Tim Harvey a5fcec480f PCI: imx6: Add DT property for link gen, default to Gen1 ... Freescale has stated [1] that the LVDS clock source of the IMX6 does not pass the PCI Gen2 clock jitter test, therefore unless an external Gen2 compliant external clock source is present and supplied back to the IMX6 PCIe core via LVDS CLK1/CLK2 you can not claim Gen2 compliance. Add a DT property to specify Gen1 vs Gen2 and check this before allowing a Gen2 link. We default to Gen1 if the property is not present because at this time there are no IMX6 boards in mainline that 'input' a clock on LVDS CLK1/CLK2. In order to be Gen2 compliant on IMX6 you need to: - Have a Gen2 compliant external clock generator and route that clock back to either LVDS CLK1 or LVDS CLK2 as an input (see IMX6SX-SabreSD reference design). - Specify this clock in the PCIe node in the DT (i.e., IMX6QDL_CLK_LVDS1_IN or IMX6QDL_CLK_LVDS2_IN instead of IMX6QDL_CLK_LVDS1_GATE which configures it as a CLK output). [1] https://community.freescale.com/message/453209 Signed-off-by: Tim Harvey <tharvey@gateworks.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> CC: Fabio Estevam <fabio.estevam@freescale.com> CC: Zhu Richard <Richard.Zhu@freescale.com> CC: Akshay Bhat <akshay.bhat@timesys.com> CC: Rob Herring <robh+dt@kernel.org> CC: Shawn Guo <shawnguo@kernel.org>		2016-04-19 19:52:44 -05:00
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bindings	PCI: imx6: Add DT property for link gen, default to Gen1	2016-04-19 19:52:44 -05:00
00-INDEX
booting-without-of.txt	sh: add device tree support and generic board using device tree	2016-03-17 19:46:11 +00:00
changesets.txt
dynamic-resolution-notes.txt
of_unittest.txt
overlay-notes.txt
todo.txt
usage-model.txt