linux-kernel - [PATCH 5/5] gpio: sysfs: emit chardev line-state events on edge store

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Message-Id: <20241024-gpio-notify-sysfs-v1-5-981f2773e785@linaro.org>
Date: Thu, 24 Oct 2024 13:32:48 +0200
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Linus Walleij <linus.walleij@...aro.org>, 
 Bartosz Golaszewski <brgl@...ev.pl>, Kent Gibson <warthog618@...il.com>
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: [PATCH 5/5] gpio: sysfs: emit chardev line-state events on edge
 store

From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

In order to emit line-state events on edge changes in sysfs, update the
EDGE flags in the descriptor in gpio_sysfs_request_irq() and emit the
event on a successful store.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
---
 drivers/gpio/gpiolib-sysfs.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index b967b76ea046..87f27a0288f9 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -178,12 +178,16 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
 		return -ENODEV;
 
 	irq_flags = IRQF_SHARED;
-	if (flags & GPIO_IRQF_TRIGGER_FALLING)
+	if (flags & GPIO_IRQF_TRIGGER_FALLING) {
 		irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
 			IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
-	if (flags & GPIO_IRQF_TRIGGER_RISING)
+		set_bit(FLAG_EDGE_FALLING, &desc->flags);
+	}
+	if (flags & GPIO_IRQF_TRIGGER_RISING) {
 		irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
 			IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
+		set_bit(FLAG_EDGE_RISING, &desc->flags);
+	}
 
 	/*
 	 * FIXME: This should be done in the irq_request_resources callback
@@ -209,6 +213,8 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
 err_unlock:
 	gpiochip_unlock_as_irq(guard.gc, gpio_chip_hwgpio(desc));
 err_put_kn:
+	clear_bit(FLAG_EDGE_RISING, &desc->flags);
+	clear_bit(FLAG_EDGE_FALLING, &desc->flags);
 	sysfs_put(data->value_kn);
 
 	return ret;
@@ -230,6 +236,8 @@ static void gpio_sysfs_free_irq(struct device *dev)
 	data->irq_flags = 0;
 	free_irq(data->irq, data);
 	gpiochip_unlock_as_irq(guard.gc, gpio_chip_hwgpio(desc));
+	clear_bit(FLAG_EDGE_RISING, &desc->flags);
+	clear_bit(FLAG_EDGE_FALLING, &desc->flags);
 	sysfs_put(data->value_kn);
 }
 
@@ -280,6 +288,8 @@ static ssize_t edge_store(struct device *dev,
 			status = size;
 	}
 
+	gpiod_line_state_notify(data->desc, GPIO_V2_LINE_CHANGED_CONFIG);
+
 	return status;
 }
 static DEVICE_ATTR_RW(edge);

-- 
2.45.2