V4L/DVB (6630): zl10353: calculate input frequency register instead of using hardcoded value

Now we know the zl10353's correct ADC clock, we can calculate the input
frequency registers correctly instead of just blindly setting them.
Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/dvb/frontends/zl10353.c

 /*
  * Driver for Zarlink DVB-T ZL10353 demodulator
  *
- * Copyright (C) 2006 Christopher Pascoe <c.pascoe@itee.uq.edu.au>
+ * Copyright (C) 2006, 2007 Christopher Pascoe <c.pascoe@itee.uq.edu.au>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.=
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <linux/kernel.h>
@@ -25,6 +25,7 @@
 #include <linux/delay.h>
 #include <linux/string.h>
 #include <linux/slab.h>
+#include <asm/div64.h>
 
 #include "dvb_frontend.h"
 #include "zl10353_priv.h"
@@ -148,6 +149,35 @@ static void zl10353_calc_nominal_rate(struct dvb_frontend *fe,
 		__FUNCTION__, bw, adc_clock, *nominal_rate);
 }
 
+static void zl10353_calc_input_freq(struct dvb_frontend *fe,
+				    u16 *input_freq)
+{
+	struct zl10353_state *state = fe->demodulator_priv;
+	u32 adc_clock = 45056;	/* 45.056 MHz */
+	int if2 = 36167;	/* 36.167 MHz */
+	int ife;
+	u64 value;
+
+	if (state->config.adc_clock)
+		adc_clock = state->config.adc_clock;
+	if (state->config.if2)
+		if2 = state->config.if2;
+
+	if (adc_clock >= if2 * 2)
+		ife = if2;
+	else {
+		ife = adc_clock - (if2 % adc_clock);
+		if (ife > adc_clock / 2)
+			ife = adc_clock - ife;
+	}
+	value = 65536ULL * ife + adc_clock / 2;
+	do_div(value, adc_clock);
+	*input_freq = -value;
+
+	dprintk("%s: if2 %d, ife %d, adc_clock %d => %d / 0x%x\n",
+		__FUNCTION__, if2, ife, adc_clock, -(int)value, *input_freq);
+}
+
 static int zl10353_sleep(struct dvb_frontend *fe)
 {
 	static u8 zl10353_softdown[] = { 0x50, 0x0C, 0x44 };
@@ -160,7 +190,7 @@ static int zl10353_set_parameters(struct dvb_frontend *fe,
 				  struct dvb_frontend_parameters *param)
 {
 	struct zl10353_state *state = fe->demodulator_priv;
-	u16 nominal_rate;
+	u16 nominal_rate, input_freq;
 	u8 pllbuf[6] = { 0x67 };
 
 	/* These settings set "auto-everything" and start the FSM. */
@@ -178,8 +208,10 @@ static int zl10353_set_parameters(struct dvb_frontend *fe,
 	zl10353_single_write(fe, TRL_NOMINAL_RATE_1, msb(nominal_rate));
 	zl10353_single_write(fe, TRL_NOMINAL_RATE_0, lsb(nominal_rate));
 
-	zl10353_single_write(fe, 0x6C, 0xCD);
-	zl10353_single_write(fe, 0x6D, 0x7E);
+	zl10353_calc_input_freq(fe, &input_freq);
+	zl10353_single_write(fe, INPUT_FREQ_1, msb(input_freq));
+	zl10353_single_write(fe, INPUT_FREQ_0, lsb(input_freq));
+
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0);
 

drivers/media/dvb/frontends/zl10353.h

 /*
  *  Driver for Zarlink DVB-T ZL10353 demodulator
  *
- *  Copyright (C) 2006 Christopher Pascoe <c.pascoe@itee.uq.edu.au>
+ *  Copyright (C) 2006, 2007 Christopher Pascoe <c.pascoe@itee.uq.edu.au>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -31,6 +31,7 @@ struct zl10353_config
 
 	/* frequencies in kHz */
 	int adc_clock;	/* default: 45056 */
+	int if2;	/* default: 36167 */
 
 	/* set if no pll is connected to the secondary i2c bus */
 	int no_tuner;

drivers/media/dvb/frontends/zl10353_priv.h

 /*
  *  Driver for Zarlink DVB-T ZL10353 demodulator
  *
- *  Copyright (C) 2006 Christopher Pascoe <c.pascoe@itee.uq.edu.au>
+ *  Copyright (C) 2006, 2007 Christopher Pascoe <c.pascoe@itee.uq.edu.au>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.=
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #ifndef _ZL10353_PRIV_
@@ -48,6 +48,8 @@ enum zl10353_reg_addr {
 	RS_UBC_0           = 0x15,
 	TRL_NOMINAL_RATE_1 = 0x65,
 	TRL_NOMINAL_RATE_0 = 0x66,
+	INPUT_FREQ_1       = 0x6C,
+	INPUT_FREQ_0       = 0x6D,
 	TUNER_GO           = 0x70,
 	FSM_GO             = 0x71,
 	CHIP_ID            = 0x7F,