On Tue, Jan 26, 2021 at 11:00:11AM +0200, Baruch Siach wrote:
commit e73b0101ae5124bf7cd3fb5d250302ad2f16a416 upstream.
The period is the sum of on and off values. That is, calculate period as
($on + $off) / clkrate
instead of
$off / clkrate - $on / clkrate
that makes no sense.
Reported-by: Russell King linux@armlinux.org.uk Reviewed-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") Signed-off-by: Baruch Siach baruch@tkos.co.il Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com
Doesn't this need something like:
[baruch: Backported to 5.10]
plus a new S-o-B?
This backported patch applies to all kernels between 4.14 and 5.10 (inclusive).
drivers/gpio/gpio-mvebu.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 2f245594a90a..ed7c5fc47f52 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -660,9 +660,8 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, spin_lock_irqsave(&mvpwm->lock, flags);
- val = (unsigned long long)
readl_relaxed(mvebu_pwmreg_blink_on_duration(mvpwm));- val *= NSEC_PER_SEC;
- u = readl_relaxed(mvebu_pwmreg_blink_on_duration(mvpwm));
- val = (unsigned long long) u * NSEC_PER_SEC; do_div(val, mvpwm->clk_rate); if (val > UINT_MAX) state->duty_cycle = UINT_MAX;
@@ -671,21 +670,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, else state->duty_cycle = 1;
- val = (unsigned long long)
readl_relaxed(mvebu_pwmreg_blink_off_duration(mvpwm));
- val = (unsigned long long) u; /* on duration */
- /* period = on + off duration */
- val += readl_relaxed(mvebu_pwmreg_blink_off_duration(mvpwm)); val *= NSEC_PER_SEC; do_div(val, mvpwm->clk_rate);
- if (val < state->duty_cycle) {
- if (val > UINT_MAX)
state->period = UINT_MAX;- else if (val)
state->period = val;- else state->period = 1;
- } else {
val -= state->duty_cycle;if (val > UINT_MAX)state->period = UINT_MAX;else if (val)state->period = val;elsestate->period = 1;- }
regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u); if (u)
Reviewed-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de
Thanks Uwe