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tuner_fc0013: improve tuning resolution
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We now use Hz instead of kHz for the internal
calculations, and thus improve the tuning resolution
to ~50 Hz (tested with DAB).

Signed-off-by: Steve Markgraf <[email protected]>
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@steve-m
steve-m committed May 27, 2012
1 parent bcb8f2b commit 75548c8
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Showing 2 changed files with 32 additions and 32 deletions.
2 changes: 1 addition & 1 deletion include/tuner_fc0013.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@
#define FC0013_CHECK_VAL 0xa3

int fc0013_init(void *dev);
int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bw);
int fc0013_set_params(void *dev, uint32_t freq, uint32_t bandwidth);
int fc0013_set_gain(void *dev, int gain);

#endif
62 changes: 31 additions & 31 deletions src/tuner_fc0013.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -168,45 +168,45 @@ static int fc0013_set_vhf_track(void *dev, uint32_t freq)
if (ret)
goto error_out;
tmp &= 0xe3;
if (freq <= 177500) { /* VHF Track: 7 */
if (freq <= 177500000) { /* VHF Track: 7 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x1c);
} else if (freq <= 184500) { /* VHF Track: 6 */
} else if (freq <= 184500000) { /* VHF Track: 6 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x18);
} else if (freq <= 191500) { /* VHF Track: 5 */
} else if (freq <= 191500000) { /* VHF Track: 5 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x14);
} else if (freq <= 198500) { /* VHF Track: 4 */
} else if (freq <= 198500000) { /* VHF Track: 4 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x10);
} else if (freq <= 205500) { /* VHF Track: 3 */
} else if (freq <= 205500000) { /* VHF Track: 3 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x0c);
} else if (freq <= 219500) { /* VHF Track: 2 */
} else if (freq <= 219500000) { /* VHF Track: 2 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x08);
} else if (freq < 300000) { /* VHF Track: 1 */
} else if (freq < 300000000) { /* VHF Track: 1 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x04);
} else { /* UHF and GPS */
} else { /* UHF and GPS */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x1c);
}

error_out:
return ret;
}

int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
int fc0013_set_params(void *dev, uint32_t freq, uint32_t bandwidth)
{
int i, ret = 0;
uint32_t freq = frequency / 1000;
uint8_t reg[7], am, pm, multi, tmp;
unsigned long f_vco;
uint16_t xtal_freq_khz_2, xin, xdiv;
uint64_t f_vco;
uint32_t xtal_freq_div_2;
uint16_t xin, xdiv;
int vco_select = 0;

xtal_freq_khz_2 = rtlsdr_get_tuner_clock(dev) / 1000 / 2;
xtal_freq_div_2 = rtlsdr_get_tuner_clock(dev) / 2;

/* set VHF track */
ret = fc0013_set_vhf_track(dev, freq);
if (ret)
goto exit;

if (freq < 300000) {
if (freq < 300000000) {
/* enable VHF filter */
ret = fc0013_readreg(dev, 0x07, &tmp);
if (ret)
Expand All @@ -222,7 +222,7 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
ret = fc0013_writereg(dev, 0x14, tmp & 0x1f);
if (ret)
goto exit;
} else if (freq <= 862000) {
} else if (freq <= 862000000) {
/* disable VHF filter */
ret = fc0013_readreg(dev, 0x07, &tmp);
if (ret)
Expand Down Expand Up @@ -257,43 +257,43 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
}

/* select frequency divider and the frequency of VCO */
if (freq < 37084) { /* freq * 96 < 3560000 */
if (freq < 37084000) { /* freq * 96 < 3560000000 */
multi = 96;
reg[5] = 0x82;
reg[6] = 0x00;
} else if (freq < 55625) { /* freq * 64 < 3560000 */
} else if (freq < 55625000) { /* freq * 64 < 3560000000 */
multi = 64;
reg[5] = 0x02;
reg[6] = 0x02;
} else if (freq < 74167) { /* freq * 48 < 3560000 */
} else if (freq < 74167000) { /* freq * 48 < 3560000000 */
multi = 48;
reg[5] = 0x42;
reg[6] = 0x00;
} else if (freq < 111250) { /* freq * 32 < 3560000 */
} else if (freq < 111250000) { /* freq * 32 < 3560000000 */
multi = 32;
reg[5] = 0x82;
reg[6] = 0x02;
} else if (freq < 148334) { /* freq * 24 < 3560000 */
} else if (freq < 148334000) { /* freq * 24 < 3560000000 */
multi = 24;
reg[5] = 0x22;
reg[6] = 0x00;
} else if (freq < 222500) { /* freq * 16 < 3560000 */
} else if (freq < 222500000) { /* freq * 16 < 3560000000 */
multi = 16;
reg[5] = 0x42;
reg[6] = 0x02;
} else if (freq < 296667) { /* freq * 12 < 3560000 */
} else if (freq < 296667000) { /* freq * 12 < 3560000000 */
multi = 12;
reg[5] = 0x12;
reg[6] = 0x00;
} else if (freq < 445000) { /* freq * 8 < 3560000 */
} else if (freq < 445000000) { /* freq * 8 < 3560000000 */
multi = 8;
reg[5] = 0x22;
reg[6] = 0x02;
} else if (freq < 593334) { /* freq * 6 < 3560000 */
} else if (freq < 593334000) { /* freq * 6 < 3560000000 */
multi = 6;
reg[5] = 0x0a;
reg[6] = 0x00;
} else if (freq < 950000) { /* freq * 4 < 3800000 */
} else if (freq < 950000000) { /* freq * 4 < 3800000000 */
multi = 4;
reg[5] = 0x12;
reg[6] = 0x02;
Expand All @@ -305,15 +305,15 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)

f_vco = freq * multi;

if (f_vco >= 3060000) {
if (f_vco >= 3060000000) {
reg[6] |= 0x08;
vco_select = 1;
}

if (freq >= 45000) {
if (freq >= 45000000) {
/* From divided value (XDIV) determined the FA and FP value */
xdiv = (uint16_t)(f_vco / xtal_freq_khz_2);
if ((f_vco - xdiv * xtal_freq_khz_2) >= (xtal_freq_khz_2 / 2))
xdiv = (uint16_t)(f_vco / xtal_freq_div_2);
if ((f_vco - xdiv * xtal_freq_div_2) >= (xtal_freq_div_2 / 2))
xdiv++;

pm = (uint8_t)(xdiv / 8);
Expand All @@ -337,8 +337,8 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)

/* From VCO frequency determines the XIN ( fractional part of Delta
Sigma PLL) and divided value (XDIV) */
xin = (uint16_t)(f_vco - (f_vco / xtal_freq_khz_2) * xtal_freq_khz_2);
xin = (xin << 15) / xtal_freq_khz_2;
xin = (uint16_t)((f_vco - (f_vco / xtal_freq_div_2) * xtal_freq_div_2) / 1000);
xin = (xin << 15) / (xtal_freq_div_2 / 1000);
if (xin >= 16384)
xin += 32768;

Expand Down

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