diff options
| author | Baruch Siach <baruch@tkos.co.il> | 2021-01-17 16:17:02 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-30 15:32:11 +0300 |
| commit | 4e5ee86dcb0003ae9ed0b477e47a1d0aaf2f8c67 (patch) | |
| tree | 76fe5f65173ee73d7008b491b9a864660d7140a7 /drivers/gpio | |
| parent | c4ff839de17f38b0ae0f8983b5c5186f8a389238 (diff) | |
| download | linux-4e5ee86dcb0003ae9ed0b477e47a1d0aaf2f8c67.tar.xz | |
gpio: mvebu: fix pwm .get_state period calculation
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>
[baruch: backport to kernels <= v5.10]
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-mvebu.c | 25 |
1 files changed, 10 insertions, 15 deletions
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 3b78dcda4736..874caed72390 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -650,9 +650,8 @@ 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; @@ -661,21 +660,17 @@ 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; - else - state->period = 1; - } regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u); if (u) |