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Diffstat (limited to '')
-rw-r--r-- | user/bsps/arm/imx.rst | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/user/bsps/arm/imx.rst b/user/bsps/arm/imx.rst index ee98f0b..e2fd7f2 100644 --- a/user/bsps/arm/imx.rst +++ b/user/bsps/arm/imx.rst @@ -174,6 +174,23 @@ config like that: SYSINIT_DRIVER_REFERENCE(ksz8091rnb, miibus); #include <machine/rtems-bsd-config.h> +On chips with two Ethernet controllers, the MDIO lines are shared between the +two controllers for a number of chips variants. This is currently supported with +some restrictions on the initialization order. For this configuration to work, +you have to make sure that the pins are assigned to the Ethernet controller that +is initialized first. The initialization order in `libbsd` depends on the order +of the Ethernet controllers in the device tree. So if (for example) `fec2` is +defined in the device tree sources before `fec1`, make sure that the MDIO lines +are routed to `fec2` and that the Ethernet PHYs are a sub-node of `fec2` in the +device tree. + +Note that the clock for the second Ethernet controller is not necessarily +enabled in the `CCM`. On the i.MX6UL/ULL, the clock will be enabled by the +startup code if the node that is compatible with `fsl,imx6ul-anatop` can be +found in the device tree. If you have trouble with the second Ethernet +controller make sure that the `ENET2_125M_EN` bit in the `CCM_ANALOG_PLL_ENET` +register is set as expected. + MMC/SDCard Driver ----------------- |