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 /** 30 * struct udevice - An instance of a driver 31 * 32 * This holds information about a device, which is a driver bound to a 33 * particular port or peripheral (essentially a driver instance). 34 * 35 * A device will come into existence through a 'bind' call, either due to 36 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node 37 * in the device tree (in which case of_offset is >= 0). In the latter case 38 * we translate the device tree information into platdata in a function 39 * implemented by the driver ofdata_to_platdata method (called just before the 40 * probe method if the device has a device tree node. 41 * 42 * All three of platdata, priv and uclass_priv can be allocated by the 43 * driver, or you can use the auto_alloc_size members of struct driver and 44 * struct uclass_driver to have driver model do this automatically. 45 * 46 * @driver: The driver used by this device 47 * @name: Name of device, typically the FDT node name 48 * @platdata: Configuration data for this device 49 * @of_offset: Device tree node offset for this device (- for none) 50 * @of_id: Pointer to the udevice_id structure which created the device 51 * @parent: Parent of this device, or NULL for the top level device 52 * @priv: Private data for this device 53 * @uclass: Pointer to uclass for this device 54 * @uclass_priv: The uclass's private data for this device 55 * @parent_priv: The parent's private data for this device 56 * @uclass_node: Used by uclass to link its devices 57 * @child_head: List of children of this device 58 * @sibling_node: Next device in list of all devices 59 * @flags: Flags for this device DM_FLAG_... 60 * @req_seq: Requested sequence number for this device (-1 = any) 61 * @seq: Allocated sequence number for this device (-1 = none). This is set up 62 * when the device is probed and will be unique within the device's uclass. 63 */ 64 struct udevice { 65 struct driver *driver; 66 const char *name; 67 void *platdata; 68 int of_offset; 69 const struct udevice_id *of_id; 70 struct udevice *parent; 71 void *priv; 72 struct uclass *uclass; 73 void *uclass_priv; 74 void *parent_priv; 75 struct list_head uclass_node; 76 struct list_head child_head; 77 struct list_head sibling_node; 78 uint32_t flags; 79 int req_seq; 80 int seq; 81 }; 82 83 /* Maximum sequence number supported */ 84 #define DM_MAX_SEQ 999 85 86 /* Returns the operations for a device */ 87 #define device_get_ops(dev) (dev->driver->ops) 88 89 /* Returns non-zero if the device is active (probed and not removed) */ 90 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED) 91 92 /** 93 * struct udevice_id - Lists the compatible strings supported by a driver 94 * @compatible: Compatible string 95 * @data: Data for this compatible string 96 */ 97 struct udevice_id { 98 const char *compatible; 99 ulong data; 100 }; 101 102 #ifdef CONFIG_OF_CONTROL 103 #define of_match_ptr(_ptr) (_ptr) 104 #else 105 #define of_match_ptr(_ptr) NULL 106 #endif /* CONFIG_OF_CONTROL */ 107 108 /** 109 * struct driver - A driver for a feature or peripheral 110 * 111 * This holds methods for setting up a new device, and also removing it. 112 * The device needs information to set itself up - this is provided either 113 * by platdata or a device tree node (which we find by looking up 114 * matching compatible strings with of_match). 115 * 116 * Drivers all belong to a uclass, representing a class of devices of the 117 * same type. Common elements of the drivers can be implemented in the uclass, 118 * or the uclass can provide a consistent interface to the drivers within 119 * it. 120 * 121 * @name: Device name 122 * @id: Identiies the uclass we belong to 123 * @of_match: List of compatible strings to match, and any identifying data 124 * for each. 125 * @bind: Called to bind a device to its driver 126 * @probe: Called to probe a device, i.e. activate it 127 * @remove: Called to remove a device, i.e. de-activate it 128 * @unbind: Called to unbind a device from its driver 129 * @ofdata_to_platdata: Called before probe to decode device tree data 130 * @child_pre_probe: Called before a child device is probed. The device has 131 * memory allocated but it has not yet been probed. 132 * @child_post_remove: Called after a child device is removed. The device 133 * has memory allocated but its device_remove() method has been called. 134 * @priv_auto_alloc_size: If non-zero this is the size of the private data 135 * to be allocated in the device's ->priv pointer. If zero, then the driver 136 * is responsible for allocating any data required. 137 * @platdata_auto_alloc_size: If non-zero this is the size of the 138 * platform data to be allocated in the device's ->platdata pointer. 139 * This is typically only useful for device-tree-aware drivers (those with 140 * an of_match), since drivers which use platdata will have the data 141 * provided in the U_BOOT_DEVICE() instantiation. 142 * @per_child_auto_alloc_size: Each device can hold private data owned by 143 * its parent. If required this will be automatically allocated if this 144 * value is non-zero. 145 * TODO(sjg@chromium.org): I'm considering dropping this, and just having 146 * device_probe_child() pass it in. So far the use case for allocating it 147 * is SPI, but I found that unsatisfactory. Since it is here I will leave it 148 * until things are clearer. 149 * @ops: Driver-specific operations. This is typically a list of function 150 * pointers defined by the driver, to implement driver functions required by 151 * the uclass. 152 * @flags: driver flags - see DM_FLAGS_... 153 */ 154 struct driver { 155 char *name; 156 enum uclass_id id; 157 const struct udevice_id *of_match; 158 int (*bind)(struct udevice *dev); 159 int (*probe)(struct udevice *dev); 160 int (*remove)(struct udevice *dev); 161 int (*unbind)(struct udevice *dev); 162 int (*ofdata_to_platdata)(struct udevice *dev); 163 int (*child_pre_probe)(struct udevice *dev); 164 int (*child_post_remove)(struct udevice *dev); 165 int priv_auto_alloc_size; 166 int platdata_auto_alloc_size; 167 int per_child_auto_alloc_size; 168 const void *ops; /* driver-specific operations */ 169 uint32_t flags; 170 }; 171 172 /* Declare a new U-Boot driver */ 173 #define U_BOOT_DRIVER(__name) \ 174 ll_entry_declare(struct driver, __name, driver) 175 176 /** 177 * dev_get_platdata() - Get the platform data for a device 178 * 179 * This checks that dev is not NULL, but no other checks for now 180 * 181 * @dev Device to check 182 * @return platform data, or NULL if none 183 */ 184 void *dev_get_platdata(struct udevice *dev); 185 186 /** 187 * dev_get_parentdata() - Get the parent data for a device 188 * 189 * The parent data is data stored in the device but owned by the parent. 190 * For example, a USB device may have parent data which contains information 191 * about how to talk to the device over USB. 192 * 193 * This checks that dev is not NULL, but no other checks for now 194 * 195 * @dev Device to check 196 * @return parent data, or NULL if none 197 */ 198 void *dev_get_parentdata(struct udevice *dev); 199 200 /** 201 * dev_get_priv() - Get the private data for a device 202 * 203 * This checks that dev is not NULL, but no other checks for now 204 * 205 * @dev Device to check 206 * @return private data, or NULL if none 207 */ 208 void *dev_get_priv(struct udevice *dev); 209 210 /** 211 * dev_get_of_data() - get the device tree data used to bind a device 212 * 213 * When a device is bound using a device tree node, it matches a 214 * particular compatible string as in struct udevice_id. This function 215 * returns the associated data value for that compatible string 216 */ 217 ulong dev_get_of_data(struct udevice *dev); 218 219 /** 220 * device_get_child() - Get the child of a device by index 221 * 222 * Returns the numbered child, 0 being the first. This does not use 223 * sequence numbers, only the natural order. 224 * 225 * @dev: Parent device to check 226 * @index: Child index 227 * @devp: Returns pointer to device 228 */ 229 int device_get_child(struct udevice *parent, int index, struct udevice **devp); 230 231 /** 232 * device_find_child_by_seq() - Find a child device based on a sequence 233 * 234 * This searches for a device with the given seq or req_seq. 235 * 236 * For seq, if an active device has this sequence it will be returned. 237 * If there is no such device then this will return -ENODEV. 238 * 239 * For req_seq, if a device (whether activated or not) has this req_seq 240 * value, that device will be returned. This is a strong indication that 241 * the device will receive that sequence when activated. 242 * 243 * @parent: Parent device 244 * @seq_or_req_seq: Sequence number to find (0=first) 245 * @find_req_seq: true to find req_seq, false to find seq 246 * @devp: Returns pointer to device (there is only one per for each seq). 247 * Set to NULL if none is found 248 * @return 0 if OK, -ve on error 249 */ 250 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq, 251 bool find_req_seq, struct udevice **devp); 252 253 /** 254 * device_get_child_by_seq() - Get a child device based on a sequence 255 * 256 * If an active device has this sequence it will be returned. If there is no 257 * such device then this will check for a device that is requesting this 258 * sequence. 259 * 260 * The device is probed to activate it ready for use. 261 * 262 * @parent: Parent device 263 * @seq: Sequence number to find (0=first) 264 * @devp: Returns pointer to device (there is only one per for each seq) 265 * Set to NULL if none is found 266 * @return 0 if OK, -ve on error 267 */ 268 int device_get_child_by_seq(struct udevice *parent, int seq, 269 struct udevice **devp); 270 271 /** 272 * device_find_child_by_of_offset() - Find a child device based on FDT offset 273 * 274 * Locates a child device by its device tree offset. 275 * 276 * @parent: Parent device 277 * @of_offset: Device tree offset to find 278 * @devp: Returns pointer to device if found, otherwise this is set to NULL 279 * @return 0 if OK, -ve on error 280 */ 281 int device_find_child_by_of_offset(struct udevice *parent, int of_offset, 282 struct udevice **devp); 283 284 /** 285 * device_get_child_by_of_offset() - Get a child device based on FDT offset 286 * 287 * Locates a child device by its device tree offset. 288 * 289 * The device is probed to activate it ready for use. 290 * 291 * @parent: Parent device 292 * @of_offset: Device tree offset to find 293 * @devp: Returns pointer to device if found, otherwise this is set to NULL 294 * @return 0 if OK, -ve on error 295 */ 296 int device_get_child_by_of_offset(struct udevice *parent, int seq, 297 struct udevice **devp); 298 299 /** 300 * device_find_first_child() - Find the first child of a device 301 * 302 * @parent: Parent device to search 303 * @devp: Returns first child device, or NULL if none 304 * @return 0 305 */ 306 int device_find_first_child(struct udevice *parent, struct udevice **devp); 307 308 /** 309 * device_find_first_child() - Find the first child of a device 310 * 311 * @devp: Pointer to previous child device on entry. Returns pointer to next 312 * child device, or NULL if none 313 * @return 0 314 */ 315 int device_find_next_child(struct udevice **devp); 316 317 #endif 318