topic Re: mini-pcie clock in i.MX Processors

mini-pcie clock

xiaoqiangyang — Thu, 27 Mar 2014 03:02:24 GMT

Hi everone,

My platform is IMX6Q-SDP and linux BSP version is L3.0.35_4.1.0_130816. Now I am testing Mini-PCIe wifi module(iwl4965) founction.

Support for iwl4965 is added in kernel driver.

A problem is that if I configure kernel like this:

Freescale MXC Implementations --->

PCI Express support

PCI Express EP mode in the IMX6 RC/EP interconnection system

PCI Express RC mode in the IMX6 RC/EP interconnection system

I can detect clock signal(100MHz) on pin11 and 13(REFCLK- and REFCLK+) during boot up. But they only lasts for about one secend

and then disappear.And PCIe link up failed:

If I configure like this:

Freescale MXC Implementations --->

PCI Express support

PCI Express EP mode in the IMX6 RC/EP interconnection system

PCI Express RC mode in the IMX6 RC/EP interconnection system

I can't get anly clock signal on those pins.

All the above can't make my pcie work and give the same error:

iMX6 PCIe PCIe RC mode imx_pcie_pltfm_probe entering.

PCIE: imx_pcie_pltfm_probe start link up.

link up failed, DB_R0:0x00571600, DB_R1:0x08200000!

IMX PCIe port: link down!

Who can help me?

Re: mini-pcie clock

igorpadykov — Mon, 31 Mar 2014 08:15:51 GMT

Hi, Xiaoqiang

clock signal(100MHz) on pins (REFCLK- and REFCLK+) is optional

signal, not all PCIe cards are using it. Freescale i.MX6 BSPs use

125MHz as this signal. You can add external 100MHz clock or try to find

card which does not require this signal. Some cards are mentioned

in Release Notes in Doc bundle, link below. Also please check

i.MX_6Dual6Quad_Linux_Reference_Manual.pdf

document sect.35.2.2 "Kernel configurations".

"L3.0.35_4.1.0_LINUX_DOCS "

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=i.MX6Q&nodeId=018rH3ZrDRB24A&fpsp=1&tab=Documentation_Tab

Re: mini-pcie clock

xiaoqiangyang — Fri, 04 Apr 2014 01:51:00 GMT

Hi chipexpert,

My kernel is built acording to the manual, but it is of no help.Now I think something is wrong with the hardware.Because the pcie have been ok before and suddenly

broken down.So I will check my hardware. Thank you very much!

Re: mini-pcie clock

jianminli — Wed, 29 Nov 2017 00:15:25 GMT

have some one drive 4965 wifi card successfully?

i configed the kernel as others do ,but has no effect.

does it need clk ?

is the power votage 3.3V? i use asm1117-3.3V to supply it