* [PATCH v3] spi: dt-bindings: microchip,pic32mzda-spi: Convert to DT schema
From: Udaya Kiran Challa @ 2026-06-17 10:10 UTC (permalink / raw)
To: tsbogend, robh, krzk+dt, conor+dt
Cc: skhan, me, linux-rtc, devicetree, linux-kernel,
Udaya Kiran Challa
Convert Microchip PIC32 SPI controller devicetree binding
from legacy text format to DT schema.
Signed-off-by: Udaya Kiran Challa <challauday369@gmail.com>
---
Changelog:
Changes since v2:
- Add cs-gpios to required property
Link to v2: https://lore.kernel.org/all/20260615115311.515404-1-challauday369@gmail.com/
Changes since v1:
- Rename schema file to microchip,pic32mzda-spi.yaml
- Update subject prefix to match SPI DT binding conventions
Link to v1:https://lore.kernel.org/all/20260614175005.435826-1-challauday369@gmail.com/
---
.../bindings/spi/microchip,pic32mzda-spi.yaml | 82 +++++++++++++++++++
.../bindings/spi/microchip,spi-pic32.txt | 34 --------
2 files changed, 82 insertions(+), 34 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml
delete mode 100644 Documentation/devicetree/bindings/spi/microchip,spi-pic32.txt
diff --git a/Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml b/Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml
new file mode 100644
index 000000000000..4669b521fa1f
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/microchip,pic32mzda-spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PIC32MZDA SPI Controller
+
+maintainers:
+ - Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+
+allOf:
+ - $ref: spi-controller.yaml#
+
+properties:
+ compatible:
+ const: microchip,pic32mzda-spi
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ items:
+ - description: Fault interrupt
+ - description: Receive interrupt
+ - description: Transmit interrupt
+
+ interrupt-names:
+ items:
+ - const: fault
+ - const: rx
+ - const: tx
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ items:
+ - const: mck0
+
+ cs-gpios:
+ maxItems: 1
+
+ dmas:
+ items:
+ - description: RX DMA channel
+ - description: TX DMA channel
+
+ dma-names:
+ items:
+ - const: spi-rx
+ - const: spi-tx
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - interrupt-names
+ - clocks
+ - clock-names
+ - cs-gpios
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/gpio/gpio.h>
+
+ spi@1f821000 {
+ compatible = "microchip,pic32mzda-spi";
+ reg = <0x1f821000 0x200>;
+ interrupts = <109 IRQ_TYPE_LEVEL_HIGH>,
+ <110 IRQ_TYPE_LEVEL_HIGH>,
+ <111 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-names = "fault", "rx", "tx";
+ clocks = <&PBCLK2>;
+ clock-names = "mck0";
+ cs-gpios = <&gpio3 4 GPIO_ACTIVE_LOW>;
+ dmas = <&dma 134>, <&dma 135>;
+ dma-names = "spi-rx", "spi-tx";
+ };
diff --git a/Documentation/devicetree/bindings/spi/microchip,spi-pic32.txt b/Documentation/devicetree/bindings/spi/microchip,spi-pic32.txt
deleted file mode 100644
index 79de379f4dc0..000000000000
--- a/Documentation/devicetree/bindings/spi/microchip,spi-pic32.txt
+++ /dev/null
@@ -1,34 +0,0 @@
-Microchip PIC32 SPI Master controller
-
-Required properties:
-- compatible: Should be "microchip,pic32mzda-spi".
-- reg: Address and length of register space for the device.
-- interrupts: Should contain all three spi interrupts in sequence
- of <fault-irq>, <receive-irq>, <transmit-irq>.
-- interrupt-names: Should be "fault", "rx", "tx" in order.
-- clocks: Phandle of the clock generating SPI clock on the bus.
-- clock-names: Should be "mck0".
-- cs-gpios: Specifies the gpio pins to be used for chipselects.
- See: Documentation/devicetree/bindings/spi/spi-bus.txt
-
-Optional properties:
-- dmas: Two or more DMA channel specifiers following the convention outlined
- in Documentation/devicetree/bindings/dma/dma.txt
-- dma-names: Names for the dma channels. There must be at least one channel
- named "spi-tx" for transmit and named "spi-rx" for receive.
-
-Example:
-
-spi1: spi@1f821000 {
- compatible = "microchip,pic32mzda-spi";
- reg = <0x1f821000 0x200>;
- interrupts = <109 IRQ_TYPE_LEVEL_HIGH>,
- <110 IRQ_TYPE_LEVEL_HIGH>,
- <111 IRQ_TYPE_LEVEL_HIGH>;
- interrupt-names = "fault", "rx", "tx";
- clocks = <&PBCLK2>;
- clock-names = "mck0";
- cs-gpios = <&gpio3 4 GPIO_ACTIVE_LOW>;
- dmas = <&dma 134>, <&dma 135>;
- dma-names = "spi-rx", "spi-tx";
-};
--
2.34.1
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* Re: [PATCH 06/12] rtc: rzn1: Sort headers alphabetically
From: Wolfram Sang @ 2026-06-17 10:04 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Prabhakar, Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Magnus Damm, linux-rtc,
linux-renesas-soc, devicetree, linux-kernel, Biju Das,
Fabrizio Castro, Lad Prabhakar
In-Reply-To: <CAMuHMdXg16frnn88_P_jHRH+HPy00wWfoqNKdOv8teSWNpMEGg@mail.gmail.com>
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> > --- a/drivers/rtc/rtc-rzn1.c
> > +++ b/drivers/rtc/rtc-rzn1.c
> > @@ -15,8 +15,8 @@
> > #include <linux/clk.h>
> > #include <linux/init.h>
> > #include <linux/iopoll.h>
> > -#include <linux/module.h>
> > #include <linux/mod_devicetable.h>
> > +#include <linux/module.h>
>
> Sorting of special characters w.r.t. alphanumericals is always
> a bit fuzzy...
I rely on the 'sort' utility which gives the same output, so:
> > #include <linux/platform_device.h>
> > #include <linux/pm_runtime.h>
> > #include <linux/rtc.h>
>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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* Re: [PATCH 05/12] rtc: rzn1: Add system suspend/resume support and wakeup capability
From: Wolfram Sang @ 2026-06-17 10:02 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, linux-rtc, linux-renesas-soc, devicetree,
linux-kernel, Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-6-prabhakar.mahadev-lad.rj@bp.renesas.com>
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> Add system-wide power management support along with wakeup capability to
> the rtc-rzn1 driver.
Do you have an actual use case for the wakeup functionality? If it is so
limited, then we should maybe not support the weak abilities until
someone has a real use case? For which then, a proper solution has been
developed and tested?
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* Re: [PATCH 04/12] rtc: Kconfig: Broaden RTC_DRV_RZN1 dependency to ARCH_RENESAS
From: Wolfram Sang @ 2026-06-17 9:57 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, linux-rtc, linux-renesas-soc, devicetree,
linux-kernel, Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-5-prabhakar.mahadev-lad.rj@bp.renesas.com>
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> - depends on ARCH_RZN1 || COMPILE_TEST
> + depends on ARCH_RENESAS || COMPILE_TEST
Yes, this helps X5H also :)
> - If you say yes here you get support for the Renesas RZ/N1 RTC.
> + If you say yes here you get support for the RTC found on Renesas RZ/N1,
> + RZ/N2H, and RZ/T2H SoCs.
Such lists are easy to get stale IMHO. What about "initially found on
Renesas RZ/N1 SoCs."?
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* Re: [PATCH 03/12] rtc: rzn1: Fix malformed MODULE_AUTHOR string
From: Wolfram Sang @ 2026-06-17 9:55 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, linux-rtc, linux-renesas-soc, devicetree,
linux-kernel, Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-4-prabhakar.mahadev-lad.rj@bp.renesas.com>
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On Mon, Jun 15, 2026 at 04:47:56PM +0100, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Fix a malformed MODULE_AUTHOR macro in the rtc-rzn1 driver where a missing
> closing angle bracket on the second author entry creates an invalid format.
> Correct it to the standard "Name <email>" format.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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* Re: [PATCH 02/12] rtc: rzn1: Handle EPROBE_DEFER for optional pps interrupt
From: Wolfram Sang @ 2026-06-17 9:55 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, linux-rtc, linux-renesas-soc, devicetree,
linux-kernel, Biju Das, Fabrizio Castro, Lad Prabhakar, stable
In-Reply-To: <20260615154805.1619693-3-prabhakar.mahadev-lad.rj@bp.renesas.com>
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Hi,
Sashiko found issues with your patch. I curated the list and agree. I
think, in probe(), 'rate' should be initialized to 32768 and 'sync_time'
should be calculated unconditionally.
Thank you and happy hacking,
Wolfram
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] If the optional 'xtal' clock is not present, `rtc->sync_time` remains 0, causing `readl_poll_timeout` to use a 0 timeout (infinite wait) and `usleep_range` to use a 0 delay.
> --
>
> commit 5d75a1049c228d2049afaf29833f1b2f212837d4
> Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Subject: rtc: rzn1: Handle EPROBE_DEFER for optional pps interrupt
>
> This commit checks for -EPROBE_DEFER from platform_get_irq_byname_optional()
> and handles the deferred probe request properly. It intercepts this specific
> error condition, assigns it to the return value, and jumps to the
> dis_runtime_pm label to avoid ignoring a valid probe deferral.
>
> Fixes: eea7791e00f33 ("rtc: rzn1: implement one-second accuracy for alarms")
> Cc: stable@vger.kernel.org
>
> > diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
> > index c4ed437354574..f81d691c8b9a2 100644
> > --- a/drivers/rtc/rtc-rzn1.c
> > +++ b/drivers/rtc/rtc-rzn1.c
> > @@ -465,6 +465,10 @@ static int rzn1_rtc_probe(struct platform_device *pdev)
> > }
> >
> > irq = platform_get_irq_byname_optional(pdev, "pps");
> > + if (irq == -EPROBE_DEFER) {
> > + ret = irq;
> > + goto dis_runtime_pm;
> > + }
> > if (irq >= 0)
> > ret = devm_request_irq(&pdev->dev, irq, rzn1_rtc_1s_irq, 0, "RZN1 RTC 1s", rtc);
>
> [Severity: High]
> If the optional xtal clock is not present, does rtc->sync_time remain 0,
> causing readl_poll_timeout() to use a 0 timeout (infinite wait) and
> usleep_range() to use a 0 delay?
>
> devm_clk_get_optional() returns NULL if the clock is absent in the device
> tree, skipping the calculation:
>
> drivers/rtc/rtc-rzn1.c:rzn1_rtc_probe() {
> ...
> xtal = devm_clk_get_optional(dev, "xtal");
> if (IS_ERR(xtal)) {
> ...
> } else if (xtal) {
> rate = clk_get_rate(xtal);
> ...
> rtc->sync_time = DIV_ROUND_UP(2 * NSEC_PER_MSEC, rate);
> }
> ...
> ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL0, val,
> !(val & RZN1_RTC_CTL0_CEST), rtc->sync_time,
> rtc->sync_time * 2);
> ...
> }
>
> In include/linux/iopoll.h, a timeout_us of 0 skips the timeout check
> entirely, which could lead to a tight infinite loop and a kernel hard lockup
> if the hardware fails to clear the CEST bit.
>
> Additionally, rtc->sync_time being 0 causes usleep_range(0, 100) in
> rzn1_rtc_set_time(), which may return almost immediately and violate the
> hardware's explicit 2-clock-cycle delay requirement (previously hardcoded to
> 61us).
>
> This regression was introduced by the commit 'rtc: rzn1: Dynamically
> calculate synchronization delay based on clock rate' later in this series.
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260615154805.1619693-1-prabhakar.mahadev-lad.rj@bp.renesas.com?part=2
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* Re: [PATCH 01/12] dt-bindings: rtc: renesas,rzn1-rtc: Add RZ/T2H and RZ/N2H support
From: Wolfram Sang @ 2026-06-17 9:38 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, linux-rtc, linux-renesas-soc, devicetree,
linux-kernel, Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-2-prabhakar.mahadev-lad.rj@bp.renesas.com>
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On Mon, Jun 15, 2026 at 04:47:54PM +0100, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Add compatible strings for the RTC block found on the Renesas RZ/T2H
> (R9A09G077) and RZ/N2H (R9A09G087) SoCs.
>
> These SoCs integrate a closely related variant of the RZ/N1 RTC IP.
> Unlike RZ/N1, they do not implement the RTCA0SUBU and RTCA0TCR
> registers. This is not a limitation for Linux support, as these
> registers are not used when the RTC operates in "scmp" clock mode, which
> is required on RZ/T2H and RZ/N2H due to their 195.3 kHz input clock.
>
> The RZ/T2H RTC variant also supports a 1Hz output signal on the
> RTCAT1HZ pin, controlled by the RTCA0CTL1[RTCA01HZE] bit. This bit is
> marked as reserved in the RZ/N1 hardware manual.
>
> Update the binding schema to require the additional clock inputs used by
> these SoCs.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Sashiko is wrong here because
a) TCR is the "Test Register"
b) TCR is not even present on RZ/N1D. Cover-letter misses that, too.
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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* Re: [PATCH 00/12] Add RTC support for Renesas RZ/T2H and RZ/N2H SoCs
From: Wolfram Sang @ 2026-06-17 9:18 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, linux-rtc, linux-renesas-soc, devicetree,
linux-kernel, Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
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Hi,
> The RTC block is closely related to the RZ/N1 implementation and can
> reuse the existing driver infrastructure when operating in SCMP mode,
> which is required on these SoCs due to their 195.3 kHz RTC input clock.
Yes, I implemented SCMP mode because the (back then) upcoming R-Car X5H
also dropped SUBU mode. And SCMP works on my RZ/N1D board as well, so I
could test it already.
> While the RZ/T2H and RZ/N2H variants do not implement the RTCA0SUBU and
> RTCA0TCR registers present on RZ/N1, those registers are not accessed by
> the driver in SCMP mode, allowing support to be added with minimal
> changes.
Note that even for RZ/N1, RTCA0TCR is marked as "not available".
> The RZ/T2H RTC variant also supports a 1 Hz output signal on the
> RTCAT1HZ pin, controlled by the RTCA0CTL1[RTCA01HZE] bit. This bit is
> marked as reserved in the RZ/N1 hardware manual, making RZ/T2H a
> distinct RTC variant despite its overall compatibility with the RZ/N1
> implementation.
R-Car X5H is the same for the above as well.
> The series consists of:
> dt-bindings updates to describe the RZ/T2H and RZ/N2H RTC variants,
> driver updates to recognize the new compatible string and enable
> support for these SoCs.
I will review and test in on my N1D-board today.
Thanks for your work and happy hacking,
Wolfram
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* Re: [PATCH v2] spi: dt-bindings: microchip,pic32mzda-spi: Convert to DT schema
From: Uday Kiran @ 2026-06-17 8:28 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: tsbogend, robh, krzk+dt, conor+dt, skhan, me, linux-rtc,
devicetree, linux-kernel
In-Reply-To: <20260617-sturdy-silver-bison-bfb6ba@quoll>
> > Convert Microchip PIC32 SPI controller devicetree binding
> > from legacy text format to DT schema.
>
> Please mention here that you dropped requirement of 'cs-gpios' because
> it is not a mandatory in hardware design nor in current Linux driver...
> and then CHECK it actually against drivers, which will lead you to
> conclusion that maybe it is wrong decision...
Thank you Krzysztof
I rechecked the driver and found that it uses spi_get_csgpiod() for
chip-select handling and sets host->num_chipselect = 1. Therefore, dropping
the cs-gpios requirement during the conversion was not justified.
I'll restore cs-gpios as a required property and resend the series with an
updated changelog.
Regards,
Udaya Kiran Challa
^ permalink raw reply
* Re: [PATCH v2] dt-bindings: rtc: Convert rtc-cmos binding to YAML
From: Krzysztof Kozlowski @ 2026-06-17 8:12 UTC (permalink / raw)
To: Teja Sai Charan B
Cc: Alexandre Belloni, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
linux-rtc, devicetree, linux-kernel
In-Reply-To: <20260616085659.12809-1-tejaasaye@gmail.com>
On Tue, Jun 16, 2026 at 02:26:58PM +0530, Teja Sai Charan B wrote:
> From: Teja Sai Charan Bellamkonda <tejaasaye@gmail.com>
>
> Convert the rtc-cmos devicetree bindings to dt schema.
Subject: s/YAML/DT schema/
>
> Signed-off-by: Teja Sai Charan Bellamkonda <tejaasaye@gmail.com>
>
> ---
>
> Changes in v2:
> - Allow intel,ce4100-rtc compatible used by existing DTS files
> ---
> .../devicetree/bindings/rtc/rtc-cmos.txt | 27 ---------
> .../devicetree/bindings/rtc/rtc-cmos.yaml | 60 +++++++++++++++++++
> result.txt | 17 ++++++
Stale file, please drop.
> 3 files changed, 77 insertions(+), 27 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/rtc/rtc-cmos.txt
> create mode 100644 Documentation/devicetree/bindings/rtc/rtc-cmos.yaml
> create mode 100644 result.txt
...
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-cmos.yaml b/Documentation/devicetree/bindings/rtc/rtc-cmos.yaml
> new file mode 100644
> index 000000000000..ba4812778115
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/rtc-cmos.yaml
> @@ -0,0 +1,60 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/rtc-cmos.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Motorola mc146818 compatible RTC
> +
> +maintainers:
> + - Alexandre Belloni <alexandre.belloni@bootlin.com>
> +
> +properties:
> + compatible:
> + oneOf:
> + - const: motorola,mc146818
> +
> + - items:
> + - const: intel,ce4100-rtc
> + - const: motorola,mc146818
These were not in original binding, so you need to mention it in the
commit msg and explain why.
I understand there is not 'rtc-cmos' compatible, so basically the
filename should be set to this fallback compatible.
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + ctrl-reg:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Initial value of the control register
> + (also known as Register B).
> +
> + freq-reg:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Initial value of the frequency register
> + (also known as Register A).
> +
> +required:
> + - compatible
> + - reg
> +
You should $ref the rtc.yaml schema and use "unevaluatedProperties:
false". Or explain in the commit msg why it is not applicable.
> +additionalProperties: false
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v2] spi: dt-bindings: microchip,pic32mzda-spi: Convert to DT schema
From: Krzysztof Kozlowski @ 2026-06-17 7:35 UTC (permalink / raw)
To: Udaya Kiran Challa
Cc: tsbogend, robh, krzk+dt, conor+dt, skhan, me, linux-rtc,
devicetree, linux-kernel
In-Reply-To: <20260615115311.515404-1-challauday369@gmail.com>
On Mon, Jun 15, 2026 at 05:23:11PM +0530, Udaya Kiran Challa wrote:
> Convert Microchip PIC32 SPI controller devicetree binding
> from legacy text format to DT schema.
Please mention here that you dropped requirement of 'cs-gpios' because
it is not a mandatory in hardware design nor in current Linux driver...
and then CHECK it actually against drivers, which will lead you to
conclusion that maybe it is wrong decision...
>
> Signed-off-by: Udaya Kiran Challa <challauday369@gmail.com>
> ---
> Changelog:
> Changes since v1:
> - Rename schema file to microchip,pic32mzda-spi.yaml
> - Update subject prefix to match SPI DT binding conventions
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH 06/12] rtc: rzn1: Sort headers alphabetically
From: Geert Uytterhoeven @ 2026-06-17 7:22 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Magnus Damm, Wolfram Sang,
linux-rtc, linux-renesas-soc, devicetree, linux-kernel, Biju Das,
Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-7-prabhakar.mahadev-lad.rj@bp.renesas.com>
On Mon, 15 Jun 2026 at 17:48, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Sorting headers alphabetically helps locating duplicates, and make it
> easier to figure out where to insert new headers.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> --- a/drivers/rtc/rtc-rzn1.c
> +++ b/drivers/rtc/rtc-rzn1.c
> @@ -15,8 +15,8 @@
> #include <linux/clk.h>
> #include <linux/init.h>
> #include <linux/iopoll.h>
> -#include <linux/module.h>
> #include <linux/mod_devicetable.h>
> +#include <linux/module.h>
Sorting of special characters w.r.t. alphanumericals is always
a bit fuzzy...
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <linux/rtc.h>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply
* Re: [PATCH 07/12] rtc: rzn1: fix alarm range check truncation on 32-bit systems
From: Geert Uytterhoeven @ 2026-06-17 7:29 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Magnus Damm, Wolfram Sang,
linux-rtc, linux-renesas-soc, devicetree, linux-kernel, Biju Das,
Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-8-prabhakar.mahadev-lad.rj@bp.renesas.com>
On Mon, 15 Jun 2026 at 17:48, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> alarm and farest were declared as unsigned long, but
> rtc_tm_to_time64() returns time64_t (s64). On 32-bit systems where
> unsigned long is 32 bits, the assignment silently truncates the upper
> 32 bits of the timestamp.
>
> Fix by declaring alarm and farest as time64_t and replacing
> time_after() with a direct signed comparison, which is correct for
> time64_t values that will never realistically overflow.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply
* Re: [PATCH 10/12] rtc: rzn1: Consistently use dev_err_probe()
From: Geert Uytterhoeven @ 2026-06-17 7:24 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Magnus Damm, Wolfram Sang,
linux-rtc, linux-renesas-soc, devicetree, linux-kernel, Biju Das,
Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-11-prabhakar.mahadev-lad.rj@bp.renesas.com>
On Mon, 15 Jun 2026 at 17:48, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Use dev_err_probe() in the IRQ request error path to make error handling
> consistent with the rest of rzn1_rtc_probe().
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply
* Re: [PATCH 03/12] rtc: rzn1: Fix malformed MODULE_AUTHOR string
From: Geert Uytterhoeven @ 2026-06-17 7:19 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, Wolfram Sang, linux-rtc, linux-renesas-soc,
devicetree, linux-kernel, Biju Das, Fabrizio Castro,
Lad Prabhakar
In-Reply-To: <20260615154805.1619693-4-prabhakar.mahadev-lad.rj@bp.renesas.com>
On Mon, 15 Jun 2026 at 17:48, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Fix a malformed MODULE_AUTHOR macro in the rtc-rzn1 driver where a missing
> closing angle bracket on the second author entry creates an invalid format.
> Correct it to the standard "Name <email>" format.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply
* Re: [PATCH v3] rtc: ds1307: handle oscillator stop flag for ds1337/ds1339/ds3231
From: Ronan Dalton @ 2026-06-17 3:34 UTC (permalink / raw)
To: alexandre.belloni@bootlin.com
Cc: sashal@kernel.org, code@tyhicks.com, giometti@enneenne.com,
linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org,
meaganlloyd@linux.microsoft.com, Chris Packham
In-Reply-To: <20260508032518.3696705-2-ronan.dalton@alliedtelesis.co.nz>
Hi Alexandre,
I just wanted to follow up on this patch because I think it may have
been missed by accident. I'm still interested in getting it merged.
Could you give it a look?
Thanks,
Ronan.
On Fri, 2026-05-08 at 15:24 +1200, Ronan Dalton wrote:
> Prior to commit 48458654659c ("rtc: ds1307: remove clear of
> oscillator
> stop flag (OSF) in probe"), the oscillator stop flag (OSF) bit was
> checked during device probe for the ds1337, ds1339, ds1341, and
> ds3231
> chips; if it was set, it would be cleared and a warning would be
> logged
> saying "SET TIME!". Since that commit, the OSF bit is no longer
> cleared,
> but the warning is still printed.
>
> Directly following that commit, there was no way to get rid of this
> warning because nothing cleared the OSF bit on these chips.
>
> The commit associated with the previous commit, 523923cfd5d6 ("rtc:
> ds1307: handle oscillator stop flag (OSF) for ds1341"), made proper
> use
> of the OSF when getting and setting the time in the RTC. However, the
> other RTC variants ds1337, ds1339 and ds3231 didn't have a
> corresponding
> change made.
>
> Given that the OSF bit is no longer cleared at probe time when it is
> set, the remaining three chips should have the same handling as the
> ds1341 chip has for the OSF bit.
>
> Fix the issue on the ds1337, ds1339 and ds3231 chips by applying the
> same logic as the ds1341 has to these chips.
>
> Note that any devices brought up between the first referenced commit
> and
> this one may begin mistrusting the time reported by the RTC until it
> is
> set again, if the bit was never explicitly cleared.
>
> Note that only the ds1339 was tested with this change, but the
> datasheets for the other chips contain essentially identical
> descriptions of the OSF bit so the same change should work.
>
> Signed-off-by: Ronan Dalton <ronan.dalton@alliedtelesis.co.nz>
> Cc: linux-rtc@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Tyler Hicks <code@tyhicks.com>
> Cc: Sasha Levin <sashal@kernel.org>
> Cc: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
> Cc: Rodolfo Giometti <giometti@enneenne.com>
> Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
> Fixes: 48458654659c ("rtc: ds1307: remove clear of oscillator stop
> flag (OSF) in probe")
> ---
> Changes in v3:
> - Remove paragraph mentioning alternative fix from commit message
>
> Changes in v2:
> - Fix hashes of referenced commits
>
> drivers/rtc/rtc-ds1307.c | 28 +++++++++++++++++-----------
> 1 file changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
> index 7205c59ff729..edf81b975dec 100644
> --- a/drivers/rtc/rtc-ds1307.c
> +++ b/drivers/rtc/rtc-ds1307.c
> @@ -269,6 +269,16 @@ static int ds1307_get_time(struct device *dev,
> struct rtc_time *t)
> if (tmp & DS1338_BIT_OSF)
> return -EINVAL;
> break;
> + case ds_1337:
> + case ds_1339:
> + case ds_1341:
> + case ds_3231:
> + ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS,
> &tmp);
> + if (ret)
> + return ret;
> + if (tmp & DS1337_BIT_OSF)
> + return -EINVAL;
> + break;
> case ds_1340:
> if (tmp & DS1340_BIT_nEOSC)
> return -EINVAL;
> @@ -279,13 +289,6 @@ static int ds1307_get_time(struct device *dev,
> struct rtc_time *t)
> if (tmp & DS1340_BIT_OSF)
> return -EINVAL;
> break;
> - case ds_1341:
> - ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS,
> &tmp);
> - if (ret)
> - return ret;
> - if (tmp & DS1337_BIT_OSF)
> - return -EINVAL;
> - break;
> case ds_1388:
> ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG,
> &tmp);
> if (ret)
> @@ -380,14 +383,17 @@ static int ds1307_set_time(struct device *dev,
> struct rtc_time *t)
> regmap_update_bits(ds1307->regmap,
> DS1307_REG_CONTROL,
> DS1338_BIT_OSF, 0);
> break;
> + case ds_1337:
> + case ds_1339:
> + case ds_1341:
> + case ds_3231:
> + regmap_update_bits(ds1307->regmap,
> DS1337_REG_STATUS,
> + DS1337_BIT_OSF, 0);
> + break;
> case ds_1340:
> regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG,
> DS1340_BIT_OSF, 0);
> break;
> - case ds_1341:
> - regmap_update_bits(ds1307->regmap,
> DS1337_REG_STATUS,
> - DS1337_BIT_OSF, 0);
> - break;
> case ds_1388:
> regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
> DS1388_BIT_OSF, 0);
^ permalink raw reply
* [PATCH v2] dt-bindings: rtc: Convert rtc-cmos binding to YAML
From: Teja Sai Charan B @ 2026-06-16 8:56 UTC (permalink / raw)
To: Alexandre Belloni, Rob Herring, Krzysztof Kozlowski, Conor Dooley
Cc: linux-rtc, devicetree, linux-kernel, Teja Sai Charan Bellamkonda
From: Teja Sai Charan Bellamkonda <tejaasaye@gmail.com>
Convert the rtc-cmos devicetree bindings to dt schema.
Signed-off-by: Teja Sai Charan Bellamkonda <tejaasaye@gmail.com>
---
Changes in v2:
- Allow intel,ce4100-rtc compatible used by existing DTS files
---
.../devicetree/bindings/rtc/rtc-cmos.txt | 27 ---------
.../devicetree/bindings/rtc/rtc-cmos.yaml | 60 +++++++++++++++++++
result.txt | 17 ++++++
3 files changed, 77 insertions(+), 27 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/rtc/rtc-cmos.txt
create mode 100644 Documentation/devicetree/bindings/rtc/rtc-cmos.yaml
create mode 100644 result.txt
diff --git a/Documentation/devicetree/bindings/rtc/rtc-cmos.txt b/Documentation/devicetree/bindings/rtc/rtc-cmos.txt
deleted file mode 100644
index 7d7b5f6bda65..000000000000
--- a/Documentation/devicetree/bindings/rtc/rtc-cmos.txt
+++ /dev/null
@@ -1,27 +0,0 @@
- Motorola mc146818 compatible RTC
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Required properties:
- - compatible : "motorola,mc146818"
- - reg : should contain registers location and length.
-
-Optional properties:
- - interrupts : should contain interrupt.
- - ctrl-reg : Contains the initial value of the control register also
- called "Register B".
- - freq-reg : Contains the initial value of the frequency register also
- called "Register A".
-
-"Register A" and "B" are usually initialized by the firmware (BIOS for
-instance). If this is not done, it can be performed by the driver.
-
-ISA Example:
-
- rtc@70 {
- compatible = "motorola,mc146818";
- interrupts = <8 3>;
- interrupt-parent = <&ioapic1>;
- ctrl-reg = <2>;
- freq-reg = <0x26>;
- reg = <1 0x70 2>;
- };
diff --git a/Documentation/devicetree/bindings/rtc/rtc-cmos.yaml b/Documentation/devicetree/bindings/rtc/rtc-cmos.yaml
new file mode 100644
index 000000000000..ba4812778115
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-cmos.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/rtc-cmos.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Motorola mc146818 compatible RTC
+
+maintainers:
+ - Alexandre Belloni <alexandre.belloni@bootlin.com>
+
+properties:
+ compatible:
+ oneOf:
+ - const: motorola,mc146818
+
+ - items:
+ - const: intel,ce4100-rtc
+ - const: motorola,mc146818
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ ctrl-reg:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Initial value of the control register
+ (also known as Register B).
+
+ freq-reg:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Initial value of the frequency register
+ (also known as Register A).
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ bus {
+ #address-cells = <2>;
+ #size-cells = <1>;
+
+ rtc@70 {
+ compatible = "motorola,mc146818";
+ reg = <1 0x70 2>;
+
+ interrupts = <8 3>;
+
+ ctrl-reg = <2>;
+ freq-reg = <0x26>;
+ };
+ };
diff --git a/result.txt b/result.txt
new file mode 100644
index 000000000000..5e90660b93ec
--- /dev/null
+++ b/result.txt
@@ -0,0 +1,17 @@
+arch/x86/kernel/x86_init.c:42: { .compatible = "motorola,mc146818" },
+arch/x86/platform/ce4100/falconfalls.dts:420: compatible = "intel,ce4100-rtc", "motorola,mc146818";
+arch/mips/boot/dts/loongson/rs780e-pch.dtsi:31: compatible = "motorola,mc146818";
+arch/mips/boot/dts/mti/malta.dts:110: compatible = "motorola,mc146818";
+arch/alpha/kernel/rtc.c:25: * We don't want to use the rtc-cmos driver, because we don't want to support
+drivers/built-in.a:1031:rtc/rtc-cmos.o/
+drivers/rtc/built-in.a:11:rtc-cmos.o/
+drivers/rtc/.rtc-mc146818-lib.o.cmd:1:savedcmd_drivers/rtc/rtc-mc146818-lib.o := gcc -Wp,-MMD,drivers/rtc/.rtc-mc146818-lib.o.d -nostdinc -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -std=gnu11 -fshort-wchar -funsigned-char -fno-common -fno-PIE -fno-strict-aliasing -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -mno-sse4a -fcf-protection=none -m64 -falign-jumps=1 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mpreferred-stack-boundary=3 -mskip-rax-setup -march=x86-64 -mtune=generic -mno-red-zone -mcmodel=kernel -mstack-protector-guard-reg=gs -mstack-protector-guard-symbol=__ref_stack_chk_guard -Wno-sign-compare -fno-asynchronous-unwind-tables -mindirect-branch=thunk-extern -mindirect-branch-register -mindirect-branch-cs-prefix -mfunction-return=thunk-extern -fno-jump-tables -mharden-sls=all -fpatchable-function-entry=16,16 -fno-delete-null-pointer-checks -O2 -fno-allow-store-data-races -fstack-protector-strong -fno-omit-frame-pointer -fno-optimize-sibling-calls -ftrivial-auto-var-init=zero -fno-stack-clash-protection -fzero-call-used-regs=used-gpr -pg -mrecord-mcount -mfentry -DCC_USING_FENTRY -falign-functions=16 -fstrict-flex-arrays=3 -fms-extensions -fno-strict-overflow -fno-stack-check -fconserve-stack -fno-builtin-wcslen -Wall -Wextra -Wundef -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Werror=strict-prototypes -Wno-format-security -Wno-trigraphs -Wno-frame-address -Wno-address-of-packed-member -Wmissing-declarations -Wmissing-prototypes -Wframe-larger-than=1024 -Wno-main -Wno-dangling-pointer -Wvla-larger-than=1 -Wno-pointer-sign -Wcast-function-type -Wno-array-bounds -Wno-stringop-overflow -Wno-alloc-size-larger-than -Wimplicit-fallthrough=5 -Werror=date-time -Werror=incompatible-pointer-types -Werror=designated-init -Wenum-conversion -Wunused -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-packed-not-aligned -Wno-format-overflow -Wno-format-truncation -Wno-stringop-truncation -Wno-override-init -Wno-missing-field-initializers -Wno-type-limits -Wno-shift-negative-value -Wno-maybe-uninitialized -Wno-sign-compare -Wno-unused-parameter -g -gdwarf-5 -fsanitize=bounds-strict -fsanitize=shift -fsanitize=bool -fsanitize=enum -DKBUILD_MODFILE='"drivers/rtc/rtc-mc146818-lib"' -DKBUILD_BASENAME='"rtc_mc146818_lib"' -DKBUILD_MODNAME='"rtc_mc146818_lib"' -D__KBUILD_MODNAME=rtc_mc146818_lib -c -o drivers/rtc/rtc-mc146818-lib.o drivers/rtc/rtc-mc146818-lib.c
+drivers/rtc/.built-in.a.cmd:1:savedcmd_drivers/rtc/built-in.a := rm -f drivers/rtc/built-in.a; printf "drivers/rtc/%s " lib.o class.o interface.o nvmem.o dev.o proc.o sysfs.o rtc-mc146818-lib.o rtc-cmos.o | xargs ar cDPrST drivers/rtc/built-in.a
+drivers/rtc/Kconfig:1065: will be called rtc-cmos.
+drivers/rtc/Makefile:45:obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
+drivers/rtc/.rtc-cmos.o.cmd:1:savedcmd_drivers/rtc/rtc-cmos.o := gcc -Wp,-MMD,drivers/rtc/.rtc-cmos.o.d -nostdinc -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -std=gnu11 -fshort-wchar -funsigned-char -fno-common -fno-PIE -fno-strict-aliasing -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -mno-sse4a -fcf-protection=none -m64 -falign-jumps=1 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mpreferred-stack-boundary=3 -mskip-rax-setup -march=x86-64 -mtune=generic -mno-red-zone -mcmodel=kernel -mstack-protector-guard-reg=gs -mstack-protector-guard-symbol=__ref_stack_chk_guard -Wno-sign-compare -fno-asynchronous-unwind-tables -mindirect-branch=thunk-extern -mindirect-branch-register -mindirect-branch-cs-prefix -mfunction-return=thunk-extern -fno-jump-tables -mharden-sls=all -fpatchable-function-entry=16,16 -fno-delete-null-pointer-checks -O2 -fno-allow-store-data-races -fstack-protector-strong -fno-omit-frame-pointer -fno-optimize-sibling-calls -ftrivial-auto-var-init=zero -fno-stack-clash-protection -fzero-call-used-regs=used-gpr -pg -mrecord-mcount -mfentry -DCC_USING_FENTRY -falign-functions=16 -fstrict-flex-arrays=3 -fms-extensions -fno-strict-overflow -fno-stack-check -fconserve-stack -fno-builtin-wcslen -Wall -Wextra -Wundef -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Werror=strict-prototypes -Wno-format-security -Wno-trigraphs -Wno-frame-address -Wno-address-of-packed-member -Wmissing-declarations -Wmissing-prototypes -Wframe-larger-than=1024 -Wno-main -Wno-dangling-pointer -Wvla-larger-than=1 -Wno-pointer-sign -Wcast-function-type -Wno-array-bounds -Wno-stringop-overflow -Wno-alloc-size-larger-than -Wimplicit-fallthrough=5 -Werror=date-time -Werror=incompatible-pointer-types -Werror=designated-init -Wenum-conversion -Wunused -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-packed-not-aligned -Wno-format-overflow -Wno-format-truncation -Wno-stringop-truncation -Wno-override-init -Wno-missing-field-initializers -Wno-type-limits -Wno-shift-negative-value -Wno-maybe-uninitialized -Wno-sign-compare -Wno-unused-parameter -g -gdwarf-5 -fsanitize=bounds-strict -fsanitize=shift -fsanitize=bool -fsanitize=enum -DKBUILD_MODFILE='"drivers/rtc/rtc-cmos"' -DKBUILD_BASENAME='"rtc_cmos"' -DKBUILD_MODNAME='"rtc_cmos"' -D__KBUILD_MODNAME=rtc_cmos -c -o drivers/rtc/rtc-cmos.o drivers/rtc/rtc-cmos.c
+drivers/rtc/.rtc-cmos.o.cmd:3:source_drivers/rtc/rtc-cmos.o := drivers/rtc/rtc-cmos.c
+drivers/rtc/.rtc-cmos.o.cmd:5:deps_drivers/rtc/rtc-cmos.o := \
+drivers/rtc/.rtc-cmos.o.cmd:1372:drivers/rtc/rtc-cmos.o: $(deps_drivers/rtc/rtc-cmos.o)
+drivers/rtc/.rtc-cmos.o.cmd:1374:$(deps_drivers/rtc/rtc-cmos.o):
+drivers/rtc/rtc-cmos.c:1382: .compatible = "motorola,mc146818",
--
2.43.0
^ permalink raw reply related
* Re: [PATCH] rtc: interface: Add rtc time jump debug in rtc_timer_do_work()
From: Jinjie Ruan @ 2026-06-16 8:12 UTC (permalink / raw)
To: Alexandre Belloni; +Cc: linux-rtc, linux-kernel
In-Reply-To: <202606160657465eab6e41@mail.local>
On 6/16/2026 2:57 PM, Alexandre Belloni wrote:
> Hi,
>
> On 16/06/2026 10:10:19+0800, Jinjie Ruan wrote:
>>
>>
>> On 6/15/2026 11:22 PM, Alexandre Belloni wrote:
>>> Hello,
>>>
>>> On 25/05/2026 21:08:25+0800, Jinjie Ruan wrote:
>>>> In virtualization environments like QEMU [1], or during hardware
>>>> clocksource anomalies, an extreme time-warp event can occur. When
>>>> the system time abruptly jumps forward, the rtc_timer_do_work() handler
>>>> falls into a prolonged processing loop to clear accumulated historical
>>>> timers via timerqueue_getnext(). Running this loop indefinitely under
>>>> the rtc->ops_lock mutex triggers a kernel softlockup, stalling
>>>> the system.
>>>>
>>>> Introduce an adaptive telemetry and loop guard mechanism to enhance debug
>>>> visibility and prevent softlockups:
>>>>
>>>> 1. Record `start_jiffies` upon entry and leverage `time_after()` to
>>>> check if the loop has monopolized the CPU for more than 1s (HZ). If so,
>>>> the handler prints a telemetry warning, triggers a WARN stack dump, and
>>>> breaks the loop to safely yield the CPU.
>>>>
>>>> 2. Track the execution via a `loop_count` metric. Printing this counter
>>>> in the warning log provides vital diagnostics to distinguish
>>>> an aggressive time-warp storm (high count) from a bogged-down callback
>>>> bug (low count).
>>>>
>>>> 3. Utilize the kernel format specifier `%ptR` to convert the raw ktime
>>>> into a human-readable timestamp (YYYY-MM-DD HH:MM:SS), allowing
>>>> developers to instantly pinpoint the exact boundary of the time
>>>> jump in dmesg.
>>>>
>>>> This non-destructive telemetry guard provides precise hardware/emulator
>>>> diagnostic visibility while ensuring core kernel availability.
>>>>
>>>> [1]: https://lore.kernel.org/all/20260114013257.3500578-1-ruanjinjie@huawei.com/
>>>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>>>> ---
>>>> drivers/rtc/interface.c | 15 +++++++++++++--
>>>> 1 file changed, 13 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
>>>> index 1906f4884a83..f6c5fd16cc4e 100644
>>>> --- a/drivers/rtc/interface.c
>>>> +++ b/drivers/rtc/interface.c
>>>> @@ -927,10 +927,12 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
>>>> */
>>>> void rtc_timer_do_work(struct work_struct *work)
>>>> {
>>>> - struct rtc_timer *timer;
>>>> + unsigned long start_jiffies = jiffies;
>>>> struct timerqueue_node *next;
>>>> - ktime_t now;
>>>> + struct rtc_timer *timer;
>>>> struct rtc_time tm;
>>>> + int loop_count = 0;
>>>> + ktime_t now;
>>>> int err;
>>>>
>>>> struct rtc_device *rtc =
>>>> @@ -945,6 +947,15 @@ void rtc_timer_do_work(struct work_struct *work)
>>>> }
>>>> now = rtc_tm_to_ktime(tm);
>>>> while ((next = timerqueue_getnext(&rtc->timerqueue))) {
>>>> + loop_count++;
>>>> +
>>>> + if (unlikely(time_after(jiffies, start_jiffies + HZ))) {
>>>> + dev_warn(&rtc->dev, "RTC time jump (loop: %d) to %ptR.\n",
>>>> + loop_count, &tm);
>>>> + WARN_ON_ONCE(1);
>>>
>>> So, your issue is that it is too slow so you make it even slower? There
>>> are already plenty of tracepoints that allow proper debugging in this
>>> loop, I'm pretty sure we don't want to bloat the kernel with more
>>> messages.
>>
>> Hi, Alexandre,
>>
>> The point here is not about the performance of the rtc_timer_do_work()
>> loop — it’s about making the problem debuggable when things go wrong.
>> And we can put it under a debug Kconfig option, so production kernels
>> see no extra overhead at all.
>
>
> But then aren't the tracepoint enough? There are 3 tracepoints in the
> loop that are exactly for debugging your issue.
Hi, Alexandre,
Regarding the `trace_rtc_timer_dequeue` and `trace_rtc_timer_enqueue`
tracepoints, they are unfortunately insufficient to pinpoint this issue
for three reasons:
1. Ring Buffer Overwrite during Softlockup:
When the loop iterates tens of millions of times continuously on a
locked-up CPU, it floods the ftrace ring buffer in milliseconds. The
earliest trace logs—which contain the exact moment the time jumped—will
be completely overwritten and lost before anyone can read them.
2. Lack of Causality Context:
These tracepoints only log the timer's expiration and queue state.They
show the symptom (infinite re-enqueuing). But these are not the primary
scene, the time jump is the primary scene. They do not capture why are
there so many UIE timers being re-enqueued?
>
>>
>> The patch is installed in the following scenarios:
>>
>> If the RTC hardware fails, or if the QEMU-emulated RTC device code in a
>> KVM virtual machine has a problem (for example, the x86 RTC emulation
>> hardware mc146818 has an overflow issue[1]), the time may jump as shown
>> in the log below, which can cause a soft lockup.
>
> This is not clear, you are not explaining the issue. You seem to mix
> system time and RTC time. What I understand is that there was a periodic
> timer enqueued and then for some reason, the system time jumped forward
> by a large amount and now rtc_timer_do_work is firing events for each of
> the missed timers. You are not explaining the relationship with the RTC
> hardware (I see none).
The time here all means the RTC time got by __rtc_read_time(), not the
system time.
And the RTC time jump is caused by RTC hardware failure or
`QEMU-emulated RTC device` code bug, which means the rtc hardware
returns an unstable rtc time or is not completely linear growth..
The original issue is as follows：
On kvm qemu with cmos rtc and mc146818 chip, after set the UIE timer
expire with a normal RTC time （for example 2026 year）, In
rtc_timer_do_work(), the rtc time jump to a future time (for example
2033 year), it will loop for a while util softlockup because all
subsequent enqueued UIE timers expires, as below:
RTC_UIE_ON:
read now: 2019:04:08:12:32:27, add timer0 (expire: 2019:04:08:12:32:28)
^^^^^^^^^^^^^^^^^^^^
...
rtc_timer_do_work() iterate the list in a loop:
read now: 2033:12:02:07:27:15
^^^^^^^^^^^^^^^^^^^
handle timer0, add timer1 to the list (expire: 2019:04:08:12:32:29)
handle timer1, add timer2 to the list (expire: 2019:04:08:12:32:30)
handle timer2, add timer3: 2019:04:08:12:32:31
...
-> softlockup
>
>>
>> However, when the issue occurs, it is only possible to know that too
>> many pending timers have accumulated in the timerqueue (for example, the
>> log shows that tens of millions of timer nodes have been processed) by
>> temporarily adding diagnostic code in rtc_timer_do_work().
>>
>
> This is not true, there are 3 tracepoints to know what is happening with
> the timers. Also, there are always exactly zero, one or two timers in
> the queue, never tens of millions.
Timer Queue Size vs. Loop Iteration Count:
You are completely correct that there are only ever 0, 1, or 2 timer
nodes linked in the timerqueue. My previous phrasing was inaccurate, I
mean the loop Iteration.
>
>> To determine whether the root cause is hardware, kernel RTC code, an RTC
>> driver issue, or an RTC hardware problem, more debugging is needed. But
>> if the problem is indeed caused by RTC hardware, adding a diagnostic
>> print of the current RTC time when the loop takes too long (as this
>> diagnostic patch does) would make it easy to tell whether QEMU or the
>> hardware is faulty.
>>
>> [1]: https://lore.kernel.org/all/20260613195116.1807273-21-mjt@tls.msk.ru/
>>
>> kworker/0:1-37 [000] .N.. 489.159634: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281423
>> kworker/0:1-37 [000] .N.. 489.159635: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281424
>> kworker/0:1-37 [000] .N.. 489.159635: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281425
>> kworker/0:1-37 [000] .N.. 489.159636: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281426
>> kworker/0:1-37 [000] .N.. 489.159637: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281427
>> kworker/0:1-37 [000] .N.. 489.159638: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281428
>> kworker/0:1-37 [000] .N.. 489.159638: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281429
>> kworker/0:1-37 [000] .N.. 489.159639: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281430
>> kworker/0:1-37 [000] .N.. 489.159640: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281431
>> kworker/0:1-37 [000] .N.. 489.159641: rtc_timer_do_work:
>> timerqueue_getnext handle timer node count: 13281432
>>
>>
>> swapper/0-1 [001] .N.. 11.579334: __rtc_read_time: rtc:
>> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
>> swapper/0-1 [001] .N.. 11.579421: __rtc_read_time: rtc:
>> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
>> swapper/0-1 [001] .N.. 11.579469: __rtc_read_time: rtc:
>> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
>> swapper/0-1 [001] .N.. 11.580816: __rtc_read_time: rtc:
>> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
>> syz-executor.5-7492 [003] .... 129.807406: __rtc_read_time: rtc:
>> 0xff11000109896800, ops->read_time:2033:05:04:07:03:51
>> syz-executor.5-7492 [003] .... 129.807419:
>> __rtc_update_irq_enable.part.8: rtc uie on: 0xff11000109896800, now:
>> 2033:05:04:07:03:51, expire: 2033:05:04:07:03:52
>>
>>
>> Best regards,
>> Jinjie
>>
>>>
>>>
>>
>
^ permalink raw reply
* Re: [PATCH] rtc: interface: Add rtc time jump debug in rtc_timer_do_work()
From: Alexandre Belloni @ 2026-06-16 6:57 UTC (permalink / raw)
To: Jinjie Ruan; +Cc: linux-rtc, linux-kernel
In-Reply-To: <06cdb8b3-8a5d-4f1d-b686-6122fa6f7af9@huawei.com>
Hi,
On 16/06/2026 10:10:19+0800, Jinjie Ruan wrote:
>
>
> On 6/15/2026 11:22 PM, Alexandre Belloni wrote:
> > Hello,
> >
> > On 25/05/2026 21:08:25+0800, Jinjie Ruan wrote:
> >> In virtualization environments like QEMU [1], or during hardware
> >> clocksource anomalies, an extreme time-warp event can occur. When
> >> the system time abruptly jumps forward, the rtc_timer_do_work() handler
> >> falls into a prolonged processing loop to clear accumulated historical
> >> timers via timerqueue_getnext(). Running this loop indefinitely under
> >> the rtc->ops_lock mutex triggers a kernel softlockup, stalling
> >> the system.
> >>
> >> Introduce an adaptive telemetry and loop guard mechanism to enhance debug
> >> visibility and prevent softlockups:
> >>
> >> 1. Record `start_jiffies` upon entry and leverage `time_after()` to
> >> check if the loop has monopolized the CPU for more than 1s (HZ). If so,
> >> the handler prints a telemetry warning, triggers a WARN stack dump, and
> >> breaks the loop to safely yield the CPU.
> >>
> >> 2. Track the execution via a `loop_count` metric. Printing this counter
> >> in the warning log provides vital diagnostics to distinguish
> >> an aggressive time-warp storm (high count) from a bogged-down callback
> >> bug (low count).
> >>
> >> 3. Utilize the kernel format specifier `%ptR` to convert the raw ktime
> >> into a human-readable timestamp (YYYY-MM-DD HH:MM:SS), allowing
> >> developers to instantly pinpoint the exact boundary of the time
> >> jump in dmesg.
> >>
> >> This non-destructive telemetry guard provides precise hardware/emulator
> >> diagnostic visibility while ensuring core kernel availability.
> >>
> >> [1]: https://lore.kernel.org/all/20260114013257.3500578-1-ruanjinjie@huawei.com/
> >> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> >> ---
> >> drivers/rtc/interface.c | 15 +++++++++++++--
> >> 1 file changed, 13 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> >> index 1906f4884a83..f6c5fd16cc4e 100644
> >> --- a/drivers/rtc/interface.c
> >> +++ b/drivers/rtc/interface.c
> >> @@ -927,10 +927,12 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
> >> */
> >> void rtc_timer_do_work(struct work_struct *work)
> >> {
> >> - struct rtc_timer *timer;
> >> + unsigned long start_jiffies = jiffies;
> >> struct timerqueue_node *next;
> >> - ktime_t now;
> >> + struct rtc_timer *timer;
> >> struct rtc_time tm;
> >> + int loop_count = 0;
> >> + ktime_t now;
> >> int err;
> >>
> >> struct rtc_device *rtc =
> >> @@ -945,6 +947,15 @@ void rtc_timer_do_work(struct work_struct *work)
> >> }
> >> now = rtc_tm_to_ktime(tm);
> >> while ((next = timerqueue_getnext(&rtc->timerqueue))) {
> >> + loop_count++;
> >> +
> >> + if (unlikely(time_after(jiffies, start_jiffies + HZ))) {
> >> + dev_warn(&rtc->dev, "RTC time jump (loop: %d) to %ptR.\n",
> >> + loop_count, &tm);
> >> + WARN_ON_ONCE(1);
> >
> > So, your issue is that it is too slow so you make it even slower? There
> > are already plenty of tracepoints that allow proper debugging in this
> > loop, I'm pretty sure we don't want to bloat the kernel with more
> > messages.
>
> Hi, Alexandre,
>
> The point here is not about the performance of the rtc_timer_do_work()
> loop — it’s about making the problem debuggable when things go wrong.
> And we can put it under a debug Kconfig option, so production kernels
> see no extra overhead at all.
But then aren't the tracepoint enough? There are 3 tracepoints in the
loop that are exactly for debugging your issue.
>
> The patch is installed in the following scenarios:
>
> If the RTC hardware fails, or if the QEMU-emulated RTC device code in a
> KVM virtual machine has a problem (for example, the x86 RTC emulation
> hardware mc146818 has an overflow issue[1]), the time may jump as shown
> in the log below, which can cause a soft lockup.
This is not clear, you are not explaining the issue. You seem to mix
system time and RTC time. What I understand is that there was a periodic
timer enqueued and then for some reason, the system time jumped forward
by a large amount and now rtc_timer_do_work is firing events for each of
the missed timers. You are not explaining the relationship with the RTC
hardware (I see none).
>
> However, when the issue occurs, it is only possible to know that too
> many pending timers have accumulated in the timerqueue (for example, the
> log shows that tens of millions of timer nodes have been processed) by
> temporarily adding diagnostic code in rtc_timer_do_work().
>
This is not true, there are 3 tracepoints to know what is happening with
the timers. Also, there are always exactly zero, one or two timers in
the queue, never tens of millions.
> To determine whether the root cause is hardware, kernel RTC code, an RTC
> driver issue, or an RTC hardware problem, more debugging is needed. But
> if the problem is indeed caused by RTC hardware, adding a diagnostic
> print of the current RTC time when the loop takes too long (as this
> diagnostic patch does) would make it easy to tell whether QEMU or the
> hardware is faulty.
>
> [1]: https://lore.kernel.org/all/20260613195116.1807273-21-mjt@tls.msk.ru/
>
> kworker/0:1-37 [000] .N.. 489.159634: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281423
> kworker/0:1-37 [000] .N.. 489.159635: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281424
> kworker/0:1-37 [000] .N.. 489.159635: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281425
> kworker/0:1-37 [000] .N.. 489.159636: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281426
> kworker/0:1-37 [000] .N.. 489.159637: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281427
> kworker/0:1-37 [000] .N.. 489.159638: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281428
> kworker/0:1-37 [000] .N.. 489.159638: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281429
> kworker/0:1-37 [000] .N.. 489.159639: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281430
> kworker/0:1-37 [000] .N.. 489.159640: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281431
> kworker/0:1-37 [000] .N.. 489.159641: rtc_timer_do_work:
> timerqueue_getnext handle timer node count: 13281432
>
>
> swapper/0-1 [001] .N.. 11.579334: __rtc_read_time: rtc:
> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
> swapper/0-1 [001] .N.. 11.579421: __rtc_read_time: rtc:
> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
> swapper/0-1 [001] .N.. 11.579469: __rtc_read_time: rtc:
> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
> swapper/0-1 [001] .N.. 11.580816: __rtc_read_time: rtc:
> 0xff11000109896800, ops->read_time:2026:01:05:09:36:21
> syz-executor.5-7492 [003] .... 129.807406: __rtc_read_time: rtc:
> 0xff11000109896800, ops->read_time:2033:05:04:07:03:51
> syz-executor.5-7492 [003] .... 129.807419:
> __rtc_update_irq_enable.part.8: rtc uie on: 0xff11000109896800, now:
> 2033:05:04:07:03:51, expire: 2033:05:04:07:03:52
>
>
> Best regards,
> Jinjie
>
> >
> >
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
^ permalink raw reply
* Re: [PATCH] rtc: interface: Add rtc time jump debug in rtc_timer_do_work()
From: Jinjie Ruan @ 2026-06-16 2:10 UTC (permalink / raw)
To: Alexandre Belloni; +Cc: linux-rtc, linux-kernel
In-Reply-To: <2026061515223171f111f5@mail.local>
On 6/15/2026 11:22 PM, Alexandre Belloni wrote:
> Hello,
>
> On 25/05/2026 21:08:25+0800, Jinjie Ruan wrote:
>> In virtualization environments like QEMU [1], or during hardware
>> clocksource anomalies, an extreme time-warp event can occur. When
>> the system time abruptly jumps forward, the rtc_timer_do_work() handler
>> falls into a prolonged processing loop to clear accumulated historical
>> timers via timerqueue_getnext(). Running this loop indefinitely under
>> the rtc->ops_lock mutex triggers a kernel softlockup, stalling
>> the system.
>>
>> Introduce an adaptive telemetry and loop guard mechanism to enhance debug
>> visibility and prevent softlockups:
>>
>> 1. Record `start_jiffies` upon entry and leverage `time_after()` to
>> check if the loop has monopolized the CPU for more than 1s (HZ). If so,
>> the handler prints a telemetry warning, triggers a WARN stack dump, and
>> breaks the loop to safely yield the CPU.
>>
>> 2. Track the execution via a `loop_count` metric. Printing this counter
>> in the warning log provides vital diagnostics to distinguish
>> an aggressive time-warp storm (high count) from a bogged-down callback
>> bug (low count).
>>
>> 3. Utilize the kernel format specifier `%ptR` to convert the raw ktime
>> into a human-readable timestamp (YYYY-MM-DD HH:MM:SS), allowing
>> developers to instantly pinpoint the exact boundary of the time
>> jump in dmesg.
>>
>> This non-destructive telemetry guard provides precise hardware/emulator
>> diagnostic visibility while ensuring core kernel availability.
>>
>> [1]: https://lore.kernel.org/all/20260114013257.3500578-1-ruanjinjie@huawei.com/
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>> ---
>> drivers/rtc/interface.c | 15 +++++++++++++--
>> 1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
>> index 1906f4884a83..f6c5fd16cc4e 100644
>> --- a/drivers/rtc/interface.c
>> +++ b/drivers/rtc/interface.c
>> @@ -927,10 +927,12 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
>> */
>> void rtc_timer_do_work(struct work_struct *work)
>> {
>> - struct rtc_timer *timer;
>> + unsigned long start_jiffies = jiffies;
>> struct timerqueue_node *next;
>> - ktime_t now;
>> + struct rtc_timer *timer;
>> struct rtc_time tm;
>> + int loop_count = 0;
>> + ktime_t now;
>> int err;
>>
>> struct rtc_device *rtc =
>> @@ -945,6 +947,15 @@ void rtc_timer_do_work(struct work_struct *work)
>> }
>> now = rtc_tm_to_ktime(tm);
>> while ((next = timerqueue_getnext(&rtc->timerqueue))) {
>> + loop_count++;
>> +
>> + if (unlikely(time_after(jiffies, start_jiffies + HZ))) {
>> + dev_warn(&rtc->dev, "RTC time jump (loop: %d) to %ptR.\n",
>> + loop_count, &tm);
>> + WARN_ON_ONCE(1);
>
> So, your issue is that it is too slow so you make it even slower? There
> are already plenty of tracepoints that allow proper debugging in this
> loop, I'm pretty sure we don't want to bloat the kernel with more
> messages.
Hi, Alexandre,
The point here is not about the performance of the rtc_timer_do_work()
loop — it’s about making the problem debuggable when things go wrong.
And we can put it under a debug Kconfig option, so production kernels
see no extra overhead at all.
The patch is installed in the following scenarios:
If the RTC hardware fails, or if the QEMU-emulated RTC device code in a
KVM virtual machine has a problem (for example, the x86 RTC emulation
hardware mc146818 has an overflow issue[1]), the time may jump as shown
in the log below, which can cause a soft lockup.
However, when the issue occurs, it is only possible to know that too
many pending timers have accumulated in the timerqueue (for example, the
log shows that tens of millions of timer nodes have been processed) by
temporarily adding diagnostic code in rtc_timer_do_work().
To determine whether the root cause is hardware, kernel RTC code, an RTC
driver issue, or an RTC hardware problem, more debugging is needed. But
if the problem is indeed caused by RTC hardware, adding a diagnostic
print of the current RTC time when the loop takes too long (as this
diagnostic patch does) would make it easy to tell whether QEMU or the
hardware is faulty.
[1]: https://lore.kernel.org/all/20260613195116.1807273-21-mjt@tls.msk.ru/
kworker/0:1-37 [000] .N.. 489.159634: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281423
kworker/0:1-37 [000] .N.. 489.159635: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281424
kworker/0:1-37 [000] .N.. 489.159635: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281425
kworker/0:1-37 [000] .N.. 489.159636: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281426
kworker/0:1-37 [000] .N.. 489.159637: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281427
kworker/0:1-37 [000] .N.. 489.159638: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281428
kworker/0:1-37 [000] .N.. 489.159638: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281429
kworker/0:1-37 [000] .N.. 489.159639: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281430
kworker/0:1-37 [000] .N.. 489.159640: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281431
kworker/0:1-37 [000] .N.. 489.159641: rtc_timer_do_work:
timerqueue_getnext handle timer node count: 13281432
swapper/0-1 [001] .N.. 11.579334: __rtc_read_time: rtc:
0xff11000109896800, ops->read_time:2026:01:05:09:36:21
swapper/0-1 [001] .N.. 11.579421: __rtc_read_time: rtc:
0xff11000109896800, ops->read_time:2026:01:05:09:36:21
swapper/0-1 [001] .N.. 11.579469: __rtc_read_time: rtc:
0xff11000109896800, ops->read_time:2026:01:05:09:36:21
swapper/0-1 [001] .N.. 11.580816: __rtc_read_time: rtc:
0xff11000109896800, ops->read_time:2026:01:05:09:36:21
syz-executor.5-7492 [003] .... 129.807406: __rtc_read_time: rtc:
0xff11000109896800, ops->read_time:2033:05:04:07:03:51
syz-executor.5-7492 [003] .... 129.807419:
__rtc_update_irq_enable.part.8: rtc uie on: 0xff11000109896800, now:
2033:05:04:07:03:51, expire: 2033:05:04:07:03:52
Best regards,
Jinjie
>
>
^ permalink raw reply
* Re: [PATCH 7/7] clk: sunxi-ng: Add Allwinner A733 RTC CCU support
From: Jerome Brunet @ 2026-06-15 17:56 UTC (permalink / raw)
To: Chen-Yu Tsai
Cc: Junhui Liu, Michael Turquette, Stephen Boyd, Jernej Skrabec,
Samuel Holland, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Maxime Ripard, linux-clk,
linux-arm-kernel, linux-sunxi, linux-kernel, linux-rtc,
devicetree, André Przywara
In-Reply-To: <CAGb2v64euL+QNXiJdTn0JygYLXg0WoguPSprKT4sKGZGVZbwug@mail.gmail.com>
On sam. 28 mars 2026 at 22:41, Chen-Yu Tsai <wens@kernel.org> wrote:
> On Wed, Jan 21, 2026 at 7:04 PM Junhui Liu <junhui.liu@pigmoral.tech> wrote:
>>
>> Add support for the internal CCU found in the RTC module of the Allwinner
>> A733 SoC. While the basic 16MHz (IOSC) and 32kHz logic remains compatible
>> with older SoCs like the sun6i, the A733 introduces several new features.
>>
>> The A733 RTC CCU supports choosing one of three external crystal
>> frequencies: 19.2MHz, 24MHz, and 26MHz. It features hardware detection
>> logic to automatically identify the frequency used on the board and
>> exports this DCXO signal as the "hosc" clock.
>>
>> Furthermore, the driver implements logic to derive a 32kHz reference
>> from the HOSC. This is achieved through a muxed clock path using fixed
>> pre-dividers to normalize the different crystal frequencies to ~32kHz.
>
> Have you tested whether the actually normalizes the frequency, i.e.
> selects a different divider based on the DCXO frequency? Otherwise
> we're just lying about the frequency.
>
>> This path reuses the same hardware mux registers as the HOSC clock.
>>
>> Additionally, this CCU provides several gate clocks for specific
>> peripherals, including SerDes, HDMI, and UFS. The driver is implemented
>> as an auxiliary driver to be bound to the sun6i-rtc driver.
>>
>> Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
>> ---
[...]
>> +};
>> +
>> +static const struct clk_parent_data hosc_parents[] = {
>> + { .fw_name = "osc24M" },
>> + { .fw_name = "osc19M" },
>> + { .fw_name = "osc26M" },
>> + { .fw_name = "osc24M" },
>> +};
>
> As mentioned in my reply to the binding, this is wrong. There is only
> one input.
>
> The most you can do is check the rate of the parent clock against the
> detected one, and _scream_ that the DT is wrong. And maybe override
> the reported frequency.
>
> If you want to do the latter, you could add a new fixed rate gated
> clock type to our library. You would fill in the rate before the
> clocks get registered. I probably wouldn't go that far. We want people
> to have correct hardware descriptions.
>
> Funnily enough Allwinner's BSP actually implements a fixed rate gate
> for the next 24M-to-32k divider clock.
What about implementing the register bellow as a read-only (and
non-cached) divider using the factors provided by Junhui ? That would be
an accurate description of the HW I think.
The oscillator gets set in DT and if the output reported past the
divider is not 32728Hz, you know you've got a problem (bad DT or HW gone
bad)
With a fixed-rate gate, you may actually end up lying about what
actually happen, if the HW does not behave as expected.
Do you prefer a fixed-rate gate still or should I try the RO divider
approach ?
>
>> +
>> +struct ccu_mux hosc_clk = {
>> + .enable = DCXO_CTRL_DCXO_EN,
>> + .mux = _SUNXI_CCU_MUX(14, 2),
>> + .common = {
>> + .reg = DCXO_CTRL_REG,
>> + .hw.init = CLK_HW_INIT_PARENTS_DATA("hosc",
>> + hosc_parents,
>> + &ccu_mux_ro_ops,
>> + 0),
>> + },
>> +};
>
> So this is wrong.
>
>> +
>> +static const struct ccu_mux_fixed_prediv hosc_32k_predivs[] = {
>> + { .index = 0, .div = 732 },
>
> Why is it 732 instead of 750?
>
>> + { .index = 1, .div = 586 },
>> + { .index = 2, .div = 793 },
>> + { .index = 3, .div = 732 },
>> +};
>> +
>> +static struct ccu_mux hosc_32k_mux_clk = {
>> + .enable = DCXO_CTRL_DCXO_EN,
>
^ permalink raw reply
* Re: [PATCH 1/7] dt-bindings: rtc: sun6i: Add Allwinner A733 support
From: Jerome Brunet @ 2026-06-15 17:46 UTC (permalink / raw)
To: Chen-Yu Tsai
Cc: Junhui Liu, Michael Turquette, Stephen Boyd, Jernej Skrabec,
Samuel Holland, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Maxime Ripard, linux-clk,
linux-arm-kernel, linux-sunxi, linux-kernel, linux-rtc,
devicetree
In-Reply-To: <CAGb2v67844OPwE6VJ0PAs5LsmCa2h0FvXOBUomZ50dM5tZ0Zow@mail.gmail.com>
On sam. 28 mars 2026 at 20:37, Chen-Yu Tsai <wens@kernel.org> wrote:
> On Wed, Jan 21, 2026 at 7:03 PM Junhui Liu <junhui.liu@pigmoral.tech> wrote:
>>
>> The RTC module in the Allwinner A733 SoC is functionally compatible with
>> the sun6i RTC, but its internal Clock Control Unit (CCU) has significant
>> changes.
>>
>> The A733 supports selecting the oscillator between three frequencies:
>> 19.2MHz, 24MHz, and 26MHz. The RTC CCU relies on hardware to detect
>> which frequency is actually used on the board. By defining all three
>> frequencies as fixed-clocks in the device tree, the driver can identify
>> the hardware-detected frequency and expose it to the rest of the system.
>
> No. The board device tree shall have the exact and correct frequency
> defined in the external crystal device node. The operating system can
> use the hardware-detected frequency to "fix" the in-system representation
> if it is off.
>
>> Additionally, the A733 RTC CCU provides several new DCXO gate clocks for
>> specific modules, including SerDes, HDMI, and UFS.
>>
>> Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
>> ---
>> .../bindings/rtc/allwinner,sun6i-a31-rtc.yaml | 38 ++++++++++++++++++++--
>> include/dt-bindings/clock/sun60i-a733-rtc.h | 16 +++++++++
>> 2 files changed, 52 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml b/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
>> index 9df5cdb6f63f..b18431955783 100644
>> --- a/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
>> +++ b/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
>> @@ -26,6 +26,7 @@ properties:
>> - allwinner,sun50i-h6-rtc
>> - allwinner,sun50i-h616-rtc
>> - allwinner,sun50i-r329-rtc
>> + - allwinner,sun60i-a733-rtc
>> - items:
>> - const: allwinner,sun50i-a64-rtc
>> - const: allwinner,sun8i-h3-rtc
>> @@ -46,11 +47,11 @@ properties:
>>
>> clocks:
>> minItems: 1
>> - maxItems: 4
>> + maxItems: 6
>>
>> clock-names:
>> minItems: 1
>> - maxItems: 4
>> + maxItems: 6
>>
>> clock-output-names:
>> minItems: 1
>> @@ -156,6 +157,38 @@ allOf:
>> - clocks
>> - clock-names
>>
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + const: allwinner,sun60i-a733-rtc
>> +
>> + then:
>> + properties:
>> + clocks:
>> + minItems: 5
>> + items:
>> + - description: Bus clock for register access
>
>> + - description: 19.2 MHz oscillator
>> + - description: 24 MHz oscillator
>> + - description: 26 MHz oscillator
>
> No. There is only one input. As in there is only one set of pins for the
> DCXO. The inputs are the same as on R329 / A523. Just use that list.
>
>> + - description: AHB parent for internal SPI clock
>> + - description: External 32768 Hz oscillator
>> +
>> + clock-names:
>> + minItems: 5
>> + items:
>> + - const: bus
>> + - const: osc19M
>> + - const: osc24M
>> + - const: osc26M
>> + - const: ahb
>> + - const: ext-osc32k
>> +
>> + required:
>> + - clocks
>> + - clock-names
>> +
>> - if:
>> properties:
>> compatible:
>> @@ -164,6 +197,7 @@ allOf:
>> - allwinner,sun8i-r40-rtc
>> - allwinner,sun50i-h616-rtc
>> - allwinner,sun50i-r329-rtc
>> + - allwinner,sun60i-a733-rtc
>>
>> then:
>> properties:
>> diff --git a/include/dt-bindings/clock/sun60i-a733-rtc.h b/include/dt-bindings/clock/sun60i-a733-rtc.h
>> new file mode 100644
>> index 000000000000..8a2b5facad73
>> --- /dev/null
>> +++ b/include/dt-bindings/clock/sun60i-a733-rtc.h
>> @@ -0,0 +1,16 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
>> +
>> +#ifndef _DT_BINDINGS_CLK_SUN60I_A733_RTC_H_
>> +#define _DT_BINDINGS_CLK_SUN60I_A733_RTC_H_
>> +
>> +#define CLK_IOSC 0
>> +#define CLK_OSC32K 1
>> +#define CLK_HOSC 2
>
> The DCXO enable control has been present since at least the H6. We just
> never added it, as we would never disable it anyway.
>
> If you compare the RTC clock trees of the A733 and A523, the only addition
> besides the new gates seems to be the LOSC auto selection. But even that
> is just an illusion, as the A523 has the same registers for that.
>
> One could say the A733 RTC is almost backward compatible to the A523, if
> not for the two fastboot registers the A523 has at 0x120 and 0x124.
>
> So I ask that you try to integrate the differences into the existing
> driver and bindings. You can tweak and export internal clks if you
> need.
I'd like to help with that. I think it is doable but I have a question
regarding the binding of the existing driver, more precisely their usage
here:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c?h=v7.1#n370
Clock indexes are supposed to be stable in DT (AFAIK) but with the code
linked the external 32k is at:
* "ext-32k" - so index 3 - if "clock-names" is present
* index 0 if clock names is not present
... but index 0 is supposed to be the bus clock according the binding
doc, whether "clock-names" is there or not :/
So what are those old r329 bindings ? is there a documentation defining
them somewhere ?
Cleaning that part would help with A733 addition in the existing driver
I think
>
>> +#define CLK_RTC_32K 3
>
> AFAICT besides being an internal clock, this is also fed to GPIO for
> debounce? We probably need to expose this on the A523 as well.
>
>
> Thanks
> ChenYu
>
>
>> +#define CLK_OSC32K_FANOUT 4
>> +#define CLK_HOSC_SERDES1 5
>> +#define CLK_HOSC_SERDES0 6
>> +#define CLK_HOSC_HDMI 7
>> +#define CLK_HOSC_UFS 8
>> +
>> +#endif /* _DT_BINDINGS_CLK_SUN60I_A733_RTC_H_ */
>>
>> --
>> 2.52.0
>>
>>
--
Jerome
^ permalink raw reply
* Re: [PATCH 01/12] dt-bindings: rtc: renesas,rzn1-rtc: Add RZ/T2H and RZ/N2H support
From: Conor Dooley @ 2026-06-15 16:22 UTC (permalink / raw)
To: Prabhakar
Cc: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, Wolfram Sang, linux-rtc, linux-renesas-soc,
devicetree, linux-kernel, Biju Das, Fabrizio Castro,
Lad Prabhakar
In-Reply-To: <20260615154805.1619693-2-prabhakar.mahadev-lad.rj@bp.renesas.com>
[-- Attachment #1: Type: text/plain, Size: 75 bytes --]
Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
^ permalink raw reply
* [PATCH 12/12] rtc: rzn1: Add support for Renesas RZ/T2H and RZ/N2H SoCs
From: Prabhakar @ 2026-06-15 15:48 UTC (permalink / raw)
To: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, Wolfram Sang
Cc: linux-rtc, linux-renesas-soc, devicetree, linux-kernel, Prabhakar,
Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Add a new compatible string "renesas,r9a09g077-rtc" to the OF match table
to support the RTC IP variant found on the RZ/T2H and RZ/N2H SoCs.
These newer SoCs integrate a closely related variant of the RZ/N1 RTC IP.
The RZ/T2H and RZ/N2H variants lack the RTCA0SUBU and RTCA0TCR registers,
those registers are not accessed or used when operating under the
rzn1_rtc_ops_scmp configurations, making the current infrastructure
compatible.
The RZ/T2H RTC variant also supports a 1 Hz output signal on the
RTCAT1HZ pin, controlled by the RTCA0CTL1[RTCA01HZE] bit. This bit is
marked as reserved in the RZ/N1 hardware manual, making RZ/T2H a
distinct RTC variant despite its overall compatibility with the RZ/N1
implementation.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
drivers/rtc/rtc-rzn1.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
index 9f9cf9882fc4..dfff8dc8c321 100644
--- a/drivers/rtc/rtc-rzn1.c
+++ b/drivers/rtc/rtc-rzn1.c
@@ -597,6 +597,7 @@ static int rzn1_rtc_resume(struct device *dev)
static DEFINE_SIMPLE_DEV_PM_OPS(rzn1_rtc_pm_ops, rzn1_rtc_suspend, rzn1_rtc_resume);
static const struct of_device_id rzn1_rtc_of_match[] = {
+ { .compatible = "renesas,r9a09g077-rtc" },
{ .compatible = "renesas,rzn1-rtc" },
{},
};
--
2.54.0
^ permalink raw reply related
* [PATCH 11/12] rtc: rzn1: use FIELD_PREP/FIELD_GET and GENMASK for register access
From: Prabhakar @ 2026-06-15 15:48 UTC (permalink / raw)
To: Miquel Raynal, Alexandre Belloni, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, Wolfram Sang
Cc: linux-rtc, linux-renesas-soc, devicetree, linux-kernel, Prabhakar,
Biju Das, Fabrizio Castro, Lad Prabhakar
In-Reply-To: <20260615154805.1619693-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Replace open-coded shift and mask operations with the bitfield API.
Note that the weekday field is changed from an explicit 0x0f mask to
an 8-bit field definition, matching the hardware manual. This does not
change behaviour, as valid weekday values cannot exceed 7.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
drivers/rtc/rtc-rzn1.c | 46 ++++++++++++++++++++++++------------------
1 file changed, 26 insertions(+), 20 deletions(-)
diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
index c7ef3c81180f..9f9cf9882fc4 100644
--- a/drivers/rtc/rtc-rzn1.c
+++ b/drivers/rtc/rtc-rzn1.c
@@ -12,6 +12,8 @@
*/
#include <linux/bcd.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/init.h>
#include <linux/iopoll.h>
@@ -40,14 +42,18 @@
#define RZN1_RTC_CTL2_STOPPED (RZN1_RTC_CTL2_WAIT | RZN1_RTC_CTL2_WST)
#define RZN1_RTC_TIME 0x30
-#define RZN1_RTC_TIME_MIN_SHIFT 8
-#define RZN1_RTC_TIME_HOUR_SHIFT 16
+#define RZN1_RTC_TIME_SEC GENMASK(7, 0)
+#define RZN1_RTC_TIME_MIN GENMASK(15, 8)
+#define RZN1_RTC_TIME_HOUR GENMASK(23, 16)
+
#define RZN1_RTC_CAL 0x34
-#define RZN1_RTC_CAL_DAY_SHIFT 8
-#define RZN1_RTC_CAL_MON_SHIFT 16
-#define RZN1_RTC_CAL_YEAR_SHIFT 24
+#define RZN1_RTC_CAL_WDAY GENMASK(7, 0)
+#define RZN1_RTC_CAL_DAY GENMASK(15, 8)
+#define RZN1_RTC_CAL_MON GENMASK(23, 16)
+#define RZN1_RTC_CAL_YEAR GENMASK(31, 24)
#define RZN1_RTC_SUBU 0x38
+#define RZN1_RTC_SUBU_RTCA0FX GENMASK(5, 0)
#define RZN1_RTC_SUBU_DEV BIT(7)
#define RZN1_RTC_SUBU_DECR BIT(6)
@@ -82,15 +88,15 @@ static void rzn1_rtc_get_time_snapshot(struct rzn1_rtc *rtc, struct rtc_time *tm
u32 val;
val = readl(rtc->base + RZN1_RTC_TIMEC);
- tm->tm_sec = bcd2bin(val);
- tm->tm_min = bcd2bin(val >> RZN1_RTC_TIME_MIN_SHIFT);
- tm->tm_hour = bcd2bin(val >> RZN1_RTC_TIME_HOUR_SHIFT);
+ tm->tm_sec = bcd2bin(FIELD_GET(RZN1_RTC_TIME_SEC, val));
+ tm->tm_min = bcd2bin(FIELD_GET(RZN1_RTC_TIME_MIN, val));
+ tm->tm_hour = bcd2bin(FIELD_GET(RZN1_RTC_TIME_HOUR, val));
val = readl(rtc->base + RZN1_RTC_CALC);
- tm->tm_wday = val & 0x0f;
- tm->tm_mday = bcd2bin(val >> RZN1_RTC_CAL_DAY_SHIFT);
- tm->tm_mon = bcd2bin(val >> RZN1_RTC_CAL_MON_SHIFT) - 1;
- tm->tm_year = bcd2bin(val >> RZN1_RTC_CAL_YEAR_SHIFT) + 100;
+ tm->tm_wday = FIELD_GET(RZN1_RTC_CAL_WDAY, val);
+ tm->tm_mday = bcd2bin(FIELD_GET(RZN1_RTC_CAL_DAY, val));
+ tm->tm_mon = bcd2bin(FIELD_GET(RZN1_RTC_CAL_MON, val)) - 1;
+ tm->tm_year = bcd2bin(FIELD_GET(RZN1_RTC_CAL_YEAR, val)) + 100;
}
static int rzn1_rtc_read_time(struct device *dev, struct rtc_time *tm)
@@ -133,15 +139,15 @@ static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm)
return ret;
}
- val = bin2bcd(tm->tm_sec);
- val |= bin2bcd(tm->tm_min) << RZN1_RTC_TIME_MIN_SHIFT;
- val |= bin2bcd(tm->tm_hour) << RZN1_RTC_TIME_HOUR_SHIFT;
+ val = FIELD_PREP(RZN1_RTC_TIME_SEC, bin2bcd(tm->tm_sec)) |
+ FIELD_PREP(RZN1_RTC_TIME_MIN, bin2bcd(tm->tm_min)) |
+ FIELD_PREP(RZN1_RTC_TIME_HOUR, bin2bcd(tm->tm_hour));
writel(val, rtc->base + RZN1_RTC_TIME);
- val = tm->tm_wday;
- val |= bin2bcd(tm->tm_mday) << RZN1_RTC_CAL_DAY_SHIFT;
- val |= bin2bcd(tm->tm_mon + 1) << RZN1_RTC_CAL_MON_SHIFT;
- val |= bin2bcd(tm->tm_year - 100) << RZN1_RTC_CAL_YEAR_SHIFT;
+ val = FIELD_PREP(RZN1_RTC_CAL_WDAY, tm->tm_wday) |
+ FIELD_PREP(RZN1_RTC_CAL_DAY, bin2bcd(tm->tm_mday)) |
+ FIELD_PREP(RZN1_RTC_CAL_MON, bin2bcd(tm->tm_mon + 1)) |
+ FIELD_PREP(RZN1_RTC_CAL_YEAR, bin2bcd(tm->tm_year - 100));
writel(val, rtc->base + RZN1_RTC_CAL);
writel(0, rtc->base + RZN1_RTC_CTL2);
@@ -306,7 +312,7 @@ static int rzn1_rtc_read_offset(struct device *dev, long *offset)
val = readl(rtc->base + RZN1_RTC_SUBU);
ppb_per_step = val & RZN1_RTC_SUBU_DEV ? 1017 : 3051;
subtract = val & RZN1_RTC_SUBU_DECR;
- val &= 0x3F;
+ val = FIELD_GET(RZN1_RTC_SUBU_RTCA0FX, val);
if (!val)
*offset = 0;
--
2.54.0
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