Adds debugging info to config function where duty cycle and period are calculated and verified.
Signed-off-by: Jonathan Richardson <jonat...@broadcom.com> --- drivers/pwm/pwm-bcm-kona.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c index 0654981..c6069c7 100644 --- a/drivers/pwm/pwm-bcm-kona.c +++ b/drivers/pwm/pwm-bcm-kona.c @@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, dc = div64_u64(val, div); /* If duty_ns or period_ns are not achievable then return */ - if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN) + if (pc < PERIOD_COUNT_MIN) { + dev_warn(chip->dev, + "%s: pwm[%d]: period=%d is not achievable, pc=%lu, prescale=%lu\n", + __func__, chan, period_ns, pc, prescale); return -EINVAL; + } + + if (dc < DUTY_CYCLE_HIGH_MIN) { + if (0 != duty_ns) { + dev_warn(chip->dev, + "%s: pwm[%d]: duty cycle=%d is not achievable, dc=%lu, prescale=%lu\n", + __func__, chan, duty_ns, dc, prescale); + } + return -EINVAL; + } /* If pc and dc are in bounds, the calculation is done */ if (pc <= PERIOD_COUNT_MAX && dc <= DUTY_CYCLE_HIGH_MAX) break; /* Otherwise, increase prescale and recalculate pc and dc */ - if (++prescale > PRESCALE_MAX) + if (++prescale > PRESCALE_MAX) { + dev_warn(chip->dev, + "%s: pwm[%d]: Prescale (=%lu) within max (=%d) for period=%d and duty cycle=%d is not achievable\n", + __func__, chan, prescale, PRESCALE_MAX, + period_ns, duty_ns); return -EINVAL; + } } + dev_dbg(chip->dev, "pwm[%d]: period=%lu, duty_high=%lu, prescale=%lu\n", + chan, pc, dc, prescale); + /* * Don't apply settings if disabled. The period and duty cycle are * always calculated above to ensure the new values are -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/