[PATCH 0/3] On-chip RTC support for ExynosAutov9

[PATCH 0/3] On-chip RTC support for ExynosAutov9

[Devang Tailor]

Enable on-chip RTC support. The on-chip RTC of this SoC is similar
to the previous versions of Samsung SoC. So re-use the existing
RTC driver with additional changes required for timer counter
specific registers.

Setting and getting hardware clock has been tested using 'hwclock'
and 'date' utilities.

Alarm interrupt has been checked with incrementing interrupt
count via "cat /proc/interrupts | grep rtc" for 10sec
wakeup time via "echo +10 > /sys/class/rtc/rtc0/wakealarm"

Devang Tailor (3):
  dt-bindings: rtc: s3c-rtc: add compatible for exynosautov9
  rtc: s3c: support for exynosautov9 on-chip RTC
  arm64: dts: exynosautov9: add RTC DT node

 .../devicetree/bindings/rtc/s3c-rtc.yaml      |  1 +
 .../boot/dts/exynos/exynosautov9-sadk.dts     |  4 +++
 arch/arm64/boot/dts/exynos/exynosautov9.dtsi  | 10 +++++++
 drivers/rtc/rtc-s3c.c                         | 26 +++++++++++++++++++
 drivers/rtc/rtc-s3c.h                         |  4 +++
 5 files changed, 45 insertions(+)


base-commit: bc6e0ba6c9bafa6241b05524b9829808056ac4ad
-- 
2.34.1

[PATCH 1/3] dt-bindings: rtc: s3c-rtc: add compatible for exynosautov9

[Devang Tailor]

Add "samsung,exynosautov9-rtc" dedicated compatible for
on-chip RTC found in ExynosAutov9 SoC.

Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
---
 Documentation/devicetree/bindings/rtc/s3c-rtc.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/rtc/s3c-rtc.yaml b/Documentation/devicetree/bindings/rtc/s3c-rtc.yaml
index bf4e11d6dffb..5daee2a5f866 100644
--- a/Documentation/devicetree/bindings/rtc/s3c-rtc.yaml
+++ b/Documentation/devicetree/bindings/rtc/s3c-rtc.yaml
@@ -13,6 +13,7 @@ properties:
   compatible:
     oneOf:
       - enum:
+          - samsung,exynosautov9-rtc
           - samsung,s3c2410-rtc
           - samsung,s3c2416-rtc
           - samsung,s3c2443-rtc
-- 
2.34.1

Re: [PATCH 1/3] dt-bindings: rtc: s3c-rtc: add compatible for exynosautov9

[Krzysztof Kozlowski]

On 02/07/2025 07:24, Devang Tailor wrote:
> Add "samsung,exynosautov9-rtc" dedicated compatible for
> on-chip RTC found in ExynosAutov9 SoC.
> 
> Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
> ---
>  Documentation/devicetree/bindings/rtc/s3c-rtc.yaml | 1 +

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 2/3] rtc: s3c: support for exynosautov9 on-chip RTC

[Devang Tailor]

The on-chip RTC of this SoC is almost similar to the previous
versions of SoC. Hence re-use the existing driver with platform specific
change to enable RTC.

This has been tested with 'hwclock' & 'date' utilities

Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
---
 drivers/rtc/rtc-s3c.c | 26 ++++++++++++++++++++++++++
 drivers/rtc/rtc-s3c.h |  4 ++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 5dd575865adf..00686aa805f2 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -384,6 +384,23 @@ static void s3c6410_rtc_disable(struct s3c_rtc *info)
 	writew(con, info->base + S3C2410_RTCCON);
 }
 
+static void exynosautov9_rtc_disable(struct s3c_rtc *info)
+{
+	unsigned int con;
+
+	con = readb(info->base + S3C2410_RTCCON);
+	con &= ~S3C2410_RTCCON_RTCEN;
+	writeb(con, info->base + S3C2410_RTCCON);
+
+	con = readb(info->base + EXYNOSAUTOV9_TICCON0);
+	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
+	writeb(con, info->base + EXYNOSAUTOV9_TICCON0);
+
+	con = readb(info->base + EXYNOSAUTOV9_TICCON1);
+	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
+	writeb(con, info->base + EXYNOSAUTOV9_TICCON1);
+}
+
 static void s3c_rtc_remove(struct platform_device *pdev)
 {
 	struct s3c_rtc *info = platform_get_drvdata(pdev);
@@ -574,6 +591,12 @@ static struct s3c_rtc_data const s3c6410_rtc_data = {
 	.disable		= s3c6410_rtc_disable,
 };
 
+static struct s3c_rtc_data const exynosautov9_rtc_data = {
+	.irq_handler		= s3c6410_rtc_irq,
+	.enable			= s3c24xx_rtc_enable,
+	.disable		= exynosautov9_rtc_disable,
+};
+
 static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
 	{
 		.compatible = "samsung,s3c2410-rtc",
@@ -590,6 +613,9 @@ static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
 	}, {
 		.compatible = "samsung,exynos3250-rtc",
 		.data = &s3c6410_rtc_data,
+	}, {
+		.compatible = "samsung,exynosautov9-rtc",
+		.data = &exynosautov9_rtc_data,
 	},
 	{ /* sentinel */ },
 };
diff --git a/drivers/rtc/rtc-s3c.h b/drivers/rtc/rtc-s3c.h
index 3552914aa611..ed57ebe06b41 100644
--- a/drivers/rtc/rtc-s3c.h
+++ b/drivers/rtc/rtc-s3c.h
@@ -14,6 +14,10 @@
 #define S3C2410_INTP_ALM	(1 << 1)
 #define S3C2410_INTP_TIC	(1 << 0)
 
+#define	EXYNOSAUTOV9_TICCON0	S3C2410_RTCREG(0x38)
+#define	EXYNOSAUTOV9_TICCON1	S3C2410_RTCREG(0x3C)
+#define	EXYNOSAUTOV9_TICCON_TICEN	(1 << 0)
+
 #define S3C2410_RTCCON		S3C2410_RTCREG(0x40)
 #define S3C2410_RTCCON_RTCEN	(1 << 0)
 #define S3C2410_RTCCON_CNTSEL	(1 << 2)
-- 
2.34.1

Re: [PATCH 2/3] rtc: s3c: support for exynosautov9 on-chip RTC

[Krzysztof Kozlowski]

On 02/07/2025 07:24, Devang Tailor wrote:
> The on-chip RTC of this SoC is almost similar to the previous
> versions of SoC. Hence re-use the existing driver with platform specific
> change to enable RTC.
> 
> This has been tested with 'hwclock' & 'date' utilities
> 
> Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
> ---
>  drivers/rtc/rtc-s3c.c | 26 ++++++++++++++++++++++++++
>  drivers/rtc/rtc-s3c.h |  4 ++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
> index 5dd575865adf..00686aa805f2 100644
> --- a/drivers/rtc/rtc-s3c.c
> +++ b/drivers/rtc/rtc-s3c.c
> @@ -384,6 +384,23 @@ static void s3c6410_rtc_disable(struct s3c_rtc *info)
>  	writew(con, info->base + S3C2410_RTCCON);
>  }
>  
> +static void exynosautov9_rtc_disable(struct s3c_rtc *info)
> +{
> +	unsigned int con;
> +
> +	con = readb(info->base + S3C2410_RTCCON);
> +	con &= ~S3C2410_RTCCON_RTCEN;
> +	writeb(con, info->base + S3C2410_RTCCON);
> +
> +	con = readb(info->base + EXYNOSAUTOV9_TICCON0);
> +	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
> +	writeb(con, info->base + EXYNOSAUTOV9_TICCON0);
> +
> +	con = readb(info->base + EXYNOSAUTOV9_TICCON1);
> +	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
> +	writeb(con, info->base + EXYNOSAUTOV9_TICCON1);

You clear these bits during disable, but why aren't they set during
enable? Why is this asymmetric? This should be clearly explained, but
both commit msg and code is completely silent.

> +}
> +
>  static void s3c_rtc_remove(struct platform_device *pdev)
>  {
>  	struct s3c_rtc *info = platform_get_drvdata(pdev);
> @@ -574,6 +591,12 @@ static struct s3c_rtc_data const s3c6410_rtc_data = {
>  	.disable		= s3c6410_rtc_disable,
>  };
>  
> +static struct s3c_rtc_data const exynosautov9_rtc_data = {

Please put const after static.



Best regards,
Krzysztof

RE: [PATCH 2/3] rtc: s3c: support for exynosautov9 on-chip RTC

[Devang Tailor]

Hi Krzysztof,


> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@kernel.org>
> Sent: 07 July 2025 14:54
> To: Devang Tailor <dev.tailor@samsung.com>;
> alexandre.belloni@bootlin.com; robh@kernel.org; krzk+dt@kernel.org;
> conor+dt@kernel.org; alim.akhtar@samsung.com; linux-rtc@vger.kernel.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; inux-arm-
> kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org;
> faraz.ata@samsung.com
> Subject: Re: [PATCH 2/3] rtc: s3c: support for exynosautov9 on-chip RTC
> 
> On 02/07/2025 07:24, Devang Tailor wrote:
> > The on-chip RTC of this SoC is almost similar to the previous versions
> > of SoC. Hence re-use the existing driver with platform specific change
> > to enable RTC.
> >
> > This has been tested with 'hwclock' & 'date' utilities
> >
> > Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
> > ---
> >  drivers/rtc/rtc-s3c.c | 26 ++++++++++++++++++++++++++
> > drivers/rtc/rtc-s3c.h |  4 ++++
> >  2 files changed, 30 insertions(+)
> >
> > diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c index
> > 5dd575865adf..00686aa805f2 100644
> > --- a/drivers/rtc/rtc-s3c.c
> > +++ b/drivers/rtc/rtc-s3c.c
> > @@ -384,6 +384,23 @@ static void s3c6410_rtc_disable(struct s3c_rtc
> *info)
> >  	writew(con, info->base + S3C2410_RTCCON);  }
> >
> > +static void exynosautov9_rtc_disable(struct s3c_rtc *info) {
> > +	unsigned int con;
> > +
> > +	con = readb(info->base + S3C2410_RTCCON);
> > +	con &= ~S3C2410_RTCCON_RTCEN;
> > +	writeb(con, info->base + S3C2410_RTCCON);
> > +
> > +	con = readb(info->base + EXYNOSAUTOV9_TICCON0);
> > +	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
> > +	writeb(con, info->base + EXYNOSAUTOV9_TICCON0);
> > +
> > +	con = readb(info->base + EXYNOSAUTOV9_TICCON1);
> > +	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
> > +	writeb(con, info->base + EXYNOSAUTOV9_TICCON1);
> 
> You clear these bits during disable, but why aren't they set during enable?
> Why is this asymmetric? This should be clearly explained, but both commit
> msg and code is completely silent.

OK. I will correct in V2 patch

> 
> > +}
> > +
> >  static void s3c_rtc_remove(struct platform_device *pdev)  {
> >  	struct s3c_rtc *info = platform_get_drvdata(pdev); @@ -574,6 +591,12
> > @@ static struct s3c_rtc_data const s3c6410_rtc_data = {
> >  	.disable		= s3c6410_rtc_disable,
> >  };
> >
> > +static struct s3c_rtc_data const exynosautov9_rtc_data = {
> 
> Please put const after static.

I tried to keep it similar to the existing format, I will correct it in V2 patch.

> 
> 
> 
> Best regards,
> Krzysztof

[PATCH 3/3] arm64: dts: exynosautov9: add RTC DT node

[Devang Tailor]

Add DT node for on-chip RTC for ExynosAutov9

Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
---
 arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts |  4 ++++
 arch/arm64/boot/dts/exynos/exynosautov9.dtsi     | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts b/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts
index de2c1de51a76..5f5167571f7a 100644
--- a/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts
+++ b/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts
@@ -106,6 +106,10 @@ &pwm {
 	status = "okay";
 };
 
+&rtc {
+	status = "okay";
+};
+
 &serial_0 {
 	pinctrl-0 = <&uart0_bus_dual>;
 	status = "okay";
diff --git a/arch/arm64/boot/dts/exynos/exynosautov9.dtsi b/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
index 66628cb32776..e655212f6a6b 100644
--- a/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
@@ -1633,6 +1633,16 @@ pwm: pwm@103f0000 {
 			clock-names = "timers";
 			status = "disabled";
 		};
+
+		rtc: rtc@10540000 {
+			compatible = "samsung,exynosautov9-rtc";
+			reg = <0x10540000 0x100>;
+			interrupts = <GIC_SPI 26 IRQ_TYPE_LEVEL_HIGH>,
+				<GIC_SPI 27 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&xtcxo>;
+			clock-names = "rtc";
+			status = "disabled";
+		};
 	};
 };
 
-- 
2.34.1

Re: [PATCH 3/3] arm64: dts: exynosautov9: add RTC DT node

[Krzysztof Kozlowski]

On 02/07/2025 07:24, Devang Tailor wrote:
> --- a/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> @@ -1633,6 +1633,16 @@ pwm: pwm@103f0000 {
>  			clock-names = "timers";
>  			status = "disabled";
>  		};
> +
> +		rtc: rtc@10540000 {
> +			compatible = "samsung,exynosautov9-rtc";
> +			reg = <0x10540000 0x100>;
> +			interrupts = <GIC_SPI 26 IRQ_TYPE_LEVEL_HIGH>,
> +				<GIC_SPI 27 IRQ_TYPE_LEVEL_HIGH>;


Misaligned. Should match earlier '<'.


Best regards,
Krzysztof

RE: [PATCH 3/3] arm64: dts: exynosautov9: add RTC DT node

[Devang Tailor]

Hi Krzysztof,


> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@kernel.org>
> Sent: 07 July 2025 14:53
> To: Devang Tailor <dev.tailor@samsung.com>;
> alexandre.belloni@bootlin.com; robh@kernel.org; krzk+dt@kernel.org;
> conor+dt@kernel.org; alim.akhtar@samsung.com; linux-rtc@vger.kernel.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; inux-arm-
> kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org;
> faraz.ata@samsung.com
> Subject: Re: [PATCH 3/3] arm64: dts: exynosautov9: add RTC DT node
> 
> On 02/07/2025 07:24, Devang Tailor wrote:
> > --- a/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> > +++ b/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> > @@ -1633,6 +1633,16 @@ pwm: pwm@103f0000 {
> >  			clock-names = "timers";
> >  			status = "disabled";
> >  		};
> > +
> > +		rtc: rtc@10540000 {
> > +			compatible = "samsung,exynosautov9-rtc";
> > +			reg = <0x10540000 0x100>;
> > +			interrupts = <GIC_SPI 26 IRQ_TYPE_LEVEL_HIGH>,
> > +				<GIC_SPI 27 IRQ_TYPE_LEVEL_HIGH>;
> 
> 
> Misaligned. Should match earlier '<'.

Will update it to match last '<' 's alignment.

> 
> 
> Best regards,
> Krzysztof