static void si4700_set_frequency(int freq)
{
static const unsigned int spacings[3] =
{
200000, /* SYSCONFIG2_SPACE_200KHZ */
100000, /* SYSCONFIG2_SPACE_100KHZ */
50000, /* SYSCONFIG2_SPACE_50KHZ */
};
static const unsigned int bands[3] =
{
87500000, /* SYSCONFIG2_BAND_875_1080 */
76000000, /* SYSCONFIG2_BAND_760_1080 */
76000000, /* SYSCONFIG2_BAND_760_900 */
};
/* check BAND and spacings */
int space = SYSCONFIG2_SPACEr(cache[SYSCONFIG2]);
int band = SYSCONFIG2_BANDr(cache[SYSCONFIG2]);
int chan = (freq - bands[band]) / spacings[space];
int readchan;
do
{
/* tuning should be done within 60 ms according to the datasheet */
si4700_write_reg(CHANNEL, CHANNEL_CHANw(chan) | CHANNEL_TUNE);
sleep(HZ * 60 / 1000);
/* get tune result */
readchan = si4700_read_reg(READCHAN) & READCHAN_READCHAN;
si4700_write_clear(CHANNEL, CHANNEL_TUNE);
} while (!((cache[STATUSRSSI] & STATUSRSSI_STC) && (readchan == chan)));
}
bool si4700_detect(void)
{
if (!tuner_present) {
tuner_power(true);
tuner_present = (si4700_read_reg(DEVICEID) == 0x1242);
tuner_power(false);
}
return tuner_present;
}
static int si4700_tuned(void)
{
/* Primitive tuning check: sufficient level and AFC not railed */
uint16_t status = si4700_read_reg(STATUSRSSI);
if (STATUSRSSI_RSSIr(status) >= SEEK_THRESHOLD &&
(status & STATUSRSSI_AFCRL) == 0)
return 1;
return 0;
}
bool si4700_detect(void)
{
bool detected;
tuner_power(true);
detected = (si4700_read_reg(DEVICEID) == 0x1242);
tuner_power(false);
return detected;
}
/* tuner abstraction layer: read something from the tuner */
int si4700_get(int setting)
{
int val = -1; /* default for unsupported query */
if(!tuner_powered() && setting != RADIO_PRESENT)
return -1;
mutex_lock(&fmr_mutex);
switch(setting)
{
case RADIO_PRESENT:
val = tuner_present;
break;
case RADIO_TUNED:
val = si4700_tuned();
break;
case RADIO_STEREO:
val = si4700_st();
break;
case RADIO_RSSI:
val = STATUSRSSI_RSSIr(si4700_read_reg(STATUSRSSI));
break;
case RADIO_RSSI_MIN:
val = RSSI_MIN;
break;
case RADIO_RSSI_MAX:
val = RSSI_MAX;
break;
#ifdef HAVE_RDS_CAP
case RADIO_EVENT:
{
#ifdef RDS_ISR_PROCESSING
int oldlevel = disable_irq_save();
#endif
val = rds_event;
rds_event = 0;
#ifdef RDS_ISR_PROCESSING
restore_irq(oldlevel);
#endif
break;
}
#endif
}
mutex_unlock(&fmr_mutex);
return val;
}
/* Read raw RDS info for processing */
bool si4700_rds_read_raw(uint16_t data[4])
{
bool retval = false;
mutex_lock(&fmr_mutex);
if (tuner_powered())
{
si4700_read_reg(RDSD);
memcpy(data, &cache[RDSA], 4 * sizeof (uint16_t));
retval = true;
}
mutex_unlock(&fmr_mutex);
return retval;
}
/* Poll i2c for the stereo status */
bool si4700_st(void)
{
return (si4700_read_reg(STATUSRSSI) & STATUSRSSI_ST) >> 8;
}
/* Poll i2c for the stereo status */
static inline int si4700_st(void)
{
return (si4700_read_reg(STATUSRSSI) & STATUSRSSI_ST) >> 8;
}