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authorBastien Curutchet <bastien.curutchet@bootlin.com>2025-01-08 18:30:12 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-01-10 18:12:33 +0300
commita01f6287c244f35eeec11ca932d09061181eed8c (patch)
tree7bcfcf9fd0c5f9ead62f8ae670a2b074cf853072 /drivers/pps
parent6d2478a103a8238c5382f8a318735aa75d49803a (diff)
downloadlinux-a01f6287c244f35eeec11ca932d09061181eed8c.tar.xz
pps: clients: gpio: Bypass edge's direction check when not needed
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> Link: https://lore.kernel.org/r/20250108153012.514925-1-bastien.curutchet@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/pps')
-rw-r--r--drivers/pps/clients/pps-gpio.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
index f77b19884f05..75c1bae30a7c 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;
}