device tree binding documentation outdated

Fabio Estevam festevam at gmail.com
Wed Oct 2 22:21:56 EDT 2013


On Wed, Oct 2, 2013 at 8:49 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:

> This apparantly is done by configuring the PLL on the IMX6 to 25MHz and
> getting it to output it on this pin, and that is done in the freescale
> BSP by this pin control setting:
>
>         MX6DL_PAD_GPIO_16__ENET_ANATOP_ETHERNET_REF_OUT
>
> Now, if you look up that in the 4.1.0 BSP:
>
> #define MX6DL_PAD_GPIO_16__ENET_ANATOP_ETHERNET_REF_OUT                        \
>                 IOMUX_PAD(0x05E4, 0x0214, 0x12, 0x080C, 0, NO_PAD_CTRL)
>
> and that says to write 0x12 to 0x20e0000 + 0x214 - the
> IOMUXC_SW_MUX_CTL_PAD_GPIO16 register.  This name clearly implies that
> the IMX6 is _outputting_ the reference clock.  The register values here
> selects MUX_MODE 2 (ENET_REF_CLK) _with_ SION set.  There is no
> configuration in this BSP for GPIO 16 in mux mode 2 without SION set.

SION bit is set for this pad in mainline as well:

MX6QDL_PAD_GPIO_16__ENET_REF_CLK      0x4001b0a8

(bit 30 is set, which indicates SION).



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