| 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 |
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 --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;
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(-)