diff mbox series

[v2,3/5] gpio: mvebu: make pwm .get_state closer to idempotent

Message ID 1d376a3500e11d8fd2ecaf9ca345977f011079af.1610529002.git.baruch@tkos.co.il
State Superseded
Headers show
Series gpio: mvebu: pwm fixes and improvements | expand

Commit Message

Baruch Siach Jan. 13, 2021, 9:22 a.m. UTC
Round up the result of division in period/duty_cycle calculation to make
the result closer to idempotent.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
 drivers/gpio/gpio-mvebu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Uwe Kleine-König Jan. 13, 2021, 9:42 a.m. UTC | #1
On Wed, Jan 13, 2021 at 11:22:43AM +0200, Baruch Siach wrote:
> Round up the result of division in period/duty_cycle calculation to make
> the result closer to idempotent.

Maybe:

Round up the divisions in .get_state() to make applying the read out
configuration idempotent in most cases as .apply rounds down.

> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>

Other than that:

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Best regards
Uwe
diff mbox series

Patch

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index c424d88e9e2b..8673ba77af5a 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -668,7 +668,7 @@  static void mvebu_pwm_get_state(struct pwm_chip *chip,
 
 	regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u);
 	val = (unsigned long long) u * NSEC_PER_SEC;
-	do_div(val, mvpwm->clk_rate);
+	val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate);
 	if (val > UINT_MAX)
 		state->duty_cycle = UINT_MAX;
 	else if (val)
@@ -680,7 +680,7 @@  static void mvebu_pwm_get_state(struct pwm_chip *chip,
 	regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u);
 	val += (unsigned long long) u; /* period = on + off duration */
 	val *= NSEC_PER_SEC;
-	do_div(val, mvpwm->clk_rate);
+	val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate);
 	if (val > UINT_MAX)
 		state->period = UINT_MAX;
 	else if (val)