xref: /openbmc/u-boot/drivers/core/device-remove.c (revision 87a62bce)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Device manager
4  *
5  * Copyright (c) 2014 Google, Inc
6  *
7  * (C) Copyright 2012
8  * Pavel Herrmann <morpheus.ibis@gmail.com>
9  */
10 
11 #include <common.h>
12 #include <errno.h>
13 #include <malloc.h>
14 #include <dm/device.h>
15 #include <dm/device-internal.h>
16 #include <dm/uclass.h>
17 #include <dm/uclass-internal.h>
18 #include <dm/util.h>
19 
20 /**
21  * device_chld_unbind() - Unbind all device's children from the device
22  *
23  * On error, the function continues to unbind all children, and reports the
24  * first error.
25  *
26  * @dev:	The device that is to be stripped of its children
27  * @return 0 on success, -ve on error
28  */
29 static int device_chld_unbind(struct udevice *dev)
30 {
31 	struct udevice *pos, *n;
32 	int ret, saved_ret = 0;
33 
34 	assert(dev);
35 
36 	list_for_each_entry_safe(pos, n, &dev->child_head, sibling_node) {
37 		ret = device_unbind(pos);
38 		if (ret && !saved_ret)
39 			saved_ret = ret;
40 	}
41 
42 	return saved_ret;
43 }
44 
45 /**
46  * device_chld_remove() - Stop all device's children
47  * @dev:	The device whose children are to be removed
48  * @pre_os_remove: Flag, if this functions is called in the pre-OS stage
49  * @return 0 on success, -ve on error
50  */
51 static int device_chld_remove(struct udevice *dev, uint flags)
52 {
53 	struct udevice *pos, *n;
54 	int ret;
55 
56 	assert(dev);
57 
58 	list_for_each_entry_safe(pos, n, &dev->child_head, sibling_node) {
59 		ret = device_remove(pos, flags);
60 		if (ret)
61 			return ret;
62 	}
63 
64 	return 0;
65 }
66 
67 int device_unbind(struct udevice *dev)
68 {
69 	const struct driver *drv;
70 	int ret;
71 
72 	if (!dev)
73 		return -EINVAL;
74 
75 	if (dev->flags & DM_FLAG_ACTIVATED)
76 		return -EINVAL;
77 
78 	if (!(dev->flags & DM_FLAG_BOUND))
79 		return -EINVAL;
80 
81 	drv = dev->driver;
82 	assert(drv);
83 
84 	if (drv->unbind) {
85 		ret = drv->unbind(dev);
86 		if (ret)
87 			return ret;
88 	}
89 
90 	ret = device_chld_unbind(dev);
91 	if (ret)
92 		return ret;
93 
94 	if (dev->flags & DM_FLAG_ALLOC_PDATA) {
95 		free(dev->platdata);
96 		dev->platdata = NULL;
97 	}
98 	if (dev->flags & DM_FLAG_ALLOC_UCLASS_PDATA) {
99 		free(dev->uclass_platdata);
100 		dev->uclass_platdata = NULL;
101 	}
102 	if (dev->flags & DM_FLAG_ALLOC_PARENT_PDATA) {
103 		free(dev->parent_platdata);
104 		dev->parent_platdata = NULL;
105 	}
106 	ret = uclass_unbind_device(dev);
107 	if (ret)
108 		return ret;
109 
110 	if (dev->parent)
111 		list_del(&dev->sibling_node);
112 
113 	devres_release_all(dev);
114 
115 	if (dev->flags & DM_FLAG_NAME_ALLOCED)
116 		free((char *)dev->name);
117 	free(dev);
118 
119 	return 0;
120 }
121 
122 /**
123  * device_free() - Free memory buffers allocated by a device
124  * @dev:	Device that is to be started
125  */
126 void device_free(struct udevice *dev)
127 {
128 	int size;
129 
130 	if (dev->driver->priv_auto_alloc_size) {
131 		free(dev->priv);
132 		dev->priv = NULL;
133 	}
134 	size = dev->uclass->uc_drv->per_device_auto_alloc_size;
135 	if (size) {
136 		free(dev->uclass_priv);
137 		dev->uclass_priv = NULL;
138 	}
139 	if (dev->parent) {
140 		size = dev->parent->driver->per_child_auto_alloc_size;
141 		if (!size) {
142 			size = dev->parent->uclass->uc_drv->
143 					per_child_auto_alloc_size;
144 		}
145 		if (size) {
146 			free(dev->parent_priv);
147 			dev->parent_priv = NULL;
148 		}
149 	}
150 
151 	devres_release_probe(dev);
152 }
153 
154 static bool flags_remove(uint flags, uint drv_flags)
155 {
156 	if ((flags & DM_REMOVE_NORMAL) ||
157 	    (flags & (drv_flags & (DM_FLAG_ACTIVE_DMA | DM_FLAG_OS_PREPARE))))
158 		return true;
159 
160 	return false;
161 }
162 
163 int device_remove(struct udevice *dev, uint flags)
164 {
165 	const struct driver *drv;
166 	int ret;
167 
168 	if (!dev)
169 		return -EINVAL;
170 
171 	if (!(dev->flags & DM_FLAG_ACTIVATED))
172 		return 0;
173 
174 	drv = dev->driver;
175 	assert(drv);
176 
177 	ret = uclass_pre_remove_device(dev);
178 	if (ret)
179 		return ret;
180 
181 	ret = device_chld_remove(dev, flags);
182 	if (ret)
183 		goto err;
184 
185 	/*
186 	 * Remove the device if called with the "normal" remove flag set,
187 	 * or if the remove flag matches any of the drivers remove flags
188 	 */
189 	if (drv->remove && flags_remove(flags, drv->flags)) {
190 		ret = drv->remove(dev);
191 		if (ret)
192 			goto err_remove;
193 	}
194 
195 	if (dev->parent && dev->parent->driver->child_post_remove) {
196 		ret = dev->parent->driver->child_post_remove(dev);
197 		if (ret) {
198 			dm_warn("%s: Device '%s' failed child_post_remove()",
199 				__func__, dev->name);
200 		}
201 	}
202 
203 	if (flags_remove(flags, drv->flags)) {
204 		device_free(dev);
205 
206 		dev->seq = -1;
207 		dev->flags &= ~DM_FLAG_ACTIVATED;
208 	}
209 
210 	return ret;
211 
212 err_remove:
213 	/* We can't put the children back */
214 	dm_warn("%s: Device '%s' failed to remove, but children are gone\n",
215 		__func__, dev->name);
216 err:
217 	ret = uclass_post_probe_device(dev);
218 	if (ret) {
219 		dm_warn("%s: Device '%s' failed to post_probe on error path\n",
220 			__func__, dev->name);
221 	}
222 
223 	return ret;
224 }
225