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path: root/drivers/media/dvb-frontends/tda10048.c
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Diffstat (limited to 'drivers/media/dvb-frontends/tda10048.c')
-rw-r--r--drivers/media/dvb-frontends/tda10048.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/media/dvb-frontends/tda10048.c b/drivers/media/dvb-frontends/tda10048.c
index 5d5e4e9e4422..1f87eb0dcf2a 100644
--- a/drivers/media/dvb-frontends/tda10048.c
+++ b/drivers/media/dvb-frontends/tda10048.c
@@ -328,7 +328,8 @@ static int tda10048_set_wref(struct dvb_frontend *fe, u32 sample_freq_hz,
u32 bw)
{
struct tda10048_state *state = fe->demodulator_priv;
- u64 t, z;
+ u64 t;
+ u32 z;
dprintk(1, "%s()\n", __func__);
@@ -341,6 +342,11 @@ static int tda10048_set_wref(struct dvb_frontend *fe, u32 sample_freq_hz,
/* t *= 2147483648 on 32bit platforms */
t *= (2048 * 1024);
t *= 1024;
+
+ /*
+ * Sample frequency is typically 55 MHz, with a theoretical maximum of
+ * 69 MHz. With a 32 bit z we have enough accuracy for up to 613 MHz.
+ */
z = 7 * sample_freq_hz;
do_div(t, z);
t += 5;
@@ -410,6 +416,7 @@ static int tda10048_set_if(struct dvb_frontend *fe, u32 bw)
struct tda10048_config *config = &state->config;
int i;
u32 if_freq_khz;
+ u64 sample_freq;
dprintk(1, "%s(bw = %d)\n", __func__, bw);
@@ -451,9 +458,11 @@ static int tda10048_set_if(struct dvb_frontend *fe, u32 bw)
dprintk(1, "- pll_pfactor = %d\n", state->pll_pfactor);
/* Calculate the sample frequency */
- state->sample_freq = state->xtal_hz * (state->pll_mfactor + 45);
- state->sample_freq /= (state->pll_nfactor + 1);
- state->sample_freq /= (state->pll_pfactor + 4);
+ sample_freq = state->xtal_hz;
+ sample_freq *= state->pll_mfactor + 45;
+ do_div(sample_freq, state->pll_nfactor + 1);
+ do_div(sample_freq, state->pll_pfactor + 4);
+ state->sample_freq = sample_freq;
dprintk(1, "- sample_freq = %d\n", state->sample_freq);
/* Update the I/F */