[PATCH 1/2] stb0899: fix inversion enum values to match usage with CFR

[Reinhard Nißl]

Throughout the zig-zag-implementations, inversion is taken into
account when reading and writing the CFR register, which contains
the derotator frequency. As swapping IQ signals changes the sign
of that register for example, the idea is to compensate that sign
change by multiplying the register value with the inversion enum
value.
The current enum values 0 and 1 for IQ_SWAP_OFF and IQ_SWAP_ON
don't work in the case IQ_SWAP_OFF, due to the multiplication by
zero (I've only found a single device which actually uses
IQ_SWAP_OFF in it's config).
I've changed the enum values to +1 and -1 to accommodate to the
intended usage.

Signed-off-by: Reinhard Nißl <rni...@gmx.de>
---
 drivers/media/dvb-frontends/stb0899_algo.c | 4 ++--
 drivers/media/dvb-frontends/stb0899_drv.h  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb-frontends/stb0899_algo.c 
b/drivers/media/dvb-frontends/stb0899_algo.c
index 14d720b..e0d31a2 100644
--- a/drivers/media/dvb-frontends/stb0899_algo.c
+++ b/drivers/media/dvb-frontends/stb0899_algo.c
@@ -444,7 +444,7 @@ static enum stb0899_status stb0899_check_range(struct 
stb0899_state *state)
        int range_offst, tp_freq;
 
        range_offst = internal->srch_range / 2000;
-       tp_freq = internal->freq + (internal->derot_freq * internal->mclk) / 
1000;
+       tp_freq = internal->freq - (internal->derot_freq * internal->mclk) / 
1000;
 
        if ((tp_freq >= params->freq - range_offst) && (tp_freq <= params->freq 
+ range_offst)) {
                internal->status = RANGEOK;
@@ -638,7 +638,7 @@ enum stb0899_status stb0899_dvbs_algo(struct stb0899_state 
*state)
                                                        "RANGE OK ! derot 
freq=%d, mclk=%d",
                                                        internal->derot_freq, 
internal->mclk);
 
-                                               internal->freq = params->freq + 
((internal->derot_freq * internal->mclk) / 1000);
+                                               internal->freq = params->freq - 
((internal->derot_freq * internal->mclk) / 1000);
                                                reg = stb0899_read_reg(state, 
STB0899_PLPARM);
                                                internal->fecrate = 
STB0899_GETFIELD(VITCURPUN, reg);
                                                dprintk(state->verbose, 
FE_DEBUG, 1,
diff --git a/drivers/media/dvb-frontends/stb0899_drv.h 
b/drivers/media/dvb-frontends/stb0899_drv.h
index 1ddad6a..139264d 100644
--- a/drivers/media/dvb-frontends/stb0899_drv.h
+++ b/drivers/media/dvb-frontends/stb0899_drv.h
@@ -45,8 +45,8 @@ struct stb0899_s2_reg {
 };
 
 enum stb0899_inversion {
-       IQ_SWAP_OFF     = 0,
-       IQ_SWAP_ON,
+       IQ_SWAP_OFF     = +1, /* inversion affects the sign of e. g. */
+       IQ_SWAP_ON      = -1, /* the derotator frequency register    */
 };
 
 #define STB0899_GPIO00                         0xf140
-- 
1.8.1.4

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