+ pps-gpio-remove-dead-capture_clear-code.patch added to mm-nonmm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: pps-gpio: remove dead capture_clear code
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     pps-gpio-remove-dead-capture_clear-code.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/pps-gpio-remove-dead-capture_clear-code.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Calvin Owens <calvin@wbinvd.org>
Subject: pps-gpio: remove dead capture_clear code
Date: Mon, 6 Jul 2026 10:19:07 -0700

The capture_clear field is never set, and all code conditional on it being
set has been unreachable since the platform data logic was removed from
pps-gpio in ee89646619ba ("pps: clients: gpio: Get rid of legacy platform
data").

I think the only logical thing to do here is to remove it all, since no
in-tree code ever actually used it in the first place, and it has been
completely dead code for over five years (since v5.13).

Sashiko asked some questions about the gpiod_get_value() call which caused
me to look deeper and figure this out, but it did not actually notice
capture_clear is never set.

Link: https://lore.kernel.org/f70196bafcf75d9782dd36ed784e42345b6e8a1b.1783355507.git.calvin@wbinvd.org
Fixes: ee89646619ba ("pps: clients: gpio: Get rid of legacy platform data")
Signed-off-by: Calvin Owens <calvin@wbinvd.org>
Closes: https://sashiko.dev/#/patchset/cover.1779733602.git.calvin%40wbinvd.org?part=1
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/pps/clients/pps-gpio.c |   35 ++-----------------------------
 1 file changed, 3 insertions(+), 32 deletions(-)

--- a/drivers/pps/clients/pps-gpio.c~pps-gpio-remove-dead-capture_clear-code
+++ a/drivers/pps/clients/pps-gpio.c
@@ -32,7 +32,6 @@ struct pps_gpio_device_data {
 	struct gpio_desc *echo_pin;
 	struct timer_list echo_timer;	/* timer to reset echo active state */
 	bool assert_falling_edge;
-	bool capture_clear;
 	unsigned int echo_active_ms;	/* PPS echo active duration */
 	unsigned long echo_timeout;	/* timer timeout value in jiffies */
 	struct pps_event_time ts;	/* timestamp captured in hardirq */
@@ -62,19 +61,8 @@ static irqreturn_t pps_gpio_irq_hardirq(
 static irqreturn_t pps_gpio_irq_thread(int irq, void *data)
 {
 	struct pps_gpio_device_data *info = data;
-	int rising_edge;
 
-	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, &info->ts, PPS_CAPTUREASSERT, data);
-	else if (info->capture_clear &&
-			((rising_edge && info->assert_falling_edge) ||
-			(!rising_edge && !info->assert_falling_edge)))
-		pps_event(info->pps, &info->ts, PPS_CAPTURECLEAR, data);
-	else
-		dev_warn_ratelimited(&info->pps->dev, "IRQ did not trigger any PPS event\n");
+	pps_event(info->pps, &info->ts, PPS_CAPTUREASSERT, data);
 
 	return IRQ_HANDLED;
 }
@@ -90,11 +78,6 @@ static void pps_gpio_echo(struct pps_dev
 		if (pps->params.mode & PPS_ECHOASSERT)
 			gpiod_set_value(info->echo_pin, 1);
 		break;
-
-	case PPS_CAPTURECLEAR:
-		if (pps->params.mode & PPS_ECHOCLEAR)
-			gpiod_set_value(info->echo_pin, 1);
-		break;
 	}
 
 	/* fire the timer */
@@ -156,15 +139,8 @@ static int pps_gpio_setup(struct device
 static unsigned long
 get_irqf_trigger_flags(const struct pps_gpio_device_data *data)
 {
-	unsigned long flags = data->assert_falling_edge ?
-		IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
-
-	if (data->capture_clear) {
-		flags |= ((flags & IRQF_TRIGGER_RISING) ?
-				IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING);
-	}
-
-	return flags;
+	return data->assert_falling_edge ? IRQF_TRIGGER_FALLING :
+					   IRQF_TRIGGER_RISING;
 }
 
 static int pps_gpio_probe(struct platform_device *pdev)
@@ -197,9 +173,6 @@ static int pps_gpio_probe(struct platfor
 	/* initialize PPS specific parts of the bookkeeping data structure. */
 	data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
 		PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC;
-	if (data->capture_clear)
-		data->info.mode |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR |
-			PPS_ECHOCLEAR;
 	data->info.owner = THIS_MODULE;
 	snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d",
 		 pdev->name, pdev->id);
@@ -211,8 +184,6 @@ static int pps_gpio_probe(struct platfor
 
 	/* register PPS source */
 	pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT;
-	if (data->capture_clear)
-		pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR;
 	data->pps = pps_register_source(&data->info, pps_default_params);
 	if (IS_ERR(data->pps)) {
 		dev_err(dev, "failed to register IRQ %d as PPS source\n",
_

Patches currently in -mm which might be from calvin@wbinvd.org are

pps-dont-try-to-wait-for-negative-timeouts-in-pps_fetch.patch
pps-dont-allow-pps_kc_bind-on-removed-devices.patch
pps-gpio-remove-dead-capture_clear-code.patch