tuner_fc001x: fix tuning for frequencies < 45 MHz

This allows tuning to 27 MHz for example (civil band).
Best results are achieved when setting the gain to
very low values.

Signed-off-by: Steve Markgraf <steve@steve-m.de>

src/tuner_fc0012.c

@@ -206,7 +206,6 @@ int fc0012_set_params(void *dev, uint32_t freq, uint32_t bandwidth)
 		vco_select = 1;
 	}
 
-	if (freq >= 45000000) {
 	/* From divided value (XDIV) determined the FA and FP value */
 	xdiv = (uint16_t)(f_vco / xtal_freq_div_2);
 	if ((f_vco - xdiv * xtal_freq_div_2) >= (xtal_freq_div_2 / 2))
@@ -228,16 +227,11 @@ int fc0012_set_params(void *dev, uint32_t freq, uint32_t bandwidth)
 		reg[2] = pm;
 	}
 
-		if (reg[1] > 15) {
+	if ((reg[1] > 15) || (reg[2] < 0x0b)) {
 		fprintf(stderr, "[FC0012] no valid PLL combination "
 				"found for %u Hz!\n", freq);
 		return -1;
 	}
-	} else {
-		/* fix for frequency less than 45 MHz */
-		reg[1] = 0x06;
-		reg[2] = 0x11;
-	}
 
 	/* fix clock out */
 	reg[6] |= 0x20;

src/tuner_fc0013.c

@@ -311,7 +311,6 @@ int fc0013_set_params(void *dev, uint32_t freq, uint32_t bandwidth)
 		vco_select = 1;
 	}
 
-	if (freq >= 45000000) {
 	/* From divided value (XDIV) determined the FA and FP value */
 	xdiv = (uint16_t)(f_vco / xtal_freq_div_2);
 	if ((f_vco - xdiv * xtal_freq_div_2) >= (xtal_freq_div_2 / 2))
@@ -333,16 +332,11 @@ int fc0013_set_params(void *dev, uint32_t freq, uint32_t bandwidth)
 		reg[2] = pm;
 	}
 
-		if (reg[1] > 15) {
+	if ((reg[1] > 15) || (reg[2] < 0x0b)) {
 		fprintf(stderr, "[FC0013] no valid PLL combination "
 				"found for %u Hz!\n", freq);
 		return -1;
 	}
-	} else {
-		/* fix for frequency less than 45 MHz */
-		reg[1] = 0x06;
-		reg[2] = 0x11;
-	}
 
 	/* fix clock out */
 	reg[6] |= 0x20;