| Message ID | 57860e4929a9d20d73f5e003a148b86a9f82310e.1610529002.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | gpio: mvebu: pwm fixes and improvements | expand |
On Wed, Jan 13, 2021 at 11:22:41AM +0200, Baruch Siach wrote: > The period is the sum of on and off values. That is, calculate period as > > ($on + $off) / clkrate > > instead of > > $off / clkrate - $on / clkrate > > that makes no sense. > > Reported-by: Russell King <linux@armlinux.org.uk> > Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") > Signed-off-by: Baruch Siach <baruch@tkos.co.il> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Best regards Uwe
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 672681a976f5..a912a8fed197 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -676,20 +676,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, else state->duty_cycle = 1; + val = (unsigned long long) u; /* on duration */ regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); - val = (unsigned long long) u * NSEC_PER_SEC; + val += (unsigned long long) u; /* period = on + off duration */ + val *= NSEC_PER_SEC; do_div(val, mvpwm->clk_rate); - if (val < state->duty_cycle) { + if (val > UINT_MAX) + state->period = UINT_MAX; + else if (val) + state->period = val; + else state->period = 1; - } else { - val -= state->duty_cycle; - if (val > UINT_MAX) - state->period = UINT_MAX; - else if (val) - state->period = val; - else - state->period = 1; - } regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u); if (u)
The period is the sum of on and off values. That is, calculate period as ($on + $off) / clkrate instead of $off / clkrate - $on / clkrate that makes no sense. Reported-by: Russell King <linux@armlinux.org.uk> Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") Signed-off-by: Baruch Siach <baruch@tkos.co.il> --- drivers/gpio/gpio-mvebu.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)