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diff --git a/Documentation/PCI/endpoint/pci-endpoint.txt b/Documentation/PCI/endpoint/pci-endpoint.txt deleted file mode 100644 index e86a96b66a6a..000000000000 --- a/Documentation/PCI/endpoint/pci-endpoint.txt +++ /dev/null @@ -1,215 +0,0 @@ - PCI ENDPOINT FRAMEWORK - Kishon Vijay Abraham I <kishon@ti.com> - -This document is a guide to use the PCI Endpoint Framework in order to create -endpoint controller driver, endpoint function driver, and using configfs -interface to bind the function driver to the controller driver. - -1. Introduction - -Linux has a comprehensive PCI subsystem to support PCI controllers that -operates in Root Complex mode. The subsystem has capability to scan PCI bus, -assign memory resources and IRQ resources, load PCI driver (based on -vendor ID, device ID), support other services like hot-plug, power management, -advanced error reporting and virtual channels. - -However the PCI controller IP integrated in some SoCs is capable of operating -either in Root Complex mode or Endpoint mode. PCI Endpoint Framework will -add endpoint mode support in Linux. This will help to run Linux in an -EP system which can have a wide variety of use cases from testing or -validation, co-processor accelerator, etc. - -2. PCI Endpoint Core - -The PCI Endpoint Core layer comprises 3 components: the Endpoint Controller -library, the Endpoint Function library, and the configfs layer to bind the -endpoint function with the endpoint controller. - -2.1 PCI Endpoint Controller(EPC) Library - -The EPC library provides APIs to be used by the controller that can operate -in endpoint mode. It also provides APIs to be used by function driver/library -in order to implement a particular endpoint function. - -2.1.1 APIs for the PCI controller Driver - -This section lists the APIs that the PCI Endpoint core provides to be used -by the PCI controller driver. - -*) devm_pci_epc_create()/pci_epc_create() - - The PCI controller driver should implement the following ops: - * write_header: ops to populate configuration space header - * set_bar: ops to configure the BAR - * clear_bar: ops to reset the BAR - * alloc_addr_space: ops to allocate in PCI controller address space - * free_addr_space: ops to free the allocated address space - * raise_irq: ops to raise a legacy, MSI or MSI-X interrupt - * start: ops to start the PCI link - * stop: ops to stop the PCI link - - The PCI controller driver can then create a new EPC device by invoking - devm_pci_epc_create()/pci_epc_create(). - -*) devm_pci_epc_destroy()/pci_epc_destroy() - - The PCI controller driver can destroy the EPC device created by either - devm_pci_epc_create() or pci_epc_create() using devm_pci_epc_destroy() or - pci_epc_destroy(). - -*) pci_epc_linkup() - - In order to notify all the function devices that the EPC device to which - they are linked has established a link with the host, the PCI controller - driver should invoke pci_epc_linkup(). - -*) pci_epc_mem_init() - - Initialize the pci_epc_mem structure used for allocating EPC addr space. - -*) pci_epc_mem_exit() - - Cleanup the pci_epc_mem structure allocated during pci_epc_mem_init(). - -2.1.2 APIs for the PCI Endpoint Function Driver - -This section lists the APIs that the PCI Endpoint core provides to be used -by the PCI endpoint function driver. - -*) pci_epc_write_header() - - The PCI endpoint function driver should use pci_epc_write_header() to - write the standard configuration header to the endpoint controller. - -*) pci_epc_set_bar() - - The PCI endpoint function driver should use pci_epc_set_bar() to configure - the Base Address Register in order for the host to assign PCI addr space. - Register space of the function driver is usually configured - using this API. - -*) pci_epc_clear_bar() - - The PCI endpoint function driver should use pci_epc_clear_bar() to reset - the BAR. - -*) pci_epc_raise_irq() - - The PCI endpoint function driver should use pci_epc_raise_irq() to raise - Legacy Interrupt, MSI or MSI-X Interrupt. - -*) pci_epc_mem_alloc_addr() - - The PCI endpoint function driver should use pci_epc_mem_alloc_addr(), to - allocate memory address from EPC addr space which is required to access - RC's buffer - -*) pci_epc_mem_free_addr() - - The PCI endpoint function driver should use pci_epc_mem_free_addr() to - free the memory space allocated using pci_epc_mem_alloc_addr(). - -2.1.3 Other APIs - -There are other APIs provided by the EPC library. These are used for binding -the EPF device with EPC device. pci-ep-cfs.c can be used as reference for -using these APIs. - -*) pci_epc_get() - - Get a reference to the PCI endpoint controller based on the device name of - the controller. - -*) pci_epc_put() - - Release the reference to the PCI endpoint controller obtained using - pci_epc_get() - -*) pci_epc_add_epf() - - Add a PCI endpoint function to a PCI endpoint controller. A PCIe device - can have up to 8 functions according to the specification. - -*) pci_epc_remove_epf() - - Remove the PCI endpoint function from PCI endpoint controller. - -*) pci_epc_start() - - The PCI endpoint function driver should invoke pci_epc_start() once it - has configured the endpoint function and wants to start the PCI link. - -*) pci_epc_stop() - - The PCI endpoint function driver should invoke pci_epc_stop() to stop - the PCI LINK. - -2.2 PCI Endpoint Function(EPF) Library - -The EPF library provides APIs to be used by the function driver and the EPC -library to provide endpoint mode functionality. - -2.2.1 APIs for the PCI Endpoint Function Driver - -This section lists the APIs that the PCI Endpoint core provides to be used -by the PCI endpoint function driver. - -*) pci_epf_register_driver() - - The PCI Endpoint Function driver should implement the following ops: - * bind: ops to perform when a EPC device has been bound to EPF device - * unbind: ops to perform when a binding has been lost between a EPC - device and EPF device - * linkup: ops to perform when the EPC device has established a - connection with a host system - - The PCI Function driver can then register the PCI EPF driver by using - pci_epf_register_driver(). - -*) pci_epf_unregister_driver() - - The PCI Function driver can unregister the PCI EPF driver by using - pci_epf_unregister_driver(). - -*) pci_epf_alloc_space() - - The PCI Function driver can allocate space for a particular BAR using - pci_epf_alloc_space(). - -*) pci_epf_free_space() - - The PCI Function driver can free the allocated space - (using pci_epf_alloc_space) by invoking pci_epf_free_space(). - -2.2.2 APIs for the PCI Endpoint Controller Library -This section lists the APIs that the PCI Endpoint core provides to be used -by the PCI endpoint controller library. - -*) pci_epf_linkup() - - The PCI endpoint controller library invokes pci_epf_linkup() when the - EPC device has established the connection to the host. - -2.2.2 Other APIs -There are other APIs provided by the EPF library. These are used to notify -the function driver when the EPF device is bound to the EPC device. -pci-ep-cfs.c can be used as reference for using these APIs. - -*) pci_epf_create() - - Create a new PCI EPF device by passing the name of the PCI EPF device. - This name will be used to bind the the EPF device to a EPF driver. - -*) pci_epf_destroy() - - Destroy the created PCI EPF device. - -*) pci_epf_bind() - - pci_epf_bind() should be invoked when the EPF device has been bound to - a EPC device. - -*) pci_epf_unbind() - - pci_epf_unbind() should be invoked when the binding between EPC device - and EPF device is lost. |