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 * @uclass_node: Used by uclass to link its devices 55 * @child_head: List of children of this device 56 * @sibling_node: Next device in list of all devices 57 * @flags: Flags for this device DM_FLAG_... 58 * @req_seq: Requested sequence number for this device (-1 = any) 59 * @seq: Allocated sequence number for this device (-1 = none) 60 */ 61 struct udevice { 62 struct driver *driver; 63 const char *name; 64 void *platdata; 65 int of_offset; 66 struct udevice *parent; 67 void *priv; 68 struct uclass *uclass; 69 void *uclass_priv; 70 struct list_head uclass_node; 71 struct list_head child_head; 72 struct list_head sibling_node; 73 uint32_t flags; 74 int req_seq; 75 int seq; 76 }; 77 78 /* Maximum sequence number supported */ 79 #define DM_MAX_SEQ 999 80 81 /* Returns the operations for a device */ 82 #define device_get_ops(dev) (dev->driver->ops) 83 84 /* Returns non-zero if the device is active (probed and not removed) */ 85 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED) 86 87 /** 88 * struct udevice_id - Lists the compatible strings supported by a driver 89 * @compatible: Compatible string 90 * @data: Data for this compatible string 91 */ 92 struct udevice_id { 93 const char *compatible; 94 ulong data; 95 }; 96 97 /** 98 * struct driver - A driver for a feature or peripheral 99 * 100 * This holds methods for setting up a new device, and also removing it. 101 * The device needs information to set itself up - this is provided either 102 * by platdata or a device tree node (which we find by looking up 103 * matching compatible strings with of_match). 104 * 105 * Drivers all belong to a uclass, representing a class of devices of the 106 * same type. Common elements of the drivers can be implemented in the uclass, 107 * or the uclass can provide a consistent interface to the drivers within 108 * it. 109 * 110 * @name: Device name 111 * @id: Identiies the uclass we belong to 112 * @of_match: List of compatible strings to match, and any identifying data 113 * for each. 114 * @bind: Called to bind a device to its driver 115 * @probe: Called to probe a device, i.e. activate it 116 * @remove: Called to remove a device, i.e. de-activate it 117 * @unbind: Called to unbind a device from its driver 118 * @ofdata_to_platdata: Called before probe to decode device tree data 119 * @priv_auto_alloc_size: If non-zero this is the size of the private data 120 * to be allocated in the device's ->priv pointer. If zero, then the driver 121 * is responsible for allocating any data required. 122 * @platdata_auto_alloc_size: If non-zero this is the size of the 123 * platform data to be allocated in the device's ->platdata pointer. 124 * This is typically only useful for device-tree-aware drivers (those with 125 * an of_match), since drivers which use platdata will have the data 126 * provided in the U_BOOT_DEVICE() instantiation. 127 * @ops: Driver-specific operations. This is typically a list of function 128 * pointers defined by the driver, to implement driver functions required by 129 * the uclass. 130 * @flags: driver flags - see DM_FLAGS_... 131 */ 132 struct driver { 133 char *name; 134 enum uclass_id id; 135 const struct udevice_id *of_match; 136 int (*bind)(struct udevice *dev); 137 int (*probe)(struct udevice *dev); 138 int (*remove)(struct udevice *dev); 139 int (*unbind)(struct udevice *dev); 140 int (*ofdata_to_platdata)(struct udevice *dev); 141 int priv_auto_alloc_size; 142 int platdata_auto_alloc_size; 143 const void *ops; /* driver-specific operations */ 144 uint32_t flags; 145 }; 146 147 /* Declare a new U-Boot driver */ 148 #define U_BOOT_DRIVER(__name) \ 149 ll_entry_declare(struct driver, __name, driver) 150 151 /** 152 * dev_get_platdata() - Get the platform data for a device 153 * 154 * This checks that dev is not NULL, but no other checks for now 155 * 156 * @dev Device to check 157 * @return platform data, or NULL if none 158 */ 159 void *dev_get_platdata(struct udevice *dev); 160 161 /** 162 * dev_get_priv() - Get the private data for a device 163 * 164 * This checks that dev is not NULL, but no other checks for now 165 * 166 * @dev Device to check 167 * @return private data, or NULL if none 168 */ 169 void *dev_get_priv(struct udevice *dev); 170 171 /** 172 * device_find_child_by_seq() - Find a child device based on a sequence 173 * 174 * This searches for a device with the given seq or req_seq. 175 * 176 * For seq, if an active device has this sequence it will be returned. 177 * If there is no such device then this will return -ENODEV. 178 * 179 * For req_seq, if a device (whether activated or not) has this req_seq 180 * value, that device will be returned. This is a strong indication that 181 * the device will receive that sequence when activated. 182 * 183 * @parent: Parent device 184 * @seq_or_req_seq: Sequence number to find (0=first) 185 * @find_req_seq: true to find req_seq, false to find seq 186 * @devp: Returns pointer to device (there is only one per for each seq). 187 * Set to NULL if none is found 188 * @return 0 if OK, -ve on error 189 */ 190 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq, 191 bool find_req_seq, struct udevice **devp); 192 193 #endif 194