Re: [RFC/PATCH 2/7] arm: omap: devicetree: add new properties for OMAP devices

[Felipe Balbi <balbi@ti.com>]

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Hi,

On Thu, Dec 11, 2014 at 01:46:28AM +0100, Sebastian Reichel wrote:
> On Wed, Dec 10, 2014 at 09:00:49AM -0600, Felipe Balbi wrote:
> > On Wed, Dec 10, 2014 at 04:37:19PM +0530, Lokesh Vutla wrote:
> > > On Wednesday 10 December 2014 03:57 AM, Felipe Balbi wrote:
> > > > In order to get rid of some more hwmod data, we
> > > > introduce a few extra properties to OMAP DT
> > > > data in order to be able to pass the needed
> > > > information through DT.
> > > > 
> > > > Signed-off-by: Felipe Balbi <balbi@ti.com>
> > > > ---
> > > >  Documentation/devicetree/bindings/arm/omap/omap.txt | 7 +++++++
> > > >  1 file changed, 7 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/arm/omap/omap.txt b/Documentation/devicetree/bindings/arm/omap/omap.txt
> > > > index 4f6a82c..c6b9515 100644
> > > > --- a/Documentation/devicetree/bindings/arm/omap/omap.txt
> > > > +++ b/Documentation/devicetree/bindings/arm/omap/omap.txt
> > > > @@ -23,6 +23,13 @@ Optional properties:
> > > >    during suspend.
> > > >  - ti,no-reset-on-init: When present, the module should not be reset at init
> > > >  - ti,no-idle-on-init: When present, the module should not be idled at init
> > > > +- ti,rev_offs: IP block revision register offset (defaults to 0)
> > > > +- ti,sysc_offs: OCP_SYSCONFIG register offset (defaults to 0)
> > > > +- ti,syss_offs: OCP_SYSSTATUS register offset (defaults to 0)
> > > > +- ti,srst_udelay: Delay needed after a softreset in usecs (defaults to 0)
> > > > +- ti,idlemodes: Slave and Master supported idling modes
> > > > +- ti,clockact: default value of clock activity bits (defaults to 0)
> > > > +- ti,sysc_type: OCP_SYSCONFIG type. Valid types are 1, 2 or 3 (defaults to 1)
> > > Once if all the hwmod data comes to dt it will be very dufficult to see all the data
> > > together. Can we separate out hwmod class data like clocks data is separated out into different node
> > > or something of the sort like below?
> > > 
> > > 	ti, hwmod_class {
> > > 		ti,class_name = <>;
> > 
> > this can be done, but I don't want to pass a class name. It's anyways
> > just the hwmod name without the digits. For those which are not, I would
> > rather change the class name to match.
> 
> I did some initial thinking on this some weeks ago, too (and then
> was short of time, so I did not continue). My suggestion for the
> binding would be:
> 
> * OCP_SYSCONFIG (power-management of IP-Cores connected to OMAP processors)
> 
> Each IP-Core connected to the bus of OMAP processors has
> three registers, which specify the IP-Core's version, its
> status and setup of PM features.
> 
> Required Properties:
> - ti,prcm-type: must be one of the following:
>    1 for OMAP2+ register style,
>    2 for OMAP4+ register style,
>    3 for AM33xx register style
> - reg: offset to revision, config and status registers
>        relative to module base address
> 
> Optional Properties:
> - ti,idlemodes:                bit field of flags (SIDLE)
>    PRCM_IDLE_FORCE               (1 << 0)
>    PRCM_IDLE_NO                  (1 << 1)
>    PRCM_IDLE_SMART               (1 << 2)
>    PRCM_IDLE_SMART_WKUP          (1 << 3)
> - ti,standbymodes:             bit field of flags (MIDLE)
>    PRCM_STANDBY_FORCE            (1 << 0)
>    PRCM_STANDBY_NO               (1 << 1)
>    PRCM_STANDBY_SMART            (1 << 2)
>    PRCM_STANDBY_SMART_WKUP       (1 << 3)
> - ti,sysc-has-autoidle:        config register has AUTOIDLE bit
> - ti,sysc-has-softreset:       config register has SOFTRESET bit
> - ti,sysc-has-enawakeup:       config register has ENAWAKEUP bit
> - ti,sysc-has-emufree:         config register has EMUFREE bit
> - ti,sysc-has-clock-activity:  config register has CLOCKACTIVITY bit
> - ti,sysc-has-dma-disable:     config register has DMADISABLE bit
> - ti,sysc-has-reset-status:    config register has RESETDONE bit
> - ti,syss-has-reset-status:    status register has RESETDONE bit

I thought about having boolean flags like this but after talking to Tony
we agreed that it would just increase the amount of string parsing
during early initialization. Besides, why have two properties using an
integer bitfield and another huge number of boolean properties ?

> - ti,reset-delay-us:           reset delay in us
> 
> Example:
> 
> ocp {
> 	gpio1: gpio@48310000 {
> 		compatible = "ti,omap3-gpio";
> 
> 		... /* IP-Core specific properties */
> 
> 		ti,sysconfig {

this is what I'm still waiting for comments from Tony. I'm not convinced
we need this extra indentation level. It really brings nothing of value.

-- 
balbi

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