On Thu, 2013-12-12 at 15:31 +0100, Douglas Gilbert wrote: > On 13-12-12 02:27 PM, Arnd Bergmann wrote: > > On Thursday 12 December 2013, Loc Ho wrote: > >> +- reg : First PHY memory resource is the SDS PHY access > >> + resource. > >> + Second PHY memory resoruce is the clock and reset > >> + resources. > >> + Third PHY memory resource is the SDS PHY access > >> + resource outside of the IP if it is type > >> + "apm,xgene-phy-ext". > > > > Why do the "clock and reset" resources not use a clock driver and a reset > > driver? > > > > I would expect these to get replaced with > > > > clocks : Reference to external clock input > > resets : Reference to reset controller input > > > >> +Optional properties: > >> +- status : Shall be "ok" if enabled or "disabled" if disabled. > >> + Default is "ok". > >> +- apm,tx-eye-tuning : Manual control to fine tune the capture of the serial > >> + bit lines from the automatic calibrated position. > >> + Two set of 3-tuple setting for Gen1, Gen2, and Gen3. > >> + Range from 0 to 0x7f in unit of one bit period. > >> + Default is 0xa. > > > > What does gen1, gen2 and gen3 refer to? Is this PCIe, SATA or serdes generations > > or all of them? > > > > Why are there two sets? > > > > Will this have to change if you add PCIe support? > > > > I would suggest using decimal notation here instead of hexadecimal since you > > are dealing with numbers couting things. Same for the others. > > > >> +- apm,tx-eye-direction : Eye tuning manual control direction. 0 means sample > >> + data earlier than the nominal sampling point. 1 means > >> + sample data later than the nominal sampling point. > >> + Two set of 3-tuple setting for Gen1, Gen2, and Gen3. > >> + Default is 0x0. > >> + > >> +- apm,tx-boost-gain : Frequency boost AC (LSB 3-bit) and DC (2-bit) > >> + gain control. Two set of 3-tuple setting for Gen1, > >> + Gen2, and Gen3. Range is between 0 to 0x1f in unit > >> + of dB. Default is 0x3. > >> + > >> +- apm,tx-amplitude : Amplitude control. Two set of 3-tuple setting for > >> + Gen1, Gen2, and Gen3. Range is between 0 to 0xf in > >> + unit of 13.3mV. Default is 0xf. > > > > Units of 13.3mV don't seem to be useful as a generic measurement. I'd > > recommend using milivolts or microvolts. > > > >> +- apm,tx-pre-cursor1 : 1st pre-cursor emphasis taps control. Two set of > >> + 3-tuple setting for Gen1, Gen2, and Gen3. Range is > >> + between 0 to 0xf in unit of 18.2mV. Default is 0x0. > >> +- apm,tx-pre-cursor2 : 2st pre-cursor emphasis taps control. Two set of > >> + 3-tuple setting for Gen1, Gen2, and Gen3. Range is > >> + between 0 to 0x7 in unit of 18.2mV. Default is 0x0. > >> +- apm,tx-post-cursor : Post-cursor emphasis taps control. Two set of > >> + 3-tuple setting for Gen1, Gen2, and Gen3. Range is > >> + between 0 to 0x1f in unit of 18.2mV. Default is 0xf. > > > > Same here. > > > >> +- apm,tx-speed : Tx operating speed. One set of 3-tuple for > >> + Gen1 (0x1), Gen2 (0x3), and Gen3 (0x7). Default is > >> + 0x7. > > > > I'm completely confused by this description. Can you rephrase this? > > It sounds like the only possible values are <1 3 7> for this property. > > Most likely Gen1, Gen2 and Gen3 are SATA-speak corresponding to SAS's > G1, G2 and G3: > > G1 Gen1 1.5 Gbps > G2 Gen2 3 Gbps > G3 Gen3 6 Gbps > G4 - 12 Gbps > G5 - 24 Gbps Electrically, SAS phys and SATA phys are identical. We already have a SAS phy abstraction in libsas ... when looking at a separable phy implementation, shouldn't we be doing something that works for both instead of just SATA? James -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
