Documentation / PCI / endpoint / pci-endpoint-cfs.txt

Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.

	                   CONFIGURING PCI ENDPOINT USING CONFIGFS
	                    Kishon Vijay Abraham I <kishon@ti.com>
	
	The PCI Endpoint Core exposes configfs entry (pci_ep) to configure the
	PCI endpoint function and to bind the endpoint function
	with the endpoint controller. (For introducing other mechanisms to
	configure the PCI Endpoint Function refer to [1]).
	
	*) Mounting configfs
	
	The PCI Endpoint Core layer creates pci_ep directory in the mounted configfs
	directory. configfs can be mounted using the following command.
	
		mount -t configfs none /sys/kernel/config
	
	*) Directory Structure
	
	The pci_ep configfs has two directories at its root: controllers and
	functions. Every EPC device present in the system will have an entry in
	the *controllers* directory and and every EPF driver present in the system
	will have an entry in the *functions* directory.
	
	/sys/kernel/config/pci_ep/
		.. controllers/
		.. functions/
	
	*) Creating EPF Device
	
	Every registered EPF driver will be listed in controllers directory. The
	entries corresponding to EPF driver will be created by the EPF core.
	
	/sys/kernel/config/pci_ep/functions/
		.. <EPF Driver1>/
			... <EPF Device 11>/
			... <EPF Device 21>/
		.. <EPF Driver2>/
			... <EPF Device 12>/
			... <EPF Device 22>/
	
	In order to create a <EPF device> of the type probed by <EPF Driver>, the
	user has to create a directory inside <EPF DriverN>.
	
	Every <EPF device> directory consists of the following entries that can be
	used to configure the standard configuration header of the endpoint function.
	(These entries are created by the framework when any new <EPF Device> is
	created)
	
		.. <EPF Driver1>/
			... <EPF Device 11>/
				... vendorid
				... deviceid
				... revid
				... progif_code
				... subclass_code
				... baseclass_code
				... cache_line_size
				... subsys_vendor_id
				... subsys_id
				... interrupt_pin
	
	*) EPC Device
	
	Every registered EPC device will be listed in controllers directory. The
	entries corresponding to EPC device will be created by the EPC core.
	
	/sys/kernel/config/pci_ep/controllers/
		.. <EPC Device1>/
			... <Symlink EPF Device11>/
			... <Symlink EPF Device12>/
			... start
		.. <EPC Device2>/
			... <Symlink EPF Device21>/
			... <Symlink EPF Device22>/
			... start
	
	The <EPC Device> directory will have a list of symbolic links to
	<EPF Device>. These symbolic links should be created by the user to
	represent the functions present in the endpoint device.
	
	The <EPC Device> directory will also have a *start* field. Once
	"1" is written to this field, the endpoint device will be ready to
	establish the link with the host. This is usually done after
	all the EPF devices are created and linked with the EPC device.
	
	
				 | controllers/
					| <Directory: EPC name>/
						| <Symbolic Link: Function>
						| start
				 | functions/
					| <Directory: EPF driver>/
						| <Directory: EPF device>/
							| vendorid
							| deviceid
							| revid
							| progif_code
							| subclass_code
							| baseclass_code
							| cache_line_size
							| subsys_vendor_id
							| subsys_id
							| interrupt_pin
							| function
	
	[1] -> Documentation/PCI/endpoint/pci-endpoint.txt

• [ endpoint ]
• [ function ]
• pci-endpoint-cfs.txt
• pci-endpoint.txt
• pci-test-function.txt
• pci-test-howto.txt
•  

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