From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>,
Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rob Herring <robh@kernel.org>,
rjw@rjwysocki.net, lukasz.luba@arm.com, heiko@sntech.de,
arnd@linaro.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>,
"moderated list:ARM/Rockchip SoC support"
<linux-arm-kernel@lists.infradead.org>,
"open list:ARM/Rockchip SoC support"
<linux-rockchip@lists.infradead.org>
Subject: Re: [PATCH v5 5/6] rockchip/soc/drivers: Add DTPM description for rk3399
Date: Wed, 5 Jan 2022 10:21:58 +0100 [thread overview]
Message-ID: <08787cb7-439e-74a4-f268-6c8de0d60a30@linaro.org> (raw)
In-Reply-To: <CAMuHMdXzs9WMksQAJXdYaQndsqK3CnQZTGYw=TSFVrDEdX8PCA@mail.gmail.com>
Hi Geert,
thanks for your feedback
On 04/01/2022 10:29, Geert Uytterhoeven wrote:
> On Fri, Dec 31, 2021 at 2:58 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>> On Sat, 18 Dec 2021 at 14:00, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
>>> The DTPM framework does support now the hierarchy description.
>>>
>>> The platform specific code can call the hierarchy creation function
>>> with an array of struct dtpm_node pointing to their parent.
>>>
>>> This patch provides a description of the big and Little CPUs and the
>>> GPU and tie them together under a virtual package name. Only rk3399 is
>>> described now.
>>>
>>> The description could be extended in the future with the memory
>>> controller with devfreq if it has the energy information.
>>>
>>> The hierarchy uses the GPU devfreq with the panfrost driver, and this
>>> one could be loaded as a module. If the hierarchy is created before
>>> the panfrost driver is loaded, it will fail. For this reason the
>>> Kconfig option depends on the panfrost Kconfig's option. If this one
>>> is compiled as a module, automatically the dtpm hierarchy code will be
>>> a module also. Module loading ordering will fix this chicken-egg
>>> problem.
>>>
>>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>
>>> --- /dev/null
>>> +++ b/drivers/soc/rockchip/dtpm.c
>>> @@ -0,0 +1,56 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright 2021 Linaro Limited
>>> + *
>>> + * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
>>> + *
>>> + * DTPM hierarchy description
>>> + */
>>> +#include <linux/dtpm.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/platform_device.h>
>>> +
>>> +static struct dtpm_node __initdata rk3399_hierarchy[] = {
>>> + [0]{ .name = "rk3399" },
>>> + [1]{ .name = "package",
>>> + .parent = &rk3399_hierarchy[0] },
>>> + [2]{ .name = "/cpus/cpu@0",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [3]{ .name = "/cpus/cpu@1",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [4]{ .name = "/cpus/cpu@2",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [5]{ .name = "/cpus/cpu@3",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [6]{ .name = "/cpus/cpu@100",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [7]{ .name = "/cpus/cpu@101",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [8]{ .name = "rockchip,rk3399-mali",
>>> + .type = DTPM_NODE_DT,
>>> + .parent = &rk3399_hierarchy[1] },
>>> + [9]{ },
>>> +};
>>
>> I will not object to this, as in the end this seems like what we need
>> to do, unless we can describe things through generic DT bindings for
>> DTPM. Right?
>>
>> Although, if the above is correct, I need to stress that I am kind of
>> worried that this doesn't really scale. We would need to copy lots of
>> information from the DTS files into platform specific c-files, to be
>> able to describe the DTPM hierarchy.
>
> The description in rk3399_hierarchy[] looks fairly similar to a
> power-domains hierarchy, like we have in e.g. the various
> drivers/soc/renesas/r8*-sysc.c files. One big difference is that the
> latter do not hardcode the node paths in the driver, but use power
> domain indices, referenced from DT in power-domains properties.
>
> Perhaps a similar approach can be used for DTPM?
> Does DTPM differ a lot from PM Domains?
Yes they differ. A DTPM node is a powerzone, a place where we can get
and set the power.
That is the reason why initially a separate binding was proposed.
> If not, perhaps no new
> properties are needed, and power-domains/#power-domain-cells can be
> used as is?
--
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next prev parent reply other threads:[~2022-01-05 9:22 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-18 13:00 [PATCH v5 0/6] powercap/drivers/dtpm: Create the dtpm hierarchy Daniel Lezcano
2021-12-18 13:00 ` [PATCH v5 1/6] powercap/drivers/dtpm: Move dtpm table from init to data section Daniel Lezcano
2021-12-31 13:33 ` Ulf Hansson
2022-01-04 8:57 ` Daniel Lezcano
2022-01-07 13:15 ` Daniel Lezcano
2022-01-07 14:49 ` Ulf Hansson
2022-01-10 13:33 ` Daniel Lezcano
2021-12-18 13:00 ` [PATCH v5 2/6] powercap/drivers/dtpm: Add hierarchy creation Daniel Lezcano
2021-12-31 13:45 ` Ulf Hansson
2022-01-05 16:00 ` Daniel Lezcano
2022-01-07 15:54 ` Ulf Hansson
2022-01-10 15:55 ` Daniel Lezcano
2022-01-11 8:28 ` Ulf Hansson
2022-01-11 17:52 ` Daniel Lezcano
2022-01-12 12:00 ` Ulf Hansson
2022-01-14 19:15 ` Daniel Lezcano
2021-12-18 13:00 ` [PATCH v5 3/6] powercap/drivers/dtpm: Add CPU DT initialization support Daniel Lezcano
2021-12-31 13:46 ` Ulf Hansson
2021-12-18 13:00 ` [PATCH v5 4/6] powercap/drivers/dtpm: Add dtpm devfreq with energy model support Daniel Lezcano
2021-12-18 13:00 ` [PATCH v5 5/6] rockchip/soc/drivers: Add DTPM description for rk3399 Daniel Lezcano
2021-12-31 13:57 ` Ulf Hansson
2022-01-04 9:29 ` Geert Uytterhoeven
2022-01-05 9:21 ` Daniel Lezcano [this message]
2022-01-05 11:25 ` Daniel Lezcano
2021-12-18 13:00 ` [PATCH v5 6/6] qcom/soc/drivers: Add DTPM description for sdm845 Daniel Lezcano
2021-12-18 19:47 ` Steev Klimaszewski
2021-12-18 20:11 ` Daniel Lezcano
2021-12-19 18:44 ` Steev Klimaszewski
2021-12-19 20:27 ` Daniel Lezcano
2022-01-07 19:27 ` Bjorn Andersson
2022-01-07 22:07 ` Daniel Lezcano
2022-01-07 23:51 ` Bjorn Andersson
2021-12-23 13:20 ` [PATCH v5 0/6] powercap/drivers/dtpm: Create the dtpm hierarchy Daniel Lezcano
2021-12-23 13:32 ` Ulf Hansson
2021-12-23 13:42 ` Daniel Lezcano
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