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 <linker_lists.h> 16 #include <linux/list.h> 17 18 struct driver_info; 19 20 /* Driver is active (probed). Cleared when it is removed */ 21 #define DM_FLAG_ACTIVATED (1 << 0) 22 23 /* DM is responsible for allocating and freeing platdata */ 24 #define DM_FLAG_ALLOC_PDATA (1 << 1) 25 26 /* DM should init this device prior to relocation */ 27 #define DM_FLAG_PRE_RELOC (1 << 2) 28 29 /* DM is responsible for allocating and freeing parent_platdata */ 30 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3) 31 32 /** 33 * struct udevice - An instance of a driver 34 * 35 * This holds information about a device, which is a driver bound to a 36 * particular port or peripheral (essentially a driver instance). 37 * 38 * A device will come into existence through a 'bind' call, either due to 39 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node 40 * in the device tree (in which case of_offset is >= 0). In the latter case 41 * we translate the device tree information into platdata in a function 42 * implemented by the driver ofdata_to_platdata method (called just before the 43 * probe method if the device has a device tree node. 44 * 45 * All three of platdata, priv and uclass_priv can be allocated by the 46 * driver, or you can use the auto_alloc_size members of struct driver and 47 * struct uclass_driver to have driver model do this automatically. 48 * 49 * @driver: The driver used by this device 50 * @name: Name of device, typically the FDT node name 51 * @platdata: Configuration data for this device 52 * @parent_platdata: The parent bus's configuration data for this device 53 * @of_offset: Device tree node offset for this device (- for none) 54 * @of_id: Pointer to the udevice_id structure which created the device 55 * @parent: Parent of this device, or NULL for the top level device 56 * @priv: Private data for this device 57 * @uclass: Pointer to uclass for this device 58 * @uclass_priv: The uclass's private data for this device 59 * @parent_priv: The parent's private data for this device 60 * @uclass_node: Used by uclass to link its devices 61 * @child_head: List of children of this device 62 * @sibling_node: Next device in list of all devices 63 * @flags: Flags for this device DM_FLAG_... 64 * @req_seq: Requested sequence number for this device (-1 = any) 65 * @seq: Allocated sequence number for this device (-1 = none). This is set up 66 * when the device is probed and will be unique within the device's uclass. 67 */ 68 struct udevice { 69 struct driver *driver; 70 const char *name; 71 void *platdata; 72 void *parent_platdata; 73 int of_offset; 74 const struct udevice_id *of_id; 75 struct udevice *parent; 76 void *priv; 77 struct uclass *uclass; 78 void *uclass_priv; 79 void *parent_priv; 80 struct list_head uclass_node; 81 struct list_head child_head; 82 struct list_head sibling_node; 83 uint32_t flags; 84 int req_seq; 85 int seq; 86 }; 87 88 /* Maximum sequence number supported */ 89 #define DM_MAX_SEQ 999 90 91 /* Returns the operations for a device */ 92 #define device_get_ops(dev) (dev->driver->ops) 93 94 /* Returns non-zero if the device is active (probed and not removed) */ 95 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED) 96 97 /** 98 * struct udevice_id - Lists the compatible strings supported by a driver 99 * @compatible: Compatible string 100 * @data: Data for this compatible string 101 */ 102 struct udevice_id { 103 const char *compatible; 104 ulong data; 105 }; 106 107 #ifdef CONFIG_OF_CONTROL 108 #define of_match_ptr(_ptr) (_ptr) 109 #else 110 #define of_match_ptr(_ptr) NULL 111 #endif /* CONFIG_OF_CONTROL */ 112 113 /** 114 * struct driver - A driver for a feature or peripheral 115 * 116 * This holds methods for setting up a new device, and also removing it. 117 * The device needs information to set itself up - this is provided either 118 * by platdata or a device tree node (which we find by looking up 119 * matching compatible strings with of_match). 120 * 121 * Drivers all belong to a uclass, representing a class of devices of the 122 * same type. Common elements of the drivers can be implemented in the uclass, 123 * or the uclass can provide a consistent interface to the drivers within 124 * it. 125 * 126 * @name: Device name 127 * @id: Identiies the uclass we belong to 128 * @of_match: List of compatible strings to match, and any identifying data 129 * for each. 130 * @bind: Called to bind a device to its driver 131 * @probe: Called to probe a device, i.e. activate it 132 * @remove: Called to remove a device, i.e. de-activate it 133 * @unbind: Called to unbind a device from its driver 134 * @ofdata_to_platdata: Called before probe to decode device tree data 135 * @child_post_bind: Called after a new child has been bound 136 * @child_pre_probe: Called before a child device is probed. The device has 137 * memory allocated but it has not yet been probed. 138 * @child_post_remove: Called after a child device is removed. The device 139 * has memory allocated but its device_remove() method has been called. 140 * @priv_auto_alloc_size: If non-zero this is the size of the private data 141 * to be allocated in the device's ->priv pointer. If zero, then the driver 142 * is responsible for allocating any data required. 143 * @platdata_auto_alloc_size: If non-zero this is the size of the 144 * platform data to be allocated in the device's ->platdata pointer. 145 * This is typically only useful for device-tree-aware drivers (those with 146 * an of_match), since drivers which use platdata will have the data 147 * provided in the U_BOOT_DEVICE() instantiation. 148 * @per_child_auto_alloc_size: Each device can hold private data owned by 149 * its parent. If required this will be automatically allocated if this 150 * value is non-zero. 151 * TODO(sjg@chromium.org): I'm considering dropping this, and just having 152 * device_probe_child() pass it in. So far the use case for allocating it 153 * is SPI, but I found that unsatisfactory. Since it is here I will leave it 154 * until things are clearer. 155 * @per_child_platdata_auto_alloc_size: A bus likes to store information about 156 * its children. If non-zero this is the size of this data, to be allocated 157 * in the child's parent_platdata pointer. 158 * @ops: Driver-specific operations. This is typically a list of function 159 * pointers defined by the driver, to implement driver functions required by 160 * the uclass. 161 * @flags: driver flags - see DM_FLAGS_... 162 */ 163 struct driver { 164 char *name; 165 enum uclass_id id; 166 const struct udevice_id *of_match; 167 int (*bind)(struct udevice *dev); 168 int (*probe)(struct udevice *dev); 169 int (*remove)(struct udevice *dev); 170 int (*unbind)(struct udevice *dev); 171 int (*ofdata_to_platdata)(struct udevice *dev); 172 int (*child_post_bind)(struct udevice *dev); 173 int (*child_pre_probe)(struct udevice *dev); 174 int (*child_post_remove)(struct udevice *dev); 175 int priv_auto_alloc_size; 176 int platdata_auto_alloc_size; 177 int per_child_auto_alloc_size; 178 int per_child_platdata_auto_alloc_size; 179 const void *ops; /* driver-specific operations */ 180 uint32_t flags; 181 }; 182 183 /* Declare a new U-Boot driver */ 184 #define U_BOOT_DRIVER(__name) \ 185 ll_entry_declare(struct driver, __name, driver) 186 187 /** 188 * dev_get_platdata() - Get the platform data for a device 189 * 190 * This checks that dev is not NULL, but no other checks for now 191 * 192 * @dev Device to check 193 * @return platform data, or NULL if none 194 */ 195 void *dev_get_platdata(struct udevice *dev); 196 197 /** 198 * dev_get_parent_platdata() - Get the parent 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 parent's platform data, or NULL if none 204 */ 205 void *dev_get_parent_platdata(struct udevice *dev); 206 207 /** 208 * dev_get_parentdata() - Get the parent data for a device 209 * 210 * The parent data is data stored in the device but owned by the parent. 211 * For example, a USB device may have parent data which contains information 212 * about how to talk to the device over USB. 213 * 214 * This checks that dev is not NULL, but no other checks for now 215 * 216 * @dev Device to check 217 * @return parent data, or NULL if none 218 */ 219 void *dev_get_parentdata(struct udevice *dev); 220 221 /** 222 * dev_get_priv() - Get the private data for a device 223 * 224 * This checks that dev is not NULL, but no other checks for now 225 * 226 * @dev Device to check 227 * @return private data, or NULL if none 228 */ 229 void *dev_get_priv(struct udevice *dev); 230 231 /** 232 * struct dev_get_parent() - Get the parent of a device 233 * 234 * @child: Child to check 235 * @return parent of child, or NULL if this is the root device 236 */ 237 struct udevice *dev_get_parent(struct udevice *child); 238 239 /** 240 * dev_get_of_data() - get the device tree data used to bind a device 241 * 242 * When a device is bound using a device tree node, it matches a 243 * particular compatible string as in struct udevice_id. This function 244 * returns the associated data value for that compatible string 245 */ 246 ulong dev_get_of_data(struct udevice *dev); 247 248 /** 249 * device_get_child() - Get the child of a device by index 250 * 251 * Returns the numbered child, 0 being the first. This does not use 252 * sequence numbers, only the natural order. 253 * 254 * @dev: Parent device to check 255 * @index: Child index 256 * @devp: Returns pointer to device 257 */ 258 int device_get_child(struct udevice *parent, int index, struct udevice **devp); 259 260 /** 261 * device_find_child_by_seq() - Find a child device based on a sequence 262 * 263 * This searches for a device with the given seq or req_seq. 264 * 265 * For seq, if an active device has this sequence it will be returned. 266 * If there is no such device then this will return -ENODEV. 267 * 268 * For req_seq, if a device (whether activated or not) has this req_seq 269 * value, that device will be returned. This is a strong indication that 270 * the device will receive that sequence when activated. 271 * 272 * @parent: Parent device 273 * @seq_or_req_seq: Sequence number to find (0=first) 274 * @find_req_seq: true to find req_seq, false to find seq 275 * @devp: Returns pointer to device (there is only one per for each seq). 276 * Set to NULL if none is found 277 * @return 0 if OK, -ve on error 278 */ 279 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq, 280 bool find_req_seq, struct udevice **devp); 281 282 /** 283 * device_get_child_by_seq() - Get a child device based on a sequence 284 * 285 * If an active device has this sequence it will be returned. If there is no 286 * such device then this will check for a device that is requesting this 287 * sequence. 288 * 289 * The device is probed to activate it ready for use. 290 * 291 * @parent: Parent device 292 * @seq: Sequence number to find (0=first) 293 * @devp: Returns pointer to device (there is only one per for each seq) 294 * Set to NULL if none is found 295 * @return 0 if OK, -ve on error 296 */ 297 int device_get_child_by_seq(struct udevice *parent, int seq, 298 struct udevice **devp); 299 300 /** 301 * device_find_child_by_of_offset() - Find a child device based on FDT offset 302 * 303 * Locates a child device by its device tree offset. 304 * 305 * @parent: Parent device 306 * @of_offset: Device tree offset to find 307 * @devp: Returns pointer to device if found, otherwise this is set to NULL 308 * @return 0 if OK, -ve on error 309 */ 310 int device_find_child_by_of_offset(struct udevice *parent, int of_offset, 311 struct udevice **devp); 312 313 /** 314 * device_get_child_by_of_offset() - Get a child device based on FDT offset 315 * 316 * Locates a child device by its device tree offset. 317 * 318 * The device is probed to activate it ready for use. 319 * 320 * @parent: Parent device 321 * @of_offset: Device tree offset to find 322 * @devp: Returns pointer to device if found, otherwise this is set to NULL 323 * @return 0 if OK, -ve on error 324 */ 325 int device_get_child_by_of_offset(struct udevice *parent, int seq, 326 struct udevice **devp); 327 328 /** 329 * device_find_first_child() - Find the first child of a device 330 * 331 * @parent: Parent device to search 332 * @devp: Returns first child device, or NULL if none 333 * @return 0 334 */ 335 int device_find_first_child(struct udevice *parent, struct udevice **devp); 336 337 /** 338 * device_find_first_child() - Find the first child of a device 339 * 340 * @devp: Pointer to previous child device on entry. Returns pointer to next 341 * child device, or NULL if none 342 * @return 0 343 */ 344 int device_find_next_child(struct udevice **devp); 345 346 #endif 347