[PATCH v8 4/9] davinci: McASP configuration for Omapl138-Hawkboard

[Victor Rodriguez]

On Thu, Nov 18, 2010 at 6:17 PM, Victor Rodriguez <vm.rod25 at gmail.com> wrote:
> On Thu, Nov 18, 2010 at 5:57 PM, Kevin Hilman
> <khilman at deeprootsystems.com> wrote:
>> "Nori, Sekhar" <nsekhar at ti.com> writes:
>>
>>> Hi Michael,
>>>
>>> On Wed, Nov 17, 2010 at 02:12:53, Michael Williamson wrote:
>>>>
>>>> Help me out.  Why do we need generic pin lists?
>>>>
>>>
>>> They might help in cases where all boards will use the same set of
>>> pins. For example, every one who uses I2C will most likely both the
>>> clock and data pins from the IP. For more complex peripherals with
>>> different pins options they serve a documentation purpose at best.
>>>
>>>> It seems to me that the "generic pin list" for da850.c isn't practical for most
>>>> (if not all) of the peripherals.  They should be done using __initdata in
>>>> each board file.
>>>
>>> Yes, agreed.
>>>
>>>>
>>>> Just a cursory glance at what's in da850.c highlights several items being set
>>>> up for the EVM and not generically.  For example:
>>>>
>>>> - da850_uart1_pins and da850_uart2_pins: I believe both have RTS/CTS pins which
>>>>   for a generic definition should be included as for UART0, but would then
>>>>   be unused as the EVM doesn't use these pins in this function.
>>>
>>> Yes, the generic pin list should have RTS and CTS pins defined for UART1
>>> and UART2. This needs fixing.
>>>
>>>>
>>>> - da850_mcasp_pins: if generic, must include all 16 AXR pins.  I think you'd
>>>>   be hard pressed to find a board configuration that would use all 16 AXR pins
>>>>   for the McASP.  I'm fairly sure the EVM uses the pins called out, and uses
>>>>   other pins for other functions.  So it's likely this structure wouldn't get used.
>>>
>>> Yes, the generic pin list should either be completed or removed
>>> altogether and the existing pin list da850_mcasp_pins should be
>>> copied into the board file and called da850_evm_mcasp_pins.
>>>
>>>>
>>>> - da850_mmcsd0_pins : includes 2 GPIO pins (specific to the EVM, though possible for
>>>>   other boards) for the card detect and write protect signals.  These pins are
>>>>   completely arbitrary for that particular board design. I also believe that
>>>>   the complete mmcsd0 port has 4 more data lines as part of it's peripheral, although
>>>>   the driver doesn't support using them.
>>>
>>> This is incorrect again. The generic pin list should be completed
>>> (or removed) and the existing list should be copied into the EVM board
>>> file as da850_evm_mmcsd0_pins.
>>>
>>>>
>>>> - da850_emif25_pins interface doesn't include the generic pins for some of
>>>>   the SDRAM functions.
>>>
>>> Yes, this should be completed (or removed). This list is unused anyway.
>>>
>>>>
>>>> - da850_cpgmac_pins defines both RMII and MII pins.  I don't think any board
>>>>   would want to configure both sets at the same time.  Seems like this should
>>>>   never get used...
>>>
>>> Agreed.
>>>
>>>>
>>>> It's also incomplete.  What about the uPP pin list?  Or the VPIF?  Etc.
>>>
>>> These should be added as the drivers for these devices are
>>> supported.
>>>
>>>>
>>>> I think a board file author should be familiar enough with the SoC to understand
>>>> what peripheral pins he should be configuring for his/her particular hardware setup
>>>> and explicitly specify them in the board file.
>>>
>>> Agree.
>>>
>>>>
>>>> If you remove the common pin-mux lists and move them to a board file, then once you
>>>> configure your specific platform, is there any more memory used than with
>>>> the common scheme?  Of course, there would be replication of pin-mux code in the board
>>>
>>> There is no memory wastage. All the pin lists are init data.
>>>
>>> I too prefer all generic pin lists which are most likely not
>>> going to be used at all to be removed. Unused stuff like this
>>> will only make code difficult to read.
>>
>> FWIW, I agree.
>>
>> Now, who wants to tackle it?
>>
>> Kevin
>>
>
> I could but I will need a little help and from all of you. :)
>
> Regards
>
> Victor Rodriguez
>

Hey I have sent the first patch in order to fix UARTs on da850. please
check if this is right

Regards

Victor Rodriguez

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