drivers/core/uclass.c - filogic/uboot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2013 Google, Inc
  *
  * (C) Copyright 2012
  * Pavel Herrmann <morpheus.ibis@gmail.com>
  */

 #define LOG_CATEGORY LOGC_DM

 #include <dm.h>
 #include <errno.h>
 #include <log.h>
 #include <malloc.h>
 #include <asm/global_data.h>
 #include <dm/device.h>
 #include <dm/device-internal.h>
 #include <dm/lists.h>
 #include <dm/uclass.h>
 #include <dm/uclass-internal.h>
 #include <dm/util.h>

 DECLARE_GLOBAL_DATA_PTR;

 struct uclass *uclass_find(enum uclass_id key)
 {
 	struct uclass *uc;

 	if (!gd->dm_root)
 		return NULL;
 	/*
 	 * TODO(sjg@chromium.org): Optimise this, perhaps moving the found
 	 * node to the start of the list, or creating a linear array mapping
 	 * id to node.
 	 */
 	list_for_each_entry(uc, gd->uclass_root, sibling_node) {
 		if (uc->uc_drv->id == key)
 			return uc;
 	}

 	return NULL;
 }

 /**
  * uclass_add() - Create new uclass in list
  * @id: Id number to create
  * @ucp: Returns pointer to uclass, or NULL on error
  * Return: 0 on success, -ve on error
  *
  * The new uclass is added to the list. There must be only one uclass for
  * each id.
  */
 static int uclass_add(enum uclass_id id, struct uclass **ucp)
 {
 	struct uclass_driver *uc_drv;
 	struct uclass *uc;
 	int ret;

 	*ucp = NULL;
 	uc_drv = lists_uclass_lookup(id);
 	if (!uc_drv) {
 		dm_warn("Cannot find uclass for id %d: please add the UCLASS_DRIVER() declaration for this UCLASS_... id\n",
 			id);
 		/*
 		 * Use a strange error to make this case easier to find. When
 		 * a uclass is not available it can prevent driver model from
 		 * starting up and this failure is otherwise hard to debug.
 		 */
 		return -EPFNOSUPPORT;
 	}
 	uc = calloc(1, sizeof(*uc));
 	if (!uc)
 		return -ENOMEM;
 	if (uc_drv->priv_auto) {
 		void *ptr;

 		ptr = calloc(1, uc_drv->priv_auto);
 		if (!ptr) {
 			ret = -ENOMEM;
 			goto fail_mem;
 		}
 		uclass_set_priv(uc, ptr);
 	}
 	uc->uc_drv = uc_drv;
 	INIT_LIST_HEAD(&uc->sibling_node);
 	INIT_LIST_HEAD(&uc->dev_head);
 	list_add(&uc->sibling_node, DM_UCLASS_ROOT_NON_CONST);

 	if (uc_drv->init) {
 		ret = uc_drv->init(uc);
 		if (ret)
 			goto fail;
 	}

 	*ucp = uc;

 	return 0;
 fail:
 	if (uc_drv->priv_auto) {
 		free(uclass_get_priv(uc));
 		uclass_set_priv(uc, NULL);
 	}
 	list_del(&uc->sibling_node);
 fail_mem:
 	free(uc);

 	return ret;
 }

 int uclass_destroy(struct uclass *uc)
 {
 	struct uclass_driver *uc_drv;
 	struct udevice *dev;
 	int ret;

 	/*
 	 * We cannot use list_for_each_entry_safe() here. If a device in this
 	 * uclass has a child device also in this uclass, it will be also be
 	 * unbound (by the recursion in the call to device_unbind() below).
 	 * We can loop until the list is empty.
 	 */
 	while (!list_empty(&uc->dev_head)) {
 		dev = list_first_entry(&uc->dev_head, struct udevice,
 				       uclass_node);
 		ret = device_remove(dev, DM_REMOVE_NORMAL | DM_REMOVE_NO_PD);
 		if (ret)
 			return log_msg_ret("remove", ret);
 		ret = device_unbind(dev);
 		if (ret)
 			return log_msg_ret("unbind", ret);
 	}

 	uc_drv = uc->uc_drv;
 	if (uc_drv->destroy)
 		uc_drv->destroy(uc);
 	list_del(&uc->sibling_node);
 	if (uc_drv->priv_auto)
 		free(uclass_get_priv(uc));
 	free(uc);

 	return 0;
 }

 int uclass_get(enum uclass_id id, struct uclass **ucp)
 {
 	struct uclass *uc;

 	/* Immediately fail if driver model is not set up */
 	if (!gd->uclass_root)
 		return -EDEADLK;
 	*ucp = NULL;
 	uc = uclass_find(id);
 	if (!uc) {
 		if (CONFIG_IS_ENABLED(OF_PLATDATA_INST))
 			return -ENOENT;
 		return uclass_add(id, ucp);
 	}
 	*ucp = uc;

 	return 0;
 }

 const char *uclass_get_name(enum uclass_id id)
 {
 	struct uclass *uc;

 	if (uclass_get(id, &uc))
 		return NULL;
 	return uc->uc_drv->name;
 }

 void *uclass_get_priv(const struct uclass *uc)
 {
 	return uc->priv_;
 }

 void uclass_set_priv(struct uclass *uc, void *priv)
 {
 	uc->priv_ = priv;
 }

 enum uclass_id uclass_get_by_namelen(const char *name, int len)
 {
 	int i;

 	for (i = 0; i < UCLASS_COUNT; i++) {
 		struct uclass_driver *uc_drv = lists_uclass_lookup(i);

 		if (uc_drv && !strncmp(uc_drv->name, name, len) &&
 		    strlen(uc_drv->name) == len)
 			return i;
 	}

 	return UCLASS_INVALID;
 }

 enum uclass_id uclass_get_by_name(const char *name)
 {
 	return uclass_get_by_namelen(name, strlen(name));
 }

 int dev_get_uclass_index(struct udevice *dev, struct uclass **ucp)
 {
 	struct udevice *iter;
 	struct uclass *uc = dev->uclass;
 	int i = 0;

 	if (list_empty(&uc->dev_head))
 		return -ENODEV;

 	uclass_foreach_dev(iter, uc) {
 		if (iter == dev) {
 			if (ucp)
 				*ucp = uc;
 			return i;
 		}
 		i++;
 	}

 	return -ENODEV;
 }

 int uclass_find_device(enum uclass_id id, int index, struct udevice **devp)
 {
 	struct uclass *uc;
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;
 	if (list_empty(&uc->dev_head))
 		return -ENODEV;

 	uclass_foreach_dev(dev, uc) {
 		if (!index--) {
 			*devp = dev;
 			return 0;
 		}
 	}

 	return -ENODEV;
 }

 int uclass_find_first_device(enum uclass_id id, struct udevice **devp)
 {
 	struct uclass *uc;
 	int ret;

 	*devp = NULL;
 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;
 	if (list_empty(&uc->dev_head))
 		return 0;

 	*devp = list_first_entry(&uc->dev_head, struct udevice, uclass_node);

 	return 0;
 }

 int uclass_find_next_device(struct udevice **devp)
 {
 	struct udevice *dev = *devp;

 	*devp = NULL;
 	if (list_is_last(&dev->uclass_node, &dev->uclass->dev_head))
 		return 0;

 	*devp = list_entry(dev->uclass_node.next, struct udevice, uclass_node);

 	return 0;
 }

 int uclass_find_device_by_namelen(enum uclass_id id, const char *name, int len,
 				  struct udevice **devp)
 {
 	struct uclass *uc;
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	if (!name)
 		return -EINVAL;
 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(dev, uc) {
 		if (!strncmp(dev->name, name, len) &&
 		    strlen(dev->name) == len) {
 			*devp = dev;
 			return 0;
 		}
 	}

 	return -ENODEV;
 }

 int uclass_find_device_by_name(enum uclass_id id, const char *name,
 			       struct udevice **devp)
 {
 	return uclass_find_device_by_namelen(id, name, strlen(name), devp);
 }

 int uclass_find_next_free_seq(struct uclass *uc)
 {
 	struct udevice *dev;
 	int max = -1;

 	/* If using aliases, start with the highest alias value */
 	if (CONFIG_IS_ENABLED(DM_SEQ_ALIAS) &&
 	    (uc->uc_drv->flags & DM_UC_FLAG_SEQ_ALIAS))
 		max = dev_read_alias_highest_id(uc->uc_drv->name);

 	/* Avoid conflict with existing devices */
 	list_for_each_entry(dev, &uc->dev_head, uclass_node) {
 		if (dev->seq_ > max)
 			max = dev->seq_;
 	}
 	/*
 	 * At this point, max will be -1 if there are no existing aliases or
 	 * devices
 	 */

 	return max + 1;
 }

 int uclass_find_device_by_seq(enum uclass_id id, int seq, struct udevice **devp)
 {
 	struct uclass *uc;
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	log_debug("%d\n", seq);
 	if (seq == -1)
 		return -ENODEV;
 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(dev, uc) {
 		log_debug("   - %d '%s'\n", dev->seq_, dev->name);
 		if (dev->seq_ == seq) {
 			*devp = dev;
 			log_debug("   - found\n");
 			return 0;
 		}
 	}
 	log_debug("   - not found\n");

 	return -ENODEV;
 }

 int uclass_find_device_by_of_offset(enum uclass_id id, int node,
 				    struct udevice **devp)
 {
 	struct uclass *uc;
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	if (node < 0)
 		return -ENODEV;
 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(dev, uc) {
 		if (dev_of_offset(dev) == node) {
 			*devp = dev;
 			return 0;
 		}
 	}

 	return -ENODEV;
 }

 int uclass_find_device_by_ofnode(enum uclass_id id, ofnode node,
 				 struct udevice **devp)
 {
 	struct uclass *uc;
 	struct udevice *dev;
 	int ret;

 	log(LOGC_DM, LOGL_DEBUG, "Looking for %s\n", ofnode_get_name(node));
 	*devp = NULL;
 	if (!ofnode_valid(node))
 		return -ENODEV;
 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(dev, uc) {
 		log(LOGC_DM, LOGL_DEBUG_CONTENT, "      - checking %s\n",
 		    dev->name);
 		if (ofnode_equal(dev_ofnode(dev), node)) {
 			*devp = dev;
 			goto done;
 		}
 	}
 	ret = -ENODEV;

 done:
 	log(LOGC_DM, LOGL_DEBUG, "   - result for %s: %s (ret=%d)\n",
 	    ofnode_get_name(node), *devp ? (*devp)->name : "(none)", ret);
 	return ret;
 }

 #if CONFIG_IS_ENABLED(OF_REAL)
 static int uclass_find_device_by_phandle_id(enum uclass_id id,
 					    uint find_phandle,
 					    struct udevice **devp)
 {
 	struct udevice *dev;
 	struct uclass *uc;
 	int ret;

 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(dev, uc) {
 		uint phandle;

 		phandle = dev_read_phandle(dev);

 		if (phandle == find_phandle) {
 			*devp = dev;
 			return 0;
 		}
 	}

 	return -ENODEV;
 }

 int uclass_find_device_by_phandle(enum uclass_id id, struct udevice *parent,
 				  const char *name, struct udevice **devp)
 {
 	int find_phandle;

 	*devp = NULL;
 	find_phandle = dev_read_u32_default(parent, name, -1);
 	if (find_phandle <= 0)
 		return -ENOENT;

 	return uclass_find_device_by_phandle_id(id, find_phandle, devp);
 }
 #endif

 int uclass_get_device_by_driver(enum uclass_id id,
 				const struct driver *find_drv,
 				struct udevice **devp)
 {
 	struct udevice *dev;
 	struct uclass *uc;
 	int ret;

 	ret = uclass_get(id, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(dev, uc) {
 		if (dev->driver == find_drv)
 			return uclass_get_device_tail(dev, 0, devp);
 	}

 	return -ENODEV;
 }

 int uclass_get_device_tail(struct udevice *dev, int ret, struct udevice **devp)
 {
 	if (ret)
 		return ret;

 	assert(dev);
 	ret = device_probe(dev);
 	if (ret)
 		return ret;

 	*devp = dev;

 	return 0;
 }

 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_device(id, index, &dev);
 	return uclass_get_device_tail(dev, ret, devp);
 }

 int uclass_get_device_by_name(enum uclass_id id, const char *name,
 			      struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_device_by_name(id, name, &dev);
 	return uclass_get_device_tail(dev, ret, devp);
 }

 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_device_by_seq(id, seq, &dev);

 	return uclass_get_device_tail(dev, ret, devp);
 }

 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
 				   struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_device_by_of_offset(id, node, &dev);
 	return uclass_get_device_tail(dev, ret, devp);
 }

 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
 				struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	log(LOGC_DM, LOGL_DEBUG, "Looking for %s\n", ofnode_get_name(node));
 	*devp = NULL;
 	ret = uclass_find_device_by_ofnode(id, node, &dev);
 	log(LOGC_DM, LOGL_DEBUG, "   - result for %s: %s (ret=%d)\n",
 	    ofnode_get_name(node), dev ? dev->name : "(none)", ret);

 	return uclass_get_device_tail(dev, ret, devp);
 }

 #if CONFIG_IS_ENABLED(OF_REAL)
 int uclass_get_device_by_of_path(enum uclass_id id, const char *path,
 				 struct udevice **devp)
 {
 	return uclass_get_device_by_ofnode(id, ofnode_path(path), devp);
 }

 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
 				    struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_device_by_phandle_id(id, phandle_id, &dev);
 	return uclass_get_device_tail(dev, ret, devp);
 }

 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
 				 const char *name, struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_device_by_phandle(id, parent, name, &dev);
 	return uclass_get_device_tail(dev, ret, devp);
 }
 #endif

 /*
  * Starting from the given device @dev, return pointer to the first device in
  * the uclass that probes successfully in @devp.
  */
 static void _uclass_next_device(struct udevice *dev, struct udevice **devp)
 {
 	for (; dev; uclass_find_next_device(&dev)) {
 		if (!device_probe(dev))
 			break;
 	}
 	*devp = dev;
 }

 void uclass_first_device(enum uclass_id id, struct udevice **devp)
 {
 	struct udevice *dev;
 	int ret;

 	ret = uclass_find_first_device(id, &dev);
 	_uclass_next_device(dev, devp);
 }

 void uclass_next_device(struct udevice **devp)
 {
 	struct udevice *dev = *devp;

 	uclass_find_next_device(&dev);
 	_uclass_next_device(dev, devp);
 }

 int uclass_first_device_err(enum uclass_id id, struct udevice **devp)
 {
 	int ret;

 	ret = uclass_first_device_check(id, devp);
 	if (ret)
 		return ret;
 	else if (!*devp)
 		return -ENODEV;

 	return 0;
 }

 int uclass_next_device_err(struct udevice **devp)
 {
 	int ret;

 	ret = uclass_next_device_check(devp);
 	if (ret)
 		return ret;
 	else if (!*devp)
 		return -ENODEV;

 	return 0;
 }

 int uclass_first_device_check(enum uclass_id id, struct udevice **devp)
 {
 	int ret;

 	*devp = NULL;
 	ret = uclass_find_first_device(id, devp);
 	if (ret)
 		return ret;
 	if (!*devp)
 		return 0;

 	return device_probe(*devp);
 }

 int uclass_next_device_check(struct udevice **devp)
 {
 	int ret;

 	ret = uclass_find_next_device(devp);
 	if (ret)
 		return ret;
 	if (!*devp)
 		return 0;

 	return device_probe(*devp);
 }

 int uclass_get_count(void)
 {
 	const struct uclass *uc;
 	int count = 0;

 	if (gd->dm_root) {
 		list_for_each_entry(uc, gd->uclass_root, sibling_node)
 			count++;
 	}

 	return count;
 }

 int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
 				struct udevice **devp)
 {
 	struct udevice *dev;
 	struct uclass *uc;

 	uclass_id_foreach_dev(id, dev, uc) {
 		if (dev_get_driver_data(dev) == driver_data) {
 			*devp = dev;

 			return device_probe(dev);
 		}
 	}

 	return -ENODEV;
 }

 int uclass_bind_device(struct udevice *dev)
 {
 	struct uclass *uc;
 	int ret;

 	uc = dev->uclass;
 	list_add_tail(&dev->uclass_node, &uc->dev_head);

 	if (dev->parent) {
 		struct uclass_driver *uc_drv = dev->parent->uclass->uc_drv;

 		if (uc_drv->child_post_bind) {
 			ret = uc_drv->child_post_bind(dev);
 			if (ret)
 				goto err;
 		}
 	}

 	return 0;
 err:
 	/* There is no need to undo the parent's post_bind call */
 	list_del(&dev->uclass_node);

 	return ret;
 }

 #if CONFIG_IS_ENABLED(DM_DEVICE_REMOVE)
 int uclass_pre_unbind_device(struct udevice *dev)
 {
 	struct uclass *uc;
 	int ret;

 	uc = dev->uclass;
 	if (uc->uc_drv->pre_unbind) {
 		ret = uc->uc_drv->pre_unbind(dev);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 int uclass_unbind_device(struct udevice *dev)
 {
 	list_del(&dev->uclass_node);

 	return 0;
 }
 #endif

 int uclass_pre_probe_device(struct udevice *dev)
 {
 	struct uclass_driver *uc_drv;
 	int ret;

 	uc_drv = dev->uclass->uc_drv;
 	if (uc_drv->pre_probe) {
 		ret = uc_drv->pre_probe(dev);
 		if (ret)
 			return ret;
 	}

 	if (!dev->parent)
 		return 0;
 	uc_drv = dev->parent->uclass->uc_drv;
 	if (uc_drv->child_pre_probe) {
 		ret = uc_drv->child_pre_probe(dev);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 int uclass_post_probe_device(struct udevice *dev)
 {
 	struct uclass_driver *uc_drv;
 	int ret;

 	if (dev->parent) {
 		uc_drv = dev->parent->uclass->uc_drv;
 		if (uc_drv->child_post_probe) {
 			ret = uc_drv->child_post_probe(dev);
 			if (ret)
 				return ret;
 		}
 	}

 	uc_drv = dev->uclass->uc_drv;
 	if (uc_drv->post_probe) {
 		ret = uc_drv->post_probe(dev);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 #if CONFIG_IS_ENABLED(DM_DEVICE_REMOVE)
 int uclass_pre_remove_device(struct udevice *dev)
 {
 	struct uclass *uc;
 	int ret;

 	uc = dev->uclass;
 	if (uc->uc_drv->pre_remove) {
 		ret = uc->uc_drv->pre_remove(dev);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }
 #endif

 int uclass_probe_all(enum uclass_id id)
 {
 	struct udevice *dev;
 	int ret, err;

 	err = uclass_first_device_check(id, &dev);

 	/* Scanning uclass to probe all devices */
 	while (dev) {
 		ret = uclass_next_device_check(&dev);
 		if (ret)
 			err = ret;
 	}

 	return err;
 }

 int uclass_id_count(enum uclass_id id)
 {
 	struct udevice *dev;
 	struct uclass *uc;
 	int count = 0;

 	uclass_id_foreach_dev(id, dev, uc)
 		count++;

 	return count;
 }

 UCLASS_DRIVER(nop) = {
 	.id		= UCLASS_NOP,
 	.name		= "nop",
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (c) 2013 Google, Inc
	*
	* (C) Copyright 2012
	* Pavel Herrmann <morpheus.ibis@gmail.com>
	*/

	#define LOG_CATEGORY LOGC_DM

	#include <dm.h>
	#include <errno.h>
	#include <log.h>
	#include <malloc.h>
	#include <asm/global_data.h>
	#include <dm/device.h>
	#include <dm/device-internal.h>
	#include <dm/lists.h>
	#include <dm/uclass.h>
	#include <dm/uclass-internal.h>
	#include <dm/util.h>

	DECLARE_GLOBAL_DATA_PTR;

	struct uclass *uclass_find(enum uclass_id key)
	{
	struct uclass *uc;

	if (!gd->dm_root)
	return NULL;
	/*
	* TODO(sjg@chromium.org): Optimise this, perhaps moving the found
	* node to the start of the list, or creating a linear array mapping
	* id to node.
	*/
	list_for_each_entry(uc, gd->uclass_root, sibling_node) {
	if (uc->uc_drv->id == key)
	return uc;
	}

	return NULL;
	}

	/**
	* uclass_add() - Create new uclass in list
	* @id: Id number to create
	* @ucp: Returns pointer to uclass, or NULL on error
	* Return: 0 on success, -ve on error
	*
	* The new uclass is added to the list. There must be only one uclass for
	* each id.
	*/
	static int uclass_add(enum uclass_id id, struct uclass **ucp)
	{
	struct uclass_driver *uc_drv;
	struct uclass *uc;
	int ret;

	*ucp = NULL;
	uc_drv = lists_uclass_lookup(id);
	if (!uc_drv) {
	dm_warn("Cannot find uclass for id %d: please add the UCLASS_DRIVER() declaration for this UCLASS_... id\n",
	id);
	/*
	* Use a strange error to make this case easier to find. When
	* a uclass is not available it can prevent driver model from
	* starting up and this failure is otherwise hard to debug.
	*/
	return -EPFNOSUPPORT;
	}
	uc = calloc(1, sizeof(*uc));
	if (!uc)
	return -ENOMEM;
	if (uc_drv->priv_auto) {
	void *ptr;

	ptr = calloc(1, uc_drv->priv_auto);
	if (!ptr) {
	ret = -ENOMEM;
	goto fail_mem;
	}
	uclass_set_priv(uc, ptr);
	}
	uc->uc_drv = uc_drv;
	INIT_LIST_HEAD(&uc->sibling_node);
	INIT_LIST_HEAD(&uc->dev_head);
	list_add(&uc->sibling_node, DM_UCLASS_ROOT_NON_CONST);

	if (uc_drv->init) {
	ret = uc_drv->init(uc);
	if (ret)
	goto fail;
	}

	*ucp = uc;

	return 0;
	fail:
	if (uc_drv->priv_auto) {
	free(uclass_get_priv(uc));
	uclass_set_priv(uc, NULL);
	}
	list_del(&uc->sibling_node);
	fail_mem:
	free(uc);

	return ret;
	}

	int uclass_destroy(struct uclass *uc)
	{
	struct uclass_driver *uc_drv;
	struct udevice *dev;
	int ret;

	/*
	* We cannot use list_for_each_entry_safe() here. If a device in this
	* uclass has a child device also in this uclass, it will be also be
	* unbound (by the recursion in the call to device_unbind() below).
	* We can loop until the list is empty.
	*/
	while (!list_empty(&uc->dev_head)) {
	dev = list_first_entry(&uc->dev_head, struct udevice,
	uclass_node);
	ret = device_remove(dev, DM_REMOVE_NORMAL \| DM_REMOVE_NO_PD);
	if (ret)
	return log_msg_ret("remove", ret);
	ret = device_unbind(dev);
	if (ret)
	return log_msg_ret("unbind", ret);
	}

	uc_drv = uc->uc_drv;
	if (uc_drv->destroy)
	uc_drv->destroy(uc);
	list_del(&uc->sibling_node);
	if (uc_drv->priv_auto)
	free(uclass_get_priv(uc));
	free(uc);

	return 0;
	}

	int uclass_get(enum uclass_id id, struct uclass **ucp)
	{
	struct uclass *uc;

	/* Immediately fail if driver model is not set up */
	if (!gd->uclass_root)
	return -EDEADLK;
	*ucp = NULL;
	uc = uclass_find(id);
	if (!uc) {
	if (CONFIG_IS_ENABLED(OF_PLATDATA_INST))
	return -ENOENT;
	return uclass_add(id, ucp);
	}
	*ucp = uc;

	return 0;
	}

	const char *uclass_get_name(enum uclass_id id)
	{
	struct uclass *uc;

	if (uclass_get(id, &uc))
	return NULL;
	return uc->uc_drv->name;
	}

	void uclass_get_priv(const struct uclass uc)
	{
	return uc->priv_;
	}

	void uclass_set_priv(struct uclass uc, void priv)
	{
	uc->priv_ = priv;
	}

	enum uclass_id uclass_get_by_namelen(const char *name, int len)
	{
	int i;

	for (i = 0; i < UCLASS_COUNT; i++) {
	struct uclass_driver *uc_drv = lists_uclass_lookup(i);

	if (uc_drv && !strncmp(uc_drv->name, name, len) &&
	strlen(uc_drv->name) == len)
	return i;
	}

	return UCLASS_INVALID;
	}

	enum uclass_id uclass_get_by_name(const char *name)
	{
	return uclass_get_by_namelen(name, strlen(name));
	}

	int dev_get_uclass_index(struct udevice dev, struct uclass *ucp)
	{
	struct udevice *iter;
	struct uclass *uc = dev->uclass;
	int i = 0;

	if (list_empty(&uc->dev_head))
	return -ENODEV;

	uclass_foreach_dev(iter, uc) {
	if (iter == dev) {
	if (ucp)
	*ucp = uc;
	return i;
	}
	i++;
	}

	return -ENODEV;
	}

	int uclass_find_device(enum uclass_id id, int index, struct udevice **devp)
	{
	struct uclass *uc;
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_get(id, &uc);
	if (ret)
	return ret;
	if (list_empty(&uc->dev_head))
	return -ENODEV;

	uclass_foreach_dev(dev, uc) {
	if (!index--) {
	*devp = dev;
	return 0;
	}
	}

	return -ENODEV;
	}

	int uclass_find_first_device(enum uclass_id id, struct udevice **devp)
	{
	struct uclass *uc;
	int ret;

	*devp = NULL;
	ret = uclass_get(id, &uc);
	if (ret)
	return ret;
	if (list_empty(&uc->dev_head))
	return 0;

	*devp = list_first_entry(&uc->dev_head, struct udevice, uclass_node);

	return 0;
	}

	int uclass_find_next_device(struct udevice **devp)
	{
	struct udevice dev = devp;

	*devp = NULL;
	if (list_is_last(&dev->uclass_node, &dev->uclass->dev_head))
	return 0;

	*devp = list_entry(dev->uclass_node.next, struct udevice, uclass_node);

	return 0;
	}

	int uclass_find_device_by_namelen(enum uclass_id id, const char *name, int len,
	struct udevice **devp)
	{
	struct uclass *uc;
	struct udevice *dev;
	int ret;

	*devp = NULL;
	if (!name)
	return -EINVAL;
	ret = uclass_get(id, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(dev, uc) {
	if (!strncmp(dev->name, name, len) &&
	strlen(dev->name) == len) {
	*devp = dev;
	return 0;
	}
	}

	return -ENODEV;
	}

	int uclass_find_device_by_name(enum uclass_id id, const char *name,
	struct udevice **devp)
	{
	return uclass_find_device_by_namelen(id, name, strlen(name), devp);
	}

	int uclass_find_next_free_seq(struct uclass *uc)
	{
	struct udevice *dev;
	int max = -1;

	/* If using aliases, start with the highest alias value */
	if (CONFIG_IS_ENABLED(DM_SEQ_ALIAS) &&
	(uc->uc_drv->flags & DM_UC_FLAG_SEQ_ALIAS))
	max = dev_read_alias_highest_id(uc->uc_drv->name);

	/* Avoid conflict with existing devices */
	list_for_each_entry(dev, &uc->dev_head, uclass_node) {
	if (dev->seq_ > max)
	max = dev->seq_;
	}
	/*
	* At this point, max will be -1 if there are no existing aliases or
	* devices
	*/

	return max + 1;
	}

	int uclass_find_device_by_seq(enum uclass_id id, int seq, struct udevice **devp)
	{
	struct uclass *uc;
	struct udevice *dev;
	int ret;

	*devp = NULL;
	log_debug("%d\n", seq);
	if (seq == -1)
	return -ENODEV;
	ret = uclass_get(id, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(dev, uc) {
	log_debug(" - %d '%s'\n", dev->seq_, dev->name);
	if (dev->seq_ == seq) {
	*devp = dev;
	log_debug(" - found\n");
	return 0;
	}
	}
	log_debug(" - not found\n");

	return -ENODEV;
	}

	int uclass_find_device_by_of_offset(enum uclass_id id, int node,
	struct udevice **devp)
	{
	struct uclass *uc;
	struct udevice *dev;
	int ret;

	*devp = NULL;
	if (node < 0)
	return -ENODEV;
	ret = uclass_get(id, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(dev, uc) {
	if (dev_of_offset(dev) == node) {
	*devp = dev;
	return 0;
	}
	}

	return -ENODEV;
	}

	int uclass_find_device_by_ofnode(enum uclass_id id, ofnode node,
	struct udevice **devp)
	{
	struct uclass *uc;
	struct udevice *dev;
	int ret;

	log(LOGC_DM, LOGL_DEBUG, "Looking for %s\n", ofnode_get_name(node));
	*devp = NULL;
	if (!ofnode_valid(node))
	return -ENODEV;
	ret = uclass_get(id, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(dev, uc) {
	log(LOGC_DM, LOGL_DEBUG_CONTENT, " - checking %s\n",
	dev->name);
	if (ofnode_equal(dev_ofnode(dev), node)) {
	*devp = dev;
	goto done;
	}
	}
	ret = -ENODEV;

	done:
	log(LOGC_DM, LOGL_DEBUG, " - result for %s: %s (ret=%d)\n",
	ofnode_get_name(node), devp ? (devp)->name : "(none)", ret);
	return ret;
	}

	#if CONFIG_IS_ENABLED(OF_REAL)
	static int uclass_find_device_by_phandle_id(enum uclass_id id,
	uint find_phandle,
	struct udevice **devp)
	{
	struct udevice *dev;
	struct uclass *uc;
	int ret;

	ret = uclass_get(id, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(dev, uc) {
	uint phandle;

	phandle = dev_read_phandle(dev);

	if (phandle == find_phandle) {
	*devp = dev;
	return 0;
	}
	}

	return -ENODEV;
	}

	int uclass_find_device_by_phandle(enum uclass_id id, struct udevice *parent,
	const char name, struct udevice *devp)
	{
	int find_phandle;

	*devp = NULL;
	find_phandle = dev_read_u32_default(parent, name, -1);
	if (find_phandle <= 0)
	return -ENOENT;

	return uclass_find_device_by_phandle_id(id, find_phandle, devp);
	}
	#endif

	int uclass_get_device_by_driver(enum uclass_id id,
	const struct driver *find_drv,
	struct udevice **devp)
	{
	struct udevice *dev;
	struct uclass *uc;
	int ret;

	ret = uclass_get(id, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(dev, uc) {
	if (dev->driver == find_drv)
	return uclass_get_device_tail(dev, 0, devp);
	}

	return -ENODEV;
	}

	int uclass_get_device_tail(struct udevice dev, int ret, struct udevice *devp)
	{
	if (ret)
	return ret;

	assert(dev);
	ret = device_probe(dev);
	if (ret)
	return ret;

	*devp = dev;

	return 0;
	}

	int uclass_get_device(enum uclass_id id, int index, struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_find_device(id, index, &dev);
	return uclass_get_device_tail(dev, ret, devp);
	}

	int uclass_get_device_by_name(enum uclass_id id, const char *name,
	struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_find_device_by_name(id, name, &dev);
	return uclass_get_device_tail(dev, ret, devp);
	}

	int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_find_device_by_seq(id, seq, &dev);

	return uclass_get_device_tail(dev, ret, devp);
	}

	int uclass_get_device_by_of_offset(enum uclass_id id, int node,
	struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_find_device_by_of_offset(id, node, &dev);
	return uclass_get_device_tail(dev, ret, devp);
	}

	int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
	struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	log(LOGC_DM, LOGL_DEBUG, "Looking for %s\n", ofnode_get_name(node));
	*devp = NULL;
	ret = uclass_find_device_by_ofnode(id, node, &dev);
	log(LOGC_DM, LOGL_DEBUG, " - result for %s: %s (ret=%d)\n",
	ofnode_get_name(node), dev ? dev->name : "(none)", ret);

	return uclass_get_device_tail(dev, ret, devp);
	}

	#if CONFIG_IS_ENABLED(OF_REAL)
	int uclass_get_device_by_of_path(enum uclass_id id, const char *path,
	struct udevice **devp)
	{
	return uclass_get_device_by_ofnode(id, ofnode_path(path), devp);
	}

	int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
	struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_find_device_by_phandle_id(id, phandle_id, &dev);
	return uclass_get_device_tail(dev, ret, devp);
	}

	int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
	const char name, struct udevice *devp)
	{
	struct udevice *dev;
	int ret;

	*devp = NULL;
	ret = uclass_find_device_by_phandle(id, parent, name, &dev);
	return uclass_get_device_tail(dev, ret, devp);
	}
	#endif

	/*
	* Starting from the given device @dev, return pointer to the first device in
	* the uclass that probes successfully in @devp.
	*/
	static void _uclass_next_device(struct udevice dev, struct udevice *devp)
	{
	for (; dev; uclass_find_next_device(&dev)) {
	if (!device_probe(dev))
	break;
	}
	*devp = dev;
	}

	void uclass_first_device(enum uclass_id id, struct udevice **devp)
	{
	struct udevice *dev;
	int ret;

	ret = uclass_find_first_device(id, &dev);
	_uclass_next_device(dev, devp);
	}

	void uclass_next_device(struct udevice **devp)
	{
	struct udevice dev = devp;

	uclass_find_next_device(&dev);
	_uclass_next_device(dev, devp);
	}

	int uclass_first_device_err(enum uclass_id id, struct udevice **devp)
	{
	int ret;

	ret = uclass_first_device_check(id, devp);
	if (ret)
	return ret;
	else if (!*devp)
	return -ENODEV;

	return 0;
	}

	int uclass_next_device_err(struct udevice **devp)
	{
	int ret;

	ret = uclass_next_device_check(devp);
	if (ret)
	return ret;
	else if (!*devp)
	return -ENODEV;

	return 0;
	}

	int uclass_first_device_check(enum uclass_id id, struct udevice **devp)
	{
	int ret;

	*devp = NULL;
	ret = uclass_find_first_device(id, devp);
	if (ret)
	return ret;
	if (!*devp)
	return 0;

	return device_probe(*devp);
	}

	int uclass_next_device_check(struct udevice **devp)
	{
	int ret;

	ret = uclass_find_next_device(devp);
	if (ret)
	return ret;
	if (!*devp)
	return 0;

	return device_probe(*devp);
	}

	int uclass_get_count(void)
	{
	const struct uclass *uc;
	int count = 0;

	if (gd->dm_root) {
	list_for_each_entry(uc, gd->uclass_root, sibling_node)
	count++;
	}

	return count;
	}

	int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
	struct udevice **devp)
	{
	struct udevice *dev;
	struct uclass *uc;

	uclass_id_foreach_dev(id, dev, uc) {
	if (dev_get_driver_data(dev) == driver_data) {
	*devp = dev;

	return device_probe(dev);
	}
	}

	return -ENODEV;
	}

	int uclass_bind_device(struct udevice *dev)
	{
	struct uclass *uc;
	int ret;

	uc = dev->uclass;
	list_add_tail(&dev->uclass_node, &uc->dev_head);

	if (dev->parent) {
	struct uclass_driver *uc_drv = dev->parent->uclass->uc_drv;

	if (uc_drv->child_post_bind) {
	ret = uc_drv->child_post_bind(dev);
	if (ret)
	goto err;
	}
	}

	return 0;
	err:
	/* There is no need to undo the parent's post_bind call */
	list_del(&dev->uclass_node);

	return ret;
	}

	#if CONFIG_IS_ENABLED(DM_DEVICE_REMOVE)
	int uclass_pre_unbind_device(struct udevice *dev)
	{
	struct uclass *uc;
	int ret;

	uc = dev->uclass;
	if (uc->uc_drv->pre_unbind) {
	ret = uc->uc_drv->pre_unbind(dev);
	if (ret)
	return ret;
	}

	return 0;
	}

	int uclass_unbind_device(struct udevice *dev)
	{
	list_del(&dev->uclass_node);

	return 0;
	}
	#endif

	int uclass_pre_probe_device(struct udevice *dev)
	{
	struct uclass_driver *uc_drv;
	int ret;

	uc_drv = dev->uclass->uc_drv;
	if (uc_drv->pre_probe) {
	ret = uc_drv->pre_probe(dev);
	if (ret)
	return ret;
	}

	if (!dev->parent)
	return 0;
	uc_drv = dev->parent->uclass->uc_drv;
	if (uc_drv->child_pre_probe) {
	ret = uc_drv->child_pre_probe(dev);
	if (ret)
	return ret;
	}

	return 0;
	}

	int uclass_post_probe_device(struct udevice *dev)
	{
	struct uclass_driver *uc_drv;
	int ret;

	if (dev->parent) {
	uc_drv = dev->parent->uclass->uc_drv;
	if (uc_drv->child_post_probe) {
	ret = uc_drv->child_post_probe(dev);
	if (ret)
	return ret;
	}
	}

	uc_drv = dev->uclass->uc_drv;
	if (uc_drv->post_probe) {
	ret = uc_drv->post_probe(dev);
	if (ret)
	return ret;
	}

	return 0;
	}

	#if CONFIG_IS_ENABLED(DM_DEVICE_REMOVE)
	int uclass_pre_remove_device(struct udevice *dev)
	{
	struct uclass *uc;
	int ret;

	uc = dev->uclass;
	if (uc->uc_drv->pre_remove) {
	ret = uc->uc_drv->pre_remove(dev);
	if (ret)
	return ret;
	}

	return 0;
	}
	#endif

	int uclass_probe_all(enum uclass_id id)
	{
	struct udevice *dev;
	int ret, err;

	err = uclass_first_device_check(id, &dev);

	/* Scanning uclass to probe all devices */
	while (dev) {
	ret = uclass_next_device_check(&dev);
	if (ret)
	err = ret;
	}

	return err;
	}

	int uclass_id_count(enum uclass_id id)
	{
	struct udevice *dev;
	struct uclass *uc;
	int count = 0;

	uclass_id_foreach_dev(id, dev, uc)
	count++;

	return count;
	}

	UCLASS_DRIVER(nop) = {
	.id = UCLASS_NOP,
	.name = "nop",
	};