[U-Boot] [PATCH v1 1/2] Revert "powerpc: mpc85xx: remove P2020DS board support"

[york sun]

On 01/31/2016 07:40 AM, Simon Glass wrote:
> Hi,
> 
> On 31 January 2016 at 07:19, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi York,
>>
>> On Sun, Jan 31, 2016 at 6:03 AM, York Sun <york.sun at nxp.com> wrote:
>>> This reverts commit 168dcc6cef7a0e13bc52fc8fa8de2866cf4033dc.
>>> Align with changes since P2020DS was removed, including adding
>>> these macros to defconfig
>>>
>>> CONFIG_SYS_NS16550
>>> CONFIG_CMD_NET
>>> CONFIG_NETDEVICES
>>> CONFIG_E1000
>>> CONFIG_CMD_DHCP
>>>
>>> Remove macros and include from board header file, including
>>> CONFIG_E1000
>>> CONFIG_MTD_NAND_VERIFY_WRITE
>>> CONFIG_SYS_NS16550
>>> config_cmd_default.h
>>> CONFIG_CMD_ELF
>>> CONFIG_CMD_SETEXPR
>>> CONFIG_CMD_NET
>>>
>>
>> While we bring this board back, I believe we should add driver model
>> support this this board as well, at least NS16550.
> 
> Yes, since today is the day we are supposed to have all serial drivers
> converted over.
> 
> Other things that could perhaps be converted, and would give PPC a
> better start on driver model: i2c, mmc, usb, Ethernet, PCI :-)
> 

I will take this chance to convert P2020DS to use DM. Need some guidance here.
For NS16550, it needs the clock. To keep it simple, let's presume platform data
is used. My trouble is the clock is not unknown at compiling time. It needs to
be updated by checking the board/soc configuration after power up. The clock is
only available after get_clocks() is called in init_sequance. Is there a way I
can update the clocks before the driver is initialized?

York