Hardware appears to treat zero value as 2^32. Take advantage of this
fact to support on/off values of up to UINT_MAX+1 == 2^32. Adjust both
.apply and .get_state to handle zero as a special case.
Rounded up division result in .get_state can't be zero, since the
dividend is now larger than 0. Remove check for this case.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Analyzed-by: Russell King <linux@armlinux.org.uk>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
spin_lock_irqsave(&mvpwm->lock, flags);
regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u);
spin_lock_irqsave(&mvpwm->lock, flags);
regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u);
- val = (unsigned long long) u * NSEC_PER_SEC;
- val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate);
- if (val)
- state->duty_cycle = val;
+ /* Hardware treats zero as 2^32. See mvebu_pwm_apply(). */
+ if (u > 0)
+ val = u;
+ val = UINT_MAX + 1ULL;
+ state->duty_cycle = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC,
+ mvpwm->clk_rate);
- val = (unsigned long long) u; /* on duration */
regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u);
regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u);
- val += (unsigned long long) u; /* period = on + off duration */
- val *= NSEC_PER_SEC;
- val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate);
- if (val)
- state->period = val;
+ /* period = on + off duration */
+ if (u > 0)
+ val += u;
+ val += UINT_MAX + 1ULL;
+ state->period = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC, mvpwm->clk_rate);
regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u);
if (u)
regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u);
if (u)
val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
do_div(val, NSEC_PER_SEC);
val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
do_div(val, NSEC_PER_SEC);
+ if (val > UINT_MAX + 1ULL)
+ /*
+ * Zero on/off values don't work as expected. Experimentation shows
+ * that zero value is treated as 2^32. This behavior is not documented.
+ */
+ if (val == UINT_MAX + 1ULL)
+ on = 0;
+ else if (val)
val = (unsigned long long) mvpwm->clk_rate * state->period;
do_div(val, NSEC_PER_SEC);
val -= on;
val = (unsigned long long) mvpwm->clk_rate * state->period;
do_div(val, NSEC_PER_SEC);
val -= on;
+ if (val > UINT_MAX + 1ULL)
+ if (val == UINT_MAX + 1ULL)
+ off = 0;
+ else if (val)