2006-10-08 18:46:27

by Michael Ira Krufky

[permalink] [raw]
Subject: [2.6.17.y PATCH 2/2] cx24123: fix PLL divisor setup

>From df9b6db4d2168cd82f8590d2f9a2d3580cdf7233 Mon Sep 17 00:00:00 2001
From: Yeasah Pell <[email protected]>
Date: Tue, 3 Oct 2006 21:57:08 -0400
Subject: [PATCH] cx24123: fix PLL divisor setup

The cx24109 datasheet says: "NOTE: if A=0, then N=N+1"

The current code is the result of a misinterpretation of the datasheet to
mean exactly the opposite of the requirement -- The actual value of N is 1 greater than the value written when A is 0, so 1 needs to be *subtracted*
from it to compensate.

Signed-off-by: Yeasah Pell <[email protected]>
Signed-off-by: Steven Toth <[email protected]>
Signed-off-by: Michael Krufky <[email protected]>
---
drivers/media/dvb/frontends/cx24123.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/dvb/frontends/cx24123.c b/drivers/media/dvb/frontends/cx24123.c
index 691dc84..afb08ff 100644
--- a/drivers/media/dvb/frontends/cx24123.c
+++ b/drivers/media/dvb/frontends/cx24123.c
@@ -579,8 +579,8 @@ static int cx24123_pll_calculate(struct
ndiv = ( ((p->frequency * vco_div * 10) / (2 * XTAL / 1000)) / 32) & 0x1ff;
adiv = ( ((p->frequency * vco_div * 10) / (2 * XTAL / 1000)) % 32) & 0x1f;

- if (adiv == 0)
- ndiv++;
+ if (adiv == 0 && ndiv > 0)
+ ndiv--;

/* control bits 11, refdiv 11, charge pump polarity 1, charge pump current, ndiv, adiv */
state->pllarg = (3 << 19) | (3 << 17) | (1 << 16) | (pump << 14) | (ndiv << 5) | adiv;