[U-Boot] [PATCH v7 00/15] SiFive FU540 Support

[Atish Patra]

On 4/18/19 4:16 PM, Kevin Hilman wrote:
> Atish Patra <atish.patra at wdc.com> writes:
> 
>> On 4/18/19 12:15 PM, Kevin Hilman wrote:
>>> Palmer, Anup,
>>>
>>> On Tue, Mar 12, 2019 at 1:55 AM Palmer Dabbelt <palmer at sifive.com> wrote:
>>>>
>>>> On Mon, 11 Mar 2019 07:33:25 PDT (-0700), bmeng.cn at gmail.com wrote:
>>>>> On Thu, Feb 14, 2019 at 7:58 AM Kevin Hilman <khilman at baylibre.com> wrote:
>>>>>>
>>>>>> Kevin Hilman <khilman at baylibre.com> writes:
>>>>>>
>>>>>>> Hi Anup,
>>>>>>>
>>>>>>> Anup Patel <Anup.Patel at wdc.com> writes:
>>>>>>>
>>>>>>>> This patchset adds SiFive Freedom Unleashed (FU540) support
>>>>>>>> to RISC-V U-Boot.
>>>>>>>>
>>>>>>>> The patches are based upon latest U-Boot source tree
>>>>>>>> (git://git.denx.de/u-boot.git) at commit id
>>>>>>>> dbe70c7d4e3d5c705a98d82952e05a591efd0683
>>>>>>>>
>>>>>>>> All drivers namely: SiFive PRCI, SiFive Serial, and Cadance
>>>>>>>> MACB Ethernet work fine on actual SiFive Unleashed board and
>>>>>>>> QEMU sifive_u machine.
>>>>>>>
>>>>>>> I tested u-boot networking (DHCP, TFTP) on my desk with a gigE switch
>>>>>>> and it worked fine.  Then, I moved it to a lab with a 100Mb switch,
>>>>>>> and DHCP doesn't work anymore.
>>>>>>
>>>>>> And to be clear, neither does TFTP if setting static
>>>>>> ipaddr/netmask/gatewayip etc.
>>>>>
>>>>> Sound to me a bug of the GEM driver on SiFive FU540 board.
>>>>
>>>> It looks to me like u-boot is missing a driver for the GEM clockmux in the
>>>> FU540.  This is necessary to switch between the clock for 1G operation and 100M
>>>> operation.  Without this you'll just get whatever clock was set up by the
>>>> previous boot stage (or even worse, reset).
>>>
>>> Anyone know if this is fixed in u-boot yet?  I've yet to try the
>>> latest mainline u-boot, but will if if it's expected to work.
>>>
>>
>> I have not seen a GEM driver for FU540 board. So I guess it is not fixed
>> it. Is it a blocker for setting up kernelCI for RISC-V ?
> 
> Not really, that's only one of the remaining issue. For now, I have
> connected it to a gigE switch, so u-boot networking is working.
> 
> But, the bigger blocker for kernelCI right now is not having
> out-of-the-box mainline support.  Mainline is still missing a serial
> driver, and a handful of Kconfig options in the default defconfig to
> make things boot[1].
> 
> If I use the 'v5.1-rc4_unleashed' from your github, along with my
> kconfig fragment[1], things are working well.
> 
> But in order to automate this for kernelCI, we need all of that
> upstream.
> 
Yeah. I agree. We need upstream drivers sooner than later.
I believe SiFive Team (Paul & co) are working on this.

He recently sent updated version of driver patches to the linux-riscv 
mailing list.


> Kevin
> 
> [1] This is the config fragment I'm adding to the default defconfig in
> mainline.  I'm not exactly sure which ones are absolutely need for basic
> boot.
> 
> CONFIG_SERIAL_SIFIVE=y
> CONFIG_SERIAL_SIFIVE_CONSOLE=y
> CONFIG_SIFIVE_PLIC=y
> CONFIG_SPI=y
> CONFIG_SPI_SIFIVE=y
> CONFIG_GPIOLIB=y
> CONFIG_GPIO_SIFIVE=y
> CONFIG_PWM_SIFIVE=y
> CONFIG_CLK_U54_PRCI=y
> CONFIG_CLK_GEMGXL_MGMT=y
> 

My working config has enabled all of the above except CONFIG_PWM_SIFIVE.
I have not played around the config that much to find out absolute 
minimum config. So this may not be the answer you are looking for :).

Regards,
Atish