On 15.11.2016 23:39, Florian Fainelli wrote: > On 11/15/2016 02:34 PM, Lino Sanfilippo wrote: >> On 15.11.2016 22:59, Andrew Lunn wrote: >>>> The link state is retrieved by a command to the application processor that is running >>>> on the network card. Also the register to set the phy configuration is write-only, so >>>> it is not even possible to do the usual mdio bit-banging in the Phy read() and write() >>>> functions (however there seems to be another application processor command reserved >>>> for retrieving the PHY settings, but I have not tried it yet). >>> >>>>> + val = MII_BMCR << 16 | SLIC_PCR_AUTONEG | >>>>> + SLIC_PCR_AUTONEG_RST; >>>>> + slic_write(sdev, SLIC_REG_WPHY, val); >>> >>> This actually looks a lot like an MDIO write operation. The upper 16 >>> bits are the register, and the lower 16 bits are the data. What you >>> don't have is the address. But maybe it is limited to one address. >>> >>> If the processor command reserved for read works in a similar way, you >>> have enough to do an MDIO bus. >>> >> >> Ok, I will give it a try. Reading values via the application processor >> is a bit awkward though, since it requires an address to a dma area as part of >> the command and then the AP informs the driver via irq that the dma memory has >> been written. So probably the irq handler will have to set some flag and >> the mdio_read() function will have to poll for that flag in place of doing >> bit-banging a register. > > That's a bit unusual compared to typical controllers that are usually > memory-mapped and that you can either write to, read/poll to know about > completion. I suppose that you could still have a mdiobus implementation > that is able to read to/from PHYs by submitting a command to the AP, > wait on a completion structure, and have the interrupt handler do the > completion of the command? > Thats essentially what I meant by setting a flag in the irq handler. The mdio function would have to check somehow if the irq has been fired (be it by means of a flag or a completion that is set by the irq handler and checked by the mdio function). So I agree that it should work (if reading via the AP command is actually possible). Lino _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
