Snr returns value not correct. Fix it.
>From f3d5c9e2b01e666eca7aa66cd15b67609a0589ea Mon Sep 17 00:00:00 2001
From: Bimow Chen <Bimow.Chen@xxxxxxxxxx>
Date: Tue, 23 Sep 2014 17:23:31 +0800
Subject: [PATCH 2/2] af9033: fix snr value not correct issue
Snr returns value not correct. Fix it.
Signed-off-by: Bimow Chen <Bimow.Chen@xxxxxxxxxx>
---
drivers/media/dvb-frontends/af9033.c | 46 +++++++++++++++++++++++++++--
drivers/media/dvb-frontends/af9033_priv.h | 5 ++-
2 files changed, 47 insertions(+), 4 deletions(-)
diff --git a/drivers/media/dvb-frontends/af9033.c b/drivers/media/dvb-frontends/af9033.c
index 0a0aeaf..37bd624 100644
--- a/drivers/media/dvb-frontends/af9033.c
+++ b/drivers/media/dvb-frontends/af9033.c
@@ -840,7 +840,7 @@ static int af9033_read_snr(struct dvb_frontend *fe, u16 *snr)
{
struct af9033_state *state = fe->demodulator_priv;
int ret, i, len;
- u8 buf[3], tmp;
+ u8 buf[3], tmp, tmp2;
u32 snr_val;
const struct val_snr *uninitialized_var(snr_lut);
@@ -851,6 +851,33 @@ static int af9033_read_snr(struct dvb_frontend *fe, u16 *snr)
snr_val = (buf[2] << 16) | (buf[1] << 8) | buf[0];
+ /* read superframe number */
+ ret = af9033_rd_reg(state, 0x80f78b, &tmp);
+ if (ret < 0)
+ goto err;
+
+ if (tmp)
+ snr_val /= tmp;
+
+ /* read current transmission mode */
+ ret = af9033_rd_reg(state, 0x80f900, &tmp);
+ if (ret < 0)
+ goto err;
+
+ switch ((tmp >> 0) & 3) {
+ case 0:
+ snr_val *= 4;
+ break;
+ case 1:
+ snr_val *= 1;
+ break;
+ case 2:
+ snr_val *= 2;
+ break;
+ default:
+ goto err;
+ }
+
/* read current modulation */
ret = af9033_rd_reg(state, 0x80f903, &tmp);
if (ret < 0)
@@ -874,13 +901,26 @@ static int af9033_read_snr(struct dvb_frontend *fe, u16 *snr)
}
for (i = 0; i < len; i++) {
- tmp = snr_lut[i].snr;
+ tmp2 = snr_lut[i].snr;
if (snr_val < snr_lut[i].val)
break;
}
- *snr = tmp * 10; /* dB/10 */
+ /* scale value to 0x0000-0xffff */
+ switch ((tmp >> 0) & 3) {
+ case 0:
+ *snr = tmp2 * 0xFFFF / 23;
+ break;
+ case 1:
+ *snr = tmp2 * 0xFFFF / 26;
+ break;
+ case 2:
+ *snr = tmp2 * 0xFFFF / 32;
+ break;
+ default:
+ goto err;
+ }
return 0;
diff --git a/drivers/media/dvb-frontends/af9033_priv.h b/drivers/media/dvb-frontends/af9033_priv.h
index 58315e0..6351626 100644
--- a/drivers/media/dvb-frontends/af9033_priv.h
+++ b/drivers/media/dvb-frontends/af9033_priv.h
@@ -180,7 +180,10 @@ static const struct val_snr qam64_snr_lut[] = {
{ 0x05570d, 26 },
{ 0x059feb, 27 },
{ 0x05bf38, 28 },
- { 0xffffff, 29 },
+ { 0x05f78f, 29 },
+ { 0x0612c3, 30 },
+ { 0x0626be, 31 },
+ { 0xffffff, 32 },
};
static const struct reg_val ofsm_init[] = {
--
1.7.0.4
