- 根目录:
- drivers
- of
- platform.c
/*
* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
* and Arnd Bergmann, IBM Corp.
* Merged from powerpc/kernel/of_platform.c and
* sparc{,64}/kernel/of_device.c by Stephen Rothwell
*
* 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.
*
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
const struct of_device_id of_default_bus_match_table[] = {
{ .compatible = "simple-bus", },
{ .compatible = "simple-mfd", },
#ifdef CONFIG_ARM_AMBA
{ .compatible = "arm,amba-bus", },
#endif /* CONFIG_ARM_AMBA */
{} /* Empty terminated list */
};
static int of_dev_node_match(struct device *dev, void *data)
{
return dev->of_node == data;
}
/**
* of_find_device_by_node - Find the platform_device associated with a node
* @np: Pointer to device tree node
*
* Returns platform_device pointer, or NULL if not found
*/
struct platform_device *of_find_device_by_node(struct device_node *np)
{
struct device *dev;
dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
return dev ? to_platform_device(dev) : NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);
#ifdef CONFIG_OF_ADDRESS
/*
* The following routines scan a subtree and registers a device for
* each applicable node.
*
* Note: sparc doesn't use these routines because it has a different
* mechanism for creating devices from device tree nodes.
*/
/**
* of_device_make_bus_id - Use the device node data to assign a unique name
* @dev: pointer to device structure that is linked to a device tree node
*
* This routine will first try using the translated bus address to
* derive a unique name. If it cannot, then it will prepend names from
* parent nodes until a unique name can be derived.
*/
void of_device_make_bus_id(struct device *dev)
{
struct device_node *node = dev->of_node;
const __be32 *reg;
u64 addr;
/* Construct the name, using parent nodes if necessary to ensure uniqueness */
while (node->parent) {
/*
* If the address can be translated, then that is as much
* uniqueness as we need. Make it the first component and return
*/
reg = of_get_property(node, "reg", NULL);
if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
(unsigned long long)addr, node->name,
dev_name(dev));
return;
}
/* format arguments only used if dev_name() resolves to NULL */
dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
strrchr(node->full_name, '/') + 1, dev_name(dev));
node = node->parent;
}
}
/**
* of_device_alloc - Allocate and initialize an of_device
* @np: device node to assign to device
* @bus_id: Name to assign to the device. May be null to use default name.
* : Parent device.
*/
struct platform_device *of_device_alloc(struct device_node *np,
const char *bus_id,
struct device *parent)
{
struct platform_device *dev;
int rc, i, num_reg = 0, num_irq;
struct resource *res, temp_res;
dev = platform_device_alloc("", -1);
if (!dev)
return NULL;
/* count the io and irq resources */
while (of_address_to_resource(np, num_reg, &temp_res) == 0)
num_reg++;
num_irq = of_irq_count(np);
/* Populate the resource table */
if (num_irq || num_reg) {
res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
if (!res) {
platform_device_put(dev);
return NULL;
}
dev->num_resources = num_reg + num_irq;
dev->resource = res;
for (i = 0; i < num_reg; i++, res++) {
rc = of_address_to_resource(np, i, res);
WARN_ON(rc);
}
if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
pr_debug("not all legacy IRQ resources mapped for %s\n",
np->name);
}
dev->dev.of_node = of_node_get(np);
dev->dev.parent = parent ? : &platform_bus;
if (bus_id)
dev_set_name(&dev->dev, "%s", bus_id);
else
of_device_make_bus_id(&dev->dev);
return dev;
}
EXPORT_SYMBOL(of_device_alloc);
static void of_dma_deconfigure(struct device *dev)
{
arch_teardown_dma_ops(dev);
}
/**
* of_platform_device_create_pdata - Alloc, initialize and register an of_device
* @np: pointer to node to create device for
* @bus_id: name to assign device
* @platform_data: pointer to populate platform_data pointer with
* : Linux device model parent device.
*
* Returns pointer to created platform device, or NULL if a device was not
* registered. Unavailable devices will not get registered.
*/
static struct platform_device *of_platform_device_create_pdata(
struct device_node *np,
const char *bus_id,
void *platform_data,
struct device *parent)
{
struct platform_device *dev;
if (!of_device_is_available(np) ||
of_node_test_and_set_flag(np, OF_POPULATED))
return NULL;
dev = of_device_alloc(np, bus_id, parent);
if (!dev)
goto err_clear_flag;
dev->dev.bus = &platform_bus_type;
dev->dev.platform_data = platform_data;
of_dma_configure(&dev->dev, dev->dev.of_node);
of_msi_configure(&dev->dev, dev->dev.of_node);
if (of_device_add(dev) != 0) {
of_dma_deconfigure(&dev->dev);
platform_device_put(dev);
goto err_clear_flag;
}
return dev;
err_clear_flag:
of_node_clear_flag(np, OF_POPULATED);
return NULL;
}
/**
* of_platform_device_create - Alloc, initialize and register an of_device
* @np: pointer to node to create device for
* @bus_id: name to assign device
* : Linux device model parent device.
*
* Returns pointer to created platform device, or NULL if a device was not
* registered. Unavailable devices will not get registered.
*/
struct platform_device *of_platform_device_create(struct device_node *np,
const char *bus_id,
struct device *parent)
{
return of_platform_device_create_pdata(np, bus_id, NULL, parent);
}
EXPORT_SYMBOL(of_platform_device_create);
#ifdef CONFIG_ARM_AMBA
static struct amba_device *of_amba_device_create(struct device_node *node,
const char *bus_id,
void *platform_data,
struct device *parent)
{
struct amba_device *dev;
const void *prop;
int i, ret;
pr_debug("Creating amba device %s\n", node->full_name);
if (!of_device_is_available(node) ||
of_node_test_and_set_flag(node, OF_POPULATED))
return NULL;
dev = amba_device_alloc(NULL, 0, 0);
if (!dev) {
pr_err("%s(): amba_device_alloc() failed for %s\n",
__func__, node->full_name);
goto err_clear_flag;
}
/* setup generic device info */
dev->dev.of_node = of_node_get(node);
dev->dev.parent = parent ? : &platform_bus;
dev->dev.platform_data = platform_data;
if (bus_id)
dev_set_name(&dev->dev, "%s", bus_id);
else
of_device_make_bus_id(&dev->dev);
of_dma_configure(&dev->dev, dev->dev.of_node);
/* Allow the HW Peripheral ID to be overridden */
prop = of_get_property(node, "arm,primecell-periphid", NULL);
if (prop)
dev->periphid = of_read_ulong(prop, 1);
/* Decode the IRQs and address ranges */
for (i = 0; i < AMBA_NR_IRQS; i++)
dev->irq[i] = irq_of_parse_and_map(node, i);
ret = of_address_to_resource(node, 0, &dev->res);
if (ret) {
pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
__func__, ret, node->full_name);
goto err_free;
}
ret = amba_device_add(dev, &iomem_resource);
if (ret) {
pr_err("%s(): amba_device_add() failed (%d) for %s\n",
__func__, ret, node->full_name);
goto err_free;
}
return dev;
err_free:
amba_device_put(dev);
err_clear_flag:
of_node_clear_flag(node, OF_POPULATED);
return NULL;
}
#else /* CONFIG_ARM_AMBA */
static struct amba_device *of_amba_device_create(struct device_node *node,
const char *bus_id,
void *platform_data,
struct device *parent)
{
return NULL;
}
#endif /* CONFIG_ARM_AMBA */
/**
* of_devname_lookup() - Given a device node, lookup the preferred Linux name
*/
static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
struct device_node *np)
{
struct resource res;
if (!lookup)
return NULL;
for(; lookup->compatible != NULL; lookup++) {
if (!of_device_is_compatible(np, lookup->compatible))
continue;
if (!of_address_to_resource(np, 0, &res))
if (res.start != lookup->phys_addr)
continue;
pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
return lookup;
}
return NULL;
}
/**
* of_platform_bus_create() - Create a device for a node and its children.
* @bus: device node of the bus to instantiate
* @matches: match table for bus nodes
* @lookup: auxdata table for matching id and platform_data with device nodes
* : parent for new device, or NULL for top level.
* @strict: require compatible property
*
* Creates a platform_device for the provided device_node, and optionally
* recursively create devices for all the child nodes.
*/
static int of_platform_bus_create(struct device_node *bus,
const struct of_device_id *matches,
const struct of_dev_auxdata *lookup,
struct device *parent, bool strict)
{
const struct of_dev_auxdata *auxdata;
struct device_node *child;
struct platform_device *dev;
const char *bus_id = NULL;
void *platform_data = NULL;
int rc = 0;
/* Make sure it has a compatible property */
if (strict && (!of_get_property(bus, "compatible", NULL))) {
pr_debug("%s() - skipping %s, no compatible prop\n",
__func__, bus->full_name);
return 0;
}
auxdata = of_dev_lookup(lookup, bus);
if (auxdata) {
bus_id = auxdata->name;
platform_data = auxdata->platform_data;
}
if (of_device_is_compatible(bus, "arm,primecell")) {
/*
* Don't return an error here to keep compatibility with older
* device tree files.
*/
of_amba_device_create(bus, bus_id, platform_data, parent);
return 0;
}
dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
if (!dev || !of_match_node(matches, bus))
return 0;
for_each_child_of_node(bus, child) {
pr_debug(" create child: %s\n", child->full_name);
rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
if (rc) {
of_node_put(child);
break;
}
}
of_node_set_flag(bus, OF_POPULATED_BUS);
return rc;
}
/**
* of_platform_bus_probe() - Probe the device-tree for platform buses
* @root: parent of the first level to probe or NULL for the root of the tree
* @matches: match table for bus nodes
* : parent to hook devices from, NULL for toplevel
*
* Note that children of the provided root are not instantiated as devices
* unless the specified root itself matches the bus list and is not NULL.
*/
int of_platform_bus_probe(struct device_node *root,
const struct of_device_id *matches,
struct device *parent)
{
struct device_node *child;
int rc = 0;
root = root ? of_node_get(root) : of_find_node_by_path("/");
if (!root)
return -EINVAL;
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)) {
rc = of_platform_bus_create(root, matches, NULL, parent, false);
} else for_each_child_of_node(root, child) {
if (!of_match_node(matches, child))
continue;
rc = of_platform_bus_create(child, matches, NULL, parent, false);
if (rc) {
of_node_put(child);
break;
}
}
of_node_put(root);
return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);
/**
* of_platform_populate() - Populate platform_devices from device tree data
* @root: parent of the first level to probe or NULL for the root of the tree
* @matches: match table, NULL to use the default
* @lookup: auxdata table for matching id and platform_data with device nodes
* : parent to hook devices from, NULL for toplevel
*
* Similar to of_platform_bus_probe(), this function walks the device tree
* and creates devices from nodes. It differs in that it follows the modern
* convention of requiring all device nodes to have a 'compatible' property,
* and it is suitable for creating devices which are children of the root
* node (of_platform_bus_probe will only create children of the root which
* are selected by the @matches argument).
*
* New board support should be using this function instead of
* of_platform_bus_probe().
*
* Returns 0 on success, < 0 on failure.
*/
int of_platform_populate(struct device_node *root,
const struct of_device_id *matches,
const struct of_dev_auxdata *lookup,
struct device *parent)
{
struct device_node *child;
int rc = 0;
root = root ? of_node_get(root) : of_find_node_by_path("/");
if (!root)
return -EINVAL;
for_each_child_of_node(root, child) {
rc = of_platform_bus_create(child, matches, lookup, parent, true);
if (rc) {
of_node_put(child);
break;
}
}
of_node_set_flag(root, OF_POPULATED_BUS);
of_node_put(root);
return rc;
}
EXPORT_SYMBOL_GPL(of_platform_populate);
int of_platform_default_populate(struct device_node *root,
const struct of_dev_auxdata *lookup,
struct device *parent)
{
return of_platform_populate(root, of_default_bus_match_table, lookup,
parent);
}
EXPORT_SYMBOL_GPL(of_platform_default_populate);
static int of_platform_device_destroy(struct device *dev, void *data)
{
/* Do not touch devices not populated from the device tree */
if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
return 0;
/* Recurse for any nodes that were treated as busses */
if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
device_for_each_child(dev, NULL, of_platform_device_destroy);
if (dev->bus == &platform_bus_type)
platform_device_unregister(to_platform_device(dev));
#ifdef CONFIG_ARM_AMBA
else if (dev->bus == &amba_bustype)
amba_device_unregister(to_amba_device(dev));
#endif
of_dma_deconfigure(dev);
of_node_clear_flag(dev->of_node, OF_POPULATED);
of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
return 0;
}
/**
* of_platform_depopulate() - Remove devices populated from device tree
* : device which children will be removed
*
* Complementary to of_platform_populate(), this function removes children
* of the given device (and, recurrently, their children) that have been
* created from their respective device tree nodes (and only those,
* leaving others - eg. manually created - unharmed).
*
* Returns 0 when all children devices have been removed or
* -EBUSY when some children remained.
*/
void of_platform_depopulate(struct device *parent)
{
if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
device_for_each_child(parent, NULL, of_platform_device_destroy);
of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
}
}
EXPORT_SYMBOL_GPL(of_platform_depopulate);
#ifdef CONFIG_OF_DYNAMIC
static int of_platform_notify(struct notifier_block *nb,
unsigned long action, void *arg)
{
struct of_reconfig_data *rd = arg;
struct platform_device *pdev_parent, *pdev;
bool children_left;
switch (of_reconfig_get_state_change(action, rd)) {
case OF_RECONFIG_CHANGE_ADD:
/* verify that the parent is a bus */
if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
return NOTIFY_OK; /* not for us */
/* already populated? (driver using of_populate manually) */
if (of_node_check_flag(rd->dn, OF_POPULATED))
return NOTIFY_OK;
/* pdev_parent may be NULL when no bus platform device */
pdev_parent = of_find_device_by_node(rd->dn->parent);
pdev = of_platform_device_create(rd->dn, NULL,
pdev_parent ? &pdev_parent->dev : NULL);
of_dev_put(pdev_parent);
if (pdev == NULL) {
pr_err("%s: failed to create for '%s'\n",
__func__, rd->dn->full_name);
/* of_platform_device_create tosses the error code */
return notifier_from_errno(-EINVAL);
}
break;
case OF_RECONFIG_CHANGE_REMOVE:
/* already depopulated? */
if (!of_node_check_flag(rd->dn, OF_POPULATED))
return NOTIFY_OK;
/* find our device by node */
pdev = of_find_device_by_node(rd->dn);
if (pdev == NULL)
return NOTIFY_OK; /* no? not meant for us */
/* unregister takes one ref away */
of_platform_device_destroy(&pdev->dev, &children_left);
/* and put the reference of the find */
of_dev_put(pdev);
break;
}
return NOTIFY_OK;
}
static struct notifier_block platform_of_notifier = {
.notifier_call = of_platform_notify,
};
void of_platform_register_reconfig_notifier(void)
{
WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
}
#endif /* CONFIG_OF_DYNAMIC */
#endif /* CONFIG_OF_ADDRESS */