From: mikko.perttunen@kapsi•fi (Mikko Perttunen)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 0/8] Tegra124 EMC (external memory controller) support
Date: Fri, 05 Sep 2014 13:55:45 +0300 [thread overview]
Message-ID: <540996B1.4010300@kapsi.fi> (raw)
In-Reply-To: <CAAObsKABUa9xD+hntyv97ZQB7Bk05kN0h0-+H7Q9ks6RT0yV2Q@mail.gmail.com>
FYI, the structure the EMC series currently takes (in my local branch)
is as follows:
- clock implementation in CAR code. This just knows about allowed rates
and which parents should have them and handles reparenting when required.
- memory/tegra124-emc: this contains the EMC rate change sequence and
exports an API which the clock driver uses.
- memory/tegra124-mc: contains API to write registers in MC memory
space, used by memory/tegra124-emc.
(I decided that this is cleaner than having a huge EMC driver that uses
an API exported by CAR)
I'm not sure if adding the bandwidth management code to the clock or
memory/emc driver would be best. But we can decide that later.
I need to clean up the series after the big refactorings; I'll submit a
new version once that's done.
Mikko
(P.S. my internship ended so I'm using this address now)
On 09/05/2014 01:22 PM, Tomeu Vizoso wrote:
> On 26 August 2014 09:42, Mikko Perttunen <mperttunen@nvidia•com> wrote:
>> On 25/08/14 20:40, Stephen Warren wrote:
>>>
>>> On 07/11/2014 08:18 AM, Mikko Perttunen wrote:
>>>>
>>>> Hi everyone,
>>>>
>>>> this series adds support for the EMC (external memory controller) clock
>>>> in the Tegra124 system-on-chip. The series has been tested on Jetson TK1.
>>>>
>>>> The first two patches remove the old "emc_mux" and "emc" clocks from the
>>>> clock tree and the device tree bindings. This is, of course, not
>>>> backwards
>>>> compatible, but as these clocks have never been useful for anything
>>>> (apart from maybe reading the boot rate of the EMC clock). If this is
>>>> still
>>>> not acceptable, the second patch can be dropped.
>>>
>>> ...
>>>
>>> Mikko, this series had some comments, especially on the DT binding
>>> (patch 5/8) and how the MC/EMC drivers interact. Is there an updated
>>> version of the series? Or, is the series replaced by Tomeu Vizoso's work?
>>
>>
>> Yes, I have a v2 with these comments addressed. One concern, though, is the
>> part writing to CLK_SOURCE_EMC. If some other driver also wants to read this
>> register (MC, likely), we might need to have an API for it in the CAR
>> driver. On the other hand, maybe not, since it's only one register. Thierry?
>>
>> Another point is that v2 adds a new API to the MC driver, which also doesn't
>> exist yet. The EMC driver can technically work without the MC driver (but
>> with a header for MC added), but I'm not sure the result would be very
>> useful.
>>
>> I believe the plan is that Tomeu's EMC code will be integrated into this EMC
>> driver once both are ready.
>
> That's mostly right. My clk constraints series just allow consumers to
> influence the effective rate of a clock, such as the EMC. And the
> pm_qos series will allow to track the total memory bandwidth needs in
> the system. I'm not sure yet where in the code this tracking will be
> done. It could be done in an EMC driver in drivers/memory, but it's
> probably too unrelated to be placed in the EMC clock driver.
>
> Regards,
>
> Tomeu
> --
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prev parent reply other threads:[~2014-09-05 10:55 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-11 14:18 [PATCH 0/8] Tegra124 EMC (external memory controller) support Mikko Perttunen
2014-07-11 14:18 ` [PATCH 1/8] clk: tegra124: Remove old emc_mux and emc clocks Mikko Perttunen
2014-07-11 14:18 ` [PATCH 2/8] ARM: tegra: Remove TEGRA124_CLK_EMC from tegra124-car.h Mikko Perttunen
2014-07-21 22:37 ` Stephen Warren
2014-07-29 8:28 ` Mikko Perttunen
2014-07-11 14:18 ` [PATCH 3/8] ARM: tegra: Add PLL_M_UD and PLL_C_UD to tegra124-car binding header Mikko Perttunen
2014-08-25 17:41 ` Stephen Warren
2014-09-17 13:41 ` Peter De Schrijver
2014-07-11 14:18 ` [PATCH 4/8] clk: tegra124: Add PLL_M_UD and PLL_C_UD clocks Mikko Perttunen
2014-07-11 14:18 ` [PATCH 5/8] of: Add Tegra124 EMC bindings Mikko Perttunen
2014-07-11 14:51 ` Thierry Reding
2014-07-11 16:01 ` Mikko Perttunen
2014-07-14 7:55 ` Mikko Perttunen
2014-07-14 8:15 ` Thierry Reding
2014-07-14 9:06 ` Mikko Perttunen
2014-07-14 9:31 ` Thierry Reding
2014-07-14 9:57 ` Mikko Perttunen
2014-07-14 10:29 ` Thierry Reding
2014-07-14 10:54 ` Mikko Perttunen
2014-07-14 11:10 ` Thierry Reding
2014-07-14 12:28 ` Mikko Perttunen
2014-07-11 16:43 ` Andrew Bresticker
2014-07-11 16:48 ` Mikko Perttunen
2014-07-21 21:28 ` Stephen Warren
2014-07-21 22:52 ` Andrew Bresticker
2014-07-22 16:45 ` Stephen Warren
2014-07-22 17:22 ` Andrew Bresticker
2014-07-22 17:34 ` Stephen Warren
2014-07-29 8:30 ` Mikko Perttunen
2014-07-29 15:49 ` Stephen Warren
2014-07-31 10:48 ` Mikko Perttunen
2014-07-31 11:05 ` Mikko Perttunen
2014-07-31 15:32 ` Stephen Warren
2014-07-21 22:36 ` Stephen Warren
2014-07-11 14:18 ` [PATCH 6/8] ARM: tegra: Add EMC to Tegra124 device tree Mikko Perttunen
2014-07-11 14:18 ` [PATCH 7/8] ARM: tegra: Add EMC timings to Jetson TK1 " Mikko Perttunen
2014-07-11 14:18 ` [PATCH 8/8] clk: tegra: Add EMC clock driver Mikko Perttunen
2014-07-22 16:57 ` Stephen Warren
2014-07-29 8:47 ` Mikko Perttunen
2014-07-29 20:19 ` Mike Turquette
2014-07-29 22:14 ` Stephen Warren
2014-07-30 9:34 ` Thierry Reding
2014-07-31 19:06 ` Mike Turquette
2014-07-31 19:53 ` Stephen Warren
2014-07-31 23:08 ` Mike Turquette
2014-08-01 6:31 ` Mikko Perttunen
2014-08-01 8:40 ` Thierry Reding
2014-08-25 17:40 ` [PATCH 0/8] Tegra124 EMC (external memory controller) support Stephen Warren
2014-08-26 7:42 ` Mikko Perttunen
2014-08-26 7:47 ` Thierry Reding
2014-08-26 8:02 ` Mikko Perttunen
2014-09-05 10:22 ` Tomeu Vizoso
2014-09-05 10:55 ` Mikko Perttunen [this message]
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