On Mon, Apr 20, 2015 at 3:03 PM, Mark Brown <broonie@xxxxxxxxxx> wrote: > On Mon, Apr 20, 2015 at 02:18:56PM -0700, Kevin Cernekee wrote: >> On Sat, Apr 18, 2015 at 4:16 AM, Mark Brown <broonie@xxxxxxxxxx> wrote: >> > On Wed, Apr 15, 2015 at 02:42:19PM -0700, Kevin Cernekee wrote: > >> >> +- VDD-supply: regulator phandle for the AVDD/DVDD/HP_VDD supply > >> > This is clearly not correct - if there are three separate physical >> > supplies there should be three separate regulators requested. They may >> > all resolve to one physical regulator on the board you are working with >> > but that might not be true on other boards. > >> In the "simplified diagram," TI shows a single AVDD/DVDD/HP_VDD supply: > >> http://www.ti.com/lit/ds/symlink/tas5717.pdf#2 > >> Page 20 also suggests the use of a single 3.3V supply for AVDD/DVDD/HP_VDD. > >> But this combines a number of separate pins. On 5711 we have >> dedicated pins for: > >> PVDD_A >> PVDD_B >> PVDD_C >> PVDD_D >> AVDD >> DVDD > > Yes, those are three separate supplies that are typically tied together > - it looks like PVDD has high current draw so is tied through multiple > pins. Each half-bridge output OUT_{A,B,C,D} has its own dedicated PVDD_{A,B,C,D} supply on 5711: http://www.ti.com/lit/ds/symlink/tas5711.pdf#7 I don't understand the statement: "those are three separate supplies that are typically tied together." AVDD/DVDD are 3.3v fixed but PVDD is 8V minimum (5711) or 4.5V minimum (5717/5719). So AVDD/DVDD can never be driven by the same regulator output as PVDD. Perhaps you were thinking of HPVDD/AVDD/DVDD on 5717/5719? The simplified application diagram on page 2 does show that AVDD/DVDD are typically tied together, and that PVDD_* are also typically tied together. But as you pointed out, there may be situations where that isn't the case, so that leaves us with up to 6 separate supplies on 5711, or 5 on 5717/5719. The typical case is probably closer to 2 or 3, though. > I'd not be surprised to see systems with AVDD tied to a separate > pin, analogue supplies often benefit from low noise supplies separate to > digital ones. Indeed if you look at the pin descriptions the analogue > and digital supplies even have separate grounds. > >> I didn't see anything in the datasheet suggesting it is OK to have >> different voltages or power states on the various supply pins (other >> than the special voltage on PVDD). > > That's more likely to go wrong if they're not controlled separately than > if they are since we will only be able to turn a single supply on or > off.. > >> I can add as many regulator entries as appropriate. What do you recommend? > > Have the driver accurately reflect the hardware, request one regulator > per supply. So, request one regulator per VDD pin? Or group all of PVDD_* into a single regulator? -- 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
