Messages in this thread | | | Date | Thu, 25 Apr 2024 14:42:40 +0200 | Subject | Re: [PATCH v3 1/1] pps: clients: gpio: Bypass edge's direction check when not needed | From | Rodolfo Giometti <> |
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On 25/04/24 14:28, Bastien Curutchet wrote: > In the IRQ handler, the GPIO's state is read to verify the direction of > the edge that triggered the interruption before generating the PPS event. > If a pulse is too short, the GPIO line can reach back its original state > before this verification and the PPS event is lost. > > This check is needed when info->capture_clear is set because it needs > interruptions on both rising and falling edges. When info->capture_clear > is not set, interruption is triggered by one edge only so this check can > be omitted. > > Add a warning if irq_handler is left without triggering any PPS event. > Bypass the edge's direction verification when info->capture_clear is not > set. > > Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
> --- > Changes in v3: > - Add a warning in irq_handler > Changes in v2: > - Modifiy the way the bypass is done to avoid code duplication > > v1: https://lore.kernel.org/all/20240410113502.73038-1-bastien.curutchet@bootlin.com/ > v2: https://lore.kernel.org/all/20240411061329.7262-1-bastien.curutchet@bootlin.com/ > > drivers/pps/clients/pps-gpio.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c > index 2f4b11b4dfcd..af62d944d051 100644 > --- a/drivers/pps/clients/pps-gpio.c > +++ b/drivers/pps/clients/pps-gpio.c > @@ -52,7 +52,9 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) > > info = data; > > - rising_edge = gpiod_get_value(info->gpio_pin); > + /* Small trick to bypass the check on edge's direction when capture_clear is unset */ > + rising_edge = info->capture_clear ? > + gpiod_get_value(info->gpio_pin) : !info->assert_falling_edge; > if ((rising_edge && !info->assert_falling_edge) || > (!rising_edge && info->assert_falling_edge)) > pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data); > @@ -60,6 +62,8 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) > ((rising_edge && info->assert_falling_edge) || > (!rising_edge && !info->assert_falling_edge))) > pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data); > + else > + dev_warn_ratelimited(info->pps->dev, "IRQ did not trigger any PPS event\n"); > > return IRQ_HANDLED; > }
-- GNU/Linux Solutions e-mail: giometti@enneenne.com Linux Device Driver giometti@linux.it Embedded Systems phone: +39 349 2432127 UNIX programming
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