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Commit 15c3597d authored by Grant Likely's avatar Grant Likely
Browse files

dt/platform: allow device name to be overridden 



Some platform code has specific requirements on the naming of devices.
This patch allows callers of of_platform_populate() to provide a
device name lookup table.

Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 5de1540b

drivers/of/platform.c

+63 −10
Original line number Diff line number Diff line
@@ -177,16 +177,19 @@ struct platform_device *of_device_alloc(struct device_node *np, 
EXPORT_SYMBOL(of_device_alloc);



/**

 * of_platform_device_create - Alloc, initialize and register an of_device

 * 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

 * @parent: 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,

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;
@@ -203,6 +206,7 @@ struct platform_device *of_platform_device_create(struct device_node *np, 
#endif

	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

	dev->dev.bus = &platform_bus_type;

	dev->dev.platform_data = platform_data;



	/* We do not fill the DMA ops for platform devices by default.

	 * This is currently the responsibility of the platform code
@@ -216,6 +220,22 @@ struct platform_device *of_platform_device_create(struct device_node *np, 


	return dev;

}



/**

 * 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

 * @parent: 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
@@ -283,6 +303,28 @@ static struct amba_device *of_amba_device_create(struct device_node *node, 
}

#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) {

		for(; lookup->name != NULL; lookup++) {

			if (!of_device_is_compatible(np, lookup->compatible))

				continue;

			if (of_address_to_resource(np, 0, &res))

				continue;

			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
@@ -295,10 +337,14 @@ static struct amba_device *of_amba_device_create(struct device_node *node, 
 */

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 */
@@ -308,18 +354,24 @@ static int of_platform_bus_create(struct device_node *bus, 
		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")) {

		of_amba_device_create(bus, NULL, NULL, parent);

		of_amba_device_create(bus, bus_id, platform_data, parent);

		return 0;

	}



	dev = of_platform_device_create(bus, NULL, parent);

	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, &dev->dev, strict);

		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);

		if (rc) {

			of_node_put(child);

			break;
@@ -353,11 +405,11 @@ int of_platform_bus_probe(struct device_node *root, 


	/* 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, parent, false);

		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, parent, false);

		rc = of_platform_bus_create(child, matches, NULL, parent, false);

		if (rc)

			break;

	}
@@ -387,6 +439,7 @@ EXPORT_SYMBOL(of_platform_bus_probe); 
 */

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;
@@ -397,7 +450,7 @@ int of_platform_populate(struct device_node *root, 
		return -EINVAL;



	for_each_child_of_node(root, child) {

		rc = of_platform_bus_create(child, matches, parent, true);

		rc = of_platform_bus_create(child, matches, lookup, parent, true);

		if (rc)

			break;

	}

include/linux/of_platform.h

+35 −0
Original line number Diff line number Diff line
@@ -19,6 +19,40 @@ 
#include <linux/of_device.h>

#include <linux/platform_device.h>



/**

 * struct of_dev_auxdata - lookup table entry for device names & platform_data

 * @compatible: compatible value of node to match against node

 * @phys_addr: Start address of registers to match against node

 * @name: Name to assign for matching nodes

 * @platform_data: platform_data to assign for matching nodes

 *

 * This lookup table allows the caller of of_platform_populate() to override

 * the names of devices when creating devices from the device tree.  The table

 * should be terminated with an empty entry.  It also allows the platform_data

 * pointer to be set.

 *

 * The reason for this functionality is that some Linux infrastructure uses

 * the device name to look up a specific device, but the Linux-specific names

 * are not encoded into the device tree, so the kernel needs to provide specific

 * values.

 *

 * Note: Using an auxdata lookup table should be considered a last resort when

 * converting a platform to use the DT.  Normally the automatically generated

 * device name will not matter, and drivers should obtain data from the device

 * node instead of from an anonymouns platform_data pointer.

 */

struct of_dev_auxdata {

	char *compatible;

	resource_size_t phys_addr;

	char *name;

	void *platform_data;

};



/* Macro to simplify populating a lookup table */

#define OF_DEV_AUXDATA(_compat,_phys,_name,_pdata) \

	{ .compatible = _compat, .phys_addr = _phys, .name = _name, \

	  .platform_data = _pdata }



/**

 * of_platform_driver - Legacy of-aware driver for platform devices.

 *
@@ -59,6 +93,7 @@ extern int of_platform_bus_probe(struct device_node *root, 
				 struct device *parent);

extern int of_platform_populate(struct device_node *root,

				const struct of_device_id *matches,

				const struct of_dev_auxdata *lookup,

				struct device *parent);

#endif /* !CONFIG_SPARC */