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