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Commit c0c6ed8d authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] r820t: fix PLL calculus 



There are a few errors at the PLL calculus, causing the device
to use wrong values.
While here, change the calculus to use 32 bits, as there's no
need for 64 bits there.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: default avatarAntti Palosaari <crope@iki.fi>
parent 064fd169

drivers/media/tuners/r820t.c

+10 −17
Original line number Diff line number Diff line
@@ -36,7 +36,6 @@ 
#include <linux/mutex.h>

#include <linux/slab.h>

#include <linux/bitrev.h>

#include <asm/div64.h>



#include "tuner-i2c.h"

#include "r820t.h"
@@ -540,7 +539,7 @@ static int r820t_set_mux(struct r820t_priv *priv, u32 freq) 
static int r820t_set_pll(struct r820t_priv *priv, enum v4l2_tuner_type type,

			 u32 freq)

{

	u64 tmp64, vco_freq;

	u32 vco_freq;

	int rc, i;

	unsigned sleep_time = 10000;

	u32 vco_fra;		/* VCO contribution by SDM (kHz) */
@@ -576,9 +575,6 @@ static int r820t_set_pll(struct r820t_priv *priv, enum v4l2_tuner_type type, 
		}

	}



	tuner_dbg("set r820t pll for frequency %d kHz = %d%s\n",

		  freq, pll_ref, refdiv2 ? " / 2" : "");



	rc = r820t_write_reg_mask(priv, 0x10, refdiv2, 0x10);

	if (rc < 0)

		return rc;
@@ -622,15 +618,9 @@ static int r820t_set_pll(struct r820t_priv *priv, enum v4l2_tuner_type type, 
	if (rc < 0)

		return rc;



	vco_freq = (u64)(freq * (u64)mix_div);



	tmp64 = vco_freq;

	do_div(tmp64, 2 * pll_ref);

	nint = (u8)tmp64;



	tmp64 = vco_freq - ((u64)2) * pll_ref * nint;

	do_div(tmp64, 1000);

	vco_fra  = (u16)(tmp64);

	vco_freq = freq * mix_div;

	nint = vco_freq / (2 * pll_ref);

	vco_fra = vco_freq - 2 * pll_ref * nint;



	/* boundary spur prevention */

	if (vco_fra < pll_ref / 64) {
@@ -677,10 +667,13 @@ static int r820t_set_pll(struct r820t_priv *priv, enum v4l2_tuner_type type, 
		n_sdm = n_sdm << 1;

	}



	rc = r820t_write_reg_mask(priv, 0x16, sdm >> 8, 0x08);

	tuner_dbg("freq %d kHz, pll ref %d%s, sdm=0x%04x\n",

		  freq, pll_ref, refdiv2 ? " / 2" : "", sdm);



	rc = r820t_write_reg(priv, 0x16, sdm >> 8);

	if (rc < 0)

		return rc;

	rc = r820t_write_reg_mask(priv, 0x15, sdm & 0xff, 0x08);

	rc = r820t_write_reg(priv, 0x15, sdm & 0xff);

	if (rc < 0)

		return rc;
@@ -1068,7 +1061,7 @@ static int r820t_set_tv_standard(struct r820t_priv *priv, 
			if (rc < 0)

				return rc;



			rc = r820t_set_pll(priv, type, filt_cal_lo);

			rc = r820t_set_pll(priv, type, filt_cal_lo * 1000);

			if (rc < 0 || !priv->has_lock)

				return rc;