* Re: [PATCH v2 2/3] dt-binding: rtc: loongson: Document Loongson-2K0300 compatible
From: Binbin Zhou @ 2026-01-07 1:22 UTC (permalink / raw)
To: Rob Herring
Cc: Binbin Zhou, Huacai Chen, Krzysztof Kozlowski, Conor Dooley,
Alexandre Belloni, linux-rtc, Xiaochuang Mao, Huacai Chen,
Xuerui Wang, loongarch, devicetree, linux-mips, Keguang Zhang
In-Reply-To: <20260106191314.GA2568583-robh@kernel.org>
Hi Rob:
Thanks for your review.
On Wed, Jan 7, 2026 at 3:13 AM Rob Herring <robh@kernel.org> wrote:
>
> On Tue, Jan 06, 2026 at 09:33:32AM +0800, Binbin Zhou wrote:
> > Add "loongson,ls2k0300-rtc" dedicated compatible to represent the RTC
> > interface of the Loongson-2K0300 chip.
> >
> > Its hardware design is similar to that of the Loongson-1B, but it does
> > not support the alarm feature.
>
> But you are requiring the interrupt property for it? Isn't it no alarm
> feature means no interrupt?
Yes, the `interrupts` attribute is not required without the alarm feature.
But my judgment condition is `not contains` (added in patch-1[1]).
There are only a few SoCs on the Loongson platform that don't support
the RTC alarm feature, so I think `not contains` looks cleaner and
simpler.
[1]: https://lore.kernel.org/all/8876bebaf08121bb5edd2500f5289284b75df011.1767663073.git.zhoubinbin@loongson.cn/
>
> >
> > Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> > ---
> > Documentation/devicetree/bindings/rtc/loongson,rtc.yaml | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/rtc/loongson,rtc.yaml b/Documentation/devicetree/bindings/rtc/loongson,rtc.yaml
> > index 8a2520f963d8..b62419c33fd5 100644
> > --- a/Documentation/devicetree/bindings/rtc/loongson,rtc.yaml
> > +++ b/Documentation/devicetree/bindings/rtc/loongson,rtc.yaml
> > @@ -23,6 +23,7 @@ properties:
> > - loongson,ls1b-rtc
> > - loongson,ls1c-rtc
> > - loongson,ls7a-rtc
> > + - loongson,ls2k0300-rtc
> > - loongson,ls2k1000-rtc
> > - items:
> > - enum:
> > @@ -49,6 +50,7 @@ if:
> > contains:
> > enum:
> > - loongson,ls1c-rtc
> > + - loongson,ls2k0300-rtc
> >
> > then:
> > required:
> > --
> > 2.47.3
> >
--
Thanks.
Binbin
^ permalink raw reply
* Re: [PATCH v2 00/17] tee: Use bus callbacks instead of driver callbacks
From: Jens Wiklander @ 2026-01-07 9:36 UTC (permalink / raw)
To: Jon Hunter
Cc: Uwe Kleine-König, Jonathan Corbet, Sumit Garg,
Olivia Mackall, Herbert Xu, Clément Léger,
Alexandre Belloni, Ard Biesheuvel, Maxime Coquelin,
Alexandre Torgue, Sumit Garg, Ilias Apalodimas, Jan Kiszka,
Sudeep Holla, Christophe JAILLET, Rafał Miłecki,
Michael Chan, Pavan Chebbi, James Bottomley, Jarkko Sakkinen,
Mimi Zohar, David Howells, Paul Moore, James Morris,
Serge E. Hallyn, Peter Huewe, op-tee, linux-kernel, linux-doc,
linux-crypto, linux-rtc, linux-efi, linux-stm32, linux-arm-kernel,
Cristian Marussi, arm-scmi, linux-mips, netdev, linux-integrity,
keyrings, linux-security-module, Jason Gunthorpe,
linux-tegra@vger.kernel.org
In-Reply-To: <d14a9c41-9df7-438f-bb58-097644d5d93f@nvidia.com>
Hi Jon,
On Tue, Jan 6, 2026 at 10:40 AM Jon Hunter <jonathanh@nvidia.com> wrote:
>
> Hi Uwe,
>
> On 15/12/2025 14:16, Uwe Kleine-König wrote:
> > Hello,
> >
> > the objective of this series is to make tee driver stop using callbacks
> > in struct device_driver. These were superseded by bus methods in 2006
> > (commit 594c8281f905 ("[PATCH] Add bus_type probe, remove, shutdown
> > methods.")) but nobody cared to convert all subsystems accordingly.
> >
> > Here the tee drivers are converted. The first commit is somewhat
> > unrelated, but simplifies the conversion (and the drivers). It
> > introduces driver registration helpers that care about setting the bus
> > and owner. (The latter is missing in all drivers, so by using these
> > helpers the drivers become more correct.)
> >
> > v1 of this series is available at
> > https://lore.kernel.org/all/cover.1765472125.git.u.kleine-koenig@baylibre.com
> >
> > Changes since v1:
> >
> > - rebase to v6.19-rc1 (no conflicts)
> > - add tags received so far
> > - fix whitespace issues pointed out by Sumit Garg
> > - fix shutdown callback to shutdown and not remove
> >
> > As already noted in v1's cover letter, this series should go in during a
> > single merge window as there are runtime warnings when the series is
> > only applied partially. Sumit Garg suggested to apply the whole series
> > via Jens Wiklander's tree.
> > If this is done the dependencies in this series are honored, in case the
> > plan changes: Patches #4 - #17 depend on the first two.
> >
> > Note this series is only build tested.
> >
> > Uwe Kleine-König (17):
> > tee: Add some helpers to reduce boilerplate for tee client drivers
> > tee: Add probe, remove and shutdown bus callbacks to tee_client_driver
> > tee: Adapt documentation to cover recent additions
> > hwrng: optee - Make use of module_tee_client_driver()
> > hwrng: optee - Make use of tee bus methods
> > rtc: optee: Migrate to use tee specific driver registration function
> > rtc: optee: Make use of tee bus methods
> > efi: stmm: Make use of module_tee_client_driver()
> > efi: stmm: Make use of tee bus methods
> > firmware: arm_scmi: optee: Make use of module_tee_client_driver()
> > firmware: arm_scmi: Make use of tee bus methods
> > firmware: tee_bnxt: Make use of module_tee_client_driver()
> > firmware: tee_bnxt: Make use of tee bus methods
> > KEYS: trusted: Migrate to use tee specific driver registration
> > function
> > KEYS: trusted: Make use of tee bus methods
> > tpm/tpm_ftpm_tee: Make use of tee specific driver registration
> > tpm/tpm_ftpm_tee: Make use of tee bus methods
>
>
> On the next-20260105 I am seeing the following warnings ...
>
> WARNING KERN Driver 'optee-rng' needs updating - please use bus_type methods
> WARNING KERN Driver 'scmi-optee' needs updating - please use bus_type methods
> WARNING KERN Driver 'tee_bnxt_fw' needs updating - please use bus_type methods
>
> I bisected the first warning and this point to the following
> commit ...
>
> # first bad commit: [a707eda330b932bcf698be9460e54e2f389e24b7] tee: Add some helpers to reduce boilerplate for tee client drivers
>
> I have not bisected the others, but guess they are related
> to this series. Do you observe the same?
Yes, I see the same.
I'm sorry, I didn't realize that someone might bisect this when I took
only a few of the patches into next. I've applied all the patches in
this series now.
Thanks,
Jens
^ permalink raw reply
* Re: [PATCH v2 00/17] tee: Use bus callbacks instead of driver callbacks
From: Jens Wiklander @ 2026-01-07 9:38 UTC (permalink / raw)
To: Sudeep Holla
Cc: Alexandre Belloni, Uwe Kleine-König, Jonathan Corbet,
Sumit Garg, Olivia Mackall, Herbert Xu, Clément Léger,
Ard Biesheuvel, Maxime Coquelin, Alexandre Torgue, Sumit Garg,
Ilias Apalodimas, Jan Kiszka, Christophe JAILLET,
Rafał Miłecki, Michael Chan, Pavan Chebbi,
James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
Paul Moore, James Morris, Serge E. Hallyn, Peter Huewe, op-tee,
linux-kernel, linux-doc, linux-crypto, linux-rtc, linux-efi,
linux-stm32, linux-arm-kernel, Cristian Marussi, arm-scmi,
linux-mips, netdev, linux-integrity, keyrings,
linux-security-module, Jason Gunthorpe
In-Reply-To: <aV0Qx5BOso5co3tm@bogus>
On Tue, Jan 6, 2026 at 2:40 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Mon, Jan 05, 2026 at 10:16:09AM +0100, Jens Wiklander wrote:
> > Hi,
> >
> > On Thu, Dec 18, 2025 at 5:29 PM Jens Wiklander
> > <jens.wiklander@linaro.org> wrote:
> > >
> > > On Thu, Dec 18, 2025 at 2:53 PM Alexandre Belloni
> > > <alexandre.belloni@bootlin.com> wrote:
> > > >
> > > > On 18/12/2025 08:21:27+0100, Jens Wiklander wrote:
> > > > > Hi,
> > > > >
> > > > > On Mon, Dec 15, 2025 at 3:17 PM Uwe Kleine-König
> > > > > <u.kleine-koenig@baylibre.com> wrote:
> > > > > >
> > > > > > Hello,
> > > > > >
> > > > > > the objective of this series is to make tee driver stop using callbacks
> > > > > > in struct device_driver. These were superseded by bus methods in 2006
> > > > > > (commit 594c8281f905 ("[PATCH] Add bus_type probe, remove, shutdown
> > > > > > methods.")) but nobody cared to convert all subsystems accordingly.
> > > > > >
> > > > > > Here the tee drivers are converted. The first commit is somewhat
> > > > > > unrelated, but simplifies the conversion (and the drivers). It
> > > > > > introduces driver registration helpers that care about setting the bus
> > > > > > and owner. (The latter is missing in all drivers, so by using these
> > > > > > helpers the drivers become more correct.)
> > > > > >
> > > > > > v1 of this series is available at
> > > > > > https://lore.kernel.org/all/cover.1765472125.git.u.kleine-koenig@baylibre.com
> > > > > >
> > > > > > Changes since v1:
> > > > > >
> > > > > > - rebase to v6.19-rc1 (no conflicts)
> > > > > > - add tags received so far
> > > > > > - fix whitespace issues pointed out by Sumit Garg
> > > > > > - fix shutdown callback to shutdown and not remove
> > > > > >
> > > > > > As already noted in v1's cover letter, this series should go in during a
> > > > > > single merge window as there are runtime warnings when the series is
> > > > > > only applied partially. Sumit Garg suggested to apply the whole series
> > > > > > via Jens Wiklander's tree.
> > > > > > If this is done the dependencies in this series are honored, in case the
> > > > > > plan changes: Patches #4 - #17 depend on the first two.
> > > > > >
> > > > > > Note this series is only build tested.
> > > > > >
> > > > > > Uwe Kleine-König (17):
> > > > > > tee: Add some helpers to reduce boilerplate for tee client drivers
> > > > > > tee: Add probe, remove and shutdown bus callbacks to tee_client_driver
> > > > > > tee: Adapt documentation to cover recent additions
> > > > > > hwrng: optee - Make use of module_tee_client_driver()
> > > > > > hwrng: optee - Make use of tee bus methods
> > > > > > rtc: optee: Migrate to use tee specific driver registration function
> > > > > > rtc: optee: Make use of tee bus methods
> > > > > > efi: stmm: Make use of module_tee_client_driver()
> > > > > > efi: stmm: Make use of tee bus methods
> > > > > > firmware: arm_scmi: optee: Make use of module_tee_client_driver()
> > > > > > firmware: arm_scmi: Make use of tee bus methods
> > > > > > firmware: tee_bnxt: Make use of module_tee_client_driver()
> > > > > > firmware: tee_bnxt: Make use of tee bus methods
> > > > > > KEYS: trusted: Migrate to use tee specific driver registration
> > > > > > function
> > > > > > KEYS: trusted: Make use of tee bus methods
> > > > > > tpm/tpm_ftpm_tee: Make use of tee specific driver registration
> > > > > > tpm/tpm_ftpm_tee: Make use of tee bus methods
> > > > > >
> > > > > > Documentation/driver-api/tee.rst | 18 +----
> > > > > > drivers/char/hw_random/optee-rng.c | 26 ++----
> > > > > > drivers/char/tpm/tpm_ftpm_tee.c | 31 +++++---
> > > > > > drivers/firmware/arm_scmi/transports/optee.c | 32 +++-----
> > > > > > drivers/firmware/broadcom/tee_bnxt_fw.c | 30 ++-----
> > > > > > drivers/firmware/efi/stmm/tee_stmm_efi.c | 25 ++----
> > > > > > drivers/rtc/rtc-optee.c | 27 ++-----
> > > > > > drivers/tee/tee_core.c | 84 ++++++++++++++++++++
> > > > > > include/linux/tee_drv.h | 12 +++
> > > > > > security/keys/trusted-keys/trusted_tee.c | 17 ++--
> > > > > > 10 files changed, 164 insertions(+), 138 deletions(-)
> > > > > >
> > > > > > base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> > > > > > --
> > > > > > 2.47.3
> > > > > >
> > > > >
> > > > > Thank you for the nice cleanup, Uwe.
> > > > >
> > > > > I've applied patch 1-3 to the branch tee_bus_callback_for_6.20 in my
> > > > > tree at https://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee.git/
> > > > >
> > > > > The branch is based on v6.19-rc1, and I'll try to keep it stable for
> > > > > others to depend on, if needed. Let's see if we can agree on taking
> > > > > the remaining patches via that branch.
> > > >
> > > > 6 and 7 can go through your branch.
> > >
> > > Good, I've added them to my branch now.
> >
> > This entire patch set should go in during a single merge window. I
> > will not send any pull request until I'm sure all patches will be
> > merged.
> >
> > So far (if I'm not mistaken), only the patches I've already added to
> > next have appeared next. I can take the rest of the patches, too, but
> > I need OK for the following:
> >
>
> [...]
>
> >
> > Sudeep, you seem happy with the following patches
> > - firmware: arm_scmi: optee: Make use of module_tee_client_driver()
> > - firmware: arm_scmi: Make use of tee bus methods
> > OK if I take them via my tree, or would you rather take them yourself?
> >
>
> I am happy if you want to take all of them in one go. I think I have
> already acked it. Please shout if you need anything else from me, happy to
> help in anyway to make it easier to handle this change set.
Thanks, I've applied all the patches in the series now, since it
otherwise causes warnings during boot.
/Jens
^ permalink raw reply
* Re: [RFC PATCH v1 4/4] rust: add PL031 RTC driver
From: Danilo Krummrich @ 2026-01-07 10:15 UTC (permalink / raw)
To: Dirk Behme
Cc: Ke Sun, Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, linux-rtc, rust-for-linux, Alvin Sun,
Joel Fernandes, Alexandre Courbot
In-Reply-To: <48d23334-b167-48a5-a645-28276eb85b00@gmail.com>
On Sun Jan 4, 2026 at 10:02 AM CET, Dirk Behme wrote:
> Do we want a common register access style in Rust drivers and want to
> encourge using the register macro for that? Or do we take what we have
> at the moment (like here) and eventually convert later to the register
> macro? Or not? Opinions?
Yes, the idea is that drivers use the register!() macro for definitions (this
has been what I am looking for since proposing it in [1]).
Please also see [2] for some more rationale and design considerations.
Ideally, we land the patch series moving the register!() macro from nova-core
(which we used as a playground for development and to proof the concept) to
common infrastructure this cycle.
This way drivers targeting next cycle or later can start using it right away.
Should we not make it in this cycle, we can also consider a feature branch to
share with upcoming drivers, but let's see how it goes first.
> I know that it is not ready yet and still in development, but what's
> about the register!() macro [1] [2]?
As mentioned above, it's not that it is not ready. We are actively using it in
nova-core for quite a while now, but we now have to move it to common
infrastructure.
It probably would have been better to do the move first and then extract generic
bitfield code afterwards, but we should be on track now. :)
- Danilo
[1] https://docs.kernel.org/gpu/nova/core/todo.html#generic-register-abstraction-rega
[2] https://lore.kernel.org/all/DD15H63RK1KJ.1J584C1QC4L28@kernel.org/
^ permalink raw reply
* [RFC PATCH v2 0/5] rust: Add RTC driver support
From: Ke Sun @ 2026-01-07 14:37 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun, Ke Sun
This patch series adds RTC (Real-Time Clock) driver support for the Rust
kernel, including the necessary infrastructure and a complete driver implementation
for the PL031 RTC.
---
v2:
- Migrate RTC driver data storage from parent device to RTC device for unified interface
- Expand AMBA bus abstractions to full driver support with enhanced functionality
- Refactor device wakeup API by moving wake IRQ setup to IRQ layer
- Simplify RTC core framework by removing multi-bus abstractions, focusing on core operations
- Optimize PL031 driver implementation and remove build assertion dependency
v1: https://lore.kernel.org/rust-for-linux/20260104060621.3757812-1-sunke@kylinos.cn/
- Add AMBA bus abstractions
- Add device wakeup support
- Add RTC core framework with multi-bus support
- Add PL031 RTC driver
base-commit:
---
Ke Sun (5):
rtc: migrate driver data to RTC device
rust: add AMBA bus driver support
rust: add device wakeup capability support
rust: add RTC core abstractions and data structures
rust: add PL031 RTC driver
drivers/rtc/Kconfig | 9 +
drivers/rtc/Makefile | 1 +
drivers/rtc/dev.c | 4 +-
drivers/rtc/interface.c | 18 +-
drivers/rtc/rtc-pl031.c | 9 +-
drivers/rtc/rtc_pl031_rust.rs | 503 ++++++++++++++++
rust/bindings/bindings_helper.h | 3 +
rust/helpers/device.c | 7 +
rust/helpers/helpers.c | 1 +
rust/helpers/rtc.c | 9 +
rust/kernel/amba.rs | 396 +++++++++++++
rust/kernel/device.rs | 17 +-
rust/kernel/irq/request.rs | 7 +
rust/kernel/lib.rs | 4 +
rust/kernel/rtc.rs | 985 ++++++++++++++++++++++++++++++++
15 files changed, 1954 insertions(+), 19 deletions(-)
create mode 100644 drivers/rtc/rtc_pl031_rust.rs
create mode 100644 rust/helpers/rtc.c
create mode 100644 rust/kernel/amba.rs
create mode 100644 rust/kernel/rtc.rs
--
2.43.0
^ permalink raw reply
* [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Ke Sun @ 2026-01-07 14:37 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun, Ke Sun
In-Reply-To: <20260107143738.3021892-1-sunke@kylinos.cn>
Unify RTC driver interface by storing driver data on the RTC device
instead of the parent device. Update RTC ops callbacks to pass the RTC
device itself rather than its parent. This change enables better
support for Rust RTC drivers that store data on the RTC device.
Signed-off-by: Ke Sun <sunke@kylinos.cn>
---
drivers/rtc/dev.c | 4 ++--
drivers/rtc/interface.c | 18 +++++++++---------
drivers/rtc/rtc-pl031.c | 9 ++-------
3 files changed, 13 insertions(+), 18 deletions(-)
diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
index baf1a8ca8b2b1..0f62ba9342e3e 100644
--- a/drivers/rtc/dev.c
+++ b/drivers/rtc/dev.c
@@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
}
default:
if (rtc->ops->param_get)
- err = rtc->ops->param_get(rtc->dev.parent, ¶m);
+ err = rtc->ops->param_get(&rtc->dev, ¶m);
else
err = -EINVAL;
}
@@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
default:
if (rtc->ops->param_set)
- err = rtc->ops->param_set(rtc->dev.parent, ¶m);
+ err = rtc->ops->param_set(&rtc->dev, ¶m);
else
err = -EINVAL;
}
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index b8b298efd9a9c..783a3ec3bb93d 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
err = -EINVAL;
} else {
memset(tm, 0, sizeof(struct rtc_time));
- err = rtc->ops->read_time(rtc->dev.parent, tm);
+ err = rtc->ops->read_time(&rtc->dev, tm);
if (err < 0) {
dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
err);
@@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
if (!rtc->ops)
err = -ENODEV;
else if (rtc->ops->set_time)
- err = rtc->ops->set_time(rtc->dev.parent, tm);
+ err = rtc->ops->set_time(&rtc->dev, tm);
else
err = -EINVAL;
@@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
alarm->time.tm_wday = -1;
alarm->time.tm_yday = -1;
alarm->time.tm_isdst = -1;
- err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
+ err = rtc->ops->read_alarm(&rtc->dev, alarm);
}
mutex_unlock(&rtc->ops_lock);
@@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
err = -EINVAL;
else
- err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
+ err = rtc->ops->set_alarm(&rtc->dev, alarm);
/*
* Check for potential race described above. If the waiting for next
@@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
err = -EINVAL;
else
- err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
+ err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
mutex_unlock(&rtc->ops_lock);
@@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
rtc->uie_rtctimer.period = ktime_set(1, 0);
err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
- err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
+ err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
if (err)
goto out;
} else {
@@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
return;
- rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
+ rtc->ops->alarm_irq_enable(&rtc->dev, false);
trace_rtc_alarm_irq_enable(0, 0);
}
@@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
return -EINVAL;
mutex_lock(&rtc->ops_lock);
- ret = rtc->ops->read_offset(rtc->dev.parent, offset);
+ ret = rtc->ops->read_offset(&rtc->dev, offset);
mutex_unlock(&rtc->ops_lock);
trace_rtc_read_offset(*offset, ret);
@@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
return -EINVAL;
mutex_lock(&rtc->ops_lock);
- ret = rtc->ops->set_offset(rtc->dev.parent, offset);
+ ret = rtc->ops->set_offset(&rtc->dev, offset);
mutex_unlock(&rtc->ops_lock);
trace_rtc_set_offset(offset, ret);
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index eab39dfa4e5fe..a605034d44cb7 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
static void pl031_remove(struct amba_device *adev)
{
- struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
-
- if (adev->irq[0])
- free_irq(adev->irq[0], ldata);
amba_release_regions(adev);
}
@@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
goto out;
}
- amba_set_drvdata(adev, ldata);
-
dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
@@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
ret = PTR_ERR(ldata->rtc);
goto out;
}
+ dev_set_drvdata(&ldata->rtc->dev, ldata);
if (!adev->irq[0])
clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
@@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
goto out;
if (adev->irq[0]) {
- ret = request_irq(adev->irq[0], pl031_interrupt,
+ ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
vendor->irqflags, "rtc-pl031", ldata);
if (ret)
goto out;
--
2.43.0
^ permalink raw reply related
* [RFC PATCH v2 2/5] rust: add AMBA bus driver support
From: Ke Sun @ 2026-01-07 14:37 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun, Ke Sun
In-Reply-To: <20260107143738.3021892-1-sunke@kylinos.cn>
Add Rust abstractions for ARM AMBA bus drivers, enabling Rust drivers
to interact with AMBA devices through a type-safe interface.
Signed-off-by: Ke Sun <sunke@kylinos.cn>
---
rust/bindings/bindings_helper.h | 1 +
rust/kernel/amba.rs | 396 ++++++++++++++++++++++++++++++++
rust/kernel/lib.rs | 2 +
3 files changed, 399 insertions(+)
create mode 100644 rust/kernel/amba.rs
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index a067038b4b422..fa697287cf71b 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -29,6 +29,7 @@
#include <linux/hrtimer_types.h>
#include <linux/acpi.h>
+#include <linux/amba/bus.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
diff --git a/rust/kernel/amba.rs b/rust/kernel/amba.rs
new file mode 100644
index 0000000000000..29b37fd3d1b56
--- /dev/null
+++ b/rust/kernel/amba.rs
@@ -0,0 +1,396 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! ARM AMBA bus abstractions.
+//!
+//! C header: [`include/linux/amba/bus.h`](srctree/include/linux/amba/bus.h)
+
+use crate::{
+ acpi,
+ bindings,
+ device,
+ device_id::{
+ RawDeviceId,
+ RawDeviceIdIndex, //
+ },
+ driver,
+ error::{
+ from_result,
+ to_result, //
+ },
+ io::{
+ mem::IoRequest,
+ resource::Resource, //
+ },
+ irq::{
+ self,
+ IrqRequest, //
+ },
+ of,
+ prelude::*,
+ sync::aref::AlwaysRefCounted,
+ types::Opaque,
+ ThisModule, //
+};
+use core::{
+ marker::PhantomData,
+ mem::offset_of,
+ ptr::NonNull, //
+};
+
+/// Device ID table type for AMBA drivers.
+pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>;
+
+/// AMBA device identifier.
+///
+/// Wraps the C `struct amba_id` from `include/linux/amba/bus.h`.
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct DeviceId(pub(crate) bindings::amba_id);
+
+// SAFETY: `DeviceId` is a transparent wrapper over `amba_id` with no additional invariants.
+unsafe impl RawDeviceId for DeviceId {
+ type RawType = bindings::amba_id;
+}
+
+// SAFETY: The offset matches the `data` field in `struct amba_id`.
+unsafe impl RawDeviceIdIndex for DeviceId {
+ const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::amba_id, data);
+
+ fn index(&self) -> usize {
+ self.0.data as usize
+ }
+}
+
+impl DeviceId {
+ /// Creates a new device ID from an AMBA device ID and mask.
+ #[inline(always)]
+ pub const fn new(id: u32, mask: u32) -> Self {
+ let mut amba: bindings::amba_id = pin_init::zeroed();
+ amba.id = id;
+ amba.mask = mask;
+ Self(amba)
+ }
+
+ /// Creates a new device ID with driver-specific data.
+ #[inline(always)]
+ pub const fn new_with_data(id: u32, mask: u32, data: usize) -> Self {
+ let mut amba: bindings::amba_id = pin_init::zeroed();
+ amba.id = id;
+ amba.mask = mask;
+ amba.data = data as *mut core::ffi::c_void;
+ Self(amba)
+ }
+
+ /// Returns the device ID.
+ #[inline(always)]
+ pub const fn id(&self) -> u32 {
+ self.0.id
+ }
+
+ /// Returns the device ID mask.
+ #[inline(always)]
+ pub const fn mask(&self) -> u32 {
+ self.0.mask
+ }
+}
+
+/// Creates an AMBA device ID table with a module alias for modpost.
+#[macro_export]
+macro_rules! amba_device_table {
+ ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => {
+ const $table_name: $crate::device_id::IdArray<
+ $crate::amba::DeviceId,
+ $id_info_type,
+ { $table_data.len() },
+ > = $crate::device_id::IdArray::new($table_data);
+
+ $crate::module_device_table!("amba", $module_table_name, $table_name);
+ };
+}
+
+/// The AMBA device representation.
+///
+/// This structure represents the Rust abstraction for a C `struct amba_device`. The
+/// implementation abstracts the usage of an already existing C `struct amba_device` within Rust
+/// code that we get passed from the C side.
+///
+/// # Invariants
+///
+/// A [`Device`] instance represents a valid `struct amba_device` created by the C portion of
+/// the kernel.
+#[repr(transparent)]
+pub struct Device<Ctx: device::DeviceContext = device::Normal>(
+ Opaque<bindings::amba_device>,
+ PhantomData<Ctx>,
+);
+
+impl<Ctx: device::DeviceContext> Device<Ctx> {
+ fn as_raw(&self) -> *mut bindings::amba_device {
+ self.0.get()
+ }
+
+ /// Returns the resource at `index`, if any.
+ pub fn resource(&self) -> Option<&Resource> {
+ // SAFETY: `self.as_raw()` returns a valid pointer to a `struct amba_device`.
+ let resource = unsafe { &raw mut (*self.as_raw()).res };
+ if resource.is_null() {
+ None
+ } else {
+ // SAFETY: `resource` is a valid pointer to a `struct resource`.
+ Some(unsafe { Resource::from_raw(resource) })
+ }
+ }
+}
+
+impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> {
+ fn as_ref(&self) -> &device::Device<Ctx> {
+ // SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a
+ // valid `struct amba_device`.
+ let dev = unsafe { &raw mut (*self.as_raw()).dev };
+ // SAFETY: `dev` points to a valid `struct device`.
+ unsafe { device::Device::from_raw(dev) }
+ }
+}
+
+// SAFETY: `Device` is a transparent wrapper that doesn't depend on its generic
+// argument.
+crate::impl_device_context_deref!(unsafe { Device });
+crate::impl_device_context_into_aref!(Device);
+
+impl Device<device::Core> {}
+
+impl Device<device::Bound> {
+ /// Returns an [`IoRequest`] for the memory resource.
+ pub fn io_request(&self) -> Option<IoRequest<'_>> {
+ self.resource()
+ // SAFETY: `resource` is valid for the lifetime of the `IoRequest`.
+ .map(|resource| unsafe { IoRequest::new(self.as_ref(), resource) })
+ }
+
+ /// Returns an [`IrqRequest`] for the IRQ at the given index.
+ pub fn irq_by_index(&self, index: u32) -> Result<IrqRequest<'_>> {
+ if index >= bindings::AMBA_NR_IRQS {
+ return Err(EINVAL);
+ }
+ // SAFETY: `self.as_raw()` returns a valid pointer to a `struct amba_device`.
+ let irq = unsafe { (*self.as_raw()).irq[index as usize] };
+ if irq == 0 {
+ return Err(ENXIO);
+ }
+ // SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`.
+ Ok(unsafe { IrqRequest::new(self.as_ref(), irq) })
+ }
+
+ /// Returns a [`irq::Registration`] for the IRQ at the given index.
+ pub fn request_irq_by_index<'a, T: irq::Handler + 'static>(
+ &'a self,
+ flags: irq::Flags,
+ index: u32,
+ name: &'static CStr,
+ handler: impl PinInit<T, Error> + 'a,
+ ) -> impl PinInit<irq::Registration<T>, Error> + 'a {
+ pin_init::pin_init_scope(move || {
+ let request = self.irq_by_index(index).map_err(|_| EINVAL)?;
+ Ok(irq::Registration::<T>::new(request, flags, name, handler))
+ })
+ }
+}
+
+// SAFETY: `Device` instances are always reference-counted via the underlying `device`.
+unsafe impl AlwaysRefCounted for Device {
+ fn inc_ref(&self) {
+ // SAFETY: A shared reference guarantees the refcount is non-zero.
+ unsafe { bindings::get_device(self.as_ref().as_raw()) };
+ }
+
+ unsafe fn dec_ref(obj: NonNull<Self>) {
+ let adev: *mut bindings::amba_device = obj.cast().as_ptr();
+ // SAFETY: `amba_device` contains `device` as its first field.
+ let dev: *mut bindings::device = unsafe { &raw mut (*adev).dev };
+ // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+ unsafe { bindings::put_device(dev) }
+ }
+}
+
+// SAFETY: `Device` is a transparent wrapper of `struct amba_device`.
+unsafe impl<Ctx: device::DeviceContext> device::AsBusDevice<Ctx> for Device<Ctx> {
+ const OFFSET: usize = offset_of!(bindings::amba_device, dev);
+}
+
+// SAFETY: `Device` is reference-counted and can be released from any thread.
+unsafe impl Send for Device {}
+
+// SAFETY: All methods of `Device` (i.e., `Device<Normal>`) are thread-safe.
+unsafe impl Sync for Device {}
+
+/// An adapter for the registration of AMBA drivers.
+pub struct Adapter<T: Driver>(T);
+
+// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
+// a preceding call to `register` has been successful.
+unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
+ type RegType = bindings::amba_driver;
+
+ unsafe fn register(
+ adrv: &Opaque<Self::RegType>,
+ name: &'static CStr,
+ module: &'static ThisModule,
+ ) -> Result {
+ let amba_table = match T::AMBA_ID_TABLE {
+ Some(table) => table.as_ptr(),
+ None => core::ptr::null(),
+ };
+ // SAFETY: It's safe to set the fields of `struct amba_driver` on initialization.
+ unsafe {
+ (*adrv.get()).drv.name = name.as_char_ptr();
+ (*adrv.get()).probe = Some(Self::probe_callback);
+ (*adrv.get()).remove = Some(Self::remove_callback);
+ (*adrv.get()).shutdown = Some(Self::shutdown_callback);
+ (*adrv.get()).id_table = amba_table;
+ }
+ // SAFETY: `adrv` is guaranteed to be a valid `RegType`.
+ to_result(unsafe { bindings::__amba_driver_register(adrv.get(), module.0) })
+ }
+
+ unsafe fn unregister(adrv: &Opaque<Self::RegType>) {
+ // SAFETY: `adrv` is guaranteed to be a valid `RegType`.
+ unsafe { bindings::amba_driver_unregister(adrv.get()) };
+ }
+}
+
+impl<T: Driver + 'static> Adapter<T> {
+ extern "C" fn probe_callback(
+ adev: *mut bindings::amba_device,
+ id: *const bindings::amba_id,
+ ) -> kernel::ffi::c_int {
+ // SAFETY: The AMBA bus only ever calls the probe callback with a valid pointer to a
+ // `struct amba_device`. `adev` is valid for the duration of `probe_callback()`.
+ let adev_internal = unsafe { &*adev.cast::<Device<device::CoreInternal>>() };
+ let info = Self::amba_id_info(adev_internal, id);
+ from_result(|| {
+ let datapin = T::probe(adev_internal, info);
+ adev_internal.as_ref().set_drvdata(datapin)?;
+ Ok(0)
+ })
+ }
+
+ extern "C" fn remove_callback(adev: *mut bindings::amba_device) {
+ // SAFETY: The AMBA bus only ever calls the remove callback with a valid pointer to a
+ // `struct amba_device`. `adev` is valid for the duration of `remove_callback()`.
+ let adev = unsafe { &*adev.cast::<Device<device::CoreInternal>>() };
+ // SAFETY: `remove_callback` is only ever called after a successful call to
+ // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
+ // and stored a `Pin<KBox<T>>`.
+ let data = unsafe { adev.as_ref().drvdata_obtain::<T>() };
+ T::unbind(adev, data.as_ref());
+ }
+
+ extern "C" fn shutdown_callback(adev: *mut bindings::amba_device) {
+ // SAFETY: `shutdown_callback` is only ever called for a valid `adev`.
+ let adev = unsafe { &*adev.cast::<Device<device::CoreInternal>>() };
+ // SAFETY: `shutdown_callback` is only ever called after a successful call to
+ // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
+ // and stored a `Pin<KBox<T>>`.
+ let data = unsafe { adev.as_ref().drvdata_obtain::<T>() };
+ T::shutdown(adev, data.as_ref());
+ }
+
+ fn amba_id_table() -> Option<IdTable<<Self as driver::Adapter>::IdInfo>> {
+ T::AMBA_ID_TABLE
+ }
+
+ fn amba_id_info(
+ _dev: &Device,
+ id: *const bindings::amba_id,
+ ) -> Option<&'static <Self as driver::Adapter>::IdInfo> {
+ if id.is_null() {
+ return None;
+ }
+ let table = Self::amba_id_table()?;
+ // SAFETY: `id` is a valid pointer to a `struct amba_id` that was matched by the kernel.
+ // `DeviceId` is a `#[repr(transparent)]` wrapper of `struct amba_id` and does not add
+ // additional invariants, so it's safe to transmute.
+ let device_id = unsafe { &*id.cast::<DeviceId>() };
+ Some(table.info(<DeviceId as RawDeviceIdIndex>::index(device_id)))
+ }
+}
+
+impl<T: Driver + 'static> driver::Adapter for Adapter<T> {
+ type IdInfo = T::IdInfo;
+
+ fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>> {
+ None
+ }
+
+ fn of_id_table() -> Option<of::IdTable<Self::IdInfo>> {
+ None
+ }
+}
+
+/// The AMBA driver trait.
+///
+/// Drivers must implement this trait in order to get an AMBA driver registered.
+pub trait Driver: Send {
+ /// The type holding information about each device id supported by the driver.
+ type IdInfo: 'static;
+ /// The table of device ids supported by the driver.
+ const AMBA_ID_TABLE: Option<IdTable<Self::IdInfo>> = None;
+
+ /// AMBA driver probe.
+ ///
+ /// Called when a new AMBA device is added or discovered.
+ /// Implementers should attempt to initialize the device here.
+ fn probe(
+ dev: &Device<device::Core>,
+ id_info: Option<&Self::IdInfo>,
+ ) -> impl PinInit<Self, Error>;
+
+ /// AMBA driver shutdown.
+ ///
+ /// Called by the kernel during system reboot or power-off to allow the [`Driver`] to bring the
+ /// [`Device`] into a safe state. Implementing this callback is optional.
+ ///
+ /// Typical actions include stopping transfers, disabling interrupts, or resetting the hardware
+ /// to prevent undesired behavior during shutdown.
+ ///
+ /// This callback is distinct from final resource cleanup, as the driver instance remains valid
+ /// after it returns. Any deallocation or teardown of driver-owned resources should instead be
+ /// handled in `Self::drop`.
+ fn shutdown(dev: &Device<device::Core>, this: Pin<&Self>) {
+ let _ = (dev, this);
+ }
+
+ /// AMBA driver unbind.
+ ///
+ /// Called when the [`Device`] is unbound from its bound [`Driver`]. Implementing this
+ /// callback is optional.
+ ///
+ /// This callback serves as a place for drivers to perform teardown operations that require a
+ /// `&Device<Core>` or `&Device<Bound>` reference. For instance, drivers may try to perform I/O
+ /// operations to gracefully tear down the device.
+ ///
+ /// Otherwise, release operations for driver resources should be performed in `Self::drop`.
+ fn unbind(dev: &Device<device::Core>, this: Pin<&Self>) {
+ let _ = (dev, this);
+ }
+}
+
+/// Declares a kernel module that exposes a single AMBA driver.
+///
+/// # Examples
+///
+/// ```ignore
+/// kernel::module_amba_driver! {
+/// type: MyDriver,
+/// name: "Module name",
+/// authors: ["Author name"],
+/// description: "Description",
+/// license: "GPL v2",
+/// }
+/// ```
+#[macro_export]
+macro_rules! module_amba_driver {
+ ($($f:tt)*) => {
+ $crate::module_driver!(<T>, $crate::amba::Adapter<T>, { $($f)* });
+ };
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index f812cf1200428..3e557335fc5fe 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -66,6 +66,8 @@
pub mod acpi;
pub mod alloc;
+#[cfg(CONFIG_ARM_AMBA)]
+pub mod amba;
#[cfg(CONFIG_AUXILIARY_BUS)]
pub mod auxiliary;
pub mod bitmap;
--
2.43.0
^ permalink raw reply related
* [RFC PATCH v2 3/5] rust: add device wakeup capability support
From: Ke Sun @ 2026-01-07 14:37 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun, Ke Sun
In-Reply-To: <20260107143738.3021892-1-sunke@kylinos.cn>
Add Rust bindings and wrappers for device wakeup functionality,
including devm_device_init_wakeup() and dev_pm_set_wake_irq().
Signed-off-by: Ke Sun <sunke@kylinos.cn>
---
rust/bindings/bindings_helper.h | 2 ++
rust/helpers/device.c | 7 +++++++
rust/kernel/device.rs | 17 ++++++++++++++++-
rust/kernel/irq/request.rs | 7 +++++++
4 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index fa697287cf71b..d6c2b06ac4107 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -88,6 +88,8 @@
#include <linux/workqueue.h>
#include <linux/xarray.h>
#include <trace/events/rust_sample.h>
+#include <linux/pm_wakeup.h>
+#include <linux/pm_wakeirq.h>
/*
* The driver-core Rust code needs to know about some C driver-core private
diff --git a/rust/helpers/device.c b/rust/helpers/device.c
index 9a4316bafedfb..cae26edd83696 100644
--- a/rust/helpers/device.c
+++ b/rust/helpers/device.c
@@ -1,6 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/device.h>
+#include <linux/pm_wakeup.h>
+#include <linux/pm_wakeirq.h>
int rust_helper_devm_add_action(struct device *dev,
void (*action)(void *),
@@ -25,3 +27,8 @@ void rust_helper_dev_set_drvdata(struct device *dev, void *data)
{
dev_set_drvdata(dev, data);
}
+
+int rust_helper_devm_device_init_wakeup(struct device *dev)
+{
+ return devm_device_init_wakeup(dev);
+}
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index c79be2e2bfe38..24fc69adf7bea 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -5,7 +5,9 @@
//! C header: [`include/linux/device.h`](srctree/include/linux/device.h)
use crate::{
- bindings, fmt,
+ bindings,
+ error::to_result,
+ fmt,
prelude::*,
sync::aref::ARef,
types::{ForeignOwnable, Opaque},
@@ -325,6 +327,19 @@ pub fn drvdata<T: 'static>(&self) -> Result<Pin<&T>> {
// - We've just checked that the type of the driver's private data is in fact `T`.
Ok(unsafe { self.drvdata_unchecked() })
}
+
+ /// Initialize device wakeup capability.
+ ///
+ /// Marks the device as wakeup-capable and enables wakeup. The wakeup capability is
+ /// automatically disabled when the device is removed (resource-managed).
+ ///
+ /// Returns `Ok(())` on success, or an error code on failure.
+ pub fn devm_init_wakeup(&self) -> Result {
+ // SAFETY: `self.as_raw()` is a valid pointer to a `struct device`.
+ // The function is exported from bindings_helper module via pub use.
+ let ret = unsafe { bindings::devm_device_init_wakeup(self.as_raw()) };
+ to_result(ret)
+ }
}
impl<Ctx: DeviceContext> Device<Ctx> {
diff --git a/rust/kernel/irq/request.rs b/rust/kernel/irq/request.rs
index b150563fdef80..c73e0c544fec7 100644
--- a/rust/kernel/irq/request.rs
+++ b/rust/kernel/irq/request.rs
@@ -120,6 +120,13 @@ pub(crate) unsafe fn new(dev: &'a Device<Bound>, irq: u32) -> Self {
pub fn irq(&self) -> u32 {
self.irq
}
+
+ /// Set the IRQ as a wake IRQ.
+ pub fn set_wake_irq(&self) -> Result {
+ // SAFETY: `self.as_raw()` is a valid pointer to a `struct device`.
+ let ret = unsafe { bindings::dev_pm_set_wake_irq(self.dev.as_raw(), self.irq as i32) };
+ to_result(ret)
+ }
}
/// A registration of an IRQ handler for a given IRQ line.
--
2.43.0
^ permalink raw reply related
* [RFC PATCH v2 4/5] rust: add RTC core abstractions and data structures
From: Ke Sun @ 2026-01-07 14:37 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun, Ke Sun
In-Reply-To: <20260107143738.3021892-1-sunke@kylinos.cn>
Add Rust abstractions for RTC subsystem, including RtcDevice,
RtcTime, RtcWkAlrm data structures, RtcOps trait for driver
operations, and devm-managed device registration support.
Signed-off-by: Ke Sun <sunke@kylinos.cn>
---
rust/helpers/helpers.c | 1 +
rust/helpers/rtc.c | 9 +
rust/kernel/lib.rs | 2 +
rust/kernel/rtc.rs | 985 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 997 insertions(+)
create mode 100644 rust/helpers/rtc.c
create mode 100644 rust/kernel/rtc.rs
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 79c72762ad9c4..1a5c103fb24ba 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -48,6 +48,7 @@
#include "rcu.c"
#include "refcount.c"
#include "regulator.c"
+#include "rtc.c"
#include "scatterlist.c"
#include "security.c"
#include "signal.c"
diff --git a/rust/helpers/rtc.c b/rust/helpers/rtc.c
new file mode 100644
index 0000000000000..862cd61670bfc
--- /dev/null
+++ b/rust/helpers/rtc.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/rtc.h>
+
+int rust_helper_devm_rtc_register_device(struct rtc_device *rtc)
+{
+ return __devm_rtc_register_device(THIS_MODULE, rtc);
+}
+
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 3e557335fc5fe..1390073e4ae27 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -135,6 +135,8 @@
pub mod rbtree;
pub mod regulator;
pub mod revocable;
+#[cfg(CONFIG_RTC_CLASS)]
+pub mod rtc;
pub mod scatterlist;
pub mod security;
pub mod seq_file;
diff --git a/rust/kernel/rtc.rs b/rust/kernel/rtc.rs
new file mode 100644
index 0000000000000..0c662b94b96f4
--- /dev/null
+++ b/rust/kernel/rtc.rs
@@ -0,0 +1,985 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! RTC (Real-Time Clock) device support.
+//!
+//! C headers: [`include/linux/rtc.h`](srctree/include/linux/rtc.h).
+//!
+//! Reference: <https://www.kernel.org/doc/html/latest/driver-api/rtc.html>
+use crate::{
+ bindings,
+ bitmap::Bitmap,
+ device::{
+ self,
+ AsBusDevice, //
+ },
+ devres,
+ error::Error,
+ prelude::*,
+ seq_file::SeqFile,
+ sync::aref::{
+ ARef, //
+ AlwaysRefCounted,
+ },
+ types::{
+ ForeignOwnable,
+ Opaque, //
+ }, //
+};
+
+use core::{
+ ffi::c_void,
+ marker::PhantomData,
+ ptr::NonNull, //
+};
+
+/// RTC time structure.
+///
+/// Wraps the C `struct rtc_time` from `include/uapi/linux/rtc.h`.
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct RtcTime(pub bindings::rtc_time);
+
+impl RtcTime {
+ /// Creates a new `RtcTime` from a time64_t value (seconds since 1970-01-01 00:00:00 UTC).
+ pub fn from_time64(time: i64) -> Self {
+ let mut tm = Self(pin_init::zeroed());
+ // SAFETY: `rtc_time64_to_tm` is a pure function that only writes to the provided
+ // `struct rtc_time` pointer. The pointer is valid because `tm.0` is a valid mutable
+ // reference, and the function does not retain any references to it.
+ unsafe {
+ bindings::rtc_time64_to_tm(time, &mut tm.0);
+ }
+ tm
+ }
+
+ /// Converts this `RtcTime` to a time64_t value (seconds since 1970-01-01 00:00:00 UTC).
+ pub fn to_time64(&self) -> i64 {
+ // SAFETY: `rtc_tm_to_time64` is a pure function that only reads from the provided
+ // `struct rtc_time` pointer. The pointer is valid because `self.0` is a valid reference,
+ // and the function does not retain any references to it.
+ unsafe { bindings::rtc_tm_to_time64(core::ptr::from_ref(&self.0).cast_mut()) }
+ }
+
+ /// Sets this `RtcTime` from a time64_t value (seconds since 1970-01-01 00:00:00 UTC).
+ pub fn set_from_time64(&mut self, time: i64) {
+ // SAFETY: `rtc_time64_to_tm` is a pure function that only writes to the provided
+ // `struct rtc_time` pointer. The pointer is valid because `self.0` is a valid mutable
+ // reference, and the function does not retain any references to it.
+ unsafe {
+ bindings::rtc_time64_to_tm(time, &mut self.0);
+ }
+ }
+
+ /// Converts a time64_t value to an RTC time structure.
+ #[inline]
+ pub fn time64_to_tm(time: i64, tm: &mut Self) {
+ tm.set_from_time64(time);
+ }
+
+ /// Converts an RTC time structure to a time64_t value (seconds since 1970-01-01 00:00:00 UTC).
+ #[inline]
+ pub fn tm_to_time64(tm: &Self) -> i64 {
+ tm.to_time64()
+ }
+
+ /// Calculates the day of the year (0-365) from the date components.
+ #[inline]
+ pub fn year_days(&self) -> i32 {
+ // SAFETY: `rtc_year_days` is a pure function that only performs calculations based on
+ // the provided parameters. The values should be from valid RTC time structures and
+ // non-negative, but the function itself is safe to call with any values.
+ unsafe {
+ bindings::rtc_year_days(
+ self.0.tm_mday as u32,
+ self.0.tm_mon as u32,
+ self.0.tm_year as u32,
+ )
+ }
+ }
+
+ /// Returns the seconds field (0-59).
+ #[inline]
+ pub fn tm_sec(&self) -> i32 {
+ self.0.tm_sec
+ }
+
+ /// Sets the seconds field (0-59).
+ #[inline]
+ pub fn set_tm_sec(&mut self, sec: i32) {
+ self.0.tm_sec = sec;
+ }
+
+ /// Returns the minutes field (0-59).
+ #[inline]
+ pub fn tm_min(&self) -> i32 {
+ self.0.tm_min
+ }
+
+ /// Sets the minutes field (0-59).
+ #[inline]
+ pub fn set_tm_min(&mut self, min: i32) {
+ self.0.tm_min = min;
+ }
+
+ /// Returns the hours field (0-23).
+ #[inline]
+ pub fn tm_hour(&self) -> i32 {
+ self.0.tm_hour
+ }
+
+ /// Sets the hours field (0-23).
+ #[inline]
+ pub fn set_tm_hour(&mut self, hour: i32) {
+ self.0.tm_hour = hour;
+ }
+
+ /// Returns the day of the month (1-31).
+ #[inline]
+ pub fn tm_mday(&self) -> i32 {
+ self.0.tm_mday
+ }
+
+ /// Sets the day of the month (1-31).
+ #[inline]
+ pub fn set_tm_mday(&mut self, mday: i32) {
+ self.0.tm_mday = mday;
+ }
+
+ /// Returns the month (0-11, where 0 is January).
+ #[inline]
+ pub fn tm_mon(&self) -> i32 {
+ self.0.tm_mon
+ }
+
+ /// Sets the month (0-11, where 0 is January).
+ #[inline]
+ pub fn set_tm_mon(&mut self, mon: i32) {
+ self.0.tm_mon = mon;
+ }
+
+ /// Returns the year (years since 1900).
+ #[inline]
+ pub fn tm_year(&self) -> i32 {
+ self.0.tm_year
+ }
+
+ /// Sets the year (years since 1900).
+ #[inline]
+ pub fn set_tm_year(&mut self, year: i32) {
+ self.0.tm_year = year;
+ }
+
+ /// Returns the day of the week (0-6, where 0 is Sunday).
+ #[inline]
+ pub fn tm_wday(&self) -> i32 {
+ self.0.tm_wday
+ }
+
+ /// Sets the day of the week (0-6, where 0 is Sunday).
+ #[inline]
+ pub fn set_tm_wday(&mut self, wday: i32) {
+ self.0.tm_wday = wday;
+ }
+
+ /// Returns the day of the year (0-365).
+ #[inline]
+ pub fn tm_yday(&self) -> i32 {
+ self.0.tm_yday
+ }
+
+ /// Sets the day of the year (0-365).
+ #[inline]
+ pub fn set_tm_yday(&mut self, yday: i32) {
+ self.0.tm_yday = yday;
+ }
+
+ /// Returns the daylight saving time flag.
+ #[inline]
+ pub fn tm_isdst(&self) -> i32 {
+ self.0.tm_isdst
+ }
+
+ /// Sets the daylight saving time flag.
+ #[inline]
+ pub fn set_tm_isdst(&mut self, isdst: i32) {
+ self.0.tm_isdst = isdst;
+ }
+}
+
+impl Default for RtcTime {
+ fn default() -> Self {
+ Self(pin_init::zeroed())
+ }
+}
+
+/// RTC wake alarm structure.
+///
+/// Wraps the C `struct rtc_wkalrm` from `include/uapi/linux/rtc.h`.
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct RtcWkAlrm(pub bindings::rtc_wkalrm);
+
+impl Default for RtcWkAlrm {
+ fn default() -> Self {
+ Self(pin_init::zeroed())
+ }
+}
+
+impl RtcWkAlrm {
+ /// Returns a reference to the alarm time.
+ #[inline]
+ pub fn get_time(&self) -> &RtcTime {
+ // SAFETY: `RtcTime` is `#[repr(transparent)]` over `bindings::rtc_time`, so the memory
+ // layout is identical. We can safely reinterpret the reference.
+ unsafe { &*(&raw const self.0.time).cast::<RtcTime>() }
+ }
+
+ /// Returns a mutable reference to the alarm time.
+ #[inline]
+ pub fn get_time_mut(&mut self) -> &mut RtcTime {
+ // SAFETY: `RtcTime` is `#[repr(transparent)]` over `bindings::rtc_time`, so the memory
+ // layout is identical. We can safely reinterpret the reference.
+ unsafe { &mut *(&raw mut self.0.time).cast::<RtcTime>() }
+ }
+
+ /// Sets the alarm time from a `RtcTime` value.
+ #[inline]
+ pub fn set_time(&mut self, time: RtcTime) {
+ self.0.time = time.0;
+ }
+
+ /// Returns the enabled field.
+ #[inline]
+ pub fn enabled(&self) -> u8 {
+ self.0.enabled
+ }
+
+ /// Sets the `enabled` field.
+ #[inline]
+ pub fn set_enabled(&mut self, enabled: u8) {
+ self.0.enabled = enabled;
+ }
+
+ /// Returns the pending field.
+ #[inline]
+ pub fn pending(&self) -> u8 {
+ self.0.pending
+ }
+
+ /// Sets the `pending` field.
+ #[inline]
+ pub fn set_pending(&mut self, pending: u8) {
+ self.0.pending = pending;
+ }
+}
+
+/// RTC parameter structure.
+///
+/// Wraps the C `struct rtc_param` from `include/uapi/linux/rtc.h`.
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct RtcParam(pub bindings::rtc_param);
+
+impl Default for RtcParam {
+ fn default() -> Self {
+ Self(pin_init::zeroed())
+ }
+}
+
+/// A Rust wrapper for the C `struct rtc_device`.
+///
+/// This type provides safe access to RTC device operations. The underlying `rtc_device`
+/// is managed by the kernel and remains valid for the lifetime of the `RtcDevice`.
+///
+/// # Invariants
+///
+/// A [`RtcDevice`] instance holds a pointer to a valid [`struct rtc_device`] that is
+/// registered and managed by the kernel.
+///
+/// # Examples
+///
+/// ```rust
+/// # use kernel::{
+/// # prelude::*,
+/// # rtc::RtcDevice, //
+/// # };
+/// // Example: Set the time range for the RTC device
+/// // rtc.set_range_min(0);
+/// // rtc.set_range_max(u64::MAX);
+/// // Ok(())
+/// // }
+/// ```
+///
+/// [`struct rtc_device`]: https://docs.kernel.org/driver-api/rtc.html
+#[repr(transparent)]
+pub struct RtcDevice<T: 'static = ()>(Opaque<bindings::rtc_device>, PhantomData<T>);
+
+impl<T: 'static> RtcDevice<T> {
+ /// Obtain the raw [`struct rtc_device`] pointer.
+ #[inline]
+ pub fn as_raw(&self) -> *mut bindings::rtc_device {
+ self.0.get()
+ }
+
+ /// Set the minimum time range for the RTC device.
+ #[inline]
+ pub fn set_range_min(&self, min: i64) {
+ // SAFETY: By the type invariants, self.as_raw() is a valid pointer to a
+ // `struct rtc_device`, and we're only writing to the `range_min` field.
+ unsafe {
+ (*self.as_raw()).range_min = min;
+ }
+ }
+
+ /// Set the maximum time range for the RTC device.
+ #[inline]
+ pub fn set_range_max(&self, max: u64) {
+ // SAFETY: By the type invariants, self.as_raw() is a valid pointer to a
+ // `struct rtc_device`, and we're only writing to the `range_max` field.
+ unsafe {
+ (*self.as_raw()).range_max = max;
+ }
+ }
+
+ /// Get the minimum time range for the RTC device.
+ #[inline]
+ pub fn range_min(&self) -> i64 {
+ // SAFETY: By the type invariants, self.as_raw() is a valid pointer to a
+ // `struct rtc_device`, and we're only reading the `range_min` field.
+ unsafe { (*self.as_raw()).range_min }
+ }
+
+ /// Get the maximum time range for the RTC device.
+ #[inline]
+ pub fn range_max(&self) -> u64 {
+ // SAFETY: By the type invariants, self.as_raw() is a valid pointer to a
+ // `struct rtc_device`, and we're only reading the `range_max` field.
+ unsafe { (*self.as_raw()).range_max }
+ }
+
+ /// Notify the RTC framework that an interrupt has occurred.
+ ///
+ /// Should be called from interrupt handlers. Schedules work to handle the interrupt
+ /// in process context.
+ #[inline]
+ pub fn update_irq(&self, num: usize, events: usize) {
+ // SAFETY: By the type invariants, self.as_raw() is a valid pointer to a
+ // `struct rtc_device`. The rtc_update_irq function handles NULL/ERR checks internally.
+ unsafe {
+ bindings::rtc_update_irq(self.as_raw(), num, events);
+ }
+ }
+
+ /// Clear a feature bit in the RTC device.
+ #[inline]
+ pub fn clear_feature(&self, feature: u32) {
+ // SAFETY: By the type invariants, self.as_raw() is a valid pointer to a
+ // `struct rtc_device`, and features is a valid bitmap array with RTC_FEATURE_CNT bits.
+ let features_bitmap = unsafe {
+ Bitmap::from_raw_mut(
+ (*self.as_raw()).features.as_mut_ptr().cast::<usize>(),
+ bindings::RTC_FEATURE_CNT as usize,
+ )
+ };
+ features_bitmap.clear_bit(feature as usize);
+ }
+}
+
+impl<T: 'static, Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for RtcDevice<T> {
+ fn as_ref(&self) -> &device::Device<Ctx> {
+ let raw = self.as_raw();
+ // SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a valid
+ // `struct rtc_device`.
+ let dev = unsafe { &raw mut (*raw).dev };
+
+ // SAFETY: `dev` points to a valid `struct device`.
+ unsafe { device::Device::from_raw(dev) }
+ }
+}
+
+// SAFETY: `RtcDevice` is a transparent wrapper of `struct rtc_device`.
+// The offset is guaranteed to point to a valid device field inside `RtcDevice`.
+unsafe impl<T: 'static, Ctx: device::DeviceContext> device::AsBusDevice<Ctx> for RtcDevice<T> {
+ const OFFSET: usize = core::mem::offset_of!(bindings::rtc_device, dev);
+}
+
+// SAFETY: Instances of `RtcDevice` are always reference-counted via the underlying `device`.
+// The `struct rtc_device` contains a `struct device dev` as its first field, and the
+// reference counting is managed through `get_device`/`put_device` on the `dev` field.
+unsafe impl<T: 'static> AlwaysRefCounted for RtcDevice<T> {
+ fn inc_ref(&self) {
+ let dev: &device::Device = self.as_ref();
+ // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero.
+ // `dev.as_raw()` is a valid pointer to a `struct device` with a non-zero refcount.
+ unsafe { bindings::get_device(dev.as_raw()) };
+ }
+
+ unsafe fn dec_ref(obj: NonNull<Self>) {
+ let rtc: *mut bindings::rtc_device = obj.cast().as_ptr();
+
+ // SAFETY: By the type invariant of `Self`, `rtc` is a pointer to a valid
+ // `struct rtc_device`. The `dev` field is the first field of `struct rtc_device`,
+ // so we can safely access it.
+ let dev = unsafe { &raw mut (*rtc).dev };
+
+ // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+ unsafe { bindings::put_device(dev) };
+ }
+}
+
+// SAFETY: `RtcDevice` is reference-counted and can be released from any thread.
+unsafe impl<T: 'static> Send for RtcDevice<T> {}
+
+// SAFETY: `RtcDevice` can be shared among threads because all immutable methods are
+// protected by the synchronization in `struct rtc_device` (via `ops_lock` mutex).
+unsafe impl<T: 'static> Sync for RtcDevice<T> {}
+
+impl<T: RtcOps> RtcDevice<T> {
+ /// Allocates a new RTC device managed by devres.
+ ///
+ /// This function allocates an RTC device and sets the driver data. The device will be
+ /// automatically freed when the parent device is removed.
+ pub fn new(
+ parent_dev: &device::Device,
+ init: impl PinInit<T, Error>,
+ ) -> Result<ARef<Self>> {
+ // SAFETY: `Device<Bound>` and `Device<CoreInternal>` have the same layout.
+ let dev_internal: &device::Device<device::CoreInternal> =
+ unsafe { &*core::ptr::from_ref(parent_dev).cast() };
+
+ // Allocate RTC device.
+ // SAFETY: `devm_rtc_allocate_device` returns a pointer to a devm-managed rtc_device.
+ // We use `dev_internal.as_raw()` which is `pub(crate)`, but we can access it through
+ // the same device pointer.
+ let rtc: *mut bindings::rtc_device =
+ unsafe { bindings::devm_rtc_allocate_device(dev_internal.as_raw()) };
+ if rtc.is_null() {
+ return Err(ENOMEM);
+ }
+
+ // Set the RTC device ops.
+ // SAFETY: We just allocated the RTC device, so it's safe to set the ops.
+ unsafe {
+ (*rtc).ops = Adapter::<T>::VTABLE.as_raw();
+ }
+
+ // SAFETY: `rtc` is a valid pointer to a newly allocated rtc_device.
+ // `RtcDevice` is `#[repr(transparent)]` over `Opaque<rtc_device>`, so we can safely cast.
+ let rtc_device = unsafe { ARef::from_raw(NonNull::new_unchecked(rtc.cast::<Self>())) };
+ rtc_device.set_drvdata(init)?;
+ Ok(rtc_device)
+ }
+
+ /// Store a pointer to the bound driver's private data.
+ pub fn set_drvdata(&self, data: impl PinInit<T, Error>) -> Result {
+ let data = KBox::pin_init(data, GFP_KERNEL)?;
+ let dev: &device::Device<device::Bound> = self.as_ref();
+
+ // SAFETY: `self.as_raw()` is a valid pointer to a `struct rtc_device`.
+ unsafe { bindings::dev_set_drvdata(dev.as_raw(), data.into_foreign().cast()) };
+ Ok(())
+ }
+
+ /// Borrow the driver's private data bound to this [`RtcDevice`].
+ pub fn drvdata(&self) -> Result<Pin<&T>> {
+ let dev: &device::Device<device::Bound> = self.as_ref();
+
+ // SAFETY: `self.as_raw()` is a valid pointer to a `struct device`.
+ let ptr = unsafe { bindings::dev_get_drvdata(dev.as_raw()) };
+
+ if ptr.is_null() {
+ return Err(ENOENT);
+ }
+
+ // SAFETY: The caller ensures that `ptr` is valid and writable.
+ Ok(unsafe { Pin::<KBox<T>>::borrow(ptr.cast()) })
+ }
+}
+
+impl<T: 'static> Drop for RtcDevice<T> {
+ fn drop(&mut self) {
+ let dev: &device::Device<device::Bound> = self.as_ref();
+ // SAFETY: By the type invariants, `self.as_raw()` is a valid pointer to a `struct device`.
+ let ptr: *mut c_void = unsafe { bindings::dev_get_drvdata(dev.as_raw()) };
+
+ // SAFETY: By the type invariants, `self.as_raw()` is a valid pointer to a `struct device`.
+ unsafe { bindings::dev_set_drvdata(dev.as_raw(), core::ptr::null_mut()) };
+
+ if !ptr.is_null() {
+ // SAFETY: `ptr` comes from a previous call to `into_foreign()`, and
+ // `dev_get_drvdata()` guarantees to return the same pointer given to
+ // `dev_set_drvdata()`.
+ unsafe { drop(Pin::<KBox<T>>::from_foreign(ptr.cast())) };
+ }
+ }
+}
+
+/// A resource guard that ensures the RTC device is properly registered.
+///
+/// This struct is intended to be managed by the `devres` framework by transferring its ownership
+/// via [`devres::register`]. This ties the lifetime of the RTC device registration
+/// to the lifetime of the underlying device.
+pub struct Registration<T: 'static> {
+ #[allow(dead_code)]
+ rtc_device: ARef<RtcDevice<T>>,
+}
+
+impl<T: 'static> Registration<T> {
+ /// Registers an RTC device with the RTC subsystem.
+ ///
+ /// Transfers its ownership to the `devres` framework, which ties its lifetime
+ /// to the parent device.
+ /// On unbind of the parent device, the `devres` entry will be dropped, automatically
+ /// cleaning up the RTC device. This function should be called from the driver's `probe`.
+ pub fn register(dev: &device::Device<device::Bound>, rtc_device: ARef<RtcDevice<T>>) -> Result {
+ let rtc_dev: &device::Device = rtc_device.as_ref();
+ let rtc_parent = rtc_dev.parent().ok_or(EINVAL)?;
+ if dev.as_raw() != rtc_parent.as_raw() {
+ return Err(EINVAL);
+ }
+
+ // Registers an RTC device with the RTC subsystem.
+ // SAFETY: The device will be automatically unregistered when the parent device
+ // is removed (devm cleanup). The helper function uses `THIS_MODULE` internally.
+ let err = unsafe { bindings::devm_rtc_register_device(rtc_device.as_raw()) };
+ if err != 0 {
+ return Err(Error::from_errno(err));
+ }
+
+ let registration = Registration { rtc_device };
+
+ devres::register(dev, registration, GFP_KERNEL)
+ }
+}
+
+/// Options for creating an RTC device.
+#[derive(Copy, Clone)]
+pub struct RtcDeviceOptions {
+ /// The name of the RTC device.
+ pub name: &'static CStr,
+}
+
+/// Trait implemented by RTC device operations.
+///
+/// This trait defines the operations that an RTC device driver must implement.
+/// Most methods are optional and have default implementations that return an error.
+#[vtable]
+pub trait RtcOps: Sized + 'static {
+ /// Read the current time from the RTC.
+ ///
+ /// This is a required method and must be implemented.
+ fn read_time(_rtcdev: &RtcDevice<Self>, _tm: &mut RtcTime) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Set the time in the RTC.
+ ///
+ /// This is a required method and must be implemented.
+ ///
+ /// Note: The parameter is `&mut` to match the C API signature, even though
+ /// it's conceptually read-only from the Rust side.
+ fn set_time(_rtcdev: &RtcDevice<Self>, _tm: &mut RtcTime) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Read the alarm time from the RTC.
+ fn read_alarm(_rtcdev: &RtcDevice<Self>, _alarm: &mut RtcWkAlrm) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Set the alarm time in the RTC.
+ ///
+ /// Note: The parameter is `&mut` to match the C API signature, even though
+ /// it's conceptually read-only from the Rust side.
+ fn set_alarm(_rtcdev: &RtcDevice<Self>, _alarm: &mut RtcWkAlrm) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Enable or disable the alarm interrupt.
+ ///
+ /// `enabled` is non-zero to enable, zero to disable.
+ fn alarm_irq_enable(_rtcdev: &RtcDevice<Self>, _enabled: u32) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Handle custom ioctl commands.
+ fn ioctl(_rtcdev: &RtcDevice<Self>, _cmd: u32, _arg: c_ulong) -> Result<c_int> {
+ Err(ENOTSUPP)
+ }
+
+ /// Show information in /proc/driver/rtc.
+ fn proc(_rtcdev: &RtcDevice<Self>, _seq: &mut SeqFile) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Read the time offset.
+ fn read_offset(_rtcdev: &RtcDevice<Self>, _offset: &mut i64) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Set the time offset.
+ fn set_offset(_rtcdev: &RtcDevice<Self>, _offset: i64) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Get an RTC parameter.
+ fn param_get(_rtcdev: &RtcDevice<Self>, _param: &mut RtcParam) -> Result {
+ Err(ENOTSUPP)
+ }
+
+ /// Set an RTC parameter.
+ ///
+ /// Note: The parameter is `&mut` to match the C API signature, even though
+ /// it's conceptually read-only from the Rust side.
+ fn param_set(_rtcdev: &RtcDevice<Self>, _param: &mut RtcParam) -> Result {
+ Err(ENOTSUPP)
+ }
+}
+
+struct Adapter<T: RtcOps> {
+ _p: PhantomData<T>,
+}
+
+impl<T: RtcOps> Adapter<T> {
+ const VTABLE: RtcOpsVTable = create_rtc_ops::<T>();
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `tm` must be a valid pointer to a `struct rtc_time`.
+ unsafe extern "C" fn read_time(
+ dev: *mut bindings::device,
+ tm: *mut bindings::rtc_time,
+ ) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `tm` is valid and writable.
+ // `RtcTime` is `#[repr(transparent)]` over `bindings::rtc_time`, so we can safely cast.
+ let rtc_tm = unsafe { &mut *tm.cast::<RtcTime>() };
+
+ match T::read_time(rtc_dev, rtc_tm) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `tm` must be a valid pointer to a `struct rtc_time`.
+ unsafe extern "C" fn set_time(
+ dev: *mut bindings::device,
+ tm: *mut bindings::rtc_time,
+ ) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `tm` is valid and writable.
+ // `RtcTime` is `#[repr(transparent)]` over `bindings::rtc_time`, so we can safely cast.
+ let rtc_tm = unsafe { &mut *tm.cast::<RtcTime>() };
+
+ match T::set_time(rtc_dev, rtc_tm) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `alarm` must be a valid pointer to a `struct rtc_wkalrm`.
+ unsafe extern "C" fn read_alarm(
+ dev: *mut bindings::device,
+ alarm: *mut bindings::rtc_wkalrm,
+ ) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `alarm` is valid and writable.
+ // `RtcWkAlrm` is `#[repr(transparent)]` over `bindings::rtc_wkalrm`, so we can safely cast.
+ let rtc_alarm = unsafe { &mut *alarm.cast::<RtcWkAlrm>() };
+
+ match T::read_alarm(rtc_dev, rtc_alarm) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `alarm` must be a valid pointer to a `struct rtc_wkalrm`.
+ unsafe extern "C" fn set_alarm(
+ dev: *mut bindings::device,
+ alarm: *mut bindings::rtc_wkalrm,
+ ) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `alarm` is valid and writable.
+ // `RtcWkAlrm` is `#[repr(transparent)]` over `bindings::rtc_wkalrm`, so we can safely cast.
+ let rtc_alarm = unsafe { &mut *alarm.cast::<RtcWkAlrm>() };
+
+ match T::set_alarm(rtc_dev, rtc_alarm) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ unsafe extern "C" fn alarm_irq_enable(dev: *mut bindings::device, enabled: c_uint) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+
+ match T::alarm_irq_enable(rtc_dev, enabled) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ unsafe extern "C" fn ioctl(dev: *mut bindings::device, cmd: c_uint, arg: c_ulong) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+
+ match T::ioctl(rtc_dev, cmd, arg) {
+ Ok(ret) => ret,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `seq` must be a valid pointer to a `struct seq_file`.
+ unsafe extern "C" fn proc(dev: *mut bindings::device, seq: *mut bindings::seq_file) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `seq` is valid and writable.
+ let seq_file = unsafe { &mut *seq.cast::<SeqFile>() };
+
+ match T::proc(rtc_dev, seq_file) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `offset` must be a valid pointer to a `long`.
+ unsafe extern "C" fn read_offset(dev: *mut bindings::device, offset: *mut c_long) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `offset` is valid and writable.
+ let mut offset_val: i64 = unsafe { *offset.cast() };
+
+ match T::read_offset(rtc_dev, &mut offset_val) {
+ Ok(()) => {
+ // SAFETY: The caller ensures that `offset` is valid and writable.
+ unsafe { *offset.cast() = offset_val as c_long };
+ 0
+ }
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ unsafe extern "C" fn set_offset(dev: *mut bindings::device, offset: c_long) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+
+ match T::set_offset(rtc_dev, offset as i64) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `param` must be a valid pointer to a `struct rtc_param`.
+ unsafe extern "C" fn param_get(
+ dev: *mut bindings::device,
+ param: *mut bindings::rtc_param,
+ ) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `param` is valid and writable.
+ // `RtcParam` is `#[repr(transparent)]` over `bindings::rtc_param`, so we can safely cast.
+ let rtc_param = unsafe { &mut *param.cast::<RtcParam>() };
+
+ match T::param_get(rtc_dev, rtc_param) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// `dev` must be a valid pointer to the `struct device` embedded in a `struct rtc_device`.
+ /// `param` must be a valid pointer to a `struct rtc_param`.
+ unsafe extern "C" fn param_set(
+ dev: *mut bindings::device,
+ param: *mut bindings::rtc_param,
+ ) -> c_int {
+ // SAFETY: The caller ensures that `dev` is a valid pointer to a `struct device`.
+ let device_dev: &device::Device = unsafe { device::Device::from_raw(dev) };
+ // SAFETY: `dev` is embedded in a `struct rtc_device`, so we can use
+ // `AsBusDevice` to get it.
+ let rtc_dev = unsafe { RtcDevice::<T>::from_device(device_dev) };
+ // SAFETY: The caller ensures that `param` is valid and writable.
+ // `RtcParam` is `#[repr(transparent)]` over `bindings::rtc_param`, so we can safely cast.
+ let rtc_param = unsafe { &mut *param.cast::<RtcParam>() };
+
+ match T::param_set(rtc_dev, rtc_param) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+ }
+}
+
+/// VTable structure wrapper for RTC operations.
+/// Mirrors [`struct rtc_class_ops`](srctree/include/linux/rtc.h).
+#[repr(transparent)]
+pub struct RtcOpsVTable(bindings::rtc_class_ops);
+
+// SAFETY: RtcOpsVTable is Send. The vtable contains only function pointers,
+// which are simple data types that can be safely moved across threads.
+// The thread-safety of calling these functions is handled by the kernel's
+// locking mechanisms.
+unsafe impl Send for RtcOpsVTable {}
+
+// SAFETY: RtcOpsVTable is Sync. The vtable is immutable after it is created,
+// so it can be safely referenced and accessed concurrently by multiple threads
+// e.g. to read the function pointers.
+unsafe impl Sync for RtcOpsVTable {}
+
+impl RtcOpsVTable {
+ /// Returns a raw pointer to the underlying `rtc_class_ops` struct.
+ pub(crate) const fn as_raw(&self) -> *const bindings::rtc_class_ops {
+ &self.0
+ }
+}
+
+/// Creates an RTC operations vtable for a type `T` that implements `RtcOps`.
+///
+/// This is used to bridge Rust trait implementations to the C `struct rtc_class_ops`
+/// expected by the kernel.
+pub const fn create_rtc_ops<T: RtcOps>() -> RtcOpsVTable {
+ let mut ops: bindings::rtc_class_ops = pin_init::zeroed();
+
+ ops.read_time = if T::HAS_READ_TIME {
+ Some(Adapter::<T>::read_time)
+ } else {
+ None
+ };
+ ops.set_time = if T::HAS_SET_TIME {
+ Some(Adapter::<T>::set_time)
+ } else {
+ None
+ };
+ ops.read_alarm = if T::HAS_READ_ALARM {
+ Some(Adapter::<T>::read_alarm)
+ } else {
+ None
+ };
+ ops.set_alarm = if T::HAS_SET_ALARM {
+ Some(Adapter::<T>::set_alarm)
+ } else {
+ None
+ };
+ ops.alarm_irq_enable = if T::HAS_ALARM_IRQ_ENABLE {
+ Some(Adapter::<T>::alarm_irq_enable)
+ } else {
+ None
+ };
+ ops.ioctl = if T::HAS_IOCTL {
+ Some(Adapter::<T>::ioctl)
+ } else {
+ None
+ };
+ ops.proc_ = if T::HAS_PROC {
+ Some(Adapter::<T>::proc)
+ } else {
+ None
+ };
+ ops.read_offset = if T::HAS_READ_OFFSET {
+ Some(Adapter::<T>::read_offset)
+ } else {
+ None
+ };
+ ops.set_offset = if T::HAS_SET_OFFSET {
+ Some(Adapter::<T>::set_offset)
+ } else {
+ None
+ };
+ ops.param_get = if T::HAS_PARAM_GET {
+ Some(Adapter::<T>::param_get)
+ } else {
+ None
+ };
+ ops.param_set = if T::HAS_PARAM_SET {
+ Some(Adapter::<T>::param_set)
+ } else {
+ None
+ };
+
+ RtcOpsVTable(ops)
+}
+
+/// Declares a kernel module that exposes a single RTC AMBA driver.
+///
+/// # Examples
+///
+///```ignore
+/// kernel::module_rtc_amba_driver! {
+/// type: MyDriver,
+/// name: "Module name",
+/// authors: ["Author name"],
+/// description: "Description",
+/// license: "GPL v2",
+/// }
+///```
+#[macro_export]
+macro_rules! module_rtc_amba_driver {
+ ($($user_args:tt)*) => {
+ $crate::module_amba_driver! {
+ $($user_args)*
+ imports_ns: ["RTC"],
+ }
+ };
+}
--
2.43.0
^ permalink raw reply related
* [RFC PATCH v2 5/5] rust: add PL031 RTC driver
From: Ke Sun @ 2026-01-07 14:37 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun, Ke Sun
In-Reply-To: <20260107143738.3021892-1-sunke@kylinos.cn>
Add Rust implementation of the PL031 RTC driver.
Signed-off-by: Ke Sun <sunke@kylinos.cn>
---
drivers/rtc/Kconfig | 9 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc_pl031_rust.rs | 503 ++++++++++++++++++++++++++++++++++
3 files changed, 513 insertions(+)
create mode 100644 drivers/rtc/rtc_pl031_rust.rs
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 50dc779f7f983..137cea1824edd 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1591,6 +1591,15 @@ config RTC_DRV_PL031
To compile this driver as a module, choose M here: the
module will be called rtc-pl031.
+config RTC_DRV_PL031_RUST
+ tristate "ARM AMBA PL031 RTC (Rust)"
+ depends on RUST && RTC_CLASS
+ help
+ This is the Rust implementation of the PL031 RTC driver.
+ It provides the same functionality as the C driver but is
+ written in Rust for improved memory safety. The driver supports
+ ARM, ST v1, and ST v2 variants of the PL031 RTC controller.
+
config RTC_DRV_AT91RM9200
tristate "AT91RM9200 or some AT91SAM9 RTC"
depends on ARCH_AT91 || COMPILE_TEST
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 6cf7e066314e1..10f540e7409b4 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -139,6 +139,7 @@ obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
obj-$(CONFIG_RTC_DRV_PIC32) += rtc-pic32.o
obj-$(CONFIG_RTC_DRV_PL030) += rtc-pl030.o
obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
+obj-$(CONFIG_RTC_DRV_PL031_RUST) += rtc_pl031_rust.o
obj-$(CONFIG_RTC_DRV_PM8XXX) += rtc-pm8xxx.o
obj-$(CONFIG_RTC_DRV_POLARFIRE_SOC) += rtc-mpfs.o
obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o
diff --git a/drivers/rtc/rtc_pl031_rust.rs b/drivers/rtc/rtc_pl031_rust.rs
new file mode 100644
index 0000000000000..f3cca5c6daa1b
--- /dev/null
+++ b/drivers/rtc/rtc_pl031_rust.rs
@@ -0,0 +1,503 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//! Rust ARM AMBA PrimeCell 031 RTC driver
+//!
+//! This driver provides Real Time Clock functionality for ARM AMBA PrimeCell 031
+//! RTC controllers and their ST Microelectronics derivatives.
+
+use core::{
+ marker::PhantomPinned,
+ ops::Deref, //
+};
+use kernel::{
+ amba,
+ bindings,
+ c_str,
+ device::{
+ self,
+ Core, //
+ },
+ devres::Devres,
+ io::mem::IoMem,
+ irq::{
+ Handler,
+ IrqReturn, //
+ },
+ prelude::*,
+ rtc::{
+ self,
+ Registration,
+ RtcDevice,
+ RtcOps,
+ RtcTime,
+ RtcWkAlrm, //
+ },
+ sync::aref::ARef, //
+};
+
+// Register offsets
+const RTC_DR: usize = 0x00;
+const RTC_MR: usize = 0x04;
+const RTC_LR: usize = 0x08;
+const RTC_CR: usize = 0x0c;
+const RTC_IMSC: usize = 0x10;
+const RTC_RIS: usize = 0x14;
+const RTC_MIS: usize = 0x18;
+const RTC_ICR: usize = 0x1c;
+// ST variants have additional timer functionality
+#[allow(dead_code)]
+const RTC_TDR: usize = 0x20;
+#[allow(dead_code)]
+const RTC_TLR: usize = 0x24;
+#[allow(dead_code)]
+const RTC_TCR: usize = 0x28;
+const RTC_YDR: usize = 0x30;
+const RTC_YMR: usize = 0x34;
+const RTC_YLR: usize = 0x38;
+const PL031_REG_SIZE: usize = RTC_YLR + 4;
+
+// Control register bits
+const RTC_CR_EN: u32 = 1 << 0;
+const RTC_CR_CWEN: u32 = 1 << 26;
+
+#[allow(dead_code)]
+const RTC_TCR_EN: u32 = 1 << 1;
+
+// Interrupt status and control register bits
+const RTC_BIT_AI: u32 = 1 << 0;
+#[allow(dead_code)]
+const RTC_BIT_PI: u32 = 1 << 1;
+
+// RTC event flags
+#[allow(dead_code)]
+const RTC_AF: u32 = bindings::RTC_AF;
+#[allow(dead_code)]
+const RTC_IRQF: u32 = bindings::RTC_IRQF;
+
+// ST v2 time format bit definitions
+const RTC_SEC_SHIFT: u32 = 0;
+const RTC_SEC_MASK: u32 = 0x3F << RTC_SEC_SHIFT;
+const RTC_MIN_SHIFT: u32 = 6;
+const RTC_MIN_MASK: u32 = 0x3F << RTC_MIN_SHIFT;
+const RTC_HOUR_SHIFT: u32 = 12;
+const RTC_HOUR_MASK: u32 = 0x1F << RTC_HOUR_SHIFT;
+const RTC_WDAY_SHIFT: u32 = 17;
+const RTC_WDAY_MASK: u32 = 0x7 << RTC_WDAY_SHIFT;
+const RTC_MDAY_SHIFT: u32 = 20;
+const RTC_MDAY_MASK: u32 = 0x1F << RTC_MDAY_SHIFT;
+const RTC_MON_SHIFT: u32 = 25;
+const RTC_MON_MASK: u32 = 0xF << RTC_MON_SHIFT;
+
+/// Vendor-specific variant identifier for PL031 RTC controllers.
+#[derive(Copy, Clone, PartialEq)]
+enum VendorVariant {
+ /// Original ARM version with 32-bit Unix timestamp format.
+ Arm,
+ /// First ST derivative with clockwatch mode and weekday support.
+ StV1,
+ /// Second ST derivative with packed BCD time format and year register.
+ StV2,
+}
+
+impl VendorVariant {
+ fn clockwatch(&self) -> bool {
+ matches!(self, VendorVariant::StV1 | VendorVariant::StV2)
+ }
+
+ #[allow(dead_code)]
+ fn st_weekday(&self) -> bool {
+ matches!(self, VendorVariant::StV1 | VendorVariant::StV2)
+ }
+
+ #[allow(dead_code)]
+ fn range_min(&self) -> i64 {
+ match self {
+ VendorVariant::Arm | VendorVariant::StV1 => 0,
+ VendorVariant::StV2 => bindings::RTC_TIMESTAMP_BEGIN_0000,
+ }
+ }
+
+ #[allow(dead_code)]
+ fn range_max(&self) -> u64 {
+ match self {
+ VendorVariant::Arm | VendorVariant::StV1 => u64::from(u32::MAX),
+ VendorVariant::StV2 => bindings::RTC_TIMESTAMP_END_9999,
+ }
+ }
+}
+
+/// The driver's private data struct. It holds all necessary devres managed resources.
+#[pin_data(PinnedDrop)]
+struct Pl031DrvData {
+ #[pin]
+ base: Devres<IoMem<PL031_REG_SIZE>>,
+ variant: VendorVariant,
+}
+
+// SAFETY: `Pl031DrvData` contains only `Send`/`Sync` types: `Devres` (Send+Sync)
+// and `VendorVariant` (Copy).
+unsafe impl Send for Pl031DrvData {}
+// SAFETY: `Pl031DrvData` contains only `Send`/`Sync` types: `Devres` (Send+Sync)
+// and `VendorVariant` (Copy).
+unsafe impl Sync for Pl031DrvData {}
+
+/// Vendor-specific variant identifier used in AMBA device table.
+#[derive(Copy, Clone)]
+struct Pl031Variant {
+ variant: VendorVariant,
+}
+
+impl Pl031Variant {
+ const ARM: Self = Self {
+ variant: VendorVariant::Arm,
+ };
+ const STV1: Self = Self {
+ variant: VendorVariant::StV1,
+ };
+ const STV2: Self = Self {
+ variant: VendorVariant::StV2,
+ };
+}
+
+// Use AMBA device table for matching
+kernel::amba_device_table!(
+ ID_TABLE,
+ MODULE_ID_TABLE,
+ <Pl031AmbaDriver as amba::Driver>::IdInfo,
+ [
+ (
+ amba::DeviceId::new(0x00041031, 0x000fffff),
+ Pl031Variant::ARM
+ ),
+ (
+ amba::DeviceId::new(0x00180031, 0x00ffffff),
+ Pl031Variant::STV1
+ ),
+ (
+ amba::DeviceId::new(0x00280031, 0x00ffffff),
+ Pl031Variant::STV2
+ ),
+ ]
+);
+
+struct Pl031AmbaDriver;
+
+impl amba::Driver for Pl031AmbaDriver {
+ type IdInfo = Pl031Variant;
+ const AMBA_ID_TABLE: Option<amba::IdTable<Self::IdInfo>> = Some(&ID_TABLE);
+
+ fn probe(
+ adev: &amba::Device<Core>,
+ id_info: Option<&Self::IdInfo>,
+ ) -> impl PinInit<Self, Error> {
+ let dev = adev.as_ref();
+ let io_request = adev.io_request().ok_or(ENODEV)?;
+ let variant = id_info
+ .map(|info| info.variant)
+ .unwrap_or(VendorVariant::Arm);
+
+ let rtcdev = RtcDevice::<Pl031DrvData>::new(
+ dev,
+ try_pin_init!(Pl031DrvData {
+ base <- IoMem::new(io_request),
+ variant,
+ }),
+ )?;
+
+ dev.devm_init_wakeup()?;
+
+ let drvdata = rtcdev.drvdata()?;
+ let base_guard = drvdata.base.try_access().ok_or(ENXIO)?;
+ let base = base_guard.deref();
+
+ let mut cr = base.read32(RTC_CR);
+ if variant.clockwatch() {
+ cr |= RTC_CR_CWEN;
+ } else {
+ cr |= RTC_CR_EN;
+ }
+ base.write32(cr, RTC_CR);
+
+ if variant.st_weekday() {
+ let bcd_year = base.read32(RTC_YDR);
+ if bcd_year == 0x2000 {
+ let st_time = base.read32(RTC_DR);
+ if (st_time & (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) == 0x02120000 {
+ base.write32(0x2000, RTC_YLR);
+ base.write32(st_time | (0x7 << RTC_WDAY_SHIFT), RTC_LR);
+ }
+ }
+ }
+
+ rtcdev.set_range_min(variant.range_min());
+ rtcdev.set_range_max(variant.range_max());
+
+ let irq_flags = if variant == VendorVariant::StV2 {
+ kernel::irq::Flags::SHARED | kernel::irq::Flags::COND_SUSPEND
+ } else {
+ kernel::irq::Flags::SHARED
+ };
+
+ let rtcdev_clone = rtcdev.clone();
+ let init = adev.request_irq_by_index(
+ irq_flags,
+ 0,
+ c_str!("rtc-pl031"),
+ try_pin_init!(Pl031IrqHandler {
+ _pin: PhantomPinned,
+ rtcdev: rtcdev_clone,
+ }),
+ );
+
+ match kernel::devres::register(dev, init, GFP_KERNEL) {
+ Ok(()) => {
+ if let Ok(irq) = adev.irq_by_index(0) {
+ irq.set_wake_irq()?;
+ }
+ }
+ Err(_) => rtcdev.clear_feature(bindings::RTC_FEATURE_ALARM),
+ }
+
+ Registration::<Pl031DrvData>::register(dev, rtcdev)?;
+ Ok(Pl031AmbaDriver)
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for Pl031DrvData {
+ fn drop(self: Pin<&mut Self>) {
+ // Resources are automatically cleaned up by devres.
+ }
+}
+
+/// Converts a Gregorian date to ST v2 RTC packed BCD format.
+///
+/// Returns a tuple of (packed_time, bcd_year) where packed_time contains
+/// month, day, weekday, hour, minute, and second in a single 32-bit value.
+fn stv2_tm_to_time(tm: &RtcTime) -> Result<(u32, u32)> {
+ let year = tm.tm_year() + 1900;
+ let mut wday = tm.tm_wday();
+
+ // Hardware wday masking doesn't work, so wday must be valid.
+ if !(-1..=6).contains(&wday) {
+ return Err(EINVAL);
+ } else if wday == -1 {
+ // wday is not provided, calculate it here.
+ let time64 = tm.to_time64();
+ let mut calc_tm = RtcTime::default();
+ calc_tm.set_from_time64(time64);
+ wday = calc_tm.tm_wday();
+ }
+
+ // Convert year to BCD.
+ let bcd_year =
+ (u32::from(bin2bcd((year % 100) as u8))) | (u32::from(bin2bcd((year / 100) as u8)) << 8);
+
+ let st_time = ((tm.tm_mon() + 1) as u32) << RTC_MON_SHIFT
+ | (tm.tm_mday() as u32) << RTC_MDAY_SHIFT
+ | ((wday + 1) as u32) << RTC_WDAY_SHIFT
+ | (tm.tm_hour() as u32) << RTC_HOUR_SHIFT
+ | (tm.tm_min() as u32) << RTC_MIN_SHIFT
+ | (tm.tm_sec() as u32) << RTC_SEC_SHIFT;
+
+ Ok((st_time, bcd_year))
+}
+
+/// Converts ST v2 RTC packed BCD format to a Gregorian date.
+///
+/// Extracts time components from the packed 32-bit value and BCD year register,
+/// then populates the RtcTime structure.
+fn stv2_time_to_tm(st_time: u32, bcd_year: u32, tm: &mut RtcTime) {
+ let year_low = bcd2bin((bcd_year & 0xFF) as u8);
+ let year_high = bcd2bin(((bcd_year >> 8) & 0xFF) as u8);
+ tm.set_tm_year(i32::from(year_low) + i32::from(year_high) * 100);
+ tm.set_tm_mon((((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1) as i32);
+ tm.set_tm_mday(((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT) as i32);
+ tm.set_tm_wday((((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1) as i32);
+ tm.set_tm_hour(((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT) as i32);
+ tm.set_tm_min(((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT) as i32);
+ tm.set_tm_sec(((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT) as i32);
+
+ // Values are from valid RTC time structures and are non-negative.
+ tm.set_tm_yday(tm.year_days());
+ tm.set_tm_year(tm.tm_year() - 1900);
+}
+
+/// Converts a binary value to BCD.
+fn bin2bcd(val: u8) -> u8 {
+ ((val / 10) << 4) | (val % 10)
+}
+
+/// Converts a BCD value to binary.
+fn bcd2bin(val: u8) -> u8 {
+ ((val >> 4) * 10) + (val & 0x0F)
+}
+
+/// Interrupt handler for PL031 RTC alarm events.
+#[pin_data]
+struct Pl031IrqHandler {
+ #[pin]
+ _pin: PhantomPinned,
+ rtcdev: ARef<RtcDevice<Pl031DrvData>>,
+}
+
+impl Handler for Pl031IrqHandler {
+ fn handle(&self, _dev: &device::Device<device::Bound>) -> IrqReturn {
+ // Get driver data using drvdata.
+ let drvdata = match self.rtcdev.drvdata() {
+ Ok(drvdata) => drvdata,
+ Err(_) => return IrqReturn::None,
+ };
+
+ // Access the MMIO base.
+ let base_guard = match drvdata.base.try_access() {
+ Some(guard) => guard,
+ None => return IrqReturn::None,
+ };
+ let base = base_guard.deref();
+
+ // Read masked interrupt status.
+ let rtcmis = base.read32(RTC_MIS);
+
+ if (rtcmis & RTC_BIT_AI) != 0 {
+ base.write32(RTC_BIT_AI, RTC_ICR);
+ self.rtcdev.update_irq(1, (RTC_AF | RTC_IRQF) as usize);
+ return IrqReturn::Handled;
+ }
+
+ IrqReturn::None
+ }
+}
+
+#[vtable]
+impl RtcOps for Pl031DrvData {
+ fn read_time(rtcdev: &RtcDevice<Self>, tm: &mut RtcTime) -> Result {
+ let drvdata = rtcdev.drvdata()?;
+ let base_guard = drvdata.base.try_access().ok_or(ENXIO)?;
+ let base = base_guard.deref();
+
+ match drvdata.variant {
+ VendorVariant::Arm | VendorVariant::StV1 => {
+ let time32: u32 = base.read32(RTC_DR);
+ let time64 = i64::from(time32);
+ tm.set_from_time64(time64);
+ }
+ VendorVariant::StV2 => {
+ let st_time = base.read32(RTC_DR);
+ let bcd_year = base.read32(RTC_YDR);
+ stv2_time_to_tm(st_time, bcd_year, tm);
+ }
+ }
+
+ Ok(())
+ }
+
+ fn set_time(rtcdev: &RtcDevice<Self>, tm: &mut RtcTime) -> Result {
+ let dev: &device::Device<device::Bound> = rtcdev.as_ref();
+ let drvdata = rtcdev.drvdata()?;
+ let base_guard = drvdata.base.try_access().ok_or(ENXIO)?;
+ let base = base_guard.deref();
+
+ match drvdata.variant {
+ VendorVariant::Arm | VendorVariant::StV1 => {
+ let time64 = tm.to_time64();
+ base.write32(time64 as u32, RTC_LR);
+ }
+ VendorVariant::StV2 => {
+ let (st_time, bcd_year) = stv2_tm_to_time(tm).inspect_err(|&err| {
+ if err == EINVAL {
+ dev_err!(dev, "invalid wday value {}\n", tm.tm_wday());
+ }
+ })?;
+ base.write32(bcd_year, RTC_YLR);
+ base.write32(st_time, RTC_LR);
+ }
+ }
+
+ Ok(())
+ }
+
+ fn read_alarm(rtcdev: &RtcDevice<Self>, alarm: &mut RtcWkAlrm) -> Result {
+ let drvdata = rtcdev.drvdata()?;
+ let base_guard = drvdata.base.try_access().ok_or(ENXIO)?;
+ let base = base_guard.deref();
+
+ match drvdata.variant {
+ VendorVariant::Arm | VendorVariant::StV1 => {
+ let time32: u32 = base.read32(RTC_MR);
+ let time64 = i64::from(time32);
+ crate::rtc::RtcTime::time64_to_tm(time64, alarm.get_time_mut());
+ }
+ VendorVariant::StV2 => {
+ let st_time = base.read32(RTC_MR);
+ let bcd_year = base.read32(RTC_YMR);
+ stv2_time_to_tm(st_time, bcd_year, alarm.get_time_mut());
+ }
+ }
+
+ alarm.set_pending(if (base.read32(RTC_RIS) & RTC_BIT_AI) != 0 {
+ 1
+ } else {
+ 0
+ });
+ alarm.set_enabled(if (base.read32(RTC_IMSC) & RTC_BIT_AI) != 0 {
+ 1
+ } else {
+ 0
+ });
+
+ Ok(())
+ }
+
+ fn set_alarm(rtcdev: &RtcDevice<Self>, alarm: &mut RtcWkAlrm) -> Result {
+ let dev: &device::Device<device::Bound> = rtcdev.as_ref();
+ let drvdata = rtcdev.drvdata()?;
+ let base_guard = drvdata.base.try_access().ok_or(ENXIO)?;
+ let base = base_guard.deref();
+
+ match drvdata.variant {
+ VendorVariant::Arm | VendorVariant::StV1 => {
+ let time64 = alarm.get_time().to_time64();
+ base.write32(time64 as u32, RTC_MR);
+ }
+ VendorVariant::StV2 => {
+ let (st_time, bcd_year) =
+ stv2_tm_to_time(alarm.get_time()).inspect_err(|&err| {
+ if err == EINVAL {
+ dev_err!(dev, "invalid wday value {}\n", alarm.get_time().tm_wday());
+ }
+ })?;
+ base.write32(bcd_year, RTC_YMR);
+ base.write32(st_time, RTC_MR);
+ }
+ }
+
+ Self::alarm_irq_enable(rtcdev, u32::from(alarm.enabled()))
+ }
+
+ fn alarm_irq_enable(rtcdev: &RtcDevice<Self>, enabled: u32) -> Result {
+ let drvdata = rtcdev.drvdata()?;
+ let base_guard = drvdata.base.try_access().ok_or(ENXIO)?;
+ let base = base_guard.deref();
+
+ // Clear any pending alarm interrupts.
+ base.write32(RTC_BIT_AI, RTC_ICR);
+
+ let mut imsc = base.read32(RTC_IMSC);
+ if enabled == 1 {
+ imsc |= RTC_BIT_AI;
+ } else {
+ imsc &= !RTC_BIT_AI;
+ }
+ base.write32(imsc, RTC_IMSC);
+
+ Ok(())
+ }
+}
+
+kernel::module_rtc_amba_driver! {
+ type: Pl031AmbaDriver,
+ name: "rtc-pl031-rust",
+ authors: ["Ke Sun <sunke@kylinos.cn>"],
+ description: "Rust PL031 RTC driver",
+ license: "GPL v2",
+}
--
2.43.0
^ permalink raw reply related
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Ke Sun @ 2026-01-07 14:41 UTC (permalink / raw)
To: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich
Cc: linux-rtc, rust-for-linux, Alvin Sun
In-Reply-To: <20260107143738.3021892-2-sunke@kylinos.cn>
This is merely a technical validation. If confirmed viable, I will
update other RTC drivers.
Best regards,
Ke Sun
On 1/7/26 22:37, Ke Sun wrote:
> Unify RTC driver interface by storing driver data on the RTC device
> instead of the parent device. Update RTC ops callbacks to pass the RTC
> device itself rather than its parent. This change enables better
> support for Rust RTC drivers that store data on the RTC device.
>
> Signed-off-by: Ke Sun <sunke@kylinos.cn>
> ---
> drivers/rtc/dev.c | 4 ++--
> drivers/rtc/interface.c | 18 +++++++++---------
> drivers/rtc/rtc-pl031.c | 9 ++-------
> 3 files changed, 13 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> index baf1a8ca8b2b1..0f62ba9342e3e 100644
> --- a/drivers/rtc/dev.c
> +++ b/drivers/rtc/dev.c
> @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
> }
> default:
> if (rtc->ops->param_get)
> - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
> + err = rtc->ops->param_get(&rtc->dev, ¶m);
> else
> err = -EINVAL;
> }
> @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
>
> default:
> if (rtc->ops->param_set)
> - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
> + err = rtc->ops->param_set(&rtc->dev, ¶m);
> else
> err = -EINVAL;
> }
> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index b8b298efd9a9c..783a3ec3bb93d 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
> err = -EINVAL;
> } else {
> memset(tm, 0, sizeof(struct rtc_time));
> - err = rtc->ops->read_time(rtc->dev.parent, tm);
> + err = rtc->ops->read_time(&rtc->dev, tm);
> if (err < 0) {
> dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
> err);
> @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
> if (!rtc->ops)
> err = -ENODEV;
> else if (rtc->ops->set_time)
> - err = rtc->ops->set_time(rtc->dev.parent, tm);
> + err = rtc->ops->set_time(&rtc->dev, tm);
> else
> err = -EINVAL;
>
> @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
> alarm->time.tm_wday = -1;
> alarm->time.tm_yday = -1;
> alarm->time.tm_isdst = -1;
> - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
> + err = rtc->ops->read_alarm(&rtc->dev, alarm);
> }
>
> mutex_unlock(&rtc->ops_lock);
> @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
> err = -EINVAL;
> else
> - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
> + err = rtc->ops->set_alarm(&rtc->dev, alarm);
>
> /*
> * Check for potential race described above. If the waiting for next
> @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> err = -EINVAL;
> else
> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
> + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
>
> mutex_unlock(&rtc->ops_lock);
>
> @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> rtc->uie_rtctimer.period = ktime_set(1, 0);
> err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
> if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
> + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
> if (err)
> goto out;
> } else {
> @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
> if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> return;
>
> - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
> + rtc->ops->alarm_irq_enable(&rtc->dev, false);
> trace_rtc_alarm_irq_enable(0, 0);
> }
>
> @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
> return -EINVAL;
>
> mutex_lock(&rtc->ops_lock);
> - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
> + ret = rtc->ops->read_offset(&rtc->dev, offset);
> mutex_unlock(&rtc->ops_lock);
>
> trace_rtc_read_offset(*offset, ret);
> @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
> return -EINVAL;
>
> mutex_lock(&rtc->ops_lock);
> - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
> + ret = rtc->ops->set_offset(&rtc->dev, offset);
> mutex_unlock(&rtc->ops_lock);
>
> trace_rtc_set_offset(offset, ret);
> diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
> index eab39dfa4e5fe..a605034d44cb7 100644
> --- a/drivers/rtc/rtc-pl031.c
> +++ b/drivers/rtc/rtc-pl031.c
> @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>
> static void pl031_remove(struct amba_device *adev)
> {
> - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
> -
> - if (adev->irq[0])
> - free_irq(adev->irq[0], ldata);
> amba_release_regions(adev);
> }
>
> @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> goto out;
> }
>
> - amba_set_drvdata(adev, ldata);
> -
> dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
> dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
>
> @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> ret = PTR_ERR(ldata->rtc);
> goto out;
> }
> + dev_set_drvdata(&ldata->rtc->dev, ldata);
>
> if (!adev->irq[0])
> clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
> @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> goto out;
>
> if (adev->irq[0]) {
> - ret = request_irq(adev->irq[0], pl031_interrupt,
> + ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
> vendor->irqflags, "rtc-pl031", ldata);
> if (ret)
> goto out;
^ permalink raw reply
* Re: [RFC PATCH v2 3/5] rust: add device wakeup capability support
From: Greg KH @ 2026-01-07 14:57 UTC (permalink / raw)
To: Ke Sun
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <20260107143738.3021892-4-sunke@kylinos.cn>
On Wed, Jan 07, 2026 at 10:37:35PM +0800, Ke Sun wrote:
> Add Rust bindings and wrappers for device wakeup functionality,
> including devm_device_init_wakeup() and dev_pm_set_wake_irq().
>
> Signed-off-by: Ke Sun <sunke@kylinos.cn>
> ---
> rust/bindings/bindings_helper.h | 2 ++
> rust/helpers/device.c | 7 +++++++
> rust/kernel/device.rs | 17 ++++++++++++++++-
> rust/kernel/irq/request.rs | 7 +++++++
> 4 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
> index fa697287cf71b..d6c2b06ac4107 100644
> --- a/rust/bindings/bindings_helper.h
> +++ b/rust/bindings/bindings_helper.h
> @@ -88,6 +88,8 @@
> #include <linux/workqueue.h>
> #include <linux/xarray.h>
> #include <trace/events/rust_sample.h>
> +#include <linux/pm_wakeup.h>
> +#include <linux/pm_wakeirq.h>
Aren't these sorted?
> /*
> * The driver-core Rust code needs to know about some C driver-core private
> diff --git a/rust/helpers/device.c b/rust/helpers/device.c
> index 9a4316bafedfb..cae26edd83696 100644
> --- a/rust/helpers/device.c
> +++ b/rust/helpers/device.c
> @@ -1,6 +1,8 @@
> // SPDX-License-Identifier: GPL-2.0
>
> #include <linux/device.h>
> +#include <linux/pm_wakeup.h>
> +#include <linux/pm_wakeirq.h>
Why are both of these needed for just one function call?
thanks,
greg k-h
^ permalink raw reply
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Greg KH @ 2026-01-07 16:12 UTC (permalink / raw)
To: Ke Sun
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <20260107143738.3021892-2-sunke@kylinos.cn>
On Wed, Jan 07, 2026 at 10:37:33PM +0800, Ke Sun wrote:
> Unify RTC driver interface by storing driver data on the RTC device
> instead of the parent device. Update RTC ops callbacks to pass the RTC
> device itself rather than its parent. This change enables better
> support for Rust RTC drivers that store data on the RTC device.
>
> Signed-off-by: Ke Sun <sunke@kylinos.cn>
> ---
> drivers/rtc/dev.c | 4 ++--
> drivers/rtc/interface.c | 18 +++++++++---------
> drivers/rtc/rtc-pl031.c | 9 ++-------
> 3 files changed, 13 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> index baf1a8ca8b2b1..0f62ba9342e3e 100644
> --- a/drivers/rtc/dev.c
> +++ b/drivers/rtc/dev.c
> @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
> }
> default:
> if (rtc->ops->param_get)
> - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
> + err = rtc->ops->param_get(&rtc->dev, ¶m);
> else
> err = -EINVAL;
> }
> @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
>
> default:
> if (rtc->ops->param_set)
> - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
> + err = rtc->ops->param_set(&rtc->dev, ¶m);
> else
> err = -EINVAL;
> }
> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index b8b298efd9a9c..783a3ec3bb93d 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
> err = -EINVAL;
> } else {
> memset(tm, 0, sizeof(struct rtc_time));
> - err = rtc->ops->read_time(rtc->dev.parent, tm);
> + err = rtc->ops->read_time(&rtc->dev, tm);
> if (err < 0) {
> dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
> err);
> @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
> if (!rtc->ops)
> err = -ENODEV;
> else if (rtc->ops->set_time)
> - err = rtc->ops->set_time(rtc->dev.parent, tm);
> + err = rtc->ops->set_time(&rtc->dev, tm);
> else
> err = -EINVAL;
>
> @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
> alarm->time.tm_wday = -1;
> alarm->time.tm_yday = -1;
> alarm->time.tm_isdst = -1;
> - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
> + err = rtc->ops->read_alarm(&rtc->dev, alarm);
> }
>
> mutex_unlock(&rtc->ops_lock);
> @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
> err = -EINVAL;
> else
> - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
> + err = rtc->ops->set_alarm(&rtc->dev, alarm);
>
> /*
> * Check for potential race described above. If the waiting for next
> @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> err = -EINVAL;
> else
> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
> + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
>
> mutex_unlock(&rtc->ops_lock);
>
> @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> rtc->uie_rtctimer.period = ktime_set(1, 0);
> err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
> if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
> + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
> if (err)
> goto out;
> } else {
> @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
> if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> return;
>
> - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
> + rtc->ops->alarm_irq_enable(&rtc->dev, false);
> trace_rtc_alarm_irq_enable(0, 0);
> }
>
> @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
> return -EINVAL;
>
> mutex_lock(&rtc->ops_lock);
> - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
> + ret = rtc->ops->read_offset(&rtc->dev, offset);
> mutex_unlock(&rtc->ops_lock);
>
> trace_rtc_read_offset(*offset, ret);
> @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
> return -EINVAL;
>
> mutex_lock(&rtc->ops_lock);
> - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
> + ret = rtc->ops->set_offset(&rtc->dev, offset);
> mutex_unlock(&rtc->ops_lock);
>
> trace_rtc_set_offset(offset, ret);
> diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
> index eab39dfa4e5fe..a605034d44cb7 100644
> --- a/drivers/rtc/rtc-pl031.c
> +++ b/drivers/rtc/rtc-pl031.c
> @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>
> static void pl031_remove(struct amba_device *adev)
> {
> - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
> -
> - if (adev->irq[0])
> - free_irq(adev->irq[0], ldata);
> amba_release_regions(adev);
> }
>
> @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> goto out;
> }
>
> - amba_set_drvdata(adev, ldata);
> -
> dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
> dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
>
> @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> ret = PTR_ERR(ldata->rtc);
> goto out;
> }
> + dev_set_drvdata(&ldata->rtc->dev, ldata);
>
> if (!adev->irq[0])
> clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
> @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> goto out;
>
> if (adev->irq[0]) {
> - ret = request_irq(adev->irq[0], pl031_interrupt,
> + ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
> vendor->irqflags, "rtc-pl031", ldata);
Are you _SURE_ you can use devm for this? it is a functional change,
one that trips lots of people up. I wouldn't make this change without
at least saying why you are doing so in the changelog text, which I
didn't see at all here.
thanks,
greg k-h
^ permalink raw reply
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Ke Sun @ 2026-01-07 23:18 UTC (permalink / raw)
To: Greg KH
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <2026010757-fester-unissued-6e5f@gregkh>
On 1/8/26 00:12, Greg KH wrote:
> On Wed, Jan 07, 2026 at 10:37:33PM +0800, Ke Sun wrote:
>> Unify RTC driver interface by storing driver data on the RTC device
>> instead of the parent device. Update RTC ops callbacks to pass the RTC
>> device itself rather than its parent. This change enables better
>> support for Rust RTC drivers that store data on the RTC device.
>>
>> Signed-off-by: Ke Sun <sunke@kylinos.cn>
>> ---
>> drivers/rtc/dev.c | 4 ++--
>> drivers/rtc/interface.c | 18 +++++++++---------
>> drivers/rtc/rtc-pl031.c | 9 ++-------
>> 3 files changed, 13 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
>> index baf1a8ca8b2b1..0f62ba9342e3e 100644
>> --- a/drivers/rtc/dev.c
>> +++ b/drivers/rtc/dev.c
>> @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
>> }
>> default:
>> if (rtc->ops->param_get)
>> - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
>> + err = rtc->ops->param_get(&rtc->dev, ¶m);
>> else
>> err = -EINVAL;
>> }
>> @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
>>
>> default:
>> if (rtc->ops->param_set)
>> - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
>> + err = rtc->ops->param_set(&rtc->dev, ¶m);
>> else
>> err = -EINVAL;
>> }
>> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
>> index b8b298efd9a9c..783a3ec3bb93d 100644
>> --- a/drivers/rtc/interface.c
>> +++ b/drivers/rtc/interface.c
>> @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
>> err = -EINVAL;
>> } else {
>> memset(tm, 0, sizeof(struct rtc_time));
>> - err = rtc->ops->read_time(rtc->dev.parent, tm);
>> + err = rtc->ops->read_time(&rtc->dev, tm);
>> if (err < 0) {
>> dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
>> err);
>> @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
>> if (!rtc->ops)
>> err = -ENODEV;
>> else if (rtc->ops->set_time)
>> - err = rtc->ops->set_time(rtc->dev.parent, tm);
>> + err = rtc->ops->set_time(&rtc->dev, tm);
>> else
>> err = -EINVAL;
>>
>> @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
>> alarm->time.tm_wday = -1;
>> alarm->time.tm_yday = -1;
>> alarm->time.tm_isdst = -1;
>> - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
>> + err = rtc->ops->read_alarm(&rtc->dev, alarm);
>> }
>>
>> mutex_unlock(&rtc->ops_lock);
>> @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
>> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
>> err = -EINVAL;
>> else
>> - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
>> + err = rtc->ops->set_alarm(&rtc->dev, alarm);
>>
>> /*
>> * Check for potential race described above. If the waiting for next
>> @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
>> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
>> err = -EINVAL;
>> else
>> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
>> + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
>>
>> mutex_unlock(&rtc->ops_lock);
>>
>> @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
>> rtc->uie_rtctimer.period = ktime_set(1, 0);
>> err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
>> if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
>> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
>> + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
>> if (err)
>> goto out;
>> } else {
>> @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
>> if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
>> return;
>>
>> - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
>> + rtc->ops->alarm_irq_enable(&rtc->dev, false);
>> trace_rtc_alarm_irq_enable(0, 0);
>> }
>>
>> @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
>> return -EINVAL;
>>
>> mutex_lock(&rtc->ops_lock);
>> - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
>> + ret = rtc->ops->read_offset(&rtc->dev, offset);
>> mutex_unlock(&rtc->ops_lock);
>>
>> trace_rtc_read_offset(*offset, ret);
>> @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
>> return -EINVAL;
>>
>> mutex_lock(&rtc->ops_lock);
>> - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
>> + ret = rtc->ops->set_offset(&rtc->dev, offset);
>> mutex_unlock(&rtc->ops_lock);
>>
>> trace_rtc_set_offset(offset, ret);
>> diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
>> index eab39dfa4e5fe..a605034d44cb7 100644
>> --- a/drivers/rtc/rtc-pl031.c
>> +++ b/drivers/rtc/rtc-pl031.c
>> @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>>
>> static void pl031_remove(struct amba_device *adev)
>> {
>> - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
>> -
>> - if (adev->irq[0])
>> - free_irq(adev->irq[0], ldata);
>> amba_release_regions(adev);
>> }
>>
>> @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>> goto out;
>> }
>>
>> - amba_set_drvdata(adev, ldata);
>> -
>> dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
>> dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
>>
>> @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>> ret = PTR_ERR(ldata->rtc);
>> goto out;
>> }
>> + dev_set_drvdata(&ldata->rtc->dev, ldata);
>>
>> if (!adev->irq[0])
>> clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
>> @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>> goto out;
>>
>> if (adev->irq[0]) {
>> - ret = request_irq(adev->irq[0], pl031_interrupt,
>> + ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
>> vendor->irqflags, "rtc-pl031", ldata);
> Are you _SURE_ you can use devm for this? it is a functional change,
Since ldata's lifecycle is now tied to the RTC device (stored via
dev_set_drvdata(&ldata->rtc->dev, ldata)), and the RTC device's lifecycle
is tied to the amba_device (via devm_rtc_allocate_device(&adev->dev)),
using devm_request_irq(&adev->dev, ...) allows us to remove the manual IRQ
release in pl031_remove, as the IRQ will be automatically released along
with the amba_device lifecycle.
Is this reasoning correct, or should I handle this differently?
thanks,
Ke Sun
> one that trips lots of people up. I wouldn't make this change without
> at least saying why you are doing so in the changelog text, which I
> didn't see at all here.
>
> thanks,
>
> greg k-h
^ permalink raw reply
* Re: [RFC PATCH v2 3/5] rust: add device wakeup capability support
From: Ke Sun @ 2026-01-07 23:35 UTC (permalink / raw)
To: Greg KH
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <2026010701-rendering-upheaval-e056@gregkh>
On 1/7/26 22:57, Greg KH wrote:
> On Wed, Jan 07, 2026 at 10:37:35PM +0800, Ke Sun wrote:
>> Add Rust bindings and wrappers for device wakeup functionality,
>> including devm_device_init_wakeup() and dev_pm_set_wake_irq().
>>
>> Signed-off-by: Ke Sun <sunke@kylinos.cn>
>> ---
>> rust/bindings/bindings_helper.h | 2 ++
>> rust/helpers/device.c | 7 +++++++
>> rust/kernel/device.rs | 17 ++++++++++++++++-
>> rust/kernel/irq/request.rs | 7 +++++++
>> 4 files changed, 32 insertions(+), 1 deletion(-)
>>
>> diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
>> index fa697287cf71b..d6c2b06ac4107 100644
>> --- a/rust/bindings/bindings_helper.h
>> +++ b/rust/bindings/bindings_helper.h
>> @@ -88,6 +88,8 @@
>> #include <linux/workqueue.h>
>> #include <linux/xarray.h>
>> #include <trace/events/rust_sample.h>
>> +#include <linux/pm_wakeup.h>
>> +#include <linux/pm_wakeirq.h>
> Aren't these sorted?
>
>> /*
>> * The driver-core Rust code needs to know about some C driver-core private
>> diff --git a/rust/helpers/device.c b/rust/helpers/device.c
>> index 9a4316bafedfb..cae26edd83696 100644
>> --- a/rust/helpers/device.c
>> +++ b/rust/helpers/device.c
>> @@ -1,6 +1,8 @@
>> // SPDX-License-Identifier: GPL-2.0
>>
>> #include <linux/device.h>
>> +#include <linux/pm_wakeup.h>
>> +#include <linux/pm_wakeirq.h>
> Why are both of these needed for just one function call?
Hi Greg,
You're absolutely right. `#include <linux/pm_wakeirq.h>` is not needed in
device.c - that was my mistake. I'll also sort the includes in
bindings_helper.h
alphabetically.
I will address both issues in the next version.
Thanks,
Ke Sun
>
> thanks,
>
> greg k-h
^ permalink raw reply
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Ke Sun @ 2026-01-08 0:24 UTC (permalink / raw)
To: Ke Sun, Greg KH
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux
In-Reply-To: <a95aff4b-5dbf-4def-803a-d5aea84113a5@kylinos.cn>
On 1/8/26 07:18, Ke Sun wrote:
>
> On 1/8/26 00:12, Greg KH wrote:
>> On Wed, Jan 07, 2026 at 10:37:33PM +0800, Ke Sun wrote:
>>> Unify RTC driver interface by storing driver data on the RTC device
>>> instead of the parent device. Update RTC ops callbacks to pass the RTC
>>> device itself rather than its parent. This change enables better
>>> support for Rust RTC drivers that store data on the RTC device.
>>>
>>> Signed-off-by: Ke Sun <sunke@kylinos.cn>
>>> ---
>>> drivers/rtc/dev.c | 4 ++--
>>> drivers/rtc/interface.c | 18 +++++++++---------
>>> drivers/rtc/rtc-pl031.c | 9 ++-------
>>> 3 files changed, 13 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
>>> index baf1a8ca8b2b1..0f62ba9342e3e 100644
>>> --- a/drivers/rtc/dev.c
>>> +++ b/drivers/rtc/dev.c
>>> @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
>>> }
>>> default:
>>> if (rtc->ops->param_get)
>>> - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
>>> + err = rtc->ops->param_get(&rtc->dev, ¶m);
>>> else
>>> err = -EINVAL;
>>> }
>>> @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
>>> default:
>>> if (rtc->ops->param_set)
>>> - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
>>> + err = rtc->ops->param_set(&rtc->dev, ¶m);
>>> else
>>> err = -EINVAL;
>>> }
>>> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
>>> index b8b298efd9a9c..783a3ec3bb93d 100644
>>> --- a/drivers/rtc/interface.c
>>> +++ b/drivers/rtc/interface.c
>>> @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc,
>>> struct rtc_time *tm)
>>> err = -EINVAL;
>>> } else {
>>> memset(tm, 0, sizeof(struct rtc_time));
>>> - err = rtc->ops->read_time(rtc->dev.parent, tm);
>>> + err = rtc->ops->read_time(&rtc->dev, tm);
>>> if (err < 0) {
>>> dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
>>> err);
>>> @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct
>>> rtc_time *tm)
>>> if (!rtc->ops)
>>> err = -ENODEV;
>>> else if (rtc->ops->set_time)
>>> - err = rtc->ops->set_time(rtc->dev.parent, tm);
>>> + err = rtc->ops->set_time(&rtc->dev, tm);
>>> else
>>> err = -EINVAL;
>>> @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct
>>> rtc_device *rtc,
>>> alarm->time.tm_wday = -1;
>>> alarm->time.tm_yday = -1;
>>> alarm->time.tm_isdst = -1;
>>> - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
>>> + err = rtc->ops->read_alarm(&rtc->dev, alarm);
>>> }
>>> mutex_unlock(&rtc->ops_lock);
>>> @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device
>>> *rtc, struct rtc_wkalrm *alarm)
>>> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
>>> err = -EINVAL;
>>> else
>>> - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
>>> + err = rtc->ops->set_alarm(&rtc->dev, alarm);
>>> /*
>>> * Check for potential race described above. If the waiting
>>> for next
>>> @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc,
>>> unsigned int enabled)
>>> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) ||
>>> !rtc->ops->alarm_irq_enable)
>>> err = -EINVAL;
>>> else
>>> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
>>> + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
>>> mutex_unlock(&rtc->ops_lock);
>>> @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device
>>> *rtc, unsigned int enabled)
>>> rtc->uie_rtctimer.period = ktime_set(1, 0);
>>> err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
>>> if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
>>> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
>>> + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
>>> if (err)
>>> goto out;
>>> } else {
>>> @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device
>>> *rtc)
>>> if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features)
>>> || !rtc->ops->alarm_irq_enable)
>>> return;
>>> - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
>>> + rtc->ops->alarm_irq_enable(&rtc->dev, false);
>>> trace_rtc_alarm_irq_enable(0, 0);
>>> }
>>> @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc,
>>> long *offset)
>>> return -EINVAL;
>>> mutex_lock(&rtc->ops_lock);
>>> - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
>>> + ret = rtc->ops->read_offset(&rtc->dev, offset);
>>> mutex_unlock(&rtc->ops_lock);
>>> trace_rtc_read_offset(*offset, ret);
>>> @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc,
>>> long offset)
>>> return -EINVAL;
>>> mutex_lock(&rtc->ops_lock);
>>> - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
>>> + ret = rtc->ops->set_offset(&rtc->dev, offset);
>>> mutex_unlock(&rtc->ops_lock);
>>> trace_rtc_set_offset(offset, ret);
>>> diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
>>> index eab39dfa4e5fe..a605034d44cb7 100644
>>> --- a/drivers/rtc/rtc-pl031.c
>>> +++ b/drivers/rtc/rtc-pl031.c
>>> @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev,
>>> struct rtc_wkalrm *alarm)
>>> static void pl031_remove(struct amba_device *adev)
>>> {
>>> - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
>>> -
>>> - if (adev->irq[0])
>>> - free_irq(adev->irq[0], ldata);
>>> amba_release_regions(adev);
>>> }
>>> @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device
>>> *adev, const struct amba_id *id)
>>> goto out;
>>> }
>>> - amba_set_drvdata(adev, ldata);
>>> -
>>> dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
>>> dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
>>> @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device
>>> *adev, const struct amba_id *id)
>>> ret = PTR_ERR(ldata->rtc);
>>> goto out;
>>> }
>>> + dev_set_drvdata(&ldata->rtc->dev, ldata);
>>> if (!adev->irq[0])
>>> clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
>>> @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev,
>>> const struct amba_id *id)
>>> goto out;
>>> if (adev->irq[0]) {
>>> - ret = request_irq(adev->irq[0], pl031_interrupt,
>>> + ret = devm_request_irq(&adev->dev, adev->irq[0],
>>> pl031_interrupt,
>>> vendor->irqflags, "rtc-pl031", ldata);
>> Are you _SURE_ you can use devm for this? it is a functional change,
>
> Since ldata's lifecycle is now tied to the RTC device (stored via
> dev_set_drvdata(&ldata->rtc->dev, ldata)), and the RTC device's lifecycle
> is tied to the amba_device (via devm_rtc_allocate_device(&adev->dev)),
> using devm_request_irq(&adev->dev, ...) allows us to remove the manual
> IRQ
> release in pl031_remove, as the IRQ will be automatically released along
> with the amba_device lifecycle.
>
>
> Is this reasoning correct, or should I handle this differently?
Correction: Should use devm_request_irq(&ldata->rtc->dev, ...) instead
of devm_request_irq(&adev->dev, ...).
While a lifecycle chain exists (ldata -> rtc -> amba_device), the IRQ
should
be bound to the device that uses it (the RTC device), matching where driver
data is stored, to avoid UAF.
>
>
> thanks,
>
> Ke Sun
>
>> one that trips lots of people up. I wouldn't make this change without
>> at least saying why you are doing so in the changelog text, which I
>> didn't see at all here.
>>
>> thanks,
>>
>> greg k-h
^ permalink raw reply
* [PATCH] rtc: max31335: use correct CONFIG symbol in IS_REACHABLE()
From: Randy Dunlap @ 2026-01-08 4:54 UTC (permalink / raw)
To: linux-kernel; +Cc: Randy Dunlap, Antoniu Miclaus, Alexandre Belloni, linux-rtc
IS_REACHABLE() is meant to be used with full symbol names from a kernel
.config file, not the shortened symbols used in Kconfig files, so
change HWMON to CONFIG_HWMON in 3 places.
Fixes: dedaf03b99d6 ("rtc: max31335: add driver support")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
---
Cc: Antoniu Miclaus <antoniu.miclaus@analog.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-rtc@vger.kernel.org
drivers/rtc/rtc-max31335.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- linux-next-20260107.orig/drivers/rtc/rtc-max31335.c
+++ linux-next-20260107/drivers/rtc/rtc-max31335.c
@@ -591,7 +591,7 @@ static struct nvmem_config max31335_nvme
.size = MAX31335_RAM_SIZE,
};
-#if IS_REACHABLE(HWMON)
+#if IS_REACHABLE(CONFIG_HWMON)
static int max31335_read_temp(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
@@ -672,7 +672,7 @@ static int max31335_clkout_register(stru
static int max31335_probe(struct i2c_client *client)
{
struct max31335_data *max31335;
-#if IS_REACHABLE(HWMON)
+#if IS_REACHABLE(CONFIG_HWMON)
struct device *hwmon;
#endif
const struct chip_desc *match;
@@ -727,7 +727,7 @@ static int max31335_probe(struct i2c_cli
return dev_err_probe(&client->dev, ret,
"cannot register rtc nvmem\n");
-#if IS_REACHABLE(HWMON)
+#if IS_REACHABLE(CONFIG_HWMON)
if (max31335->chip->temp_reg) {
hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name, max31335,
&max31335_chip_info, NULL);
^ permalink raw reply
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Greg KH @ 2026-01-08 5:46 UTC (permalink / raw)
To: Ke Sun
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <a95aff4b-5dbf-4def-803a-d5aea84113a5@kylinos.cn>
On Thu, Jan 08, 2026 at 07:18:30AM +0800, Ke Sun wrote:
>
> On 1/8/26 00:12, Greg KH wrote:
> > On Wed, Jan 07, 2026 at 10:37:33PM +0800, Ke Sun wrote:
> > > Unify RTC driver interface by storing driver data on the RTC device
> > > instead of the parent device. Update RTC ops callbacks to pass the RTC
> > > device itself rather than its parent. This change enables better
> > > support for Rust RTC drivers that store data on the RTC device.
> > >
> > > Signed-off-by: Ke Sun <sunke@kylinos.cn>
> > > ---
> > > drivers/rtc/dev.c | 4 ++--
> > > drivers/rtc/interface.c | 18 +++++++++---------
> > > drivers/rtc/rtc-pl031.c | 9 ++-------
> > > 3 files changed, 13 insertions(+), 18 deletions(-)
> > >
> > > diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> > > index baf1a8ca8b2b1..0f62ba9342e3e 100644
> > > --- a/drivers/rtc/dev.c
> > > +++ b/drivers/rtc/dev.c
> > > @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
> > > }
> > > default:
> > > if (rtc->ops->param_get)
> > > - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
> > > + err = rtc->ops->param_get(&rtc->dev, ¶m);
> > > else
> > > err = -EINVAL;
> > > }
> > > @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
> > > default:
> > > if (rtc->ops->param_set)
> > > - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
> > > + err = rtc->ops->param_set(&rtc->dev, ¶m);
> > > else
> > > err = -EINVAL;
> > > }
> > > diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> > > index b8b298efd9a9c..783a3ec3bb93d 100644
> > > --- a/drivers/rtc/interface.c
> > > +++ b/drivers/rtc/interface.c
> > > @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
> > > err = -EINVAL;
> > > } else {
> > > memset(tm, 0, sizeof(struct rtc_time));
> > > - err = rtc->ops->read_time(rtc->dev.parent, tm);
> > > + err = rtc->ops->read_time(&rtc->dev, tm);
> > > if (err < 0) {
> > > dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
> > > err);
> > > @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
> > > if (!rtc->ops)
> > > err = -ENODEV;
> > > else if (rtc->ops->set_time)
> > > - err = rtc->ops->set_time(rtc->dev.parent, tm);
> > > + err = rtc->ops->set_time(&rtc->dev, tm);
> > > else
> > > err = -EINVAL;
> > > @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
> > > alarm->time.tm_wday = -1;
> > > alarm->time.tm_yday = -1;
> > > alarm->time.tm_isdst = -1;
> > > - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
> > > + err = rtc->ops->read_alarm(&rtc->dev, alarm);
> > > }
> > > mutex_unlock(&rtc->ops_lock);
> > > @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
> > > else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
> > > err = -EINVAL;
> > > else
> > > - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
> > > + err = rtc->ops->set_alarm(&rtc->dev, alarm);
> > > /*
> > > * Check for potential race described above. If the waiting for next
> > > @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> > > else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> > > err = -EINVAL;
> > > else
> > > - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
> > > + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
> > > mutex_unlock(&rtc->ops_lock);
> > > @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> > > rtc->uie_rtctimer.period = ktime_set(1, 0);
> > > err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
> > > if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
> > > - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
> > > + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
> > > if (err)
> > > goto out;
> > > } else {
> > > @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
> > > if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> > > return;
> > > - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
> > > + rtc->ops->alarm_irq_enable(&rtc->dev, false);
> > > trace_rtc_alarm_irq_enable(0, 0);
> > > }
> > > @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
> > > return -EINVAL;
> > > mutex_lock(&rtc->ops_lock);
> > > - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
> > > + ret = rtc->ops->read_offset(&rtc->dev, offset);
> > > mutex_unlock(&rtc->ops_lock);
> > > trace_rtc_read_offset(*offset, ret);
> > > @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
> > > return -EINVAL;
> > > mutex_lock(&rtc->ops_lock);
> > > - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
> > > + ret = rtc->ops->set_offset(&rtc->dev, offset);
> > > mutex_unlock(&rtc->ops_lock);
> > > trace_rtc_set_offset(offset, ret);
> > > diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
> > > index eab39dfa4e5fe..a605034d44cb7 100644
> > > --- a/drivers/rtc/rtc-pl031.c
> > > +++ b/drivers/rtc/rtc-pl031.c
> > > @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> > > static void pl031_remove(struct amba_device *adev)
> > > {
> > > - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
> > > -
> > > - if (adev->irq[0])
> > > - free_irq(adev->irq[0], ldata);
> > > amba_release_regions(adev);
> > > }
> > > @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> > > goto out;
> > > }
> > > - amba_set_drvdata(adev, ldata);
> > > -
> > > dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
> > > dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
> > > @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> > > ret = PTR_ERR(ldata->rtc);
> > > goto out;
> > > }
> > > + dev_set_drvdata(&ldata->rtc->dev, ldata);
> > > if (!adev->irq[0])
> > > clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
> > > @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> > > goto out;
> > > if (adev->irq[0]) {
> > > - ret = request_irq(adev->irq[0], pl031_interrupt,
> > > + ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
> > > vendor->irqflags, "rtc-pl031", ldata);
> > Are you _SURE_ you can use devm for this? it is a functional change,
>
> Since ldata's lifecycle is now tied to the RTC device (stored via
> dev_set_drvdata(&ldata->rtc->dev, ldata)), and the RTC device's lifecycle
> is tied to the amba_device (via devm_rtc_allocate_device(&adev->dev)),
> using devm_request_irq(&adev->dev, ...) allows us to remove the manual IRQ
> release in pl031_remove, as the IRQ will be automatically released along
> with the amba_device lifecycle.
Please test this. There are loads of race conditions that can happen
when irqs are bound to devm lifecycles. You are changing the behavior
here, so be very careful.
And again, this is a change that was not documented in the changelog,
and should not be part of this patch, it should be stand-alone.
thanks,
greg k-h
^ permalink raw reply
* [PATCH v5 0/3] spacemit: fix P1 sub-device Kconfig defaults and dependencies
From: Troy Mitchell @ 2026-01-08 8:38 UTC (permalink / raw)
To: Lee Jones, Yixun Lan, Alex Elder, Andi Shyti, Alexandre Belloni,
Liam Girdwood, Mark Brown
Cc: linux-kernel, linux-riscv, spacemit, linux-i2c, linux-rtc,
Troy Mitchell
This series fixes Kconfig default value and dependency handling for
the SpacemiT P1 PMIC and its sub-devices.
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
Troy Mitchell (3):
regulator: spacemit: MFD_SPACEMIT_P1 as dependencies
mfd: simple-mfd-i2c: add default value
rtc: spacemit: default module when MFD_SPACEMIT_P1 is enabled
drivers/mfd/Kconfig | 1 +
drivers/regulator/Kconfig | 5 ++---
drivers/rtc/Kconfig | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
---
base-commit: b87881a3c93345252ce8559ad763369febfdb75d
change-id: 20251021-p1-kconfig-fix-6d2b59d03b8f
Best regards,
--
Troy Mitchell <troy.mitchell@linux.spacemit.com>
^ permalink raw reply
* [PATCH v5 1/3] regulator: spacemit: MFD_SPACEMIT_P1 as dependencies
From: Troy Mitchell @ 2026-01-08 8:38 UTC (permalink / raw)
To: Lee Jones, Yixun Lan, Alex Elder, Andi Shyti, Alexandre Belloni,
Liam Girdwood, Mark Brown
Cc: linux-kernel, linux-riscv, spacemit, linux-i2c, linux-rtc,
Troy Mitchell
In-Reply-To: <20260108-p1-kconfig-fix-v5-0-6fe19f460269@linux.spacemit.com>
REGULATOR_SPACEMIT_P1 is a subdevice of P1 and should depend on
MFD_SPACEMIT_P1 rather than selecting it directly. Using 'select'
does not always respect the parent's dependencies, so 'depends on'
is the safer and more correct choice.
Since MFD_SPACEMIT_P1 already depends on I2C_K1, the dependency
in REGULATOR_SPACEMIT_P1 is now redundant.
Additionally, the default value depends on MFD_SPACEMIT_P1 rather
than ARCH_SPACEMIT.
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Alex Elder <elder@riscstar.com>
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
Change log in v5:
- nothing
- Link to v4: https://lore.kernel.org/all/20251225-p1-kconfig-fix-v4-1-44b6728117c1@linux.spacemit.com/
Change log in v4:
- default m if MFD_SPACEMIT_P1 instead of default MFD_SPACEMIT_P1
Link to v3: https://lore.kernel.org/all/20251118-p1-kconfig-fix-v3-3-8839c5ac5db3@linux.spacemit.com/
Changelog in v3:
- modify commit message
- change default value from ARCH_SPACEMIT to MFD_SPACEMIT_P1
- Link to v2: https://lore.kernel.org/all/20251027-p1-kconfig-fix-v2-4-49688f30bae8@linux.spacemit.com/
---
drivers/regulator/Kconfig | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index d2335276cce5ffbd500bbaf251d1761a9116aee9..b51888a9a78f399a6af3294fc19f60792576332c 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1496,9 +1496,8 @@ config REGULATOR_SLG51000
config REGULATOR_SPACEMIT_P1
tristate "SpacemiT P1 regulators"
depends on ARCH_SPACEMIT || COMPILE_TEST
- depends on I2C
- select MFD_SPACEMIT_P1
- default ARCH_SPACEMIT
+ depends on MFD_SPACEMIT_P1
+ default m if MFD_SPACEMIT_P1
help
Enable support for regulators implemented by the SpacemiT P1
power controller. The P1 implements 6 high-efficiency buck
--
2.52.0
^ permalink raw reply related
* [PATCH v5 2/3] mfd: simple-mfd-i2c: add default value
From: Troy Mitchell @ 2026-01-08 8:38 UTC (permalink / raw)
To: Lee Jones, Yixun Lan, Alex Elder, Andi Shyti, Alexandre Belloni,
Liam Girdwood, Mark Brown
Cc: linux-kernel, linux-riscv, spacemit, linux-i2c, linux-rtc,
Troy Mitchell
In-Reply-To: <20260108-p1-kconfig-fix-v5-0-6fe19f460269@linux.spacemit.com>
The default value of the P1 sub-device depends on the value
of P1, so P1 should have a default value here.
Acked-by: Alex Elder <elder@riscstar.com>
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
Change log in v5:
- nothing
- Link to v4: https://lore.kernel.org/all/20251225-p1-kconfig-fix-v4-2-44b6728117c1@linux.spacemit.com/
Change log in v4:
- default m if ARCH_SPACEMIT instead of default ARCH_SPACEMIT
- Link to v3: https://lore.kernel.org/all/20251118-p1-kconfig-fix-v3-4-8839c5ac5db3@linux.spacemit.com/
---
drivers/mfd/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index aace5766b38aa5e46e32a8a7b42eea238159fbcf..c757bc365029dc794c658fc5b10084a0f29ac9b6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1276,6 +1276,7 @@ config MFD_SPACEMIT_P1
depends on ARCH_SPACEMIT || COMPILE_TEST
depends on I2C
select MFD_SIMPLE_MFD_I2C
+ default m if ARCH_SPACEMIT
help
This option supports the I2C-based SpacemiT P1 PMIC, which
contains regulators, a power switch, GPIOs, an RTC, and more.
--
2.52.0
^ permalink raw reply related
* [PATCH v5 3/3] rtc: spacemit: default module when MFD_SPACEMIT_P1 is enabled
From: Troy Mitchell @ 2026-01-08 8:38 UTC (permalink / raw)
To: Lee Jones, Yixun Lan, Alex Elder, Andi Shyti, Alexandre Belloni,
Liam Girdwood, Mark Brown
Cc: linux-kernel, linux-riscv, spacemit, linux-i2c, linux-rtc,
Troy Mitchell
In-Reply-To: <20260108-p1-kconfig-fix-v5-0-6fe19f460269@linux.spacemit.com>
The RTC driver defaulted to the same value as MFD_SPACEMIT_P1, which
caused it to be built-in automatically whenever the PMIC support was
set to y.
This is not always desirable, as the RTC function is not required on
all platforms using the SpacemiT P1 PMIC.
Acked-by: Alex Elder <elder@riscstar.com>
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
Change log in v5:
- add Alex's tag
- Link to v4: https://lore.kernel.org/all/20251225-p1-kconfig-fix-v4-3-44b6728117c1@linux.spacemit.com/
---
drivers/rtc/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 50dc779f7f983074df7882200c90f0df21d142f2..53866493e9bbaf35ff0de85cbfe43e8343eadc1e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -410,7 +410,7 @@ config RTC_DRV_SPACEMIT_P1
tristate "SpacemiT P1 RTC"
depends on ARCH_SPACEMIT || COMPILE_TEST
depends on MFD_SPACEMIT_P1
- default MFD_SPACEMIT_P1
+ default m if MFD_SPACEMIT_P1
help
Enable support for the RTC function in the SpacemiT P1 PMIC.
This driver can also be built as a module, which will be called
--
2.52.0
^ permalink raw reply related
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Ke Sun @ 2026-01-08 9:02 UTC (permalink / raw)
To: Greg KH
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <2026010841-accuracy-skimmed-9f0b@gregkh>
On 1/8/26 13:46, Greg KH wrote:
> On Thu, Jan 08, 2026 at 07:18:30AM +0800, Ke Sun wrote:
>> On 1/8/26 00:12, Greg KH wrote:
>>> On Wed, Jan 07, 2026 at 10:37:33PM +0800, Ke Sun wrote:
>>>> Unify RTC driver interface by storing driver data on the RTC device
>>>> instead of the parent device. Update RTC ops callbacks to pass the RTC
>>>> device itself rather than its parent. This change enables better
>>>> support for Rust RTC drivers that store data on the RTC device.
>>>>
>>>> Signed-off-by: Ke Sun <sunke@kylinos.cn>
>>>> ---
>>>> drivers/rtc/dev.c | 4 ++--
>>>> drivers/rtc/interface.c | 18 +++++++++---------
>>>> drivers/rtc/rtc-pl031.c | 9 ++-------
>>>> 3 files changed, 13 insertions(+), 18 deletions(-)
>>>>
>>>> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
>>>> index baf1a8ca8b2b1..0f62ba9342e3e 100644
>>>> --- a/drivers/rtc/dev.c
>>>> +++ b/drivers/rtc/dev.c
>>>> @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
>>>> }
>>>> default:
>>>> if (rtc->ops->param_get)
>>>> - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
>>>> + err = rtc->ops->param_get(&rtc->dev, ¶m);
>>>> else
>>>> err = -EINVAL;
>>>> }
>>>> @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
>>>> default:
>>>> if (rtc->ops->param_set)
>>>> - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
>>>> + err = rtc->ops->param_set(&rtc->dev, ¶m);
>>>> else
>>>> err = -EINVAL;
>>>> }
>>>> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
>>>> index b8b298efd9a9c..783a3ec3bb93d 100644
>>>> --- a/drivers/rtc/interface.c
>>>> +++ b/drivers/rtc/interface.c
>>>> @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
>>>> err = -EINVAL;
>>>> } else {
>>>> memset(tm, 0, sizeof(struct rtc_time));
>>>> - err = rtc->ops->read_time(rtc->dev.parent, tm);
>>>> + err = rtc->ops->read_time(&rtc->dev, tm);
>>>> if (err < 0) {
>>>> dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
>>>> err);
>>>> @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
>>>> if (!rtc->ops)
>>>> err = -ENODEV;
>>>> else if (rtc->ops->set_time)
>>>> - err = rtc->ops->set_time(rtc->dev.parent, tm);
>>>> + err = rtc->ops->set_time(&rtc->dev, tm);
>>>> else
>>>> err = -EINVAL;
>>>> @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
>>>> alarm->time.tm_wday = -1;
>>>> alarm->time.tm_yday = -1;
>>>> alarm->time.tm_isdst = -1;
>>>> - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
>>>> + err = rtc->ops->read_alarm(&rtc->dev, alarm);
>>>> }
>>>> mutex_unlock(&rtc->ops_lock);
>>>> @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
>>>> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
>>>> err = -EINVAL;
>>>> else
>>>> - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
>>>> + err = rtc->ops->set_alarm(&rtc->dev, alarm);
>>>> /*
>>>> * Check for potential race described above. If the waiting for next
>>>> @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
>>>> else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
>>>> err = -EINVAL;
>>>> else
>>>> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
>>>> + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
>>>> mutex_unlock(&rtc->ops_lock);
>>>> @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
>>>> rtc->uie_rtctimer.period = ktime_set(1, 0);
>>>> err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
>>>> if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
>>>> - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
>>>> + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
>>>> if (err)
>>>> goto out;
>>>> } else {
>>>> @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
>>>> if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
>>>> return;
>>>> - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
>>>> + rtc->ops->alarm_irq_enable(&rtc->dev, false);
>>>> trace_rtc_alarm_irq_enable(0, 0);
>>>> }
>>>> @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
>>>> return -EINVAL;
>>>> mutex_lock(&rtc->ops_lock);
>>>> - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
>>>> + ret = rtc->ops->read_offset(&rtc->dev, offset);
>>>> mutex_unlock(&rtc->ops_lock);
>>>> trace_rtc_read_offset(*offset, ret);
>>>> @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
>>>> return -EINVAL;
>>>> mutex_lock(&rtc->ops_lock);
>>>> - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
>>>> + ret = rtc->ops->set_offset(&rtc->dev, offset);
>>>> mutex_unlock(&rtc->ops_lock);
>>>> trace_rtc_set_offset(offset, ret);
>>>> diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
>>>> index eab39dfa4e5fe..a605034d44cb7 100644
>>>> --- a/drivers/rtc/rtc-pl031.c
>>>> +++ b/drivers/rtc/rtc-pl031.c
>>>> @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>>>> static void pl031_remove(struct amba_device *adev)
>>>> {
>>>> - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
>>>> -
>>>> - if (adev->irq[0])
>>>> - free_irq(adev->irq[0], ldata);
>>>> amba_release_regions(adev);
>>>> }
>>>> @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>>>> goto out;
>>>> }
>>>> - amba_set_drvdata(adev, ldata);
>>>> -
>>>> dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
>>>> dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
>>>> @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>>>> ret = PTR_ERR(ldata->rtc);
>>>> goto out;
>>>> }
>>>> + dev_set_drvdata(&ldata->rtc->dev, ldata);
>>>> if (!adev->irq[0])
>>>> clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
>>>> @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>>>> goto out;
>>>> if (adev->irq[0]) {
>>>> - ret = request_irq(adev->irq[0], pl031_interrupt,
>>>> + ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
>>>> vendor->irqflags, "rtc-pl031", ldata);
>>> Are you _SURE_ you can use devm for this? it is a functional change,
>> Since ldata's lifecycle is now tied to the RTC device (stored via
>> dev_set_drvdata(&ldata->rtc->dev, ldata)), and the RTC device's lifecycle
>> is tied to the amba_device (via devm_rtc_allocate_device(&adev->dev)),
>> using devm_request_irq(&adev->dev, ...) allows us to remove the manual IRQ
>> release in pl031_remove, as the IRQ will be automatically released along
>> with the amba_device lifecycle.
> Please test this. There are loads of race conditions that can happen
> when irqs are bound to devm lifecycles. You are changing the behavior
> here, so be very careful.
Yes, I'm testing this with pl031 (qemu), ds3231, rk808, and other devices.
Using rtcwake and hwclock for concurrent access, while continuously
unbinding/binding devices.
>
> And again, this is a change that was not documented in the changelog,
> and should not be part of this patch, it should be stand-alone.
Regarding the RTC C refactoring that affects 182 files, should I put all
changes in one patch, or create separate patches for each file?
Best regards,
Ke Sun
>
> thanks,
>
> greg k-h
^ permalink raw reply
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Greg KH @ 2026-01-08 9:10 UTC (permalink / raw)
To: Ke Sun
Cc: Alexandre Belloni, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, linux-rtc, rust-for-linux,
Alvin Sun
In-Reply-To: <7c6af8a1-9c5e-46b1-8c17-8ffd443fa6aa@kylinos.cn>
On Thu, Jan 08, 2026 at 05:02:30PM +0800, Ke Sun wrote:
>
> On 1/8/26 13:46, Greg KH wrote:
> > On Thu, Jan 08, 2026 at 07:18:30AM +0800, Ke Sun wrote:
> > > On 1/8/26 00:12, Greg KH wrote:
> > > > On Wed, Jan 07, 2026 at 10:37:33PM +0800, Ke Sun wrote:
> > > > > Unify RTC driver interface by storing driver data on the RTC device
> > > > > instead of the parent device. Update RTC ops callbacks to pass the RTC
> > > > > device itself rather than its parent. This change enables better
> > > > > support for Rust RTC drivers that store data on the RTC device.
> > > > >
> > > > > Signed-off-by: Ke Sun <sunke@kylinos.cn>
> > > > > ---
> > > > > drivers/rtc/dev.c | 4 ++--
> > > > > drivers/rtc/interface.c | 18 +++++++++---------
> > > > > drivers/rtc/rtc-pl031.c | 9 ++-------
> > > > > 3 files changed, 13 insertions(+), 18 deletions(-)
> > > > >
> > > > > diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> > > > > index baf1a8ca8b2b1..0f62ba9342e3e 100644
> > > > > --- a/drivers/rtc/dev.c
> > > > > +++ b/drivers/rtc/dev.c
> > > > > @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
> > > > > }
> > > > > default:
> > > > > if (rtc->ops->param_get)
> > > > > - err = rtc->ops->param_get(rtc->dev.parent, ¶m);
> > > > > + err = rtc->ops->param_get(&rtc->dev, ¶m);
> > > > > else
> > > > > err = -EINVAL;
> > > > > }
> > > > > @@ -440,7 +440,7 @@ static long rtc_dev_ioctl(struct file *file,
> > > > > default:
> > > > > if (rtc->ops->param_set)
> > > > > - err = rtc->ops->param_set(rtc->dev.parent, ¶m);
> > > > > + err = rtc->ops->param_set(&rtc->dev, ¶m);
> > > > > else
> > > > > err = -EINVAL;
> > > > > }
> > > > > diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> > > > > index b8b298efd9a9c..783a3ec3bb93d 100644
> > > > > --- a/drivers/rtc/interface.c
> > > > > +++ b/drivers/rtc/interface.c
> > > > > @@ -91,7 +91,7 @@ static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
> > > > > err = -EINVAL;
> > > > > } else {
> > > > > memset(tm, 0, sizeof(struct rtc_time));
> > > > > - err = rtc->ops->read_time(rtc->dev.parent, tm);
> > > > > + err = rtc->ops->read_time(&rtc->dev, tm);
> > > > > if (err < 0) {
> > > > > dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
> > > > > err);
> > > > > @@ -155,7 +155,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
> > > > > if (!rtc->ops)
> > > > > err = -ENODEV;
> > > > > else if (rtc->ops->set_time)
> > > > > - err = rtc->ops->set_time(rtc->dev.parent, tm);
> > > > > + err = rtc->ops->set_time(&rtc->dev, tm);
> > > > > else
> > > > > err = -EINVAL;
> > > > > @@ -200,7 +200,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
> > > > > alarm->time.tm_wday = -1;
> > > > > alarm->time.tm_yday = -1;
> > > > > alarm->time.tm_isdst = -1;
> > > > > - err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
> > > > > + err = rtc->ops->read_alarm(&rtc->dev, alarm);
> > > > > }
> > > > > mutex_unlock(&rtc->ops_lock);
> > > > > @@ -441,7 +441,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
> > > > > else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
> > > > > err = -EINVAL;
> > > > > else
> > > > > - err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
> > > > > + err = rtc->ops->set_alarm(&rtc->dev, alarm);
> > > > > /*
> > > > > * Check for potential race described above. If the waiting for next
> > > > > @@ -568,7 +568,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> > > > > else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> > > > > err = -EINVAL;
> > > > > else
> > > > > - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
> > > > > + err = rtc->ops->alarm_irq_enable(&rtc->dev, enabled);
> > > > > mutex_unlock(&rtc->ops_lock);
> > > > > @@ -618,7 +618,7 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> > > > > rtc->uie_rtctimer.period = ktime_set(1, 0);
> > > > > err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
> > > > > if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
> > > > > - err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
> > > > > + err = rtc->ops->alarm_irq_enable(&rtc->dev, 1);
> > > > > if (err)
> > > > > goto out;
> > > > > } else {
> > > > > @@ -874,7 +874,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
> > > > > if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
> > > > > return;
> > > > > - rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
> > > > > + rtc->ops->alarm_irq_enable(&rtc->dev, false);
> > > > > trace_rtc_alarm_irq_enable(0, 0);
> > > > > }
> > > > > @@ -1076,7 +1076,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
> > > > > return -EINVAL;
> > > > > mutex_lock(&rtc->ops_lock);
> > > > > - ret = rtc->ops->read_offset(rtc->dev.parent, offset);
> > > > > + ret = rtc->ops->read_offset(&rtc->dev, offset);
> > > > > mutex_unlock(&rtc->ops_lock);
> > > > > trace_rtc_read_offset(*offset, ret);
> > > > > @@ -1111,7 +1111,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
> > > > > return -EINVAL;
> > > > > mutex_lock(&rtc->ops_lock);
> > > > > - ret = rtc->ops->set_offset(rtc->dev.parent, offset);
> > > > > + ret = rtc->ops->set_offset(&rtc->dev, offset);
> > > > > mutex_unlock(&rtc->ops_lock);
> > > > > trace_rtc_set_offset(offset, ret);
> > > > > diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
> > > > > index eab39dfa4e5fe..a605034d44cb7 100644
> > > > > --- a/drivers/rtc/rtc-pl031.c
> > > > > +++ b/drivers/rtc/rtc-pl031.c
> > > > > @@ -284,10 +284,6 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> > > > > static void pl031_remove(struct amba_device *adev)
> > > > > {
> > > > > - struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
> > > > > -
> > > > > - if (adev->irq[0])
> > > > > - free_irq(adev->irq[0], ldata);
> > > > > amba_release_regions(adev);
> > > > > }
> > > > > @@ -320,8 +316,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> > > > > goto out;
> > > > > }
> > > > > - amba_set_drvdata(adev, ldata);
> > > > > -
> > > > > dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
> > > > > dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
> > > > > @@ -356,6 +350,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> > > > > ret = PTR_ERR(ldata->rtc);
> > > > > goto out;
> > > > > }
> > > > > + dev_set_drvdata(&ldata->rtc->dev, ldata);
> > > > > if (!adev->irq[0])
> > > > > clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
> > > > > @@ -369,7 +364,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
> > > > > goto out;
> > > > > if (adev->irq[0]) {
> > > > > - ret = request_irq(adev->irq[0], pl031_interrupt,
> > > > > + ret = devm_request_irq(&adev->dev, adev->irq[0], pl031_interrupt,
> > > > > vendor->irqflags, "rtc-pl031", ldata);
> > > > Are you _SURE_ you can use devm for this? it is a functional change,
> > > Since ldata's lifecycle is now tied to the RTC device (stored via
> > > dev_set_drvdata(&ldata->rtc->dev, ldata)), and the RTC device's lifecycle
> > > is tied to the amba_device (via devm_rtc_allocate_device(&adev->dev)),
> > > using devm_request_irq(&adev->dev, ...) allows us to remove the manual IRQ
> > > release in pl031_remove, as the IRQ will be automatically released along
> > > with the amba_device lifecycle.
> > Please test this. There are loads of race conditions that can happen
> > when irqs are bound to devm lifecycles. You are changing the behavior
> > here, so be very careful.
>
> Yes, I'm testing this with pl031 (qemu), ds3231, rk808, and other devices.
>
> Using rtcwake and hwclock for concurrent access, while continuously
>
> unbinding/binding devices.
Ok, great, but again, make this a separate patch.
> > And again, this is a change that was not documented in the changelog,
> > and should not be part of this patch, it should be stand-alone.
>
> Regarding the RTC C refactoring that affects 182 files, should I put all
>
> changes in one patch, or create separate patches for each file?
Don't know, whatever you find easier. What would you want to review if
you were on the recieving end of it?
thanks,
greg k-h
^ permalink raw reply
* Re: [RFC PATCH v2 1/5] rtc: migrate driver data to RTC device
From: Danilo Krummrich @ 2026-01-08 11:06 UTC (permalink / raw)
To: Ke Sun
Cc: Ke Sun, Greg KH, Alexandre Belloni, Miguel Ojeda, Boqun Feng,
Gary Guo, Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Alice Ryhl, Trevor Gross, linux-rtc, rust-for-linux
In-Reply-To: <66e517b1-bc83-4c73-b2ea-73a31757ab44@gmail.com>
On Thu Jan 8, 2026 at 1:24 AM CET, Ke Sun wrote:
> Correction: Should use devm_request_irq(&ldata->rtc->dev, ...) instead
>
> of devm_request_irq(&adev->dev, ...).
>
>
> While a lifecycle chain exists (ldata -> rtc -> amba_device), the IRQ
> should
>
> be bound to the device that uses it (the RTC device), matching where driver
>
> data is stored, to avoid UAF.
No, that is wrong.
Your RTC device is a class device, not a bus device. I.e. it is not a
representation of physical device on the bus.
However, the requested IRQ is a physical device resource that belongs to a bus
device, which in your case is an AMBA device. (Please also see my reply [1] from
the previous version again.)
Therefore device resources are only valid to access and hold on to for a driver
as long as it is bound to the corresponding bus device.
This is the fundamental reason why it is desirable to guard the lifetime of the
class device and its callbacks with devres, to ensure that it is always valid to
access device resources from class device callbacks.
In C drivers, you just have to do the right thing, otherwise you indeed end up
with UAFs. In Rust, we can leverage the type system to make it impossible for
drivers to mess this up.
[1] https://lore.kernel.org/all/DFHJM2HAG7Q3.1HGZ3P7H55FD2@kernel.org/
^ permalink raw reply
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