diff options
Diffstat (limited to 'include/linux/fwnode.h')
| -rw-r--r-- | include/linux/fwnode.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 9d9dc444d787..8feeb94b8acc 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -17,6 +17,7 @@ struct device; struct fwnode_handle { struct fwnode_handle *secondary; const struct fwnode_operations *ops; + struct device *dev; }; /** @@ -67,6 +68,44 @@ struct fwnode_reference_args { * endpoint node. * @graph_get_port_parent: Return the parent node of a port node. * @graph_parse_endpoint: Parse endpoint for port and endpoint id. + * @add_links: Called after the device corresponding to the fwnode is added + * using device_add(). The function is expected to create device + * links to all the suppliers of the device that are available at + * the time this function is called. The function must NOT stop + * at the first failed device link if other unlinked supplier + * devices are present in the system. This is necessary for the + * driver/bus sync_state() callbacks to work correctly. + * + * For example, say Device-C depends on suppliers Device-S1 and + * Device-S2 and the dependency is listed in that order in the + * firmware. Say, S1 gets populated from the firmware after + * late_initcall_sync(). Say S2 is populated and probed way + * before that in device_initcall(). When C is populated, if this + * add_links() function doesn't continue past a "failed linking to + * S1" and continue linking C to S2, then S2 will get a + * sync_state() callback before C is probed. This is because from + * the perspective of S2, C was never a consumer when its + * sync_state() evaluation is done. To avoid this, the add_links() + * function has to go through all available suppliers of the + * device (that corresponds to this fwnode) and link to them + * before returning. + * + * If some suppliers are not yet available (indicated by an error + * return value), this function will be called again when other + * devices are added to allow creating device links to any newly + * available suppliers. + * + * Return 0 if device links have been successfully created to all + * the known suppliers of this device or if the supplier + * information is not known. + * + * Return -ENODEV if the suppliers needed for probing this device + * have not been registered yet (because device links can only be + * created to devices registered with the driver core). + * + * Return -EAGAIN if some of the suppliers of this device have not + * been registered yet, but none of those suppliers are necessary + * for probing the device. */ struct fwnode_operations { struct fwnode_handle *(*get)(struct fwnode_handle *fwnode); @@ -106,6 +145,8 @@ struct fwnode_operations { (*graph_get_port_parent)(struct fwnode_handle *fwnode); int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode, struct fwnode_endpoint *endpoint); + int (*add_links)(const struct fwnode_handle *fwnode, + struct device *dev); }; #define fwnode_has_op(fwnode, op) \ @@ -127,5 +168,6 @@ struct fwnode_operations { if (fwnode_has_op(fwnode, op)) \ (fwnode)->ops->op(fwnode, ## __VA_ARGS__); \ } while (false) +#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev) #endif |