2 * Copyright (c) 2013 Google, Inc
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
6 * Marek Vasut <marex@denx.de>
8 * SPDX-License-Identifier: GPL-2.0+
14 #include <dm/uclass-id.h>
16 #include <linker_lists.h>
17 #include <linux/list.h>
21 /* Driver is active (probed). Cleared when it is removed */
22 #define DM_FLAG_ACTIVATED (1 << 0)
24 /* DM is responsible for allocating and freeing platdata */
25 #define DM_FLAG_ALLOC_PDATA (1 << 1)
27 /* DM should init this device prior to relocation */
28 #define DM_FLAG_PRE_RELOC (1 << 2)
30 /* DM is responsible for allocating and freeing parent_platdata */
31 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
33 /* Allocate driver private data on a DMA boundary */
34 #define DM_FLAG_ALLOC_PRIV_DMA (1 << 4)
37 * struct udevice - An instance of a driver
39 * This holds information about a device, which is a driver bound to a
40 * particular port or peripheral (essentially a driver instance).
42 * A device will come into existence through a 'bind' call, either due to
43 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
44 * in the device tree (in which case of_offset is >= 0). In the latter case
45 * we translate the device tree information into platdata in a function
46 * implemented by the driver ofdata_to_platdata method (called just before the
47 * probe method if the device has a device tree node.
49 * All three of platdata, priv and uclass_priv can be allocated by the
50 * driver, or you can use the auto_alloc_size members of struct driver and
51 * struct uclass_driver to have driver model do this automatically.
53 * @driver: The driver used by this device
54 * @name: Name of device, typically the FDT node name
55 * @platdata: Configuration data for this device
56 * @parent_platdata: The parent bus's configuration data for this device
57 * @of_offset: Device tree node offset for this device (- for none)
58 * @driver_data: Driver data word for the entry that matched this device with
60 * @parent: Parent of this device, or NULL for the top level device
61 * @priv: Private data for this device
62 * @uclass: Pointer to uclass for this device
63 * @uclass_priv: The uclass's private data for this device
64 * @parent_priv: The parent's private data for this device
65 * @uclass_node: Used by uclass to link its devices
66 * @child_head: List of children of this device
67 * @sibling_node: Next device in list of all devices
68 * @flags: Flags for this device DM_FLAG_...
69 * @req_seq: Requested sequence number for this device (-1 = any)
70 * @seq: Allocated sequence number for this device (-1 = none). This is set up
71 * when the device is probed and will be unique within the device's uclass.
74 const struct driver *driver;
77 void *parent_platdata;
80 struct udevice *parent;
82 struct uclass *uclass;
85 struct list_head uclass_node;
86 struct list_head child_head;
87 struct list_head sibling_node;
93 /* Maximum sequence number supported */
94 #define DM_MAX_SEQ 999
96 /* Returns the operations for a device */
97 #define device_get_ops(dev) (dev->driver->ops)
99 /* Returns non-zero if the device is active (probed and not removed) */
100 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
103 * struct udevice_id - Lists the compatible strings supported by a driver
104 * @compatible: Compatible string
105 * @data: Data for this compatible string
108 const char *compatible;
112 #ifdef CONFIG_OF_CONTROL
113 #define of_match_ptr(_ptr) (_ptr)
115 #define of_match_ptr(_ptr) NULL
116 #endif /* CONFIG_OF_CONTROL */
119 * struct driver - A driver for a feature or peripheral
121 * This holds methods for setting up a new device, and also removing it.
122 * The device needs information to set itself up - this is provided either
123 * by platdata or a device tree node (which we find by looking up
124 * matching compatible strings with of_match).
126 * Drivers all belong to a uclass, representing a class of devices of the
127 * same type. Common elements of the drivers can be implemented in the uclass,
128 * or the uclass can provide a consistent interface to the drivers within
132 * @id: Identiies the uclass we belong to
133 * @of_match: List of compatible strings to match, and any identifying data
135 * @bind: Called to bind a device to its driver
136 * @probe: Called to probe a device, i.e. activate it
137 * @remove: Called to remove a device, i.e. de-activate it
138 * @unbind: Called to unbind a device from its driver
139 * @ofdata_to_platdata: Called before probe to decode device tree data
140 * @child_post_bind: Called after a new child has been bound
141 * @child_pre_probe: Called before a child device is probed. The device has
142 * memory allocated but it has not yet been probed.
143 * @child_post_remove: Called after a child device is removed. The device
144 * has memory allocated but its device_remove() method has been called.
145 * @priv_auto_alloc_size: If non-zero this is the size of the private data
146 * to be allocated in the device's ->priv pointer. If zero, then the driver
147 * is responsible for allocating any data required.
148 * @platdata_auto_alloc_size: If non-zero this is the size of the
149 * platform data to be allocated in the device's ->platdata pointer.
150 * This is typically only useful for device-tree-aware drivers (those with
151 * an of_match), since drivers which use platdata will have the data
152 * provided in the U_BOOT_DEVICE() instantiation.
153 * @per_child_auto_alloc_size: Each device can hold private data owned by
154 * its parent. If required this will be automatically allocated if this
156 * TODO(sjg@chromium.org): I'm considering dropping this, and just having
157 * device_probe_child() pass it in. So far the use case for allocating it
158 * is SPI, but I found that unsatisfactory. Since it is here I will leave it
159 * until things are clearer.
160 * @per_child_platdata_auto_alloc_size: A bus likes to store information about
161 * its children. If non-zero this is the size of this data, to be allocated
162 * in the child's parent_platdata pointer.
163 * @ops: Driver-specific operations. This is typically a list of function
164 * pointers defined by the driver, to implement driver functions required by
166 * @flags: driver flags - see DM_FLAGS_...
171 const struct udevice_id *of_match;
172 int (*bind)(struct udevice *dev);
173 int (*probe)(struct udevice *dev);
174 int (*remove)(struct udevice *dev);
175 int (*unbind)(struct udevice *dev);
176 int (*ofdata_to_platdata)(struct udevice *dev);
177 int (*child_post_bind)(struct udevice *dev);
178 int (*child_pre_probe)(struct udevice *dev);
179 int (*child_post_remove)(struct udevice *dev);
180 int priv_auto_alloc_size;
181 int platdata_auto_alloc_size;
182 int per_child_auto_alloc_size;
183 int per_child_platdata_auto_alloc_size;
184 const void *ops; /* driver-specific operations */
188 /* Declare a new U-Boot driver */
189 #define U_BOOT_DRIVER(__name) \
190 ll_entry_declare(struct driver, __name, driver)
193 * dev_get_platdata() - Get the platform data for a device
195 * This checks that dev is not NULL, but no other checks for now
197 * @dev Device to check
198 * @return platform data, or NULL if none
200 void *dev_get_platdata(struct udevice *dev);
203 * dev_get_parent_platdata() - Get the parent platform data for a device
205 * This checks that dev is not NULL, but no other checks for now
207 * @dev Device to check
208 * @return parent's platform data, or NULL if none
210 void *dev_get_parent_platdata(struct udevice *dev);
213 * dev_get_parentdata() - Get the parent data for a device
215 * The parent data is data stored in the device but owned by the parent.
216 * For example, a USB device may have parent data which contains information
217 * about how to talk to the device over USB.
219 * This checks that dev is not NULL, but no other checks for now
221 * @dev Device to check
222 * @return parent data, or NULL if none
224 void *dev_get_parentdata(struct udevice *dev);
227 * dev_get_priv() - Get the private data for a device
229 * This checks that dev is not NULL, but no other checks for now
231 * @dev Device to check
232 * @return private data, or NULL if none
234 void *dev_get_priv(struct udevice *dev);
237 * struct dev_get_parent() - Get the parent of a device
239 * @child: Child to check
240 * @return parent of child, or NULL if this is the root device
242 struct udevice *dev_get_parent(struct udevice *child);
245 * dev_get_uclass_priv() - Get the private uclass data for a device
247 * This checks that dev is not NULL, but no other checks for now
249 * @dev Device to check
250 * @return private uclass data for this device, or NULL if none
252 void *dev_get_uclass_priv(struct udevice *dev);
255 * dev_get_driver_data() - get the driver data used to bind a device
257 * When a device is bound using a device tree node, it matches a
258 * particular compatible string as in struct udevice_id. This function
259 * returns the associated data value for that compatible string. This is
260 * the 'data' field in struct udevice_id.
262 * For USB devices, this is the driver_info field in struct usb_device_id.
264 * @dev: Device to check
266 ulong dev_get_driver_data(struct udevice *dev);
269 * device_get_uclass_id() - return the uclass ID of a device
271 * @dev: Device to check
272 * @return uclass ID for the device
274 enum uclass_id device_get_uclass_id(struct udevice *dev);
277 * device_get_child() - Get the child of a device by index
279 * Returns the numbered child, 0 being the first. This does not use
280 * sequence numbers, only the natural order.
282 * @dev: Parent device to check
283 * @index: Child index
284 * @devp: Returns pointer to device
286 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
289 * device_find_child_by_seq() - Find a child device based on a sequence
291 * This searches for a device with the given seq or req_seq.
293 * For seq, if an active device has this sequence it will be returned.
294 * If there is no such device then this will return -ENODEV.
296 * For req_seq, if a device (whether activated or not) has this req_seq
297 * value, that device will be returned. This is a strong indication that
298 * the device will receive that sequence when activated.
300 * @parent: Parent device
301 * @seq_or_req_seq: Sequence number to find (0=first)
302 * @find_req_seq: true to find req_seq, false to find seq
303 * @devp: Returns pointer to device (there is only one per for each seq).
304 * Set to NULL if none is found
305 * @return 0 if OK, -ve on error
307 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
308 bool find_req_seq, struct udevice **devp);
311 * device_get_child_by_seq() - Get a child device based on a sequence
313 * If an active device has this sequence it will be returned. If there is no
314 * such device then this will check for a device that is requesting this
317 * The device is probed to activate it ready for use.
319 * @parent: Parent device
320 * @seq: Sequence number to find (0=first)
321 * @devp: Returns pointer to device (there is only one per for each seq)
322 * Set to NULL if none is found
323 * @return 0 if OK, -ve on error
325 int device_get_child_by_seq(struct udevice *parent, int seq,
326 struct udevice **devp);
329 * device_find_child_by_of_offset() - Find a child device based on FDT offset
331 * Locates a child device by its device tree offset.
333 * @parent: Parent device
334 * @of_offset: Device tree offset to find
335 * @devp: Returns pointer to device if found, otherwise this is set to NULL
336 * @return 0 if OK, -ve on error
338 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
339 struct udevice **devp);
342 * device_get_child_by_of_offset() - Get a child device based on FDT offset
344 * Locates a child device by its device tree offset.
346 * The device is probed to activate it ready for use.
348 * @parent: Parent device
349 * @of_offset: Device tree offset to find
350 * @devp: Returns pointer to device if found, otherwise this is set to NULL
351 * @return 0 if OK, -ve on error
353 int device_get_child_by_of_offset(struct udevice *parent, int seq,
354 struct udevice **devp);
357 * device_find_first_child() - Find the first child of a device
359 * @parent: Parent device to search
360 * @devp: Returns first child device, or NULL if none
363 int device_find_first_child(struct udevice *parent, struct udevice **devp);
366 * device_find_first_child() - Find the first child of a device
368 * @devp: Pointer to previous child device on entry. Returns pointer to next
369 * child device, or NULL if none
372 int device_find_next_child(struct udevice **devp);
375 * dev_get_addr() - Get the reg property of a device
377 * @dev: Pointer to a device
381 fdt_addr_t dev_get_addr(struct udevice *dev);
384 * device_has_children() - check if a device has any children
386 * @dev: Device to check
387 * @return true if the device has one or more children
389 bool device_has_children(struct udevice *dev);
392 * device_has_active_children() - check if a device has any active children
394 * @dev: Device to check
395 * @return true if the device has one or more children and at least one of
396 * them is active (probed).
398 bool device_has_active_children(struct udevice *dev);
401 * device_is_last_sibling() - check if a device is the last sibling
403 * This function can be useful for display purposes, when special action needs
404 * to be taken when displaying the last sibling. This can happen when a tree
405 * view of devices is being displayed.
407 * @dev: Device to check
408 * @return true if there are no more siblings after this one - i.e. is it
411 bool device_is_last_sibling(struct udevice *dev);