Re: [PATCH 06/12] ARM: dts: am335x-bone-common: Enable PRU-ICSS interconnect node

From: Tony Lindgren <tony@atomide.com>
To: Suman Anna <s-anna@ti.com>
Cc: Roger Quadros <rogerq@ti.com>, Tero Kristo <t-kristo@ti.com>,
	linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: Re: [PATCH 06/12] ARM: dts: am335x-bone-common: Enable PRU-ICSS interconnect node
Date: Wed, 26 Feb 2020 18:07:13 -0800	[thread overview]
Message-ID: <20200227020713.GE37466@atomide.com> (raw)
In-Reply-To: <b1fe18b5-f779-aea5-8c66-41c0de66c39f@ti.com>

* Suman Anna <s-anna@ti.com> [200227 00:59]:
> Hi Tony,
> 
> On 2/26/20 4:39 PM, Tony Lindgren wrote:
> > * Tony Lindgren <tony@atomide.com> [200226 22:38]:
> >> * Suman Anna <s-anna@ti.com> [200226 20:35]:
> >>> On 2/26/20 12:29 PM, Tony Lindgren wrote:
> >>>> * Suman Anna <s-anna@ti.com> [200225 20:47]:
> >>>>> The PRU-ICSS target module node was left in disabled state in the base
> >>>>> am33xx-l4.dtsi file. Enable this node on all the AM335x beaglebone
> >>>>> boards as they mostly use a AM3358 or a AM3359 SoC which do contain
> >>>>> the PRU-ICSS IP.
> >>>>
> >>>> Just get rid of the top level status = "disabled". The default
> >>>> is enabled, and the device is there for sure inside the SoC.
> >>>> And then there's no need for pointless status = "okay" tinkering
> >>>> in the board specific dts files so no need for this patch.
> >>>
> >>> The IP is not available on all SoCs, and there are about 40 different
> >>> board files atm across AM33xx and AM437x, and am not sure what SoCs they
> >>> are actually using.
> >>
> >> Oh that issue again.. Maybe take a look at patch "[PATCH 2/3] bus: ti-sysc:
> >> Detect display subsystem related devices" if you can add runtime
> >> detection for the accelerators there similar to what I hadded for omap3.
> >> acclerators.
> > 
> > Sorry I meant instead patch "[PATCH 6/7] bus: ti-sysc: Implement SoC
> > revision handling".
> 
> OK, looked down that path a bit more and looking through mach-omap2/id.c
>  and soc.h, I see some of the part number infrastructure build on top of
> DEV_FEATURE bits for some SoCs. The DEVICE_ID registers only have the
> generic family and the Silicon Revision number for AM33xx and AM437x and
> we currently do not have any infrastructure around exact SoC
> identification for AM33xx and AM437x atleast.
> 
> Do you have the bit-field split for the DEV_FEATURE bits somewhere,
> because I couldn't find any in either the DM or the TRM. On AM437x,
> there is no difference between AM4372 and AM4376 DEV_FEATURE value even
> though the former doesn't have the PRUSS. On AM335x, may be bit 0
> signifies the presence of PRUSS??

OK not sure how that could be detected. Maybe check the efuses on
the newer SoCs?

Regards,

Tony