Documentation: PCI: Add specification for the *PCI test* function device

	- 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.

endpoint/pci-test-function.txt

	- specification of *PCI test* function device.

				PCI TEST

		    Kishon Vijay Abraham I <kishon@ti.com>

Traditionally PCI RC has always been validated by using standard

PCI cards like ethernet PCI cards or USB PCI cards or SATA PCI cards.

However with the addition of EP-core in linux kernel, it is possible

to configure a PCI controller that can operate in EP mode to work as

a test device.

The PCI endpoint test device is a virtual device (defined in software)

used to test the endpoint functionality and serve as a sample driver

for other PCI endpoint devices (to use the EP framework).

The PCI endpoint test device has the following registers:

	1) PCI_ENDPOINT_TEST_MAGIC

	2) PCI_ENDPOINT_TEST_COMMAND

	3) PCI_ENDPOINT_TEST_STATUS

	4) PCI_ENDPOINT_TEST_SRC_ADDR

	5) PCI_ENDPOINT_TEST_DST_ADDR

	6) PCI_ENDPOINT_TEST_SIZE

	7) PCI_ENDPOINT_TEST_CHECKSUM

*) PCI_ENDPOINT_TEST_MAGIC

This register will be used to test BAR0. A known pattern will be written

and read back from MAGIC register to verify BAR0.

*) PCI_ENDPOINT_TEST_COMMAND:

This register will be used by the host driver to indicate the function

that the endpoint device must perform.

Bitfield Description:

  Bit 0		: raise legacy IRQ

  Bit 1		: raise MSI IRQ

  Bit 2 - 7	: MSI interrupt number

  Bit 8		: read command (read data from RC buffer)

  Bit 9		: write command (write data to RC buffer)

  Bit 10	: copy command (copy data from one RC buffer to another

		  RC buffer)

*) PCI_ENDPOINT_TEST_STATUS

This register reflects the status of the PCI endpoint device.

Bitfield Description:

  Bit 0		: read success

  Bit 1		: read fail

  Bit 2		: write success

  Bit 3		: write fail

  Bit 4		: copy success

  Bit 5		: copy fail

  Bit 6		: IRQ raised

  Bit 7		: source address is invalid

  Bit 8		: destination address is invalid

*) PCI_ENDPOINT_TEST_SRC_ADDR

This register contains the source address (RC buffer address) for the

COPY/READ command.

*) PCI_ENDPOINT_TEST_DST_ADDR

This register contains the destination address (RC buffer address) for

the COPY/WRITE command.