16ll << 40) / 10000;
+	y = ((s64)y * x >> 29) + (398ll << 35) / 10000;
+	y = ((s64)y * x >> 30) + (5491ll << 29) / 10000;
+	y = ((s64)y * x >> 30) + (30965ll << 23) / 10000;
+	*snr = y >> 15;
+	return 0;
+}
+
 static int va1j5jf8007t_get_frontend_algo(struct dvb_frontend *fe)
 {
 	return DVBFE_ALGO_HW;
@@ -224,7 +270,7 @@ va1j5jf8007t_tune(struct dvb_frontend *fe,
 {
 	struct va1j5jf8007t_state *state;
 	int ret;
-	int lock, retry;
+	int lock = 0, retry = 0;
 
 	state = fe->demodulator_priv;
 
@@ -393,6 +439,7 @@ static struct dvb_frontend_ops va1j5jf8007t_ops = {
 			FE_CAN_GUARD_INTERVAL_AUTO | FE_CAN_HIERARCHY_AUTO,
 	},
 
+	.read_snr = va1j5jf8007t_read_snr,
 	.get_frontend_algo = va1j5jf8007t_get_frontend_algo,
 	.read_status = va1j5jf8007t_read_status,
 	.tune = va1j5jf8007t_tune,