xref: /openbmc/u-boot/include/dm/device.h (revision 456ee909)
1 /*
2  * Copyright (c) 2013 Google, Inc
3  *
4  * (C) Copyright 2012
5  * Pavel Herrmann <morpheus.ibis@gmail.com>
6  * Marek Vasut <marex@denx.de>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #ifndef _DM_DEVICE_H
12 #define _DM_DEVICE_H
13 
14 #include <dm/uclass-id.h>
15 #include <fdtdec.h>
16 #include <linker_lists.h>
17 #include <linux/list.h>
18 
19 struct driver_info;
20 
21 /* Driver is active (probed). Cleared when it is removed */
22 #define DM_FLAG_ACTIVATED	(1 << 0)
23 
24 /* DM is responsible for allocating and freeing platdata */
25 #define DM_FLAG_ALLOC_PDATA	(1 << 1)
26 
27 /* DM should init this device prior to relocation */
28 #define DM_FLAG_PRE_RELOC	(1 << 2)
29 
30 /* DM is responsible for allocating and freeing parent_platdata */
31 #define DM_FLAG_ALLOC_PARENT_PDATA	(1 << 3)
32 
33 /* DM is responsible for allocating and freeing uclass_platdata */
34 #define DM_FLAG_ALLOC_UCLASS_PDATA	(1 << 4)
35 
36 /* Allocate driver private data on a DMA boundary */
37 #define DM_FLAG_ALLOC_PRIV_DMA	(1 << 5)
38 
39 /**
40  * struct udevice - An instance of a driver
41  *
42  * This holds information about a device, which is a driver bound to a
43  * particular port or peripheral (essentially a driver instance).
44  *
45  * A device will come into existence through a 'bind' call, either due to
46  * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
47  * in the device tree (in which case of_offset is >= 0). In the latter case
48  * we translate the device tree information into platdata in a function
49  * implemented by the driver ofdata_to_platdata method (called just before the
50  * probe method if the device has a device tree node.
51  *
52  * All three of platdata, priv and uclass_priv can be allocated by the
53  * driver, or you can use the auto_alloc_size members of struct driver and
54  * struct uclass_driver to have driver model do this automatically.
55  *
56  * @driver: The driver used by this device
57  * @name: Name of device, typically the FDT node name
58  * @platdata: Configuration data for this device
59  * @parent_platdata: The parent bus's configuration data for this device
60  * @uclass_platdata: The uclass's configuration data for this device
61  * @of_offset: Device tree node offset for this device (- for none)
62  * @driver_data: Driver data word for the entry that matched this device with
63  *		its driver
64  * @parent: Parent of this device, or NULL for the top level device
65  * @priv: Private data for this device
66  * @uclass: Pointer to uclass for this device
67  * @uclass_priv: The uclass's private data for this device
68  * @parent_priv: The parent's private data for this device
69  * @uclass_node: Used by uclass to link its devices
70  * @child_head: List of children of this device
71  * @sibling_node: Next device in list of all devices
72  * @flags: Flags for this device DM_FLAG_...
73  * @req_seq: Requested sequence number for this device (-1 = any)
74  * @seq: Allocated sequence number for this device (-1 = none). This is set up
75  * when the device is probed and will be unique within the device's uclass.
76  */
77 struct udevice {
78 	const struct driver *driver;
79 	const char *name;
80 	void *platdata;
81 	void *parent_platdata;
82 	void *uclass_platdata;
83 	int of_offset;
84 	ulong driver_data;
85 	struct udevice *parent;
86 	void *priv;
87 	struct uclass *uclass;
88 	void *uclass_priv;
89 	void *parent_priv;
90 	struct list_head uclass_node;
91 	struct list_head child_head;
92 	struct list_head sibling_node;
93 	uint32_t flags;
94 	int req_seq;
95 	int seq;
96 };
97 
98 /* Maximum sequence number supported */
99 #define DM_MAX_SEQ	999
100 
101 /* Returns the operations for a device */
102 #define device_get_ops(dev)	(dev->driver->ops)
103 
104 /* Returns non-zero if the device is active (probed and not removed) */
105 #define device_active(dev)	((dev)->flags & DM_FLAG_ACTIVATED)
106 
107 /**
108  * struct udevice_id - Lists the compatible strings supported by a driver
109  * @compatible: Compatible string
110  * @data: Data for this compatible string
111  */
112 struct udevice_id {
113 	const char *compatible;
114 	ulong data;
115 };
116 
117 #ifdef CONFIG_OF_CONTROL
118 #define of_match_ptr(_ptr)	(_ptr)
119 #else
120 #define of_match_ptr(_ptr)	NULL
121 #endif /* CONFIG_OF_CONTROL */
122 
123 /**
124  * struct driver - A driver for a feature or peripheral
125  *
126  * This holds methods for setting up a new device, and also removing it.
127  * The device needs information to set itself up - this is provided either
128  * by platdata or a device tree node (which we find by looking up
129  * matching compatible strings with of_match).
130  *
131  * Drivers all belong to a uclass, representing a class of devices of the
132  * same type. Common elements of the drivers can be implemented in the uclass,
133  * or the uclass can provide a consistent interface to the drivers within
134  * it.
135  *
136  * @name: Device name
137  * @id: Identiies the uclass we belong to
138  * @of_match: List of compatible strings to match, and any identifying data
139  * for each.
140  * @bind: Called to bind a device to its driver
141  * @probe: Called to probe a device, i.e. activate it
142  * @remove: Called to remove a device, i.e. de-activate it
143  * @unbind: Called to unbind a device from its driver
144  * @ofdata_to_platdata: Called before probe to decode device tree data
145  * @child_post_bind: Called after a new child has been bound
146  * @child_pre_probe: Called before a child device is probed. The device has
147  * memory allocated but it has not yet been probed.
148  * @child_post_remove: Called after a child device is removed. The device
149  * has memory allocated but its device_remove() method has been called.
150  * @priv_auto_alloc_size: If non-zero this is the size of the private data
151  * to be allocated in the device's ->priv pointer. If zero, then the driver
152  * is responsible for allocating any data required.
153  * @platdata_auto_alloc_size: If non-zero this is the size of the
154  * platform data to be allocated in the device's ->platdata pointer.
155  * This is typically only useful for device-tree-aware drivers (those with
156  * an of_match), since drivers which use platdata will have the data
157  * provided in the U_BOOT_DEVICE() instantiation.
158  * @per_child_auto_alloc_size: Each device can hold private data owned by
159  * its parent. If required this will be automatically allocated if this
160  * value is non-zero.
161  * TODO(sjg@chromium.org): I'm considering dropping this, and just having
162  * device_probe_child() pass it in. So far the use case for allocating it
163  * is SPI, but I found that unsatisfactory. Since it is here I will leave it
164  * until things are clearer.
165  * @per_child_platdata_auto_alloc_size: A bus likes to store information about
166  * its children. If non-zero this is the size of this data, to be allocated
167  * in the child's parent_platdata pointer.
168  * @ops: Driver-specific operations. This is typically a list of function
169  * pointers defined by the driver, to implement driver functions required by
170  * the uclass.
171  * @flags: driver flags - see DM_FLAGS_...
172  */
173 struct driver {
174 	char *name;
175 	enum uclass_id id;
176 	const struct udevice_id *of_match;
177 	int (*bind)(struct udevice *dev);
178 	int (*probe)(struct udevice *dev);
179 	int (*remove)(struct udevice *dev);
180 	int (*unbind)(struct udevice *dev);
181 	int (*ofdata_to_platdata)(struct udevice *dev);
182 	int (*child_post_bind)(struct udevice *dev);
183 	int (*child_pre_probe)(struct udevice *dev);
184 	int (*child_post_remove)(struct udevice *dev);
185 	int priv_auto_alloc_size;
186 	int platdata_auto_alloc_size;
187 	int per_child_auto_alloc_size;
188 	int per_child_platdata_auto_alloc_size;
189 	const void *ops;	/* driver-specific operations */
190 	uint32_t flags;
191 };
192 
193 /* Declare a new U-Boot driver */
194 #define U_BOOT_DRIVER(__name)						\
195 	ll_entry_declare(struct driver, __name, driver)
196 
197 /**
198  * dev_get_platdata() - Get the platform data for a device
199  *
200  * This checks that dev is not NULL, but no other checks for now
201  *
202  * @dev		Device to check
203  * @return platform data, or NULL if none
204  */
205 void *dev_get_platdata(struct udevice *dev);
206 
207 /**
208  * dev_get_parent_platdata() - Get the parent platform data for a device
209  *
210  * This checks that dev is not NULL, but no other checks for now
211  *
212  * @dev		Device to check
213  * @return parent's platform data, or NULL if none
214  */
215 void *dev_get_parent_platdata(struct udevice *dev);
216 
217 /**
218  * dev_get_uclass_platdata() - Get the uclass platform data for a device
219  *
220  * This checks that dev is not NULL, but no other checks for now
221  *
222  * @dev		Device to check
223  * @return uclass's platform data, or NULL if none
224  */
225 void *dev_get_uclass_platdata(struct udevice *dev);
226 
227 /**
228  * dev_get_parentdata() - Get the parent data for a device
229  *
230  * The parent data is data stored in the device but owned by the parent.
231  * For example, a USB device may have parent data which contains information
232  * about how to talk to the device over USB.
233  *
234  * This checks that dev is not NULL, but no other checks for now
235  *
236  * @dev		Device to check
237  * @return parent data, or NULL if none
238  */
239 void *dev_get_parentdata(struct udevice *dev);
240 
241 /**
242  * dev_get_priv() - Get the private data for a device
243  *
244  * This checks that dev is not NULL, but no other checks for now
245  *
246  * @dev		Device to check
247  * @return private data, or NULL if none
248  */
249 void *dev_get_priv(struct udevice *dev);
250 
251 /**
252  * struct dev_get_parent() - Get the parent of a device
253  *
254  * @child:	Child to check
255  * @return parent of child, or NULL if this is the root device
256  */
257 struct udevice *dev_get_parent(struct udevice *child);
258 
259 /**
260  * dev_get_uclass_priv() - Get the private uclass data for a device
261  *
262  * This checks that dev is not NULL, but no other checks for now
263  *
264  * @dev		Device to check
265  * @return private uclass data for this device, or NULL if none
266  */
267 void *dev_get_uclass_priv(struct udevice *dev);
268 
269 /**
270  * dev_get_driver_data() - get the driver data used to bind a device
271  *
272  * When a device is bound using a device tree node, it matches a
273  * particular compatible string as in struct udevice_id. This function
274  * returns the associated data value for that compatible string. This is
275  * the 'data' field in struct udevice_id.
276  *
277  * For USB devices, this is the driver_info field in struct usb_device_id.
278  *
279  * @dev:	Device to check
280  */
281 ulong dev_get_driver_data(struct udevice *dev);
282 
283 /**
284  * dev_get_driver_ops() - get the device's driver's operations
285  *
286  * This checks that dev is not NULL, and returns the pointer to device's
287  * driver's operations.
288  *
289  * @dev:	Device to check
290  * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
291  */
292 const void *dev_get_driver_ops(struct udevice *dev);
293 
294 /*
295  * device_get_uclass_id() - return the uclass ID of a device
296  *
297  * @dev:	Device to check
298  * @return uclass ID for the device
299  */
300 enum uclass_id device_get_uclass_id(struct udevice *dev);
301 
302 /*
303  * dev_get_uclass_name() - return the uclass name of a device
304  *
305  * This checks that dev is not NULL.
306  *
307  * @dev:	Device to check
308  * @return  pointer to the uclass name for the device
309  */
310 const char *dev_get_uclass_name(struct udevice *dev);
311 
312 /**
313  * device_get_child() - Get the child of a device by index
314  *
315  * Returns the numbered child, 0 being the first. This does not use
316  * sequence numbers, only the natural order.
317  *
318  * @dev:	Parent device to check
319  * @index:	Child index
320  * @devp:	Returns pointer to device
321  */
322 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
323 
324 /**
325  * device_find_child_by_seq() - Find a child device based on a sequence
326  *
327  * This searches for a device with the given seq or req_seq.
328  *
329  * For seq, if an active device has this sequence it will be returned.
330  * If there is no such device then this will return -ENODEV.
331  *
332  * For req_seq, if a device (whether activated or not) has this req_seq
333  * value, that device will be returned. This is a strong indication that
334  * the device will receive that sequence when activated.
335  *
336  * @parent: Parent device
337  * @seq_or_req_seq: Sequence number to find (0=first)
338  * @find_req_seq: true to find req_seq, false to find seq
339  * @devp: Returns pointer to device (there is only one per for each seq).
340  * Set to NULL if none is found
341  * @return 0 if OK, -ve on error
342  */
343 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
344 			     bool find_req_seq, struct udevice **devp);
345 
346 /**
347  * device_get_child_by_seq() - Get a child device based on a sequence
348  *
349  * If an active device has this sequence it will be returned. If there is no
350  * such device then this will check for a device that is requesting this
351  * sequence.
352  *
353  * The device is probed to activate it ready for use.
354  *
355  * @parent: Parent device
356  * @seq: Sequence number to find (0=first)
357  * @devp: Returns pointer to device (there is only one per for each seq)
358  * Set to NULL if none is found
359  * @return 0 if OK, -ve on error
360  */
361 int device_get_child_by_seq(struct udevice *parent, int seq,
362 			    struct udevice **devp);
363 
364 /**
365  * device_find_child_by_of_offset() - Find a child device based on FDT offset
366  *
367  * Locates a child device by its device tree offset.
368  *
369  * @parent: Parent device
370  * @of_offset: Device tree offset to find
371  * @devp: Returns pointer to device if found, otherwise this is set to NULL
372  * @return 0 if OK, -ve on error
373  */
374 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
375 				   struct udevice **devp);
376 
377 /**
378  * device_get_child_by_of_offset() - Get a child device based on FDT offset
379  *
380  * Locates a child device by its device tree offset.
381  *
382  * The device is probed to activate it ready for use.
383  *
384  * @parent: Parent device
385  * @of_offset: Device tree offset to find
386  * @devp: Returns pointer to device if found, otherwise this is set to NULL
387  * @return 0 if OK, -ve on error
388  */
389 int device_get_child_by_of_offset(struct udevice *parent, int of_offset,
390 				  struct udevice **devp);
391 
392 /**
393  * device_get_global_by_of_offset() - Get a device based on FDT offset
394  *
395  * Locates a device by its device tree offset, searching globally throughout
396  * the all driver model devices.
397  *
398  * The device is probed to activate it ready for use.
399  *
400  * @of_offset: Device tree offset to find
401  * @devp: Returns pointer to device if found, otherwise this is set to NULL
402  * @return 0 if OK, -ve on error
403  */
404 int device_get_global_by_of_offset(int of_offset, struct udevice **devp);
405 
406 /**
407  * device_find_first_child() - Find the first child of a device
408  *
409  * @parent: Parent device to search
410  * @devp: Returns first child device, or NULL if none
411  * @return 0
412  */
413 int device_find_first_child(struct udevice *parent, struct udevice **devp);
414 
415 /**
416  * device_find_first_child() - Find the first child of a device
417  *
418  * @devp: Pointer to previous child device on entry. Returns pointer to next
419  *		child device, or NULL if none
420  * @return 0
421  */
422 int device_find_next_child(struct udevice **devp);
423 
424 /**
425  * dev_get_addr() - Get the reg property of a device
426  *
427  * @dev: Pointer to a device
428  *
429  * @return addr
430  */
431 fdt_addr_t dev_get_addr(struct udevice *dev);
432 
433 /**
434  * device_has_children() - check if a device has any children
435  *
436  * @dev:	Device to check
437  * @return true if the device has one or more children
438  */
439 bool device_has_children(struct udevice *dev);
440 
441 /**
442  * device_has_active_children() - check if a device has any active children
443  *
444  * @dev:	Device to check
445  * @return true if the device has one or more children and at least one of
446  * them is active (probed).
447  */
448 bool device_has_active_children(struct udevice *dev);
449 
450 /**
451  * device_is_last_sibling() - check if a device is the last sibling
452  *
453  * This function can be useful for display purposes, when special action needs
454  * to be taken when displaying the last sibling. This can happen when a tree
455  * view of devices is being displayed.
456  *
457  * @dev:	Device to check
458  * @return true if there are no more siblings after this one - i.e. is it
459  * last in the list.
460  */
461 bool device_is_last_sibling(struct udevice *dev);
462 
463 #endif
464