The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e73b0101ae5124bf7cd3fb5d250302ad2f16a416 Mon Sep 17 00:00:00 2001
From: Baruch Siach baruch@tkos.co.il Date: Sun, 17 Jan 2021 15:17:02 +0200 Subject: [PATCH] gpio: mvebu: fix pwm .get_state period calculation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
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
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)