[PATCH 01/10] dt-bindings: bus: Minimal TI sysc interconnect target module binding

* Matthijs van Duin [off-list ref] [170924 23:36]:

On Wed, Sep 20, 2017 at 03:46:12PM -0700, Tony Lindgren wrote:

quoted

+- compatible	shall be one of the following generic types:
+
+		"ti,sysc-type1"
+		"ti,sysc-type2"
+		"ti,sysc-type3"

Is the meaning of these documented anywhere?  I'm assuming one of them
corresponds to the standard omap2/3 sysconfig/sysstatus:

Yes that's the type1 sysc. Pretty much the only documentation is what
we already have defined in the kernel, see:

$ grep "#define SYSC_TYPE" arch/arm/mach-omap2/omap_hwmod.h

	sysconfig:
	bit   0     rw  auto-idle / auto-gating
	bit   1     -x  soft-reset
	bit   2     rw  wakeup enabled
	bits  3- 4  rw  (slave) idle mode
	bit   5     rw  emu-free
	bits  6- 7  z-
	bit   8     rw  interface clock not gated when module in idle
	bit   9     rw  functional clock not gated when module in idle
	bits 10-11  z-
	bits 12-13  rw  standby mode (master idle mode)
	sysstatus:
	bit   0     r-  reset done

and one to the standard omap4/5 sysconfig:

	bit   0     rx  soft-reset
	bit   1     rw  emu-free
	bits  2- 3  rw  (slave) idle mode
	bits  4- 5  rw  standby mode (master idle mode)
	bits  6- 7  z-
	bits  8-15  rw  auxiliary clocks (rare)

Yeah and that's what we call sysc type 2 in the kernel.

What's the third?  I'm not really aware of any other standard layout,
just a whole bunch of non-standard ones.

The sysc type3 is what we have on am335x/ti81xx, see:

$ git grep -B10 -A1 "&omap_hwmod_sysc_type3" arch/arm/mach-omap2

quoted

+		or one of the following derivative types for hardware
+		needing special workarounds:

To add to the collection: omap4/5 isp5 (part of iss) has:
	bit   0     r-  auto-idle / auto-gating
	bit   1     rx  soft-reset (requires special procedure)
	bits  2- 3  z-
	bits  4- 5  rw  standby mode (master idle mode)

OK, I don't think we have that yet.

quoted

+Note that other SoCs, such as am335x can have multipe child devices. On am335x
+there are two MUSB instances, two USB PHY instances, and a single CPPI41 DMA
+instance as children of a single interconnet target module.

ISS (omap4/5, dm814x) is also fun since it has top-level sysconfig, but
most of the child modules (e.g. isp5 and simcop) also have their own
sysconfig, and some child modules of simcop again have sysconfig.

Interesting. Sounds like there's yet another interconnect instance
lurking there similar to L4 ABE?

Regards,

Tony