public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: info@free-electrons•com (Gregory CLEMENT)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4 07/13] ARM: dts: mvebu: Add a new set of registers to the PMSU node
Date: Wed, 19 Feb 2014 18:49:13 +0100	[thread overview]
Message-ID: <5304EE99.7000102@free-electrons.com> (raw)
In-Reply-To: <20140219170033.4ca8343b@skate>

On 19/02/2014 17:00, Thomas Petazzoni wrote:
> Dear Gregory CLEMENT,
> 
> On Thu, 13 Feb 2014 18:33:30 +0100, Gregory CLEMENT wrote:
> 
>>  - reg: Should contain PMSU registers location and length. First pair
>> -  for the per-CPU SW Reset Control registers, second pair for the
>> -  Power Management Service Unit.
>> +  for the per-CPU SW Reset Control registers, second pair for the CPU
>> +  Power Management Service Unit registers, third pair for the Fabric Power
>> +  Management Service Unit registers.
>>  
>>  Example:
>>  
>> -armada-370-xp-pmsu at d0022000 {
>> +armada-370-xp-pmsu at 22000 {
>>  	compatible = "marvell,armada-370-xp-pmsu";
>> -	reg = <0xd0022100 0x430>,
>> -	      <0xd0020800 0x20>;
>> +	reg = <0x22100 0x430>,
>> +	      <0x20800 0x20>,
>> +	      <0x22000 0x24>;
> 
> I am not too happy with this because:
> 
>  *) We have to remove the second register pair from the PMSU. I haven't
>     yet posted the patches on LAKML for SMP on 375 and 38x, but the 375
>     doesn't have a PMSU. It however has the same CPU reset control
>     registers as 370 and XP. Therefore, these 0x20800 registers have to
>     be handled by a separate driver (that uses the reset framework),
>     and not handled by the PMSU driver. This way, Armada 370/XP can use
>     PMSU+CPU reset, while 375 will only use CPU reset.
> 
>  *) I think making the PMSU register start at 0x22100 was a mistake.
>     The PMSU registers actually start at 0x22000 and they seem to go all
>     the way to 0x23000. So we should have only one register pair. This
>     of course raises some backward compatibility questions for the DT.

I agree to use something like:

armada-370-xp-pmsu at 22000 {
	compatible = "marvell,armada-xp-pmsu"; /* new compatible string */
	reg = <0x22000 0x1000>;
	};


and I think the best option would be to introduce a new compatible string
for this. In the same time we continue to support the old compatible string
but we print a big warning during the kernel boot that this compatible string
is deprecated, and we will finally remove it a few release.

Thanks,

Gregory


> 
> Thomas
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
+33 602 196 044

  reply	other threads:[~2014-02-19 17:49 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-13 17:33 [PATCH v4 00/13] CPU idle for Armada XP Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 01/13] ARM: PJ4B: Add cpu_suspend/cpu_resume hooks for PJ4B Gregory CLEMENT
2014-02-14 16:06   ` Lorenzo Pieralisi
2014-03-25 22:57     ` Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 02/13] ARM: mvebu: remove the address parameter for ll_set_cpu_coherent Gregory CLEMENT
2014-02-19 16:06   ` Thomas Petazzoni
2014-02-13 17:33 ` [PATCH v4 03/13] ARM: mvebu: ll_set_cpu_coherent always uses the current CPU Gregory CLEMENT
2014-02-19 16:09   ` Thomas Petazzoni
2014-02-19 16:17     ` Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 04/13] ARM: mvebu: Remove the unused argument of set_cpu_coherent() Gregory CLEMENT
2014-02-19 16:27   ` Thomas Petazzoni
2014-02-13 17:33 ` [PATCH v4 05/13] ARM: mvebu: Low level function to disable HW coherency support Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 06/13] ARM: mvebu: Add a new set of registers for pmsu Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 07/13] ARM: dts: mvebu: Add a new set of registers to the PMSU node Gregory CLEMENT
2014-02-17  2:57   ` Jason Cooper
2014-02-19 16:00   ` Thomas Petazzoni
2014-02-19 17:49     ` Gregory CLEMENT [this message]
2014-02-19 18:21       ` Thomas Petazzoni
2014-02-13 17:33 ` [PATCH v4 08/13] ARM: mvebu: Allow to power down L2 cache controller in idle mode Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 09/13] ARM: mvebu: Add the PMSU related part of the cpu idle functions Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 10/13] ARM: mvebu: Set the start address of a CPU in a separate function Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 11/13] ARM: mvebu: Register notifier callback for the cpuidle transition Gregory CLEMENT
2014-02-13 17:33 ` [PATCH v4 12/13] cpuidle: mvebu: Add initial CPU idle support for Armada 370/XP SoC Gregory CLEMENT
2014-02-14 17:00   ` Lorenzo Pieralisi
2014-03-25 22:57     ` Gregory CLEMENT
2014-02-17  8:49   ` Daniel Lezcano
2014-03-25 22:57     ` Gregory CLEMENT
2014-02-19 16:51   ` Thomas Petazzoni
2014-02-19 17:19     ` Gregory CLEMENT
2014-02-19 18:32       ` Thomas Petazzoni
2014-02-13 17:33 ` [PATCH v4 13/13] ARM: mvebu: register the cpuidle driver for the Armada XP SoCs Gregory CLEMENT
2014-02-19 16:46   ` Thomas Petazzoni
2014-02-19 16:52     ` Gregory CLEMENT
2014-02-19 17:01       ` Thomas Petazzoni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5304EE99.7000102@free-electrons.com \
    --to=info@free-electrons$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox