[U-Boot-Users] [PATCH] add config options for VSC8601 RGMII PHY

[Andre Schwarz]

Andy,

thanks for your comments.


Andy Fleming schrieb:
> On Thu, Apr 24, 2008 at 9:45 AM, Andre Schwarz
> <andre.schwarz at matrix-vision.de> wrote:
>
>   
>>  {MIIM_VSC8601_EPHY_CON,MIIM_VSC8601_EPHY_CON_INIT_SKEW,NULL},
>>  +#if defined(CFG_VSC8601_SKEW_TX) && defined(CFG_VSC8601_SKEW_RX)
>>  +                {MIIM_EXT_PAGE_ACCESS,1,NULL},
>>  +#define VSC8101_SKEW    (CFG_VSC8601_SKEW_TX<<14)|(CFG_VSC8601_SKEW_RX<<12)
>>  +                {MIIM_VSC8601_SKEW_CTRL,VSC8101_SKEW,NULL},
>>  +                {MIIM_EXT_PAGE_ACCESS,0,NULL},
>>  +#endif
>>   #endif
>>     
>
>
> I'm not sure this is the best solution to this.  It seems like it
> wouldn't scale well.  Either we need to set a bit somewhere that the
> phy driver can read (and thereby determine how to configure the skew),
> or we need to set the value to write in the board config file.  I'm
> partial to the first solution, as it encapsulates the information
> inside the code that deals with it.
>
> [...]
>
>   
I don't understand "scale well". What should be scalable ?

Of course using a function would be better.
I silently assumed that the other bits are set to zero which is true
after reset.
There are only two other bits : Packet size and 10M preamble mode.
Both should be left untouched, i.e. "0".

>>   /* Broadcom BCM54xx -- taken from linux sungem_phy */
>>   #define MIIM_BCM54xx_AUXSTATUS            0x19
>>   #define MIIM_BCM54xx_AUXSTATUS_LINKMODE_MASK    0x0700
>>  @@ -163,6 +165,8 @@
>>   /* Vitesse VSC8601 Extended PHY Control Register 1 */
>>   #define MIIM_VSC8601_EPHY_CON            0x17
>>   #define MIIM_VSC8601_EPHY_CON_INIT_SKEW    0x1120
>>  +#define MIIM_VSC8601_SKEW_CTRL        0x1c
>>  +#define MIIM_VSC8601_EPHY_CON_INIT_SKEW    0x1120
>>     
>
> Am I crazy, or did you just doubly define MIIM_VSC8601_EPHY_CON_INIT_SKEW?
>   
This obviously is a mistake - sorry.



regards,
Andre

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