[U-Boot] U-Boot, dm, ubi: struct device is declared twice

[Heiko Schocher <hs@denx.de>]

Hello Simon,

Am 02.05.2014 16:29, schrieb Simon Glass:
> Hi,
>
> On 2 May 2014 01:16, Heiko Schocher<hs@denx.de>  wrote:
>> Hello Marek,
>>
>> Am 02.05.2014 08:06, schrieb Marek Vasut:
>>
>>> On Friday, May 02, 2014 at 07:19:01 AM, Heiko Schocher wrote:
>>>>
>>>> Hello Simon, Marek,
>>>>
>>>> just updating to current mainline code and defining
>>>> CONFIG_SYS_GENERIC_BOARD pops up the following error:
>>>>
>>>>     CC      common/board_r.o
>>>> In file included from include/linux/mtd/flashchip.h:21:0,
>>>>                     from include/linux/mtd/nand.h:31,
>>>>                     from include/nand.h:39,
>>>>                     from common/board_r.c:40:
>>>> include/ubi_uboot.h:202:8: error: redefinition of 'struct device'
>>>>     struct device {
>>>>            ^
>>>> In file included from include/dm.h:10:0,
>>>>                     from common/board_r.c:21:
>>>> include/dm/device.h:56:8: note: originally defined here
>>>>     struct device {
>>>>            ^
>>>> make[1]: *** [common/board_r.o] Fehler 1
>>>> make: *** [common] Fehler 2
>>>> pollux:u-boot hs [20140502] $
>>>>
>>>> for a not yet mainlined imx6 board using UBI/UBIFS on nand. I am
>>>> currently sync current Linux MTD/UBI and UBIFS code to U-Boot, but
>>>> I think this error should pop up for all boards using DM and UBI ...
>>>
>>>
>>> In the ideal case, we should use the same struct device for both UBI and
>>> DM, but
>>
>>
>> Yes, that was also my first thought ...
>>
>>
>>> we cannot do that. Thus, renaming the DM struct device would be the best
>>> option
>>> for now.
>>
>>
>> Ok. I prepare a patch for this.
>
> Linux also has struct device, so I wondered how it avoids this problem
> and took a look.

Yes, the MTD/UBI and UBIFS subsystem is Code from Linux and it uses
the linux "struct device". I wonder, how DM and UBI compile together.

Is this tried somewhere?

(As I see drivers/usb/musb-new uses also "struct device" ...)

> This header file seems like a special thing for U-Boot - I wonder if

Yes, it includes some missing defines, structs for the UBI Subsystem,
so we could use Linux Code ... but we have also "include/linux/compat.h
for this ... Maybe it is worth to delete this include/ubi_uboot.h
and move the missing symbols to include/linux/compat.h?

> it would be better to use #define at the top of the C file for the

Yes, I thought about this too ...

The UBI subsystem in U-Boot has defined "UBI_LINUX" instead of
"__UBOOT__" ... which surprised me too.

  maybe I prepare such a change (delete "UBI_LINUX" and use
"__UBOOT__") for the new sync with current Linux MTD/UBI and UBIFS
layer?

> compatibility stuff (#define device ubi_device) rather than modify dm?

Hmm... I can try this ... but I am not really happy to have
such a define.

> It does seem very strange to me, particularly as from what I can tell,
> struct device is just a cut down version of the Linux struct.

Wouldn;t it be better to move this to include/linux/device.h then?

Looking in U-Boot:include/dm/device.h "struct device":

struct device {
*        struct driver *driver;
*        const char *name;
*        void *platdata;
*        int of_offset;
         struct device *parent;
*        void *priv;
*        struct uclass *uclass;
*        void *uclass_priv;
*        struct list_head uclass_node;
*        struct list_head child_head;
*        struct list_head sibling_node;
*        uint32_t flags;
};

All "*" are different to current mainline linux or not in it ...
so I prefer first to rename the DM "struct device" into for example
"struct u_device" ... Maybe we can sync them once with the linux
"struct device"

bye,
Heiko
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