Correction of reading from frontend and represents
a SNR nonlinear scale of minimum signal to full signal.
Signed-off-by: Malcolm Priestley <tvboxspy@xxxxxxxxx>
---
drivers/media/dvb/frontends/it913x-fe.c | 56 +++++++++++++++++++++++++++----
1 files changed, 49 insertions(+), 7 deletions(-)
diff --git a/drivers/media/dvb/frontends/it913x-fe.c b/drivers/media/dvb/frontends/it913x-fe.c
index 6d12dcc..07c1b46 100644
--- a/drivers/media/dvb/frontends/it913x-fe.c
+++ b/drivers/media/dvb/frontends/it913x-fe.c
@@ -53,6 +53,8 @@ struct it913x_fe_state {
struct ite_config *config;
u8 i2c_addr;
u32 frequency;
+ fe_modulation_t constellation;
+ fe_transmit_mode_t transmission_mode;
u32 crystalFrequency;
u32 adcFrequency;
u8 tuner_type;
@@ -496,14 +498,50 @@ static int it913x_fe_read_signal_strength(struct dvb_frontend *fe,
return 0;
}
-static int it913x_fe_read_snr(struct dvb_frontend *fe, u16* snr)
+static int it913x_fe_read_snr(struct dvb_frontend *fe, u16 *snr)
{
struct it913x_fe_state *state = fe->demodulator_priv;
- int ret = it913x_read_reg_u8(state, SIGNAL_QUALITY);
- ret = (ret * 0xff) / 0x64;
- ret |= (ret << 0x8);
- *snr = ~ret;
- return 0;
+ int ret;
+ u8 reg[3];
+ u32 snr_val, snr_min, snr_max;
+ u32 temp;
+
+ ret = it913x_read_reg(state, 0x2c, reg, sizeof(reg));
+
+ snr_val = (u32)(reg[2] << 16) | (reg[1] < 8) | reg[0];
+
+ ret |= it913x_read_reg(state, 0xf78b, reg, 1);
+ if (reg[0])
+ snr_val /= reg[0];
+
+ if (state->transmission_mode == TRANSMISSION_MODE_2K)
+ snr_val *= 4;
+ else if (state->transmission_mode == TRANSMISSION_MODE_4K)
+ snr_val *= 2;
+
+ if (state->constellation == QPSK) {
+ snr_min = 0xb4711;
+ snr_max = 0x191451;
+ } else if (state->constellation == QAM_16) {
+ snr_min = 0x4f0d5;
+ snr_max = 0xc7925;
+ } else if (state->constellation == QAM_64) {
+ snr_min = 0x256d0;
+ snr_max = 0x626be;
+ } else
+ return -EINVAL;
+
+ if (snr_val < snr_min)
+ *snr = 0;
+ else if (snr_val < snr_max) {
+ temp = (snr_val - snr_min) >> 5;
+ temp *= 0xffff;
+ temp /= (snr_max - snr_min) >> 5;
+ *snr = (u16)temp;
+ } else
+ *snr = 0xffff;
+
+ return (ret < 0) ? -ENODEV : 0;
}
static int it913x_fe_read_ber(struct dvb_frontend *fe, u32 *ber)
@@ -530,9 +568,13 @@ static int it913x_fe_get_frontend(struct dvb_frontend *fe,
if (reg[3] < 3)
p->u.ofdm.constellation = fe_con[reg[3]];
+ state->constellation = p->u.ofdm.constellation;
+
if (reg[0] < 3)
p->u.ofdm.transmission_mode = fe_mode[reg[0]];
+ state->transmission_mode = p->u.ofdm.transmission_mode;
+
if (reg[1] < 4)
p->u.ofdm.guard_interval = fe_gi[reg[1]];
@@ -888,5 +930,5 @@ static struct dvb_frontend_ops it913x_fe_ofdm_ops = {
MODULE_DESCRIPTION("it913x Frontend and it9137 tuner");
MODULE_AUTHOR("Malcolm Priestley tvboxspy@xxxxxxxxx");
-MODULE_VERSION("1.09");
+MODULE_VERSION("1.10");
MODULE_LICENSE("GPL");
--
1.7.5.4
--
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