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[PATCH 15/37] Documentation: PCI: Guide to use PCI Endpoint Core Layer

From Kishon Vijay Abraham I <kishon@ti.com>
Newsgroups linux.kernel
Subject [PATCH 15/37] Documentation: PCI: Guide to use PCI Endpoint Core Layer
Date 2017-01-12 11:40 +0100
Message-ID <sYKXw-2QD-29@gated-at.bofh.it> (permalink)
References <sYKNQ-2Nu-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Add Documentation to help users use endpoint library to enable endpoint
mode in the PCI controller and add new PCI endpoint functions.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 Documentation/PCI/00-INDEX                  |    2 +
 Documentation/PCI/endpoint/pci-endpoint.txt |  190 +++++++++++++++++++++++++++
 2 files changed, 192 insertions(+)
 create mode 100644 Documentation/PCI/endpoint/pci-endpoint.txt

diff --git a/Documentation/PCI/00-INDEX b/Documentation/PCI/00-INDEX
index 147231f..ba950b2 100644
--- a/Documentation/PCI/00-INDEX
+++ b/Documentation/PCI/00-INDEX
@@ -12,3 +12,5 @@ pci.txt
 	- info on the PCI subsystem for device driver authors
 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.
diff --git a/Documentation/PCI/endpoint/pci-endpoint.txt b/Documentation/PCI/endpoint/pci-endpoint.txt
new file mode 100644
index 0000000..68a7839
--- /dev/null
+++ b/Documentation/PCI/endpoint/pci-endpoint.txt
@@ -0,0 +1,190 @@
+			    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
+vendorid, deviceid), support other services like hot-plug, power management,
+advanced error reporting and virtual channels.
+
+However PCI controller IPs integrated in certain SoC 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 of 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 or MSI 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()
+
+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 or MSI Interrupt.
+
+*) 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.
+
+2.1.3 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 upto 8 functions according to the specification.
+
+*) pci_epc_remove_epf()
+
+   Remove the pci endpoint function from pci endpoint controller.
+
+2.2 PCI Endpoint Function(EPF) Library
+
+The EPF library provides APIs to be used by the function driver and the EPC
+library in order 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.
-- 
1.7.9.5

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[PATCH 00/37] PCI: Support for configurable PCI endpoint Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:30 +0100
  [PATCH 23/37] PCI: dwc: Add *ops* to start and stop pcie link Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:30 +0100
  [PATCH 26/37] PCI: dwc: dra7xx: Facilitate wrapper and msi interrupts to be enabled independently Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 32/37] Documentation: misc-devices: Add Documentation for pci-endpoint-test driver Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in dw_pcie_setup_rc Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in  dw_pcie_setup_rc Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:30 +0100
      Re: [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in  dw_pcie_setup_rc Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 06:30 +0100
        Re: [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in  dw_pcie_setup_rc Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-16 11:30 +0100
  [PATCH 29/37] PCI: dwc: dra7xx: Workaround for errata id i870 Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 07/37] PCI: dwc: designware: Get device pointer at the start of dw_pcie_host_init Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 07/37] PCI: dwc: designware: Get device pointer at the  start of dw_pcie_host_init Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:30 +0100
  [PATCH 20/37] Documentation: PCI: Add binding documentation for pci-test endpoint function Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 33/37] tools: PCI: Add a userspace tool to test PCI endpoint Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 35/37] MAINTAINERS: add PCI EP maintainer Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 37/37] ARM: dts: DRA7: Add pcie1 dt node for EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 30/37] dt-bindings: PCI: dra7xx: Add dt bindings to enable legacy mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 17/37] Documentation: PCI: Guide to use pci endpoint configfs Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 34/37] tools: PCI: Add sample test script to invoke pcitest Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 22/37] PCI: dwc: Modify dbi accessors to access data of 4/2/1 bytes Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 15/37] Documentation: PCI: Guide to use PCI Endpoint Core Layer Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 36/37] ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 36/37] ARM: DRA7: clockdomain: Change the CLKTRCTRL of  CM_PCIE_CLKSTCTRL to SW_WKUP Tony Lindgren <tony@atomide.com> - 2017-01-13 18:20 +0100
      Re: [PATCH 36/37] ARM: DRA7: clockdomain: Change the CLKTRCTRL of  CM_PCIE_CLKSTCTRL to SW_WKUP Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 07:10 +0100
  [PATCH 05/37] PCI: dwc: Add platform_set_drvdata Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 05/37] PCI: dwc: Add platform_set_drvdata Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:20 +0100
  [PATCH 19/37] PCI: endpoint: functions: Add an EP function to test PCI Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 18/37] Documentation: PCI: Add specification for the *pci test* function device Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 25/37] dt-bindings: PCI: Add dt bindings for pci designware EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 27/37] PCI: dwc: dra7xx: Add EP mode support Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 28/37] dt-bindings: PCI: dra7xx: Add dt bindings for pci dra7xx EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 31/37] misc: Add host side pci driver for pci test function device Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 24/37] PCI: dwc: designware: Add EP mode support Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 21/37] PCI: dwc: Modify dbi accessors to take dbi_base as argument Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 10/37] PCI: dwc: designware: Fix style errors in pcie-designware.c Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:50 +0100
    Re: [PATCH 10/37] PCI: dwc: designware: Fix style errors in  pcie-designware.c Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 17:50 +0100
  [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and core  files Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:50 +0100
    Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:00 +0100
      Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 06:30 +0100
        Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-16 11:30 +0100
          Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 12:40 +0100
            Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-16 14:40 +0100
  [PATCH 03/37] PCI: dwc: dra7xx: Populate cpu_addr_fixup ops Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:50 +0100

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