Add Documentation to help users use PCI endpoint to configure PCI endpoint function and to bind the endpoint function with endpoint controller. Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> Acked-By: Joao Pinto <jpinto@xxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- Documentation/PCI/00-INDEX | 2 + Documentation/PCI/endpoint/pci-endpoint-cfs.txt | 105 ++++++++++++++++++++++++ 2 files changed, 107 insertions(+) create mode 100644 Documentation/PCI/endpoint/pci-endpoint-cfs.txt diff --git a/Documentation/PCI/00-INDEX b/Documentation/PCI/00-INDEX index ba950b296bd8..bf8223a1bf08 100644 --- a/Documentation/PCI/00-INDEX +++ b/Documentation/PCI/00-INDEX @@ -14,3 +14,5 @@ pcieaer-howto.txt - the PCI Express Advanced Error Reporting Driver Guide HOWTO endpoint/pci-endpoint.txt - guide to add endpoint controller driver and endpoint function driver. +endpoint/pci-endpoint-cfs.txt + - guide to use configfs to configure the PCI endpoint function. diff --git a/Documentation/PCI/endpoint/pci-endpoint-cfs.txt b/Documentation/PCI/endpoint/pci-endpoint-cfs.txt new file mode 100644 index 000000000000..d740f29960a4 --- /dev/null +++ b/Documentation/PCI/endpoint/pci-endpoint-cfs.txt @@ -0,0 +1,105 @@ + CONFIGURING PCI ENDPOINT USING CONFIGFS + Kishon Vijay Abraham I <kishon@xxxxxx> + +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 -- 2.11.0
