diff mbox series

[3/5] gpio: mvebu: make pwm apply/get_state closer to idempotent

Message ID 1c8864722e4c74d1d8d5d4a213998a1672be9992.1610362661.git.baruch@tkos.co.il (mailing list archive)
State New, archived
Headers show
Series gpio: mvebu: pwm fixes and improvements | expand

Commit Message

Baruch Siach Jan. 11, 2021, 11:17 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 | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Uwe Kleine-König Jan. 11, 2021, 8:20 p.m. UTC | #1
On Mon, Jan 11, 2021 at 01:17:04PM +0200, Baruch Siach wrote:
> 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 | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
> index c424d88e9e2b..6fc64846eda3 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)
> @@ -707,7 +707,7 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>  	unsigned int on, off;
>  
>  	val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
> -	do_div(val, NSEC_PER_SEC);
> +	val = DIV_ROUND_UP_ULL(val, NSEC_PER_SEC);

.apply must continue to round down.

Best regards
Uwe

>  	if (val > UINT_MAX)
>  		return -EINVAL;
>  	if (val)
> @@ -716,7 +716,7 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>  		on = 1;
>  
>  	val = (unsigned long long) mvpwm->clk_rate * state->period;
> -	do_div(val, NSEC_PER_SEC);
> +	val = DIV_ROUND_UP_ULL(val, NSEC_PER_SEC);
>  	val -= on;
>  	if (val > UINT_MAX)
>  		return -EINVAL;
> -- 
> 2.29.2
> 
>
diff mbox series

Patch

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index c424d88e9e2b..6fc64846eda3 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)
@@ -707,7 +707,7 @@  static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned int on, off;
 
 	val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
-	do_div(val, NSEC_PER_SEC);
+	val = DIV_ROUND_UP_ULL(val, NSEC_PER_SEC);
 	if (val > UINT_MAX)
 		return -EINVAL;
 	if (val)
@@ -716,7 +716,7 @@  static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 		on = 1;
 
 	val = (unsigned long long) mvpwm->clk_rate * state->period;
-	do_div(val, NSEC_PER_SEC);
+	val = DIV_ROUND_UP_ULL(val, NSEC_PER_SEC);
 	val -= on;
 	if (val > UINT_MAX)
 		return -EINVAL;