On Wed, Feb 17, 2021 at 10:33:18AM +0100, Patrick Wildt wrote:
> Am Wed, Feb 17, 2021 at 11:56:16AM +1100 schrieb Jonathan Gray:
> > Add a driver for "simple-pm-bus" a way to enable a clock and/or
> > power domain for a group of devices.
> > 
> > https://www.kernel.org/doc/Documentation/devicetree/bindings/bus/simple-pm-bus.txt
> > 
> > This is needed to use am335x/omap4 dtbs from linux 5.11.
> 
> "A Simple Power-Managed Bus is a transparent bus that doesn't need a real
> driver, as it's typically initialized by the boot loader."
> 
> That's a bit funny though. :-)  But I think they meant "it doesn't need
> a real driver, apart from the generic simple-pm-bus driver".
> 
> 
> > Index: sys/dev/fdt/files.fdt
> > ===================================================================
> > RCS file: /cvs/src/sys/dev/fdt/files.fdt,v
> > retrieving revision 1.146
> > diff -u -p -r1.146 files.fdt
> > --- sys/dev/fdt/files.fdt   5 Feb 2021 00:05:20 -0000       1.146
> > +++ sys/dev/fdt/files.fdt   17 Feb 2021 00:49:02 -0000
> > @@ -23,6 +23,10 @@ device   simplepanel
> >  attach     simplepanel at fdt
> >  file       dev/fdt/simplepanel.c           simplepanel
> >  
> > +device     simplepmbus: fdt
> > +attach     simplepmbus at fdt
> > +file       dev/fdt/simplepmbus.c           simplepmbus
> > +
> >  device     sxiccmu
> >  attach     sxiccmu at fdt
> >  file       dev/fdt/sxiccmu.c               sxiccmu
> > Index: share/man/man4/Makefile
> > ===================================================================
> > RCS file: /cvs/src/share/man/man4/Makefile,v
> > retrieving revision 1.792
> > diff -u -p -r1.792 Makefile
> > --- share/man/man4/Makefile 4 Feb 2021 16:25:38 -0000       1.792
> > +++ share/man/man4/Makefile 17 Feb 2021 00:49:02 -0000
> > @@ -72,7 +72,8 @@ MAN=      aac.4 abcrtc.4 abl.4 ac97.4 acphy.4
> >     rl.4 rlphy.4 route.4 rsu.4 rtsx.4 rum.4 run.4 rtw.4 rtwn.4 \
> >     safe.4 safte.4 sbus.4 schsio.4 scsi.4 sd.4 \
> >     sdmmc.4 sdhc.4 se.4 ses.4 sf.4 sili.4 \
> > -   simpleamp.4 simpleaudio.4 simplefb.4 simplepanel.4 siop.4 sis.4 sk.4 \
> > +   simpleamp.4 simpleaudio.4 simplefb.4 simplepanel.4 simplepmbus.4 \
> > +   siop.4 sis.4 sk.4 \
> >     sm.4 smsc.4 softraid.4 spdmem.4 sdtemp.4 speaker.4 sppp.4 sqphy.4 \
> >     ssdfb.4 st.4 ste.4 stge.4 sti.4 stp.4 sv.4 switch.4 sxiccmu.4 \
> >     sxidog.4 sximmc.4 sxipio.4 sxipwm.4 sxirsb.4 sxirtc.4 sxisid.4 \
> > Index: sys/arch/armv7/conf/GENERIC
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/armv7/conf/GENERIC,v
> > retrieving revision 1.134
> > diff -u -p -r1.134 GENERIC
> > --- sys/arch/armv7/conf/GENERIC     4 Feb 2021 16:25:39 -0000       1.134
> > +++ sys/arch/armv7/conf/GENERIC     17 Feb 2021 00:49:02 -0000
> > @@ -31,6 +31,7 @@ config            bsd     swap generic
> >  # The main bus device
> >  mainbus0   at root
> >  simplebus* at fdt?
> > +simplepmbus*       at fdt?
> >  cpu0               at mainbus?
> >  
> >  # Cortex-A9
> > Index: sys/arch/armv7/conf/RAMDISK
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/armv7/conf/RAMDISK,v
> > retrieving revision 1.119
> > diff -u -p -r1.119 RAMDISK
> > --- sys/arch/armv7/conf/RAMDISK     18 Jun 2020 08:48:04 -0000      1.119
> > +++ sys/arch/armv7/conf/RAMDISK     17 Feb 2021 00:49:02 -0000
> > @@ -30,6 +30,7 @@ config            bsd root on rd0a swap on rd0b
> >  mainbus0   at root
> >  softraid0  at root
> >  simplebus* at fdt?
> > +simplepmbus*       at fdt?
> >  cpu0               at mainbus?
> >  
> >  # Cortex-A9
> > --- /dev/null       Wed Feb 17 11:49:05 2021
> > +++ sys/dev/fdt/simplepmbus.c       Tue Feb 16 17:24:55 2021
> > @@ -0,0 +1,62 @@
> > +/* $OpenBSD$       */
> > +/*
> > + * Copyright (c) 2021 Jonathan Gray <j...@openbsd.org>
> > + *
> > + * Permission to use, copy, modify, and distribute this software for any
> > + * purpose with or without fee is hereby granted, provided that the above
> > + * copyright notice and this permission notice appear in all copies.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
> > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
> > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
> > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
> > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
> > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
> > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> > + */
> > +
> > +#include <sys/param.h>
> > +#include <sys/device.h>
> > +
> > +#include <machine/fdt.h>
> > +
> > +#include <dev/ofw/openfirm.h>
> > +#include <dev/ofw/ofw_clock.h>
> > +#include <dev/ofw/ofw_power.h>
> > +
> > +#include <arm/simplebus/simplebusvar.h>
> 
> Maybe like this, was we have in rkpinctrl?
> 
> #ifdef __armv7__
> #include <arm/simplebus/simplebusvar.h>
> #else
> #include <arm64/dev/simplebusvar.h>
> #endif

The known arm64 usage is quite small. The only use in
5.11 linux/arch/arm64/boot/dts/ is qcom/msm8996.dtsi

Though it would be nice if a machine include could be used without the
ifdef for cases like this in general.

> 
> Generally I was wondering if we shouldn't just add this to simplebus.c
> itself?  You'd need to add a compatible to the match function, and in
> the attach function you'd need to check for the compatible and then
> do
> 
>       power_domain_enable(faa->fa_node);
>       clock_enable_all(faa->fa_node);
> 
> in the if-block.
> 
> Haven't made my mind up yet what I like better, maybe kettenis@ has an
> opinion.

The binding text has

'While "simple-pm-bus" follows the "simple-bus" set of properties, as specified
in the Devicetree Specification, it is not an extension of "simple-bus".'

> 
> Patrick
> 
> > +
> > +int        simplepmbus_match(struct device *, void *, void *);
> > +void       simplepmbus_attach(struct device *, struct device *, void *);
> > +
> > +struct simplepmbus_softc {
> > +   struct simplebus_softc sc_bus;
> > +};
> > +
> > +struct cfattach simplepmbus_ca = {
> > +   sizeof(struct simplepmbus_softc), simplepmbus_match, simplepmbus_attach
> > +};
> > +
> > +struct cfdriver simplepmbus_cd = {
> > +   NULL, "simplepmbus", DV_DULL
> > +};
> > +
> > +int
> > +simplepmbus_match(struct device *parent, void *cfdata, void *aux)
> > +{
> > +   struct fdt_attach_args *faa = aux;
> > +
> > +   return OF_is_compatible(faa->fa_node, "simple-pm-bus");
> > +}
> > +
> > +void
> > +simplepmbus_attach(struct device *parent, struct device *self, void *aux)
> > +{
> > +   struct simplepmbus_softc *sc = (struct simplepmbus_softc *)self;
> > +   struct fdt_attach_args *faa = aux;
> > +
> > +   power_domain_enable(faa->fa_node);
> > +   clock_enable_all(faa->fa_node);
> > +
> > +   simplebus_attach(parent, &sc->sc_bus.sc_dev, faa);
> > +}
> > --- /dev/null       Wed Feb 17 11:49:07 2021
> > +++ share/man/man4/simplepmbus.4    Wed Feb 17 11:31:06 2021
> > @@ -0,0 +1,36 @@
> > +.\"        $OpenBSD$
> > +.\"
> > +.\" Copyright (c) 2021 Jonathan Gray <j...@openbsd.org>
> > +.\"
> > +.\" Permission to use, copy, modify, and distribute this software for any
> > +.\" purpose with or without fee is hereby granted, provided that the above
> > +.\" copyright notice and this permission notice appear in all copies.
> > +.\"
> > +.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL 
> > WARRANTIES
> > +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
> > +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
> > +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
> > +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
> > +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
> > +.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> > +.\"
> > +.Dd $Mdocdate$
> > +.Dt SIMPLEPMBUS 4
> > +.Os
> > +.Sh NAME
> > +.Nm simplepmbus
> > +.Nd simple power managed bus
> > +.Sh SYNOPSIS
> > +.Cd "simplepmbus* at fdt?"
> > +.Sh DESCRIPTION
> > +The
> > +.Nm
> > +driver provides an abstraction to enable a clock and/or power domain for
> > +a group of devices.
> > +.Sh SEE ALSO
> > +.Xr mainbus 4
> > +.Sh HISTORY
> > +The
> > +.Nm
> > +driver first appeared in
> > +.Ox 6.9 .
> > 
> 
> 

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