| Message ID | 20210418205747.1488248-1-uwe@kleine-koenig.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | pwm: atmel: Fix duty cycle calculation in .get_state() | expand |
Hello, On Sun, Apr 18, 2021 at 10:57:47PM +0200, Uwe Kleine-König wrote: > - tmp = (u64)cdty * NSEC_PER_SEC; > + tmp = (u64)(cdty - cprd) * NSEC_PER_SEC; This is wrong, it must be cprd - cdty. I will send a fixed patch together with another patch that improves precision of _apply. Best regards Uwe
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index d49da708337f..c30a0dac4b2d 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -319,7 +319,7 @@ static void atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, cdty = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, atmel_pwm->data->regs.duty); - tmp = (u64)cdty * NSEC_PER_SEC; + tmp = (u64)(cdty - cprd) * NSEC_PER_SEC; tmp <<= pres; state->duty_cycle = DIV64_U64_ROUND_UP(tmp, rate);
The CDTY register contains the number of inactive cycles. .apply() does this correctly, however .get_state got this wrong. Fixes: 651b510a74d4 ("pwm: atmel: Implement .get_state()") Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> --- drivers/pwm/pwm-atmel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)