[U-Boot] [PATCH 1/2] tegra: clean up board include hell

[Simon Glass]

Hi,

On Thu, Sep 27, 2012 at 3:32 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 09/27/2012 03:52 PM, Lucas Stach wrote:
>> The prototypes used in board files were all scattered out, which lead to
>> code duplication between SPL and normal U-Boot and some prototypes not actually
>> being used. Consolidate this in a common board header.
>
>> This will allow to push down the calling of the pinmux functions into the
>> respective drivers and this way cut down on complexity from the common board
>> code.
>
> I don't think that (calling pinmux from drivers) would be a good idea.
> The entire pinmux should be set up globally when the system boots in
> order to avoid conflicts part-way through a change, and to avoid
> duplicating pinmux calls into every single driver. Unless a particular
> driver actively needs to switch between different pinmux configurations
> at run-time (e.g. an I2C bus mux that uses pinmux to do the muxing).

Well I'm not so keen on this approach. Ultimately we want to be able
to start a driver (and set up its pinmux) only if it is needed during
boot. The idea behind funcmux is that it is a single line call from a
driver or board to select the required setting, so the overhead is
small - and we know that for most peripherals there are only a small
number of options.

I can't predict where we might end up with fdt-based pinmux, but it
seems to me that global pinmux should be a board/implementer option,
not something required by the use of Tegra.

Just my 2c worth.

>
> That said, this change to simplify all the #includes is probably
> reasonable. One comment below.
>
>> diff --git a/arch/arm/include/asm/arch-tegra/board.h b/arch/arm/include/asm/arch-tegra/board.h
>
>> -/* Setup UARTs for the board according to the selected config */
>> +/* Set up pinmux to make UART usable */
>> +void gpio_config_uart(void);      /* CONFIG_SPI_UART_SWITCH */
>> +void gpio_early_init_uart(void);  /*!CONFIG_SPI_UART_SWITCH */
>> +
>> +/* Set up early UART output */
>>  void board_init_uart_f(void);
>>
>> +/* Set up any early GPIOs the board might need for proper operation */
>> +void gpio_early_init(void);  /* overrideable GPIO config        */
>
> I think we should just rip out all the CONFIG_SPI_UART_SWITCH stuff.
> It's only there to support one board with a completely broken HW design.
> Still, that could happen in a separate patch after this though.

Yes I agree the seaboard is broken, but this is an upstream board and
is in fact the only one I have to test with. Could we perhaps delay
ripping this out for a little while longer?

Regards,
Simon

> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot