On 08/13, Mike Turquette wrote: > Quoting Stephen Boyd (2013-08-12 22:03:34) > > The clock controller is hardware and the number of clock outputs > > is fixed. Isn't all hardware fixed until you start talking about > > FPGAs? The next minor revision of the clock controller may add > > more clocks or remove clocks from that base design, but otherwise > > the two are 90% the same and generally software compatible. It > > isn't until we start a new generation of chips that we make major > > changes to the design. Is that loose enough to qualify? > > > > These bindings attempt to follow the regulator bindings. With > > regulators there is a node for each regulator and we describe > > physical characteristics of those regulators within the nodes but > > we don't describe the software interface (bits, masks, shifts, > > etc). I imagine we could extend these clock nodes to describe > > physical characteristics such as min/max frequency or if the > > bootloader has left the clocks on. Right now we're using the > > nodes to describe what types of clocks there are and how the > > clock tree is layed out. > > > > Or perhaps you're talking about clock sharing? We share the clock > > controller with multiple masters (processors running other OSes) > > and the partitioning of the clocks is mostly predefined. We just > > won't use some clocks because they're reserved for other > > processors. They're still part of the same clock controller > > hardware block but we don't want to control them on Linux because > > we'll trample over other processors and most likely hang the > > system. I wonder how this would work for hexagon and krait both > > running linux on the same SoC. If all DT says is that there is a > > gcc here at this address how are we supposed to know that we > > shouldn't use some clock? > > Do Krait and Hexagon have the same register map? On the ARM SoCs I am > familiar with the masters have differing views of register addresses for > the same peripherals and hardware blocks. So you couldn't use the same > DTS in a straightforward way if this is true for your system. > They both have the same view of the register map. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- 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
