[U-Boot] [PATCH 3/3] x86: coreboot: Wrap cros_ec initialization

[Simon Glass]

Hi Bin,

On 3 January 2015 at 20:12, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Sun, Jan 4, 2015 at 11:01 AM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Bin,
>>
>> On 3 January 2015 at 19:58, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> Hi Simon,
>>>
>>> On Sun, Jan 4, 2015 at 10:33 AM, Simon Glass <sjg at chromium.org> wrote:
>>>> Hi Bin,
>>>>
>>>> On 3 January 2015 at 07:40, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>> cros_ec_board_init() should be called only when CONFIG_CROS_EC is
>>>>> enabled. Also undef CONFIG_CROS_EC in the coreboot configuration.
>>>>>
>>>>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>>>>>
>>>>> ---
>>>>>
>>>>>  board/coreboot/coreboot/coreboot.c | 2 ++
>>>>>  include/configs/coreboot.h         | 4 +++-
>>>>>  2 files changed, 5 insertions(+), 1 deletion(-)
>>>>
>>>> Can we just remove the node in the device tree? The current 'coreboot'
>>>> config is designed to run on link (Chromebook Pixel) so it does have
>>>> an EC. Maybe we should have a separate device tree file for the qemu
>>>> version?
>>>>
>>>
>>> Looks that removing ec node from dts should work with current code
>>> logic in cros_ec_init(). Yes, we can have a separate device tree file
>>> for maybe a generic board (not naming it as qemu.dts), and make this
>>> generic board dts file as the default dts for coreboot board? How
>>> about the defines in coreboot.h? Should we make it undefined like I
>>> did in this patch?
>>
>> That sounds good, but I would prefer to use the same board config file
>> if possible, perhaps just changing the CONFIG_DEFAULT_DEVICE_TREE?
>
> Yes, just changing the CONFIG_DEFAULT_DEVICE_TREE to the same board
> dts file, say for example, I can change CONFIG_DEFAULT_DEVICE_TREE to
> use crownbay.dts to build a U-Boot to be loaded by coreboot. The two
> question remain: which board dts file should be used as the default
> one in coreboot-x86_defconfig file? And how about those CROS_EX
> defines in coreboot.h? Right now we have SYS_CONFIG_NAME but it is not
> a visible Kconfig option so we cannot change it. Ideally we should
> just change CONFIG_DEFAULT_DEVICE_TREE and SYS_CONFIG_NAME to allow
> the U-Boot for coreboot to run on different boards.

At present it is link, which is not idea for qemu. We probably need an
easier way to select from multiple device trees to use for a board
config. But for now perhaps we should have:

- coreboot-link
- coreboot-generic (qemu)
- chromebook_link
- crownbay

The first two can be the same apart from the device tree. From
experience once configs split it is really hard to get them joined, so
we should keep an eye on this.

If I understand you correctly, I'd prefer to keep the CROS_EC defines
in coreboot.h, meaning that the function is available if enabled by
device tree.

Regards,
Simon