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5a66a8ff86
In U-Boot it is pretty common to number devices from 0 and access them on the command line using this numbering. While it may come to pass that we will move away from this numbering, the possibility seems remote at present. Given that devices within a uclass will have an implied numbering, it makes sense to build this into driver model as a core feature. The cost is fairly small in terms of code and data space. With each uclass having numbered devices we can ask for SPI port 0 or serial port 1 and receive a single device. Devices typically request a sequence number using aliases in the device tree. These are resolved when the device is probed, to deal with conflicts. Sequence numbers need not be sequential and holes are permitted. At present there is no support for sequence numbers using static platform data. It could easily be added to 'struct driver_info' if needed, but it seems better to add features as we find a use for them, and the use of -1 to mean 'no sequence' makes the default value somewhat painful. Signed-off-by: Simon Glass <sjg@chromium.org>
109 lines
2.9 KiB
C
109 lines
2.9 KiB
C
/*
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* Copyright (c) 2013 Google, Inc
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*
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* (C) Copyright 2012
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* Pavel Herrmann <morpheus.ibis@gmail.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef _DM_UCLASS_INTERNAL_H
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#define _DM_UCLASS_INTERNAL_H
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/**
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* uclass_find_device() - Return n-th child of uclass
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* @id: Id number of the uclass
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* @index: Position of the child in uclass's list
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* #devp: Returns pointer to device, or NULL on error
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*
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* The device is not prepared for use - this is an internal function
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*
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* @return the uclass pointer of a child at the given index or
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* return NULL on error.
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*/
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int uclass_find_device(enum uclass_id id, int index, struct udevice **devp);
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/**
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* uclass_bind_device() - Associate device with a uclass
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*
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* Connect the device into uclass's list of devices.
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*
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* @dev: Pointer to the device
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* #return 0 on success, -ve on error
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*/
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int uclass_bind_device(struct udevice *dev);
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/**
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* uclass_unbind_device() - Deassociate device with a uclass
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*
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* Disconnect the device from uclass's list of devices.
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*
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* @dev: Pointer to the device
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* #return 0 on success, -ve on error
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*/
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int uclass_unbind_device(struct udevice *dev);
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/**
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* uclass_post_probe_device() - Deal with a device that has just been probed
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*
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* Perform any post-processing of a probed device that is needed by the
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* uclass.
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*
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* @dev: Pointer to the device
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* #return 0 on success, -ve on error
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*/
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int uclass_post_probe_device(struct udevice *dev);
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/**
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* uclass_pre_remove_device() - Handle a device which is about to be removed
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*
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* Perform any pre-processing of a device that is about to be removed.
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*
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* @dev: Pointer to the device
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* #return 0 on success, -ve on error
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*/
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int uclass_pre_remove_device(struct udevice *dev);
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/**
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* uclass_find() - Find uclass by its id
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*
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* @id: Id to serach for
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* @return pointer to uclass, or NULL if not found
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*/
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struct uclass *uclass_find(enum uclass_id key);
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/**
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* uclass_destroy() - Destroy a uclass
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*
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* Destroy a uclass and all its devices
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*
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* @uc: uclass to destroy
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* @return 0 on success, -ve on error
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*/
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int uclass_destroy(struct uclass *uc);
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/**
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* uclass_find_device_by_seq() - Find uclass device based on ID and sequence
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*
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* This searches for a device with the given seq or req_seq.
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*
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* For seq, if an active device has this sequence it will be returned.
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* If there is no such device then this will return -ENODEV.
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*
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* For req_seq, if a device (whether activated or not) has this req_seq
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* value, that device will be returned. This is a strong indication that
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* the device will receive that sequence when activated.
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*
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* The device is NOT probed, it is merely returned.
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*
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* @id: ID to look up
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* @seq_or_req_seq: Sequence number to find (0=first)
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* @find_req_seq: true to find req_seq, false to find seq
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* @devp: Returns pointer to device (there is only one per for each seq)
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* @return 0 if OK, -ve on error
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*/
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int uclass_find_device_by_seq(enum uclass_id id, int seq_or_req_seq,
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bool find_req_seq, struct udevice **devp);
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#endif
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