From: Lee Jones <lee@kernel.org>
To: Hector Martin <marcan@marcan.st>
Cc: Russell King <rmk+kernel@armlinux.org.uk>,
Arnd Bergmann <arnd@arndb.de>,
Linus Walleij <linus.walleij@linaro.org>,
Alyssa Rosenzweig <alyssa@rosenzweig.io>,
asahi@lists.linux.dev, Bartosz Golaszewski <brgl@bgdev.pl>,
linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org,
Sven Peter <sven@svenpeter.dev>
Subject: Re: [PATCH 4/6] platform/apple: Add new Apple Mac SMC driver
Date: Mon, 31 Oct 2022 09:29:26 +0000 [thread overview]
Message-ID: <Y1+VdnmMUfIKTwWF@google.com> (raw)
In-Reply-To: <dcd692aa-1525-4fc5-5198-37f803725c4f@marcan.st>
On Mon, 31 Oct 2022, Hector Martin wrote:
> On 31/10/2022 17.48, Lee Jones wrote:
> > On Sat, 29 Oct 2022, Hector Martin wrote:
> >
> >> On 09/09/2022 16.50, Lee Jones wrote:
> >>>> What's the point of just having effectively an array of mfd_cell and
> >>>> wrappers to call into the mfd core in the drivers/mfd/ tree and the
> >>>> rest of the driver elsewhere?
> >>>
> >>> They should be separate drivers, with MFD registering the Platform.
> >>
> >> Why? What purpose does this serve? I'm still confused. There's one
> >> parent device, which provides services to the child devices. There isn't
> >> one parent device which wraps a platform service which is used by
> >> children. This makes no sense. The platform device is the root, if it
> >> exposes MFD services, then it has to be in that direction, not the other
> >> way around.
> >>
> >> Look at how this patch series is architected. There is smc_core.c, which
> >> implements SMC helpers and wrappers on top of a generic backend, and
> >> registers with the MFD subsystem. And then there is smc_rtkit.c which is
> >> the actual platform implementation on top of the RTKit framework, and is
> >> the actual platform device entry point.
> >>
> >> A priori, the only thing that makes sense to me right now would be to
> >> move smc_core.c into drivers/mfd, and leave smc_rtkit.c in platform.
> >> That way the mfd registration would be in drivers/mfd (as would be the
> >> services offered to sub-drivers), but the actual backend implementation
> >> would be in platform/ (and there would eventually be others, e.g. at
> >> least two more for x86 systems). That does mean that the driver entry
> >> point will be in platform/, with mfd/smc_core.c serving as effectively
> >> library code to plumb in the mfd stuff into one of several possible
> >> platform devices. Would that work for you?
> >
> > Yes, sounds sensible. However, keep all of the abstraction craziness
> > somewhere else and fetch and share all of your shared resources from
> > the MFD (SMC) driver.
>
> I'm not sure what you mean by that. The abstraction (smc_core.c) *is*
> the shared resource. All it does is wrap ops callbacks with a mutex and
> add a couple helpers for finding keys. Do you literally want us to just
> have this in drivers/mfd?
>
> // SPDX-License-Identifier: GPL-2.0-only OR MIT
> /*
> * Apple SMC MFD wrapper
> * Copyright The Asahi Linux Contributors
> */
>
> #include <linux/device.h>
> #include "smc.h"
>
> static const struct mfd_cell apple_smc_devs[] = {
> {
> .name = "macsmc-gpio",
> },
> {
> .name = "macsmc-hid",
> },
> {
> .name = "macsmc-power",
> },
> {
> .name = "macsmc-reboot",
> },
> {
> .name = "macsmc-rtc",
> },
> };
>
> int apple_smc_add_mfd_devices(struct device *dev)
> {
> ret = mfd_add_devices(dev, -1, apple_smc_devs,
> ARRAY_SIZE(apple_smc_devs), NULL, 0, NULL);
> if (ret)
> return dev_err_probe(dev, ret, "Subdevice initialization failed");
>
> return 0;
> }
> EXPORT_SYMBOL(apple_smc_add_mfd_devices);
>
> int apple_smc_remove_mfd_devices(struct device *dev)
> {
> mfd_remove_devices(smc->dev);
>
> return 0;
> }
> EXPORT_SYMBOL(apple_smc_add_mfd_devices);
>
> MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");
> MODULE_LICENSE("Dual MIT/GPL");
> MODULE_DESCRIPTION("Apple SMC MFD wrapper");
>
> Because this feels *immensely* silly and pointless.
... and hacky. I agree.
[BTW: if this is all you want to do, have you considered simple-mfd?]
No, I want you to author a proper MFD device.
The hardware you're describing in this submission *is* an MFD. So use
the subsystem properly, instead of abusing it as a shim API to simply
register platform devices.
Request the device-wide memory (and other shared resources) here.
Conduct core operations and initialisation here, then call into your
Platform and other child devices to initiate the real work.
--
Lee Jones [李琼斯]
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next prev parent reply other threads:[~2022-10-31 9:30 UTC|newest]
Thread overview: 171+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 13:54 [PATCH 0/6] Add Apple Mac System Management Controller GPIOs Russell King (Oracle)
2022-09-01 13:54 ` [PATCH 1/6] dt-bindings: mfd: add binding for Apple Mac System Management Controller Russell King (Oracle)
2022-09-01 15:06 ` Krzysztof Kozlowski
2022-09-01 15:12 ` Russell King (Oracle)
2022-09-01 15:15 ` Krzysztof Kozlowski
2022-09-01 15:24 ` Russell King (Oracle)
2022-09-01 15:45 ` Krzysztof Kozlowski
2022-09-01 15:56 ` Russell King (Oracle)
2022-09-01 16:25 ` Krzysztof Kozlowski
2022-09-01 16:47 ` Russell King (Oracle)
2022-09-01 22:33 ` Rob Herring
2022-09-02 15:06 ` Mark Kettenis
2022-09-02 17:28 ` Rob Herring
2022-09-05 10:24 ` Russell King (Oracle)
2022-09-06 9:04 ` Russell King (Oracle)
2022-09-06 9:31 ` Mark Kettenis
2022-09-06 11:22 ` Linus Walleij
2022-09-06 11:36 ` Hector Martin
2022-09-06 11:57 ` Linus Walleij
2022-09-06 13:28 ` Hector Martin
2022-09-06 13:43 ` Russell King (Oracle)
2022-09-06 13:53 ` Hector Martin
2022-09-06 14:25 ` Mark Kettenis
2022-09-06 14:54 ` Russell King (Oracle)
2022-09-06 15:38 ` Mark Kettenis
2022-09-06 15:55 ` Rob Herring
2022-09-06 13:46 ` Linus Walleij
2022-09-06 15:34 ` Rob Herring
2022-09-06 16:10 ` Rob Herring
2022-09-06 17:00 ` Hector Martin
2022-09-06 17:35 ` Rob Herring
2022-09-06 17:40 ` Sven Peter
2022-09-06 18:38 ` Hector Martin
2022-09-07 9:39 ` Mark Kettenis
2022-09-01 22:26 ` Rob Herring
2022-09-02 14:49 ` Mark Kettenis
2022-09-02 17:04 ` Rob Herring
2022-09-01 19:14 ` Rob Herring
2022-09-01 13:54 ` [PATCH 2/6] dt-bindings: gpio: add binding for the GPIO block for Apple Mac SMC Russell King (Oracle)
2022-09-01 15:11 ` Krzysztof Kozlowski
2022-09-01 15:14 ` Russell King (Oracle)
2022-09-01 13:54 ` [PATCH 3/6] soc: apple: rtkit: Add apple_rtkit_poll Russell King
2022-09-01 17:00 ` Sven Peter
2022-09-01 17:25 ` Eric Curtin
2022-09-01 13:54 ` [PATCH 4/6] platform/apple: Add new Apple Mac SMC driver Russell King
2022-09-01 17:50 ` Sven Peter
2022-09-05 10:55 ` Russell King (Oracle)
2022-09-05 16:53 ` Hector Martin
2022-09-01 19:26 ` Andy Shevchenko
2022-09-02 6:45 ` Sven Peter
2022-09-05 14:45 ` Hector Martin
2022-09-05 15:00 ` Andy Shevchenko
2022-09-08 10:58 ` Lee Jones
2022-09-08 11:28 ` Hector Martin
2022-09-08 12:31 ` Lee Jones
2022-09-08 12:58 ` Hector Martin
2022-09-08 13:29 ` Linus Walleij
2022-09-08 13:36 ` Lee Jones
2022-09-08 13:58 ` Hector Martin
2022-09-09 7:50 ` Lee Jones
2022-09-12 10:03 ` Russell King (Oracle)
2022-09-12 10:55 ` Lee Jones
2022-10-28 15:36 ` Russell King (Oracle)
2022-10-31 8:46 ` Lee Jones
2022-10-31 9:03 ` Hector Martin
2022-10-31 9:44 ` Russell King (Oracle)
2022-10-31 17:24 ` Lee Jones
2022-10-31 19:47 ` Russell King (Oracle)
2022-11-01 9:59 ` Lee Jones
2022-10-29 6:40 ` Hector Martin
2022-10-31 8:48 ` Lee Jones
2022-10-31 8:58 ` Hector Martin
2022-10-31 9:29 ` Lee Jones [this message]
2022-10-31 9:44 ` Hector Martin
2022-10-31 17:23 ` Lee Jones
2022-10-31 19:34 ` Russell King (Oracle)
2022-11-02 13:12 ` Lee Jones
2022-11-02 15:54 ` Russell King (Oracle)
2022-09-01 13:54 ` [PATCH 5/6] gpio: Add new gpio-macsmc driver for Apple Macs Russell King
2022-09-01 18:55 ` Andy Shevchenko
2022-09-01 21:51 ` Martin Povišer
2022-09-02 6:31 ` Andy Shevchenko
[not found] ` <3B649A66-8116-432D-B88A-B5CE493EF930@cutebit.org>
[not found] ` <CAHp75VeB3_sZ2vsSxMSsLeJSkyemDh9iOPHXJCN1mhodA13LNQ@mail.gmail.com>
2022-09-02 11:12 ` Martin Povišer
2022-09-02 13:33 ` Andy Shevchenko
2022-09-02 13:36 ` Andy Shevchenko
2022-09-02 13:37 ` Martin Povišer
2022-09-02 14:41 ` Andy Shevchenko
2022-09-02 14:45 ` Russell King (Oracle)
2022-09-02 10:05 ` Russell King (Oracle)
2022-09-02 10:37 ` Andy Shevchenko
2022-09-02 11:32 ` Russell King (Oracle)
2022-09-02 13:39 ` Andy Shevchenko
2022-09-02 14:46 ` Russell King (Oracle)
2022-09-02 14:53 ` Andy Shevchenko
2022-09-02 15:34 ` Russell King (Oracle)
2022-09-02 15:43 ` Andy Shevchenko
2022-09-05 10:20 ` Russell King (Oracle)
2022-09-05 10:32 ` Andy Shevchenko
2022-09-05 13:10 ` Russell King (Oracle)
2022-09-05 13:16 ` Andy Shevchenko
2022-09-05 14:01 ` Russell King (Oracle)
2022-09-05 14:02 ` Russell King (Oracle)
2022-09-05 14:42 ` Andy Shevchenko
2022-09-05 14:53 ` Russell King (Oracle)
2022-09-05 14:50 ` Andy Shevchenko
2022-09-05 15:52 ` Hector Martin
2022-09-05 15:56 ` Russell King (Oracle)
2022-09-05 15:32 ` Russell King (Oracle)
2022-09-05 15:44 ` Martin Povišer
2022-09-05 15:58 ` Hector Martin
2022-09-05 16:13 ` Russell King (Oracle)
2022-09-05 19:10 ` Linus Walleij
2022-09-06 6:51 ` Hector Martin
2022-09-05 15:47 ` Hector Martin
2022-09-05 15:39 ` Hector Martin
2022-09-05 15:16 ` Hector Martin
2022-09-05 15:04 ` Hector Martin
2022-09-02 9:42 ` Linus Walleij
2022-09-01 13:54 ` [PATCH 6/6] gpio: macsmc: Add IRQ support Russell King
2022-09-01 18:03 ` Andy Shevchenko
2022-09-05 11:54 ` Russell King (Oracle)
[not found] ` <CAHp75VeDGCp8J6wnmCqGpV++vs2Zur9Mfp71Dk8dVXcuHFnCrQ@mail.gmail.com>
2022-09-05 13:21 ` Andy Shevchenko
2022-09-02 13:21 ` Linus Walleij
2022-09-05 12:47 ` Russell King (Oracle)
2022-09-05 13:19 ` Fwd: " Andy Shevchenko
2022-09-05 21:43 ` Russell King (Oracle)
2022-09-05 13:27 ` Linus Walleij
2022-09-06 7:00 ` Hector Martin
2022-09-06 7:47 ` Russell King (Oracle)
2022-09-06 8:00 ` Hector Martin
2022-09-01 15:12 ` [PATCH 0/6] Add Apple Mac System Management Controller GPIOs Krzysztof Kozlowski
2022-10-27 15:35 ` Russell King (Oracle)
2022-11-08 16:32 ` [PATCH v3 0/7] " Russell King (Oracle)
2022-11-08 16:33 ` [PATCH v3 1/7] mfd: Add core Apple Mac SMC driver Russell King
2022-11-14 9:52 ` Lee Jones
2022-11-14 10:35 ` Andy Shevchenko
2022-11-08 16:33 ` [PATCH v3 2/7] lib/vsprintf: Add support for generic FOURCCs by extending %p4cc Russell King
2022-11-14 15:34 ` Petr Mladek
2022-11-14 15:46 ` Andy Shevchenko
2022-11-14 16:18 ` Petr Mladek
2022-11-14 16:15 ` Russell King (Oracle)
2022-11-14 16:46 ` Russell King (Oracle)
2022-11-22 12:43 ` Petr Mladek
2022-11-22 14:49 ` Petr Mladek
2022-11-08 16:33 ` [PATCH v3 3/7] dt-bindings: mfd: add binding for Apple Mac System Management Controller Russell King (Oracle)
2022-11-08 20:42 ` Linus Walleij
2022-11-08 20:55 ` Krzysztof Kozlowski
2022-11-08 22:22 ` Russell King (Oracle)
2022-11-09 8:35 ` Krzysztof Kozlowski
2022-11-09 22:17 ` Rob Herring
2022-11-10 11:35 ` Hector Martin
2022-11-10 11:48 ` Russell King (Oracle)
2022-11-10 14:00 ` Krzysztof Kozlowski
2022-11-10 14:14 ` Russell King (Oracle)
2022-11-10 14:21 ` Krzysztof Kozlowski
2022-11-10 14:23 ` Russell King (Oracle)
2022-11-10 14:36 ` Krzysztof Kozlowski
2022-11-10 14:43 ` Russell King (Oracle)
2022-11-14 10:05 ` Lee Jones
2022-11-08 22:30 ` Rob Herring
2022-11-08 16:33 ` [PATCH v3 4/7] platform/apple: Add new Apple Mac SMC driver Russell King
2022-11-08 16:33 ` [PATCH v3 5/7] arm64: dts: apple: Add SMC node to t8103 devicetrees Russell King
2022-11-08 16:33 ` [PATCH v3 6/7] dt-bindings: gpio: add binding for the GPIO block for Apple Mac SMC Russell King (Oracle)
2022-11-08 20:56 ` Krzysztof Kozlowski
2022-11-08 22:09 ` Russell King (Oracle)
2022-11-09 7:31 ` Hector Martin
2022-11-09 8:36 ` Krzysztof Kozlowski
2022-11-09 9:12 ` Russell King (Oracle)
2022-11-09 9:19 ` Krzysztof Kozlowski
2022-11-08 22:30 ` Rob Herring
2022-11-08 16:33 ` [PATCH v3 7/7] gpio: Add new gpio-macsmc driver for Apple Macs Russell King
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