72b7c68ccd
Enable the PCIE EP RC for iMX
- hw setup:
* two imx boards, one is used as pcie rc, the other is used
as pcie ep.
RC TX N/P <--> EP RX N/P
RX N/P <--> EP TX N/P
- sw setup:
* when build rc image, make sure that
CONFIG_PCI_IMX6=y
CONFIG_RC_MODE_IN_EP_RC_SYS=y
* when build ep image
CONFIG_PCI_IMX6=y
CONFIG_EP_MODE_IN_EP_RC_SYS=y
- features:
* set-up link between rc and ep by their stand-alone
ref clk running internally.
* in ep's system, ep can access the reserved ddr memory
(default address:0x4000_0000 on imx6q sd board, and
0xb000_0000 on imx6sx sdb and imx7d arm2 boards) of
pcie rc's system, by the interconnection between pcie
ep and pcie rc.
* provide one example, howto configure the bar# of ep and so on,
when pcie ep emaluates one memory ram ep device
* setup one new outbound memory region at rc side, let imx pcie rc
can access the memory of imx pcie ep in imx pcie rc ep validation
system.
- NOTE:
* boot up ep platform firstly, then boot up rc platform.
* For imx6q/6dl/6sx/7d sabresd boards, make sure that mem=768M is
contained in the kernel command line,
since the start address of the upper 256mb of the 1g ddr mem is
reserved to do the pcie ep rc access operations in default.
- RC access memory of EP:
- EP:
write the <ddr_region_address> to the bar0 of ep.
echo <ddr_region_address> > /sys/devices/.../pcie/ep_bar0_addr
- RC:
access the <pcie_mem_base_addr>, and this address
would be mapped to the <ddr_region_address> of ep.
- Note:
ddr_region_address pcie_mem_base_addr bar0_addr
imx6qdl 0x4000_0000 0x0100_0000 0x01ff_c010
imx6sx 0xb000_0000 0x0800_0000 0x08ff_c010
imx7d 0xb000_0000 0x4000_0000 0x3380_0010
imx8mq 0xb820_0000 0x2000_0000 0x33c0_0010
imx8mm 0xb820_0000 0x1800_0000 0x3380_0010
imx8qm 0x9020_0000 0x6000_0000 0x5f00_0010
imx8qxp 0x9020_0000 0x7000_0000 0x5f01_0010
- The example of the RC access memory of EP
step1:
EP side:
echo 0x90200000 > /sys/devices/platform/bus@5f000000/5f000000.pcie
/ep_bar0_addr
root@imx8_all:~# ./memtool 90200000 4
Reading 0x4 count starting at address 0x90200000
0x90200000: 00000000 00000000 00000000 00000000
RC side:
./memtool 60000000=55aa55aa
Writing 32-bit value 0x55AA55AA to address 0x60000000
EP side:
root@imx8_all:~# ./memtool 90200000 4
Reading 0x4 count starting at address 0x90200000
0x90200000: 55AA55AA 00000000 00000000 00000000
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.