[PATCH v3 1/2] net: fec: Add possibility to enable TXC delay

[Stefano Babic]

On 17.04.20 18:56, Philippe Schenker wrote:
> On Fri, 2020-04-17 at 18:35 +0200, Stefano Babic wrote:
>> Hi Philippe,
>>
>> On 11/03/20 11:52, Philippe Schenker wrote:
>>> This patch enables the possibility to set FEC_ENET_ENABLE_TXC_DELAY
>>> or
>>> FEC_ENET_ENABLE_RXC_DELAY so one can via a define enable the RXC or
>>> TXC
>>> delay in the MAC.
>>>
>>> Signed-off-by: Philippe Schenker <philippe.schenker at toradex.com>
>>> Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov at toradex.com>
>>>
>>> ---
>>>
>>> Changes in v3:
>>> - Add Olek's reviewed-by tag
>>>
>>> Changes in v2: None
>>>
>>>  drivers/net/fec_mxc.c | 10 ++++++++++
>>>  drivers/net/fec_mxc.h |  2 ++
>>>  2 files changed, 12 insertions(+)
>>>
>>> diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
>>> index bc5b63d7881..345d37be4e8 100644
>>> --- a/drivers/net/fec_mxc.c
>>> +++ b/drivers/net/fec_mxc.c
>>> @@ -503,6 +503,16 @@ static int fec_open(struct eth_device *edev)
>>>  	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_ETHER_EN,
>>>  	       &fec->eth->ecntrl);
>>>  
>>> +#ifdef FEC_ENET_ENABLE_TXC_DELAY
>>> +	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_TXC_DLY,
>>> +	       &fec->eth->ecntrl);
>>> +#endif
>>> +
>>> +#ifdef FEC_ENET_ENABLE_RXC_DELAY
>>> +	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_RXC_DLY,
>>> +	       &fec->eth->ecntrl);
>>> +#endif
>>> +
>>>  #if defined(CONFIG_MX25) || defined(CONFIG_MX53) ||
>>> defined(CONFIG_MX6SL)
>>>  	udelay(100);
>>>  
>>> diff --git a/drivers/net/fec_mxc.h b/drivers/net/fec_mxc.h
>>> index 159aec89679..3c8fdda2638 100644
>>> --- a/drivers/net/fec_mxc.h
>>> +++ b/drivers/net/fec_mxc.h
>>> @@ -188,6 +188,8 @@ struct ethernet_regs {
>>>  #define FEC_ECNTRL_ETHER_EN		0x00000002	/* enable
>>> the FEC */
>>>  #define FEC_ECNTRL_SPEED		0x00000020
>>>  #define FEC_ECNTRL_DBSWAP		0x00000100
>>> +#define FEC_ECNTRL_TXC_DLY		0x00010000	/* TXC delayed */
>>> +#define FEC_ECNTRL_RXC_DLY		0x00020000	/* RXC delayed */
>>>  
>>>  #define FEC_X_WMRK_STRFWD		0x00000100
>>>  
>>>
>>
>> But these are not exactly the properties removed by verdin-imx8mm in
>> DTS, that is for example rgmii_rxc_dly ? And then, should not be
>> better
>> to support it in DT instead of a CONFIG_ ?
> 
> Hi Stefano,
> 
> I'll add Igor in cc as I'm not that familiar with most recent
> development on u-boot. Yes you are right. Those tags (rgmii_rxc_dly) are
> exactly the same. However they came in from our downstream branch and
> were never meant for mainline u-boot. We dropped them in favor of the
> proper phy-mode 'rgmii-id' in linux. Those originally probably also
> originated from our downstream linux branch...
> 
> But U-Boot does not support phy-modes on KSZ PHYs so I felt this was a
> straight forward and easy solution

This is an easy and straighforward solution, sure. Strange enough, your
solution in DT is exactly as Oliver's did here:

http://patchwork.ozlabs.org/project/uboot/patch/20200203135619.10180-1-oliver.graute@kococonnector.com/

Both of you tried to get in in DT.

> for u-boot that we can enable as soon
> as we have our new PHY KSZ9131 on our board. At the moment there is
> KSZ9031 placed which does indeed not support this.

Anyway, until the property is not mainlined to Linux, I am fine to merge
your series.

Regards,
Stefano

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