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_pre_probe: Called before a child device is probed. The device has 136 * memory allocated but it has not yet been probed. 137 * @child_post_remove: Called after a child device is removed. The device 138 * has memory allocated but its device_remove() method has been called. 139 * @priv_auto_alloc_size: If non-zero this is the size of the private data 140 * to be allocated in the device's ->priv pointer. If zero, then the driver 141 * is responsible for allocating any data required. 142 * @platdata_auto_alloc_size: If non-zero this is the size of the 143 * platform data to be allocated in the device's ->platdata pointer. 144 * This is typically only useful for device-tree-aware drivers (those with 145 * an of_match), since drivers which use platdata will have the data 146 * provided in the U_BOOT_DEVICE() instantiation. 147 * @per_child_auto_alloc_size: Each device can hold private data owned by 148 * its parent. If required this will be automatically allocated if this 149 * value is non-zero. 150 * TODO(sjg@chromium.org): I'm considering dropping this, and just having 151 * device_probe_child() pass it in. So far the use case for allocating it 152 * is SPI, but I found that unsatisfactory. Since it is here I will leave it 153 * until things are clearer. 154 * @per_child_platdata_auto_alloc_size: A bus likes to store information about 155 * its children. If non-zero this is the size of this data, to be allocated 156 * in the child's parent_platdata pointer. 157 * @ops: Driver-specific operations. This is typically a list of function 158 * pointers defined by the driver, to implement driver functions required by 159 * the uclass. 160 * @flags: driver flags - see DM_FLAGS_... 161 */ 162 struct driver { 163 char *name; 164 enum uclass_id id; 165 const struct udevice_id *of_match; 166 int (*bind)(struct udevice *dev); 167 int (*probe)(struct udevice *dev); 168 int (*remove)(struct udevice *dev); 169 int (*unbind)(struct udevice *dev); 170 int (*ofdata_to_platdata)(struct udevice *dev); 171 int (*child_pre_probe)(struct udevice *dev); 172 int (*child_post_remove)(struct udevice *dev); 173 int priv_auto_alloc_size; 174 int platdata_auto_alloc_size; 175 int per_child_auto_alloc_size; 176 int per_child_platdata_auto_alloc_size; 177 const void *ops; /* driver-specific operations */ 178 uint32_t flags; 179 }; 180 181 /* Declare a new U-Boot driver */ 182 #define U_BOOT_DRIVER(__name) \ 183 ll_entry_declare(struct driver, __name, driver) 184 185 /** 186 * dev_get_platdata() - Get the platform data for a device 187 * 188 * This checks that dev is not NULL, but no other checks for now 189 * 190 * @dev Device to check 191 * @return platform data, or NULL if none 192 */ 193 void *dev_get_platdata(struct udevice *dev); 194 195 /** 196 * dev_get_parent_platdata() - Get the parent platform data for a device 197 * 198 * This checks that dev is not NULL, but no other checks for now 199 * 200 * @dev Device to check 201 * @return parent's platform data, or NULL if none 202 */ 203 void *dev_get_parent_platdata(struct udevice *dev); 204 205 /** 206 * dev_get_parentdata() - Get the parent data for a device 207 * 208 * The parent data is data stored in the device but owned by the parent. 209 * For example, a USB device may have parent data which contains information 210 * about how to talk to the device over USB. 211 * 212 * This checks that dev is not NULL, but no other checks for now 213 * 214 * @dev Device to check 215 * @return parent data, or NULL if none 216 */ 217 void *dev_get_parentdata(struct udevice *dev); 218 219 /** 220 * dev_get_priv() - Get the private data for a device 221 * 222 * This checks that dev is not NULL, but no other checks for now 223 * 224 * @dev Device to check 225 * @return private data, or NULL if none 226 */ 227 void *dev_get_priv(struct udevice *dev); 228 229 /** 230 * struct dev_get_parent() - Get the parent of a device 231 * 232 * @child: Child to check 233 * @return parent of child, or NULL if this is the root device 234 */ 235 struct udevice *dev_get_parent(struct udevice *child); 236 237 /** 238 * dev_get_of_data() - get the device tree data used to bind a device 239 * 240 * When a device is bound using a device tree node, it matches a 241 * particular compatible string as in struct udevice_id. This function 242 * returns the associated data value for that compatible string 243 */ 244 ulong dev_get_of_data(struct udevice *dev); 245 246 /** 247 * device_get_child() - Get the child of a device by index 248 * 249 * Returns the numbered child, 0 being the first. This does not use 250 * sequence numbers, only the natural order. 251 * 252 * @dev: Parent device to check 253 * @index: Child index 254 * @devp: Returns pointer to device 255 */ 256 int device_get_child(struct udevice *parent, int index, struct udevice **devp); 257 258 /** 259 * device_find_child_by_seq() - Find a child device based on a sequence 260 * 261 * This searches for a device with the given seq or req_seq. 262 * 263 * For seq, if an active device has this sequence it will be returned. 264 * If there is no such device then this will return -ENODEV. 265 * 266 * For req_seq, if a device (whether activated or not) has this req_seq 267 * value, that device will be returned. This is a strong indication that 268 * the device will receive that sequence when activated. 269 * 270 * @parent: Parent device 271 * @seq_or_req_seq: Sequence number to find (0=first) 272 * @find_req_seq: true to find req_seq, false to find seq 273 * @devp: Returns pointer to device (there is only one per for each seq). 274 * Set to NULL if none is found 275 * @return 0 if OK, -ve on error 276 */ 277 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq, 278 bool find_req_seq, struct udevice **devp); 279 280 /** 281 * device_get_child_by_seq() - Get a child device based on a sequence 282 * 283 * If an active device has this sequence it will be returned. If there is no 284 * such device then this will check for a device that is requesting this 285 * sequence. 286 * 287 * The device is probed to activate it ready for use. 288 * 289 * @parent: Parent device 290 * @seq: Sequence number to find (0=first) 291 * @devp: Returns pointer to device (there is only one per for each seq) 292 * Set to NULL if none is found 293 * @return 0 if OK, -ve on error 294 */ 295 int device_get_child_by_seq(struct udevice *parent, int seq, 296 struct udevice **devp); 297 298 /** 299 * device_find_child_by_of_offset() - Find a child device based on FDT offset 300 * 301 * Locates a child device by its device tree offset. 302 * 303 * @parent: Parent device 304 * @of_offset: Device tree offset to find 305 * @devp: Returns pointer to device if found, otherwise this is set to NULL 306 * @return 0 if OK, -ve on error 307 */ 308 int device_find_child_by_of_offset(struct udevice *parent, int of_offset, 309 struct udevice **devp); 310 311 /** 312 * device_get_child_by_of_offset() - Get a child device based on FDT offset 313 * 314 * Locates a child device by its device tree offset. 315 * 316 * The device is probed to activate it ready for use. 317 * 318 * @parent: Parent device 319 * @of_offset: Device tree offset to find 320 * @devp: Returns pointer to device if found, otherwise this is set to NULL 321 * @return 0 if OK, -ve on error 322 */ 323 int device_get_child_by_of_offset(struct udevice *parent, int seq, 324 struct udevice **devp); 325 326 /** 327 * device_find_first_child() - Find the first child of a device 328 * 329 * @parent: Parent device to search 330 * @devp: Returns first child device, or NULL if none 331 * @return 0 332 */ 333 int device_find_first_child(struct udevice *parent, struct udevice **devp); 334 335 /** 336 * device_find_first_child() - Find the first child of a device 337 * 338 * @devp: Pointer to previous child device on entry. Returns pointer to next 339 * child device, or NULL if none 340 * @return 0 341 */ 342 int device_find_next_child(struct udevice **devp); 343 344 #endif 345