Re: Device tree question

[Gary Thomas <gary@mlbassoc.com>]

On 2015-07-13 09:14, Robin Findley wrote:
> On 07/13/2015 10:37 AM, Gary Thomas wrote:
>> A bit off topic, but perhaps someone here knows the answer :-)
>>
>> If my device tree has a device/element that is enabled, why would
>> that device be disabled when I boot?  I have this on my (LS1021) board:
>>           quadspi@1550000 {
>>               compatible = "fsl,ls1-qspi";
>>               #address-cells = <0x00000001>;
>>               #size-cells = <0x00000000>;
>>               reg = <0x00000000 0x01550000 0x00000000 0x00010000 0x00000000
> 0x40000000 0x00000000 0x04000000>;
>>               reg-names = "QuadSPI", "QuadSPI-memory";
>>               interrupts = <0x00000000 0x00000083 0x00000004>;
>>               clock-names = "qspi_en", "qspi";
>>               clocks = <0x00000003 0x00000001 0x00000003 0x00000001>;
>>               big-endian;
>>               amba-base = <0x40000000>;
>>               num-cs = <0x00000002>;
>>               status = "okay";
>>               s70fl01gs@0 {
>>                   #address-cells = <0x00000001>;
>>                   #size-cells = <0x00000001>;
>>                   compatible = "spansion,s70fl01gs";
>>                   spi-max-frequency = <0x02faf080>;
>>                   reg = <0x00000000>;
>>                   partition@0 {
>>                       label = "s70fl01gs-0";
>>                       reg = <0x00000000 0x04000000>;
>>                   };
>>               };
>>           };
>>
>> However when I boot the system, this device is disabled.
>>     # cat /proc/device-tree/soc/quadspi@1550000/status
>>     disabled
>> I know this must happen very early on as the device driver
>> for this device is never even probed.
>>
>> Any ideas where/why this becomes disabled and how I keep that
>> from happening?
>
>
> Have you checked the rest of your device tree files (top-level and includes)
> to see if quadspi is referenced anywhere else?  A later assignment can
> override an earlier one.

Yes and no, there are no overrides.

Besides, the listing above is from dumping the compiled device
tree using fdtdump, so includes and multiple sections addressing
the same element have been collapsed.

Thanks


-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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