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[media] it913x-fe ver 1.10 correct SNR reading from frontend

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Correction of reading from frontend and represents
a SNR nonlinear scale of minimum signal to full signal.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Malcolm Priestley 2011-11-06 11:19:14 -03:00 committed by Mauro Carvalho Chehab
parent c540d9f13d
commit 3339a5b165
1 changed files with 49 additions and 7 deletions
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56
drivers/media/dvb/frontends/it913x-fe.c
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@ -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@gmail.com");
MODULE_VERSION("1.09");
MODULE_VERSION("1.10");
MODULE_LICENSE("GPL");