[media] it913x-fe ver 1.15 read signal strenght using reg VAR_P_INBAND
Read signal strength using VAR_P_INBAND and apply FEC preferred values.
Note this does not work on IT9137 devices even with dvb-usb-it9135-01.fw
firmware.
Config read_sl allows switch between read signal strength and signal
level.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/frontends/it913x-fe.c b/drivers/media/dvb/frontends/it913x-fe.c
index ccc36bf..84df03c 100644
--- a/drivers/media/dvb/frontends/it913x-fe.c
+++ b/drivers/media/dvb/frontends/it913x-fe.c
@@ -57,6 +57,7 @@
u32 frequency;
fe_modulation_t constellation;
fe_transmit_mode_t transmission_mode;
+ u8 priority;
u32 crystalFrequency;
u32 adcFrequency;
u8 tuner_type;
@@ -500,19 +501,87 @@
return 0;
}
+/* FEC values based on fe_code_rate_t non supported values 0*/
+int it913x_qpsk_pval[] = {0, -93, -91, -90, 0, -89, -88};
+int it913x_16qam_pval[] = {0, -87, -85, -84, 0, -83, -82};
+int it913x_64qam_pval[] = {0, -82, -80, -78, 0, -77, -76};
+
+static int it913x_get_signal_strength(struct dvb_frontend *fe)
+{
+ struct dtv_frontend_properties *p = &fe->dtv_property_cache;
+ struct it913x_fe_state *state = fe->demodulator_priv;
+ u8 code_rate;
+ int ret, temp;
+ u8 lna_gain_os;
+
+ ret = it913x_read_reg_u8(state, VAR_P_INBAND);
+ if (ret < 0)
+ return ret;
+
+ /* VHF/UHF gain offset */
+ if (state->frequency < 300000000)
+ lna_gain_os = 7;
+ else
+ lna_gain_os = 14;
+
+ temp = (ret - 100) - lna_gain_os;
+
+ if (state->priority == PRIORITY_HIGH)
+ code_rate = p->code_rate_HP;
+ else
+ code_rate = p->code_rate_LP;
+
+ if (code_rate >= ARRAY_SIZE(it913x_qpsk_pval))
+ return -EINVAL;
+
+ deb_info("Reg VAR_P_INBAND:%d Calc Offset Value:%d", ret, temp);
+
+ /* Apply FEC offset values*/
+ switch (p->modulation) {
+ case QPSK:
+ temp -= it913x_qpsk_pval[code_rate];
+ break;
+ case QAM_16:
+ temp -= it913x_16qam_pval[code_rate];
+ break;
+ case QAM_64:
+ temp -= it913x_64qam_pval[code_rate];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (temp < -15)
+ ret = 0;
+ else if ((-15 <= temp) && (temp < 0))
+ ret = (2 * (temp + 15)) / 3;
+ else if ((0 <= temp) && (temp < 20))
+ ret = 4 * temp + 10;
+ else if ((20 <= temp) && (temp < 35))
+ ret = (2 * (temp - 20)) / 3 + 90;
+ else if (temp >= 35)
+ ret = 100;
+
+ deb_info("Signal Strength :%d", ret);
+
+ return ret;
+}
+
static int it913x_fe_read_signal_strength(struct dvb_frontend *fe,
u16 *strength)
{
struct it913x_fe_state *state = fe->demodulator_priv;
- int ret = it913x_read_reg_u8(state, SIGNAL_LEVEL);
- /*SIGNAL_LEVEL always returns 100%! so using FE_HAS_SIGNAL as switch*/
- if (state->it913x_status & FE_HAS_SIGNAL)
- ret = (ret * 0xff) / 0x64;
- else
- ret = 0x0;
- ret |= ret << 0x8;
- *strength = ret;
- return 0;
+ int ret = 0;
+ if (state->config->read_slevel) {
+ if (state->it913x_status & FE_HAS_SIGNAL)
+ ret = it913x_read_reg_u8(state, SIGNAL_LEVEL);
+ } else
+ ret = it913x_get_signal_strength(fe);
+
+ if (ret >= 0)
+ *strength = (u16)((u32)ret * 0xffff / 0x64);
+
+ return (ret < 0) ? -ENODEV : 0;
}
static int it913x_fe_read_snr(struct dvb_frontend *fe, u16 *snr)
@@ -606,6 +675,8 @@
if (reg[2] < 4)
p->hierarchy = fe_hi[reg[2]];
+ state->priority = reg[5];
+
p->code_rate_HP = (reg[6] < 6) ? fe_code[reg[6]] : FEC_NONE;
p->code_rate_LP = (reg[7] < 6) ? fe_code[reg[7]] : FEC_NONE;
@@ -972,5 +1043,5 @@
MODULE_DESCRIPTION("it913x Frontend and it9137 tuner");
MODULE_AUTHOR("Malcolm Priestley tvboxspy@gmail.com");
-MODULE_VERSION("1.13");
+MODULE_VERSION("1.15");
MODULE_LICENSE("GPL");