[U-Boot] [PATCH 07/10] mvebu: a37xx: Add init for ESPRESSBin Topaz switch

[Konstantin Porotchkin <kostap@marvell.com>]

On 02/15/2017 11:07 AM, Konstantin Porotchkin wrote:
> Hi, Joe,
>
> On 02/14/2017 07:17 PM, Joe Hershberger wrote:
>> On Tue, Feb 14, 2017 at 6:32 AM, Stefan Roese <sr@denx.de> wrote:
>> > (added Joe to Cc as network custodian)
>> >
>> >
>> > On 14.02.2017 13:13, Konstantin Porotchkin wrote:
>> >>
>> >> Hi, Stefan,
>> >>
>> >> On 2/14/2017 13:49, Stefan Roese wrote:
>> >>>
>> >>> Hi Kosta,
>> >>>
>> >>> On 13.02.2017 14:38, kostap at marvell.com wrote:
>> >>>>
>> >>>> From: Konstantin Porotchkin <kostap@marvell.com>
>> >>>>
>> >>>> Implement the board-specific network init function for
>> >>>> ESPRESSOBin community board, setting the on-board Topaz
>> >>>> switch port to forward mode and allow network connection
>> >>>> through any of the available Etherenet ports.
>> >>>>
>> >>>> Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
>> >>>> Cc: Stefan Roese <sr@denx.de>
>> >>>> Cc: Igal Liberman <igall@marvell.com>
>> >>>> ---
>> >>>>  board/Marvell/mvebu_db-88f3720/board.c | 49
>> >>>> ++++++++++++++++++++++++++++++++++
>> >>>>  1 file changed, 49 insertions(+)
>> >>>>
>> >>>> diff --git a/board/Marvell/mvebu_db-88f3720/board.c
>> >>>> b/board/Marvell/mvebu_db-88f3720/board.c
>> >>>> index 3337f3f..45098ce 100644
>> >>>> --- a/board/Marvell/mvebu_db-88f3720/board.c
>> >>>> +++ b/board/Marvell/mvebu_db-88f3720/board.c
>> >>>> @@ -6,6 +6,7 @@
>> >>>>
>> >>>>  #include <common.h>
>> >>>>  #include <i2c.h>
>> >>>> +#include <phy.h>
>> >>>>  #include <asm/io.h>
>> >>>>  #include <asm/arch/cpu.h>
>> >>>>  #include <asm/arch/soc.h>
>> >>>> @@ -156,3 +157,51 @@ int board_xhci_enable(void)
>> >>>>
>> >>>>      return 0;
>> >>>>  }
>> >>>> +
>> >>>> +static int mii_multi_chip_mode_write(struct mii_dev *bus, int
>> >>>> dev_smi_addr,
>> >>>> +                     int smi_addr, int reg, u16 value)
>> >>>> +{
>> >>>> +    u16 data = 0;
>> >>>> +
>> >>>> +    if (bus->write(bus, dev_smi_addr, 0, 1, value) != 0) {
>> >>>> +        printf("Error writing to the PHY addr=%02x reg=%02x\n",
>> >>>> +               smi_addr, reg);
>> >>>> +        return -EFAULT;
>> >>>> +    }
>> >>>> +
>> >>>> +    data = (1 << 15) | (1 << 12) | (1 << 10) | (smi_addr << 5) |
>> reg;
>> >>>> +    if (bus->write(bus, dev_smi_addr, 0, 0, data) != 0) {
>> >>>> +        printf("Error writing to the PHY addr=%02x reg=%02x\n",
>> >>>> +               smi_addr, reg);
>> >>>> +        return -EFAULT;
>> >>>> +    }
>> >>>> +
>> >>>> +    return 0;
>> >>>> +}
>> >>>> +
>> >>>> +
>> >>>> +int board_network_enable(struct mii_dev *bus)
>> >>>> +{
>> >>>> +    if
>> (!of_machine_is_compatible("marvell,armada-3720-espressobin"))
>> >>>> +        return 0;
>> >>>> +
>> >>>> +    /*
>> >>>> +     * FIXME: remove this code once Topaz driver gets available
>> >>>> +     * A3720 Community Board Only
>> >>>> +     * Configure Topaz switch (88E6341)
>> >>>> +     * Set port 0,1,2,3 to forwarding Mode
>> >>>> +     */
>> >>>
>> >>>
>> >>> Just checking: Is this "Topaz switch driver" something thats being
>> >>> worked on or in the queue to do?
>> >>
>> >>
>> >> I currently do not have it in my queue.
>> >> I think the driver exists in the kernel (or will exist in 4.10/4.11
>> >> release), so we may want to port it if required.
>> >> Which switch operations are needed at u-bot stage?
>> >
>> >
>> > I'm not 100% sure if there is anything really "needed" other than
>> > to get some ports into operation for the ethernet driver connected
>> > to this switch. So it might be that such a few register writes
>> > are acceptable - I'm pretty sure other boards do it this way as
>> > well.
>> >
>> > On the other hand you could take a look at the
>> > "drivers/net/phy/mv88e61xx.c" switch driver. Might be that this is
>> > something similar to what you want / need.
>>
>> I think the switch driver to model after is drivers/net/vsc9953.c -
>> there is a command: cmd/ethsw.c / include ethsw.h that implements the
>> framework (doc/README.t1040-l2switch).
>
> I will check this code, thank you for the reference!
>>
>> There is also the drivers/net/cpsw.c that just hard-codes the config.
>> Eth switches have varying levels of support. What level of support are
>> you able to implement?
> I am not really sure about level of support required by the u-boot.
> The Linux driver configures the 3 output ports of this switch as lan0, lan1
> and wan interfaces, so they are presented to the kernel as separate NICs.
> So if I set the NFS server on lan0 and the cable connected to lan1, the
> connection attempt will fail.
> The u-boot code however just sets the switch ports to follow all the
> traffic
> to the CPU. So when I tfttpload image using default neta0 interface, any
> switch port will work for that.
> Anyway, I will check what is supported by the reference code you just
> pointed
> and check what I can provide.
> I personally not an expert in this Topaz switch internals and may need
> to request help
> from other Marvell teams for doing something smarter than the code already
> provided in this patch.
I went trough the Vitesse driver and understood that at this moment I 
cannot implement something similar.
There are two reasons for this:
1. I am not an expert in SOHO switches.
2. It looks like a long task and it is not included in my current schedule.
So I will try to make this code more readable by adding some defines 
that replace the numeric values at least for pointing to the register 
names. My current target is to enable early adopters of the Espressobin 
board to work with the mainline u-boot sources.
Is it a good reason and will this temporary solution be acceptable?

>>
>> Thanks,
>> -Joe
>>
>