gpiolib: rewrite gpiodev_add_to_list (a961f9b4) · Commits · 戴 / test

drivers/gpio/gpiolib.c

+25 −40

Original line number	Diff line number	Diff line
		@@ -206,58 +206,43 @@ EXPORT_SYMBOL_GPL(gpiod_get_direction);
		*/
		static int gpiodev_add_to_list(struct gpio_device *gdev)
		{
		struct gpio_device *iterator;
		struct gpio_device *previous = NULL;

		if (!gdev->chip)
		return -EINVAL;
		struct gpio_device prev, next;

		if (list_empty(&gpio_devices)) {
		/* initial entry in list */
		list_add_tail(&gdev->list, &gpio_devices);
		return 0;
		}

		list_for_each_entry(iterator, &gpio_devices, list) {
		if (iterator->base >= gdev->base + gdev->ngpio) {
		/*
		* Iterator is the first GPIO chip so there is no
		* previous one
		*/
		if (!previous) {
		goto found;
		} else {
		/*
		* We found a valid range(means
		* [base, base + ngpio - 1]) between previous
		* and iterator chip.
		*/
		if (previous->base + previous->ngpio
		<= gdev->base)
		goto found;
		}
		next = list_entry(gpio_devices.next, struct gpio_device, list);
		if (gdev->base + gdev->ngpio <= next->base) {
		/* add before first entry */
		list_add(&gdev->list, &gpio_devices);
		return 0;
		}
		previous = iterator;

		prev = list_entry(gpio_devices.prev, struct gpio_device, list);
		if (prev->base + prev->ngpio <= gdev->base) {
		/* add behind last entry */
		list_add_tail(&gdev->list, &gpio_devices);
		return 0;
		}

		/*
		* We are beyond the last chip in the list and iterator now
		* points to the head.
		* Let iterator point to the last chip in the list.
		*/
		list_for_each_entry_safe(prev, next, &gpio_devices, list) {
		/* at the end of the list */
		if (&next->list == &gpio_devices)
		break;

		iterator = list_last_entry(&gpio_devices, struct gpio_device, list);
		if (iterator->base + iterator->ngpio <= gdev->base) {
		list_add(&gdev->list, &iterator->list);
		/* add between prev and next */
		if (prev->base + prev->ngpio <= gdev->base
		&& gdev->base + gdev->ngpio <= next->base) {
		list_add(&gdev->list, &prev->list);
		return 0;
		}
		}

		dev_err(&gdev->dev,
		"GPIO integer space overlap, cannot add chip\n");
		dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
		return -EBUSY;

		found:
		list_add_tail(&gdev->list, &iterator->list);
		return 0;
		}

		/**

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