Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Bastien Curutchet <> | Subject | [PATCH v3 1/1] pps: clients: gpio: Bypass edge's direction check when not needed | Date | Thu, 25 Apr 2024 14:28:52 +0200 |
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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> --- 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; } -- 2.44.0
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