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charset="us-ascii" From: Vincent Mailhol CAN XL optimal sample point for PWM encoding (when TMS is on) differs from the NRZ optimal one. There is thus a need to calculate a different sample point depending whether TMS is on or off. This is a preparation change: move the sample point calculation from can_calc_bittiming() into the new can_calc_sample_point_nrz() function. In an upcoming change, a function will be added to calculate the sample point for PWM encoding. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp --- drivers/net/can/dev/calc_bittiming.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/net/can/dev/calc_bittiming.c b/drivers/net/can/dev/calc_bittiming.c index 46f6f5942abb..35db90be9c9a 100644 --- a/drivers/net/can/dev/calc_bittiming.c +++ b/drivers/net/can/dev/calc_bittiming.c @@ -8,10 +8,22 @@ #include #include #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ +/* CiA recommended sample points for Non Return to Zero encoding. */ +static int can_calc_sample_point_nrz(const struct can_bittiming *bt) +{ + if (bt->bitrate > 800 * KILO /* BPS */) + return 750; + + if (bt->bitrate > 500 * KILO /* BPS */) + return 800; + + return 875; +} + /* Bit-timing calculation derived from: * * Code based on LinCAN sources and H8S2638 project * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz * Copyright 2005 Stanislav Marek @@ -76,21 +88,14 @@ int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, unsigned int best_brp = 0; /* current best value for brp */ unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0; u64 v64; int err; - /* Use CiA recommended sample points */ - if (bt->sample_point) { + if (bt->sample_point) sample_point = bt->sample_point; - } else { - if (bt->bitrate > 800 * KILO /* BPS */) - sample_point = 750; - else if (bt->bitrate > 500 * KILO /* BPS */) - sample_point = 800; - else - sample_point = 875; - } + else + sample_point = can_calc_sample_point_nrz(bt); /* tseg even = round down, odd = round up */ for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { tsegall = CAN_SYNC_SEG + tseg / 2; -- 2.47.3