From: Ben Dooks <ben.dooks@codethink.co.uk>
To: linux-pwm@vger.kernel.org
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
ben.dooks@codethink.co.uk, u.kleine-koenig@pengutronix.de,
Thierry Reding <thierry.reding@gmail.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Greentime Hu <greentime.hu@sifive.com>,
jarkko.nikula@linux.intel.com,
William Salmon <william.salmon@sifive.com>,
Jude Onyenegecha <jude.onyenegecha@sifive.com>
Subject: [PATCH v9 5/6] pwm: dwc: round rate divisions up
Date: Thu, 7 Sep 2023 17:12:41 +0100 [thread overview]
Message-ID: <20230907161242.67190-6-ben.dooks@codethink.co.uk> (raw)
In-Reply-To: <20230907161242.67190-1-ben.dooks@codethink.co.uk>
As suggested, round up the counter variables to ensure we
always produce a longer period calculation.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
drivers/pwm/pwm-dwc-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-dwc-core.c b/drivers/pwm/pwm-dwc-core.c
index 3b856685029d..6358e3345210 100644
--- a/drivers/pwm/pwm-dwc-core.c
+++ b/drivers/pwm/pwm-dwc-core.c
@@ -50,13 +50,13 @@ static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
* 2^32 periods.
*/
tmp = state->duty_cycle * dwc->clk_rate;
- tmp = DIV_ROUND_CLOSEST_ULL(tmp, NSEC_PER_SEC);
+ tmp = DIV_ROUND_UP_ULL(tmp, NSEC_PER_SEC);
if (tmp < 1 || tmp > (1ULL << 32))
return -ERANGE;
low = tmp - 1;
tmp = (state->period - state->duty_cycle) * dwc->clk_rate;
- tmp = DIV_ROUND_CLOSEST_ULL(tmp, NSEC_PER_SEC);
+ tmp = DIV_ROUND_UP_ULL(tmp, NSEC_PER_SEC);
if (tmp < 1 || tmp > (1ULL << 32))
return -ERANGE;
high = tmp - 1;
--
2.40.1
next prev parent reply other threads:[~2023-09-07 18:36 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-07 16:12 [PATCH v9 0/6] designware pwm driver updates Ben Dooks
2023-09-07 16:12 ` [PATCH v9 1/6] pwm: dwc: split pci out of core driver Ben Dooks
2023-09-07 21:15 ` Uwe Kleine-König
2023-09-07 16:12 ` [PATCH v9 2/6] pwm: dwc: make timer clock configurable Ben Dooks
2023-09-07 16:12 ` [PATCH v9 3/6] pwm: dwc: add PWM bit unset in get_state call Ben Dooks
2023-09-22 17:35 ` Uwe Kleine-König
2023-09-25 7:02 ` Ben Dooks
2023-09-07 16:12 ` [PATCH v9 4/6] pwm: dwc: use clock rate in hz to avoid rounding issues Ben Dooks
2023-09-07 21:34 ` Uwe Kleine-König
2023-09-11 7:33 ` Ben Dooks
2023-09-11 19:47 ` Uwe Kleine-König
2023-09-07 16:12 ` Ben Dooks [this message]
2023-09-07 21:36 ` [PATCH v9 5/6] pwm: dwc: round rate divisions up Uwe Kleine-König
2023-09-07 16:12 ` [PATCH v9 6/6] pwm: dwc: add of/platform support Ben Dooks
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