When setting up an encoder channel, the setup value includes a polarity and direction, but these are the same bit of the setup value: S626_CLKPOL_POS = S626_CNTDIR_UP = 0 S626_CLKPOL_NEG = S626_CNTDIR_DOWN = 1 In the construction of the setup value, both the CLKPOL and the CNTDIR constants are shifted by the same amount `S626_BF_CLKPOL`. Only the following combinations are set up currently (this may change if user configuration of the encoder is implemented properly): (S626_CLKPOL_POS << S626_BF_CLKPOL) (S626_CLKPOL_POS << S626_BF_CLKPOL) | (S626_CNTDIR_UP << S626_BF_CLKPOL) (S626_CLKPOL_POS << S626_BF_CLKPOL) | (S626_CNTDIR_DOWN << S626_BF_CLKPOL) The first two are used in "counter" mode and is equivalent to: (S626_CLKPOL_POS << S626_BF_CLKPOL) The last one is used in "timer" mode and is equivalent to: (S626_CNTDIR_DOWN << S626_BF_CLKPOL) Use the shorter equivalents. The comments in "s626.h" indicate that the 'CLKPOL' constants make more sense for the "counter" mode (when the encoders operate as up/down counters) and the 'CNTDIR' constants make more sense for the "timer" mode. Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> --- drivers/staging/comedi/drivers/s626.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c index d9aba7c..dd138a0 100644 --- a/drivers/staging/comedi/drivers/s626.c +++ b/drivers/staging/comedi/drivers/s626.c @@ -2036,8 +2036,6 @@ static void s626_timer_load(struct comedi_device *dev, (S626_INDXSRC_SOFT << S626_BF_INDXSRC) | /* Operating mode is Timer. */ (S626_CLKSRC_TIMER << S626_BF_CLKSRC) | - /* Active high clock. */ - (S626_CLKPOL_POS << S626_BF_CLKPOL) | /* Count direction is Down. */ (S626_CNTDIR_DOWN << S626_BF_CLKPOL) | /* Clock multiplier is 1x. */ @@ -2528,8 +2526,6 @@ static void s626_counters_init(struct comedi_device *dev) (S626_CLKSRC_COUNTER << S626_BF_CLKSRC) | /* Active high clock. */ (S626_CLKPOL_POS << S626_BF_CLKPOL) | - /* Count direction is up. */ - (S626_CNTDIR_UP << S626_BF_CLKPOL) | /* Clock multiplier is 1x. */ (S626_CLKMULT_1X << S626_BF_CLKMULT) | /* Enabled by index */ -- 1.8.4 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
