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