linux/arch/powerpc/kernel/of_platform.c

/*
 *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
 *			 <benh@kernel.crashing.org>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#undef DEBUG

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>

#include <asm/errno.h>
#include <asm/dcr.h>
#include <asm/of_device.h>
#include <asm/of_platform.h>
#include <asm/topology.h>

/*
 * The list of OF IDs below is used for matching bus types in the
 * system whose devices are to be exposed as of_platform_devices.
 *
 * This is the default list valid for most platforms. This file provides
 * functions who can take an explicit list if necessary though
 *
 * The search is always performed recursively looking for children of
 * the provided device_node and recursively if such a children matches
 * a bus type in the list
 */

static struct of_device_id of_default_bus_ids[] = {
	{ .type = "soc", },
	{ .compatible = "soc", },
	{ .type = "spider", },
	{ .type = "axon", },
	{ .type = "plb5", },
	{ .type = "plb4", },
	{ .type = "opb", },
	{},
};

/*
 *
 * OF platform device type definition & base infrastructure
 *
 */

static int of_platform_bus_match(struct device *dev, struct device_driver *drv)
{
	struct of_device * of_dev = to_of_device(dev);
	struct of_platform_driver * of_drv = to_of_platform_driver(drv);
	const struct of_device_id * matches = of_drv->match_table;

	if (!matches)
		return 0;

	return of_match_device(matches, of_dev) != NULL;
}

static int of_platform_device_probe(struct device *dev)
{
	int error = -ENODEV;
	struct of_platform_driver *drv;
	struct of_device *of_dev;
	const struct of_device_id *match;

	drv = to_of_platform_driver(dev->driver);
	of_dev = to_of_device(dev);

	if (!drv->probe)
		return error;

	of_dev_get(of_dev);

	match = of_match_device(drv->match_table, of_dev);
	if (match)
		error = drv->probe(of_dev, match);
	if (error)
		of_dev_put(of_dev);

	return error;
}

static int of_platform_device_remove(struct device *dev)
{
	struct of_device * of_dev = to_of_device(dev);
	struct of_platform_driver * drv = to_of_platform_driver(dev->driver);

	if (dev->driver && drv->remove)
		drv->remove(of_dev);
	return 0;
}

static int of_platform_device_suspend(struct device *dev, pm_message_t state)
{
	struct of_device * of_dev = to_of_device(dev);
	struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
	int error = 0;

	if (dev->driver && drv->suspend)
		error = drv->suspend(of_dev, state);
	return error;
}

static int of_platform_device_resume(struct device * dev)
{
	struct of_device * of_dev = to_of_device(dev);
	struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
	int error = 0;

	if (dev->driver && drv->resume)
		error = drv->resume(of_dev);
	return error;
}

struct bus_type of_platform_bus_type = {
       .name	= "of_platform",
       .match	= of_platform_bus_match,
       .probe	= of_platform_device_probe,
       .remove	= of_platform_device_remove,
       .suspend	= of_platform_device_suspend,
       .resume	= of_platform_device_resume,
};
EXPORT_SYMBOL(of_platform_bus_type);

static int __init of_bus_driver_init(void)
{
	return bus_register(&of_platform_bus_type);
}

postcore_initcall(of_bus_driver_init);

int of_register_platform_driver(struct of_platform_driver *drv)
{
	/* initialize common driver fields */
	drv->driver.name = drv->name;
	drv->driver.bus = &of_platform_bus_type;

	/* register with core */
	return driver_register(&drv->driver);
}
EXPORT_SYMBOL(of_register_platform_driver);

void of_unregister_platform_driver(struct of_platform_driver *drv)
{
	driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(of_unregister_platform_driver);

static void of_platform_make_bus_id(struct of_device *dev)
{
	struct device_node *node = dev->node;
	char *name = dev->dev.bus_id;
	const u32 *reg;
	u64 addr;

	/*
	 * If it's a DCR based device, use 'd' for native DCRs
	 * and 'D' for MMIO DCRs.
	 */
#ifdef CONFIG_PPC_DCR
	reg = get_property(node, "dcr-reg", NULL);
	if (reg) {
#ifdef CONFIG_PPC_DCR_NATIVE
		snprintf(name, BUS_ID_SIZE, "d%x.%s",
			 *reg, node->name);
#else /* CONFIG_PPC_DCR_NATIVE */
		addr = of_translate_dcr_address(node, *reg, NULL);
		if (addr != OF_BAD_ADDR) {
			snprintf(name, BUS_ID_SIZE,
				 "D%llx.%s", (unsigned long long)addr,
				 node->name);
			return;
		}
#endif /* !CONFIG_PPC_DCR_NATIVE */
	}
#endif /* CONFIG_PPC_DCR */

	/*
	 * For MMIO, get the physical address
	 */
	reg = get_property(node, "reg", NULL);
	if (reg) {
		addr = of_translate_address(node, reg);
		if (addr != OF_BAD_ADDR) {
			snprintf(name, BUS_ID_SIZE,
				 "%llx.%s", (unsigned long long)addr,
				 node->name);
			return;
		}
	}

	/*
	 * No BusID, use the node name and pray
	 */
	snprintf(name, BUS_ID_SIZE, "%s", node->name);
}

struct of_device* of_platform_device_create(struct device_node *np,
					    const char *bus_id,
					    struct device *parent)
{
	struct of_device *dev;

	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return NULL;
	memset(dev, 0, sizeof(*dev));

	dev->node = of_node_get(np);
	dev->dma_mask = 0xffffffffUL;
	dev->dev.dma_mask = &dev->dma_mask;
	dev->dev.parent = parent;
	dev->dev.bus = &of_platform_bus_type;
	dev->dev.release = of_release_dev;
	dev->dev.archdata.of_node = np;
	dev->dev.archdata.numa_node = of_node_to_nid(np);

	/* We do not fill the DMA ops for platform devices by default.
	 * This is currently the responsibility of the platform code
	 * to do such, possibly using a device notifier
	 */

	if (bus_id)
		strlcpy(dev->dev.bus_id, bus_id, BUS_ID_SIZE);
	else
		of_platform_make_bus_id(dev);

	if (of_device_register(dev) != 0) {
		kfree(dev);
		return NULL;
	}

	return dev;
}
EXPORT_SYMBOL(of_platform_device_create);



/**
 * of_platform_bus_create - Create an OF device for a bus node and all its
 * children. Optionally recursively instanciate matching busses.
 * @bus: device node of the bus to instanciate
 * @matches: match table, NULL to use the default, OF_NO_DEEP_PROBE to
 * disallow recursive creation of child busses
 */
static int of_platform_bus_create(struct device_node *bus,
				  struct of_device_id *matches,
				  struct device *parent)
{
	struct device_node *child;
	struct of_device *dev;
	int rc = 0;

	for (child = NULL; (child = of_get_next_child(bus, child)); ) {
		pr_debug("   create child: %s\n", child->full_name);
		dev = of_platform_device_create(child, NULL, parent);
		if (dev == NULL)
			rc = -ENOMEM;
		else if (!of_match_node(matches, child))
			continue;
		if (rc == 0) {
			pr_debug("   and sub busses\n");
			rc = of_platform_bus_create(child, matches, &dev->dev);
		} if (rc) {
			of_node_put(child);
			break;
		}
	}
	return rc;
}

/**
 * of_platform_bus_probe - Probe the device-tree for platform busses
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table, NULL to use the default
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Note that children of the provided root are not instanciated as devices
 * unless the specified root itself matches the bus list and is not NULL.
 */

int of_platform_bus_probe(struct device_node *root,
			  struct of_device_id *matches,
			  struct device *parent)
{
	struct device_node *child;
	struct of_device *dev;
	int rc = 0;

	if (matches == NULL)
		matches = of_default_bus_ids;
	if (matches == OF_NO_DEEP_PROBE)
		return -EINVAL;
	if (root == NULL)
		root = of_find_node_by_path("/");
	else
		of_node_get(root);

	pr_debug("of_platform_bus_probe()\n");
	pr_debug(" starting at: %s\n", root->full_name);

	/* Do a self check of bus type, if there's a match, create
	 * children
	 */
	if (of_match_node(matches, root)) {
		pr_debug(" root match, create all sub devices\n");
		dev = of_platform_device_create(root, NULL, parent);
		if (dev == NULL) {
			rc = -ENOMEM;
			goto bail;
		}
		pr_debug(" create all sub busses\n");
		rc = of_platform_bus_create(root, matches, &dev->dev);
		goto bail;
	}
	for (child = NULL; (child = of_get_next_child(root, child)); ) {
		if (!of_match_node(matches, child))
			continue;

		pr_debug("  match: %s\n", child->full_name);
		dev = of_platform_device_create(child, NULL, parent);
		if (dev == NULL)
			rc = -ENOMEM;
		else
			rc = of_platform_bus_create(child, matches, &dev->dev);
		if (rc) {
			of_node_put(child);
			break;
		}
	}
 bail:
	of_node_put(root);
	return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);

static int of_dev_node_match(struct device *dev, void *data)
{
	return to_of_device(dev)->node == data;
}

struct of_device *of_find_device_by_node(struct device_node *np)
{
	struct device *dev;

	dev = bus_find_device(&of_platform_bus_type,
			      NULL, np, of_dev_node_match);
	if (dev)
		return to_of_device(dev);
	return NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);

static int of_dev_phandle_match(struct device *dev, void *data)
{
	phandle *ph = data;
	return to_of_device(dev)->node->linux_phandle == *ph;
}

struct of_device *of_find_device_by_phandle(phandle ph)
{
	struct device *dev;

	dev = bus_find_device(&of_platform_bus_type,
			      NULL, &ph, of_dev_phandle_match);
	if (dev)
		return to_of_device(dev);
	return NULL;
}
EXPORT_SYMBOL(of_find_device_by_phandle);