path: root/drivers/base/platform.c

// SPDX-License-Identifier: GPL-2.0
/*
 * platform.c - platform 'pseudo' bus for legacy devices
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 *
 * Please see Documentation/driver-api/driver-model/platform.rst for more
 * information.
 */

#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/memblock.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
#include <linux/idr.h>
#include <linux/acpi.h>
#include <linux/clk/clk-conf.h>
#include <linux/limits.h>
#include <linux/property.h>
#include <linux/kmemleak.h>
#include <linux/types.h>

#include "base.h"
#include "power/power.h"

/* For automatically allocated device IDs */
static DEFINE_IDA(platform_devid_ida);

struct device platform_bus = {
	.init_name	= "platform",
};
EXPORT_SYMBOL_GPL(platform_bus);

/**
 * platform_get_resource - get a resource for a device
 * @dev: platform device
 * @type: resource type
 * @num: resource index
 */
struct resource *platform_get_resource(struct platform_device *dev,
				       unsigned int type, unsigned int num)
{
	u32 i;

	for (i = 0; i < dev->num_resources; i++) {
		struct resource *r = &dev->resource[i];

		if (type == resource_type(r) && num-- == 0)
			return r;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(platform_get_resource);

/**
 * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
 *				    device
 *
 * @pdev: platform device to use both for memory resource lookup as well as
 *        resource management
 * @index: resource index
 */
#ifdef CONFIG_HAS_IOMEM
void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
					     unsigned int index)
{
	struct resource *res;

	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
	return devm_ioremap_resource(&pdev->dev, res);
}
EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
#endif /* CONFIG_HAS_IOMEM */

static int __platform_get_irq(struct platform_device *dev, unsigned int num)
{
#ifdef CONFIG_SPARC
	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
	if (!dev || num >= dev->archdata.num_irqs)
		return -ENXIO;
	return dev->archdata.irqs[num];
#else
	struct resource *r;
	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
		int ret;

		ret = of_irq_get(dev->dev.of_node, num);
		if (ret > 0 || ret == -EPROBE_DEFER)
			return ret;
	}

	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
	if (has_acpi_companion(&dev->dev)) {
		if (r && r->flags & IORESOURCE_DISABLED) {
			int ret;

			ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
			if (ret)
				return ret;
		}
	}

	/*
	 * The resources may pass trigger flags to the irqs that need
	 * to be set up. It so happens that the trigger flags for
	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
	 * settings.
	 */
	if (r && r->flags & IORESOURCE_BITS) {
		struct irq_data *irqd;

		irqd = irq_get_irq_data(r->start);
		if (!irqd)
			return -ENXIO;
		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
	}

	if (r)
		return r->start;

	/*
	 * For the index 0 interrupt, allow falling back to GpioInt
	 * resources. While a device could have both Interrupt and GpioInt
	 * resources, making this fallback ambiguous, in many common cases
	 * the device will only expose one IRQ, and this fallback
	 * allows a common code path across either kind of resource.
	 */
	if (num == 0 && has_acpi_companion(&dev->dev)) {
		int ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);

		/* Our callers expect -ENXIO for missing IRQs. */
		if (ret >= 0 || ret == -EPROBE_DEFER)
			return ret;
	}

	return -ENXIO;
#endif
}

/**
 * platform_get_irq - get an IRQ for a device
 * @dev: platform device
 * @num: IRQ number index
 *
 * Gets an IRQ for a platform device and prints an error message if finding the
 * IRQ fails. Device drivers should check the return value for errors so as to
 * not pass a negative integer value to the request_irq() APIs.
 *
 * Example:
 *		int irq = platform_get_irq(pdev, 0);
 *		if (irq < 0)
 *			return irq;
 *
 * Return: IRQ number on success, negative error number on failure.
 */
int platform_get_irq(struct platform_device *dev, unsigned int num)
{
	int ret;

	ret = __platform_get_irq(dev, num);
	if (ret < 0 && ret != -EPROBE_DEFER)
		dev_err(&dev->dev, "IRQ index %u not found\n", num);

	return ret;
}
EXPORT_SYMBOL_GPL(platform_get_irq);

/**
 * platform_get_irq_optional - get an optional IRQ for a device
 * @dev: platform device
 * @num: IRQ number index
 *
 * Gets an IRQ for a platform device. Device drivers should check the return
 * value for errors so as to not pass a negative integer value to the
 * request_irq() APIs. This is the same as platform_get_irq(), except that it
 * does not print an error message if an IRQ can not be obtained.
 *
 * Example:
 *		int irq = platform_get_irq_optional(pdev, 0);
 *		if (irq < 0)
 *			return irq;
 *
 * Return: IRQ number on success, negative error number on failure.
 */
int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
{
	return __platform_get_irq(dev, num);
}
EXPORT_SYMBOL_GPL(platform_get_irq_optional);

/**
 * platform_irq_count - Count the number of IRQs a platform device uses
 * @dev: platform device
 *
 * Return: Number of IRQs a platform device uses or EPROBE_DEFER
 */
int platform_irq_count(struct platform_device *dev)
{
	int ret, nr = 0;

	while ((ret = __platform_get_irq(dev, nr)) >= 0)
		nr++;

	if (ret == -EPROBE_DEFER)
		return ret;

	return nr;
}
EXPORT_SYMBOL_GPL(platform_irq_count);

/**
 * platform_get_resource_byname - get a resource for a device by name
 * @dev: platform device
 * @type: resource type
 * @name: resource name
 */
struct resource *platform_get_resource_byname(struct platform_device *dev,
					      unsigned int type,
					      const char *name)
{
	u32 i;

	for (i = 0; i < dev->num_resources; i++) {
		struct resource *r = &dev->resource[i];

		if (unlikely(!r->name))
			continue;

		if (type == resource_type(r) && !strcmp(r