[PATCH v4 0/4] add NXP RTC driver support for S32G2/S32G3 SoCs

[PATCH v4 0/4] add NXP RTC driver support for S32G2/S32G3 SoCs

[Ciprian Costea]

From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

This patch series add support for the NXP
RTC hardware module present on S32G2/S32G3 SoCs.

The RTC module is used to enable Suspend to RAM (STR) support.
RTC tracks clock time during system suspend. It represents a
time-based wakeup source for the S32G2/S32G3 SoCs.

RTC is not battery-powered and it is not kept alive during
system reset.

Following is an example of Suspend to RAM trigger on
S32G2/S32G3 SoCs, using userspace tools such as rtcwake:
# rtcwake -s 2 -m mem
# rtcwake: assuming RTC uses UTC ...
# rtcwake: wakeup from "mem" using /dev/rtc0 at Wed Feb  6 06:28:36 2036
#

Changes in V4:
- Dropped 'assigned-*' clock management approach.
  Simplified RTC Runtime and Suspend/Standby clock configuration.
- Simplified error paths on probe function
- Removed node label from bindings example
- Several cosmetic coding style fixes

Changes in V3:
- Removed 'nxp,s32g3-rtc' compatible string
- Change to 'remove' callback from 'remove_new'
- Used 'dev.parent' from 'struct rtc_device' instead of
  defining a specific 'struct device' in driver data
- Fixed several errors reported by kernel test robot
- Removed 'assigned-clocks', 'assigned-clock-parents' and
  'assigned-clock-rates' from required properties in the
  binding documentation.
- Refactored S32G RTC driver such that a default clock source
  and divisors configuration will be applied in case 'assigned-clocks'
  and 'assigned-clock-parents' properties are missing.

Changes in V2:
- Removed 'clksel' support from dts bindings.
  Used clock parents support from CCF to better illustrate the
  RTC hardware IP from S32G2/S32G3.
- Removed frequency dividers support from dts bindings.
  Used assigned clock frequencies support from CCF instead.
- Reduced the interval while RTC is voluntarily disabled to a simple
  register write in order to avoid any race condition between a possbile
  rollover and 'suspend' callback execution flow.
- Updated bindings documentation with respect to clocking support.
- Fixed a potential unused variable warning reported
  by kernel test robot.
- Updated to usage of 'devm_rtc_allocate_device' and 'devm_rtc_register_device'
  instead of deprecated 'devm_rtc_device_register'.

Ciprian Marian Costea (4):
  dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs
  rtc: s32g: add NXP S32G2/S32G3 SoC support
  arm64: defconfig: add S32G RTC module support
  MAINTAINERS: add NXP S32G RTC driver

 .../devicetree/bindings/rtc/nxp,s32g-rtc.yaml |  78 ++
 MAINTAINERS                                   |   2 +
 arch/arm64/configs/defconfig                  |   1 +
 drivers/rtc/Kconfig                           |  11 +
 drivers/rtc/Makefile                          |   1 +
 drivers/rtc/rtc-s32g.c                        | 692 ++++++++++++++++++
 6 files changed, 785 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
 create mode 100644 drivers/rtc/rtc-s32g.c

-- 
2.45.2

[PATCH v4 1/4] dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs

[Ciprian Costea]

From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

RTC tracks clock time during system suspend and it is used as a wakeup
source on S32G2/S32G3 architecture.

RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
during system reset.

Co-developed-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
Signed-off-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
---
 .../devicetree/bindings/rtc/nxp,s32g-rtc.yaml | 78 +++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml

diff --git a/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
new file mode 100644
index 000000000000..231811579e1b
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
@@ -0,0 +1,78 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/nxp,s32g-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP S32G2/S32G3 Real Time Clock (RTC)
+
+maintainers:
+  - Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
+  - Ciprian Marian Costea <ciprianmarian.costea@nxp.com>
+
+description:
+  RTC hardware module present on S32G2/S32G3 SoCs is used as a wakeup
+  source. It is not kept alive during system reset and it is not
+  battery-powered.
+
+  RTC hardware module contains a hardware mux with 4 entries/inputs
+  for clock source selection. On S32G2/S32G3 SoCs, this mux is used
+  to select between a clock source for runtime which brings more
+  precision but is not available during system standby, and a clock
+  source for suspend state.
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - nxp,s32g2-rtc
+      - items:
+          - const: nxp,s32g3-rtc
+          - const: nxp,s32g2-rtc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 2
+    items:
+      - description: ipg clock drives the access to the
+          RTC iomapped registers
+      - description: Runtime clock source. It must be a clock
+          source for the RTC module. It will be disabled by hardware
+          during Standby/Suspend.
+      - description: Standby/Suspend clock source. It is optional
+          and can be used in case the RTC will continue ticking during
+          platform/system suspend.
+
+  clock-names:
+    minItems: 2
+    maxItems: 3
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    rtc@40060000 {
+        compatible = "nxp,s32g3-rtc",
+                   "nxp,s32g2-rtc";
+        reg = <0x40060000 0x1000>;
+        interrupts = <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clks 54>, <&clks 56>, <&clks 55>;
+        clock-names = "ipg",
+            "rtc_runtime_s2",
+            "rtc_standby_s0";
+    };
-- 
2.45.2

Re: [PATCH v4 1/4] dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs

[Frank Li]

On Mon, Nov 11, 2024 at 03:59:37PM +0200, Ciprian Costea wrote:
> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>
> RTC tracks clock time during system suspend and it is used as a wakeup
> source on S32G2/S32G3 architecture.
>
> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
> during system reset.
>
> Co-developed-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
> Signed-off-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
> Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> ---
>  .../devicetree/bindings/rtc/nxp,s32g-rtc.yaml | 78 +++++++++++++++++++
>  1 file changed, 78 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
>
> diff --git a/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
> new file mode 100644
> index 000000000000..231811579e1b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
> @@ -0,0 +1,78 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/nxp,s32g-rtc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP S32G2/S32G3 Real Time Clock (RTC)
> +
> +maintainers:
> +  - Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> +  - Ciprian Marian Costea <ciprianmarian.costea@nxp.com>
> +
> +description:
> +  RTC hardware module present on S32G2/S32G3 SoCs is used as a wakeup
> +  source. It is not kept alive during system reset and it is not
> +  battery-powered.
> +
> +  RTC hardware module contains a hardware mux with 4 entries/inputs
> +  for clock source selection. On S32G2/S32G3 SoCs, this mux is used
> +  to select between a clock source for runtime which brings more
> +  precision but is not available during system standby, and a clock
> +  source for suspend state.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - enum:
> +          - nxp,s32g2-rtc
> +      - items:
> +          - const: nxp,s32g3-rtc
> +          - const: nxp,s32g2-rtc
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    minItems: 2
> +    items:
> +      - description: ipg clock drives the access to the
> +          RTC iomapped registers
> +      - description: Runtime clock source. It must be a clock
> +          source for the RTC module. It will be disabled by hardware
> +          during Standby/Suspend.
> +      - description: Standby/Suspend clock source. It is optional
> +          and can be used in case the RTC will continue ticking during
> +          platform/system suspend.

wrap at 80, keep wrap pos consisent in this file.

> +
> +  clock-names:
> +    minItems: 2
> +    maxItems: 3
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    rtc@40060000 {
> +        compatible = "nxp,s32g3-rtc",
> +                   "nxp,s32g2-rtc";

align to previous line "

> +        reg = <0x40060000 0x1000>;
> +        interrupts = <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>;
> +        clocks = <&clks 54>, <&clks 56>, <&clks 55>;
> +        clock-names = "ipg",
> +            "rtc_runtime_s2",
> +            "rtc_standby_s0";

align to previous line "

> +    };
> --
> 2.45.2
>

Re: [PATCH v4 1/4] dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs

[Ciprian Marian Costea]

On 11/11/2024 5:14 PM, Frank Li wrote:
> On Mon, Nov 11, 2024 at 03:59:37PM +0200, Ciprian Costea wrote:
>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>
>> RTC tracks clock time during system suspend and it is used as a wakeup
>> source on S32G2/S32G3 architecture.
>>
>> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
>> during system reset.
>>
>> Co-developed-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
>> Signed-off-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
>> Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
>> Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>> ---
>>   .../devicetree/bindings/rtc/nxp,s32g-rtc.yaml | 78 +++++++++++++++++++
>>   1 file changed, 78 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
>> new file mode 100644
>> index 000000000000..231811579e1b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
>> @@ -0,0 +1,78 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/rtc/nxp,s32g-rtc.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: NXP S32G2/S32G3 Real Time Clock (RTC)
>> +
>> +maintainers:
>> +  - Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
>> +  - Ciprian Marian Costea <ciprianmarian.costea@nxp.com>
>> +
>> +description:
>> +  RTC hardware module present on S32G2/S32G3 SoCs is used as a wakeup
>> +  source. It is not kept alive during system reset and it is not
>> +  battery-powered.
>> +
>> +  RTC hardware module contains a hardware mux with 4 entries/inputs
>> +  for clock source selection. On S32G2/S32G3 SoCs, this mux is used
>> +  to select between a clock source for runtime which brings more
>> +  precision but is not available during system standby, and a clock
>> +  source for suspend state.
>> +
>> +properties:
>> +  compatible:
>> +    oneOf:
>> +      - enum:
>> +          - nxp,s32g2-rtc
>> +      - items:
>> +          - const: nxp,s32g3-rtc
>> +          - const: nxp,s32g2-rtc
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    minItems: 2
>> +    items:
>> +      - description: ipg clock drives the access to the
>> +          RTC iomapped registers
>> +      - description: Runtime clock source. It must be a clock
>> +          source for the RTC module. It will be disabled by hardware
>> +          during Standby/Suspend.
>> +      - description: Standby/Suspend clock source. It is optional
>> +          and can be used in case the RTC will continue ticking during
>> +          platform/system suspend.
> 
> wrap at 80, keep wrap pos consisent in this file.
> 

Hello Frank,

Thanks for your review.
I will update wrapping to 80 characters in V5.

>> +
>> +  clock-names:
>> +    minItems: 2
>> +    maxItems: 3
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - interrupts
>> +  - clocks
>> +  - clock-names
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +
>> +    rtc@40060000 {
>> +        compatible = "nxp,s32g3-rtc",
>> +                   "nxp,s32g2-rtc";
> 
> align to previous line "
> 

I will update this alignment in V5.

>> +        reg = <0x40060000 0x1000>;
>> +        interrupts = <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>;
>> +        clocks = <&clks 54>, <&clks 56>, <&clks 55>;
>> +        clock-names = "ipg",
>> +            "rtc_runtime_s2",
>> +            "rtc_standby_s0";
> 
> align to previous line "

I will update this alignment in V5.


Best Regards,
Ciprian

> 
>> +    };
>> --
>> 2.45.2
>>

Re: [PATCH v4 1/4] dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs

[Conor Dooley]

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On Mon, Nov 11, 2024 at 03:59:37PM +0200, Ciprian Costea wrote:
> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> 
> RTC tracks clock time during system suspend and it is used as a wakeup
> source on S32G2/S32G3 architecture.
> 
> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
> during system reset.
> 
> Co-developed-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
> Signed-off-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@nxp.com>
> Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> ---
>  .../devicetree/bindings/rtc/nxp,s32g-rtc.yaml | 78 +++++++++++++++++++
>  1 file changed, 78 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
> new file mode 100644
> index 000000000000..231811579e1b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
> @@ -0,0 +1,78 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/nxp,s32g-rtc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP S32G2/S32G3 Real Time Clock (RTC)
> +
> +maintainers:
> +  - Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> +  - Ciprian Marian Costea <ciprianmarian.costea@nxp.com>
> +
> +description:
> +  RTC hardware module present on S32G2/S32G3 SoCs is used as a wakeup
> +  source. It is not kept alive during system reset and it is not
> +  battery-powered.
> +
> +  RTC hardware module contains a hardware mux with 4 entries/inputs
> +  for clock source selection. On S32G2/S32G3 SoCs, this mux is used
> +  to select between a clock source for runtime which brings more
> +  precision but is not available during system standby, and a clock
> +  source for suspend state.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - enum:
> +          - nxp,s32g2-rtc
> +      - items:
> +          - const: nxp,s32g3-rtc
> +          - const: nxp,s32g2-rtc
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    minItems: 2
> +    items:
> +      - description: ipg clock drives the access to the
> +          RTC iomapped registers
> +      - description: Runtime clock source. It must be a clock
> +          source for the RTC module. It will be disabled by hardware
> +          during Standby/Suspend.
> +      - description: Standby/Suspend clock source. It is optional
> +          and can be used in case the RTC will continue ticking during
> +          platform/system suspend.
> +
> +  clock-names:
> +    minItems: 2
> +    maxItems: 3

You actually have to provide the clock-names, otherwise you can't rely
on them

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Re: [PATCH v4 1/4] dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs

[Conor Dooley]

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On Mon, Nov 11, 2024 at 08:05:50PM +0000, Conor Dooley wrote:
> On Mon, Nov 11, 2024 at 03:59:37PM +0200, Ciprian Costea wrote:
> > +  clock-names:
> > +    minItems: 2
> > +    maxItems: 3
> 
> You actually have to provide the clock-names, otherwise you can't rely
> on them

Oh, and drop the "rtc_" prefix while you're at it.

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Re: [PATCH v4 1/4] dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs

[Ciprian Marian Costea]

On 11/11/2024 10:06 PM, Conor Dooley wrote:
> On Mon, Nov 11, 2024 at 08:05:50PM +0000, Conor Dooley wrote:
>> On Mon, Nov 11, 2024 at 03:59:37PM +0200, Ciprian Costea wrote:
>>> +  clock-names:
>>> +    minItems: 2
>>> +    maxItems: 3
>>
>> You actually have to provide the clock-names, otherwise you can't rely
>> on them
> 
> Oh, and drop the "rtc_" prefix while you're at it.

Hi Conor,

Thanks for taking time and reviewing this patchset.
I will list the actual clock-names and remove the 'rtc_' prefix in V5.

Best Regards,
Ciprian

[PATCH v4 2/4] rtc: s32g: add NXP S32G2/S32G3 SoC support

[Ciprian Costea]

From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

Add a RTC driver for NXP S32G2/S32G3 SoCs.

The RTC module is used to enable Suspend to RAM (STR) support on NXP
S32G2/S32G3 SoC based boards.

RTC tracks clock time during system suspend.

RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
during system reset.

Co-developed-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
Co-developed-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
---
 drivers/rtc/Kconfig    |  11 +
 drivers/rtc/Makefile   |   1 +
 drivers/rtc/rtc-s32g.c | 692 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 704 insertions(+)
 create mode 100644 drivers/rtc/rtc-s32g.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e87c3d74565c..18fc3577f6cd 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -2054,4 +2054,15 @@ config RTC_DRV_SSD202D
 	  This driver can also be built as a module, if so, the module
 	  will be called "rtc-ssd20xd".
 
+config RTC_DRV_S32G
+	tristate "RTC driver for S32G2/S32G3 SoCs"
+	depends on ARCH_S32 || COMPILE_TEST
+	depends on COMMON_CLK
+	help
+	  Say yes to enable RTC driver for platforms based on the
+	  S32G2/S32G3 SoC family.
+
+	  This RTC module can be used as a wakeup source.
+	  Please note that it is not battery-powered.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 8ee79cb18322..a63d010a753c 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
 obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
 obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
 obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
+obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
 obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
 obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
 obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
new file mode 100644
index 000000000000..c3792b674a18
--- /dev/null
+++ b/drivers/rtc/rtc-s32g.c
@@ -0,0 +1,692 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2024 NXP
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/iopoll.h>
+#include <linux/math64.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define RTCC_OFFSET	0x4ul
+#define RTCS_OFFSET	0x8ul
+#define RTCCNT_OFFSET	0xCul
+#define APIVAL_OFFSET	0x10ul
+#define RTCVAL_OFFSET	0x14ul
+
+/* RTCC fields */
+#define RTCC_CNTEN				BIT(31)
+#define RTCC_RTCIE_SHIFT		30
+#define RTCC_RTCIE				BIT(RTCC_RTCIE_SHIFT)
+#define RTCC_ROVREN				BIT(28)
+#define RTCC_APIEN				BIT(15)
+#define RTCC_APIIE				BIT(14)
+#define RTCC_CLKSEL_OFFSET		12
+#define RTCC_CLKSEL_MASK		GENMASK(13, 12)
+#define RTCC_CLKSEL(n)			(((n) << 12) & RTCC_CLKSEL_MASK)
+#define RTCC_DIV512EN			BIT(11)
+#define RTCC_DIV32EN			BIT(10)
+
+/* RTCS fields */
+#define RTCS_RTCF		BIT(29)
+#define RTCS_INV_RTC		BIT(18)
+#define RTCS_APIF		BIT(13)
+#define RTCS_ROVRF		BIT(10)
+
+#define ROLLOVER_VAL		GENMASK(31, 0)
+#define RTC_SYNCH_TIMEOUT	(100 * USEC_PER_MSEC)
+
+#define RTC_CLK_MUX_SIZE	4
+
+/*
+ * S32G2 and S32G3 SoCs have RTC clock source 1 reserved and
+ * should not be used.
+ */
+#define RTC_QUIRK_SRC1_RESERVED			BIT(2)
+
+enum {
+	RTC_CLK_SRC0,
+	RTC_CLK_SRC1,
+	RTC_CLK_SRC2,
+	RTC_CLK_SRC3
+};
+
+enum {
+	DIV1 = 1,
+	DIV32 = 32,
+	DIV512 = 512,
+	DIV512_32 = 16384
+};
+
+static const char *rtc_clk_src[RTC_CLK_MUX_SIZE * 2] = {
+	"rtc_runtime_s0",
+	"rtc_runtime_s1",
+	"rtc_runtime_s2",
+	"rtc_runtime_s3",
+	"rtc_standby_s0",
+	"rtc_standby_s1",
+	"rtc_standby_s2",
+	"rtc_standby_s3"
+};
+
+struct rtc_time_base {
+	s64 sec;
+	u64 cycles;
+	u64 rollovers;
+	struct rtc_time tm;
+};
+
+struct rtc_priv {
+	struct rtc_device *rdev;
+	void __iomem *rtc_base;
+	struct clk *ipg;
+	struct clk *runtime_clk;
+	struct clk *suspend_clk;
+	const struct rtc_soc_data *rtc_data;
+	struct rtc_time_base base;
+	u64 rtc_hz;
+	u64 rollovers;
+	int dt_irq_id;
+	int runtime_src_idx;
+	int suspend_src_idx;
+};
+
+struct rtc_soc_data {
+	u32 runtime_div;
+	u32 suspend_div;
+	u32 quirks;
+};
+
+static const struct rtc_soc_data rtc_s32g2_data = {
+	.runtime_div = DIV512,
+	.suspend_div = DIV512,
+	.quirks = RTC_QUIRK_SRC1_RESERVED,
+};
+
+static int is_src1_reserved(struct rtc_priv *priv)
+{
+	return priv->rtc_data->quirks & RTC_QUIRK_SRC1_RESERVED;
+}
+
+static u64 cycles_to_sec(u64 hz, u64 cycles)
+{
+	return div_u64(cycles, hz);
+}
+
+/**
+ * Convert a number of seconds to a value suitable for RTCVAL in our clock's
+ * current configuration.
+ * @rtcval: The value to go into RTCVAL[RTCVAL]
+ * Returns: 0 for success, -EINVAL if @seconds push the counter at least
+ *          twice the rollover interval
+ */
+static int sec_to_rtcval(const struct rtc_priv *priv,
+			 unsigned long seconds, u32 *rtcval)
+{
+	u32 rtccnt, delta_cnt;
+	u32 target_cnt = 0;
+
+	/* For now, support at most one rollover of the counter */
+	if (!seconds || seconds > cycles_to_sec(priv->rtc_hz, ROLLOVER_VAL))
+		return -EINVAL;
+
+	/*
+	 * RTCCNT is read-only; we must return a value relative to the
+	 * current value of the counter (and hope we don't linger around
+	 * too much before we get to enable the interrupt)
+	 */
+	delta_cnt = seconds * priv->rtc_hz;
+	rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
+
+	if (~rtccnt < delta_cnt)
+		target_cnt = (delta_cnt - ~rtccnt);
+	else
+		target_cnt = rtccnt + delta_cnt;
+
+	/*
+	 * According to RTCVAL register description,
+	 * its minimum value should be 4.
+	 */
+	if (unlikely(target_cnt < 4))
+		target_cnt = 4;
+
+	*rtcval = target_cnt;
+
+	return 0;
+}
+
+static irqreturn_t rtc_handler(int irq, void *dev)
+{
+	struct rtc_priv *priv = platform_get_drvdata(dev);
+	u32 status;
+
+	status = ioread32(priv->rtc_base + RTCS_OFFSET);
+	if (status & RTCS_ROVRF) {
+		if (priv->rollovers == ULONG_MAX)
+			priv->rollovers = 0;
+		else
+			priv->rollovers++;
+	}
+
+	if (status & RTCS_RTCF) {
+		iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
+		rtc_update_irq(priv->rdev, 1, RTC_AF);
+	}
+
+	if (status & RTCS_APIF)
+		rtc_update_irq(priv->rdev, 1, RTC_PF);
+
+	iowrite32(status, priv->rtc_base + RTCS_OFFSET);
+
+	return IRQ_HANDLED;
+}
+
+static int get_time_left(struct device *dev, struct rtc_priv *priv,
+			 u32 *sec)
+{
+	u32 rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
+	u32 rtcval = ioread32(priv->rtc_base + RTCVAL_OFFSET);
+
+	if (rtcval < rtccnt) {
+		dev_err(dev, "RTC timer expired before entering suspend\n");
+		return -EIO;
+	}
+
+	*sec = cycles_to_sec(priv->rtc_hz, rtcval - rtccnt);
+
+	return 0;
+}
+
+static s64 s32g_rtc_get_time_or_alrm(struct rtc_priv *priv,
+				     u32 offset)
+{
+	u64 cycles, base_cycles;
+	u32 counter;
+	s64 sec;
+
+	counter = ioread32(priv->rtc_base + offset);
+	cycles = priv->rollovers * ROLLOVER_VAL + counter;
+	base_cycles = priv->base.cycles + priv->base.rollovers * ROLLOVER_VAL;
+
+	if (cycles < base_cycles)
+		return -EINVAL;
+
+	cycles -= base_cycles;
+	sec = priv->base.sec + cycles_to_sec(priv->rtc_hz, cycles);
+
+	return sec;
+}
+
+static int s32g_rtc_read_time(struct device *dev,
+			      struct rtc_time *tm)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+	s64 sec;
+
+	if (!tm)
+		return -EINVAL;
+
+	sec = s32g_rtc_get_time_or_alrm(priv, RTCCNT_OFFSET);
+	if (sec < 0)
+		return -EINVAL;
+
+	rtc_time64_to_tm(sec, tm);
+
+	return 0;
+}
+
+static int s32g_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+	u32 rtcc, sec_left;
+	s64 sec;
+
+	if (!alrm)
+		return -EINVAL;
+
+	sec = s32g_rtc_get_time_or_alrm(priv, RTCVAL_OFFSET);
+	if (sec < 0)
+		return -EINVAL;
+
+	rtc_time64_to_tm(sec, &alrm->time);
+
+	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
+	alrm->enabled = sec && (rtcc & RTCC_RTCIE);
+
+	alrm->pending = 0;
+	if (alrm->enabled && !get_time_left(dev, priv, &sec_left))
+		alrm->pending = !!sec_left;
+
+	return 0;
+}
+
+static int s32g_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+	u32 rtcc;
+
+	if (!priv->dt_irq_id)
+		return -EIO;
+
+	/*
+	 * RTCIE cannot be deasserted because it will also disable the
+	 * rollover interrupt.
+	 */
+	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
+	if (enabled)
+		rtcc |= RTCC_RTCIE;
+
+	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
+
+	return 0;
+}
+
+static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+	struct rtc_time time_crt;
+	long long t_crt, t_alrm;
+	u32 rtcval, rtcs;
+	int ret = 0;
+
+	iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
+
+	t_alrm = rtc_tm_to_time64(&alrm->time);
+
+	/*
+	 * Assuming the alarm is being set relative to the same time
+	 * returned by our s32g_rtc_read_time callback
+	 */
+	ret = s32g_rtc_read_time(dev, &time_crt);
+	if (ret)
+		return ret;
+
+	t_crt = rtc_tm_to_time64(&time_crt);
+	if (t_alrm <= t_crt) {
+		dev_warn(dev, "Alarm is set in the past\n");
+		return -EINVAL;
+	}
+
+	ret = sec_to_rtcval(priv, t_alrm - t_crt, &rtcval);
+	if (ret) {
+		/*
+		 * Rollover support enables RTC alarm
+		 * for a maximum timespan of ~3 months.
+		 */
+		dev_warn(dev, "Alarm is set too far in the future\n");
+		return ret;
+	}
+
+	ret = read_poll_timeout(ioread32, rtcs, !(rtcs & RTCS_INV_RTC),
+				0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
+	if (ret) {
+		dev_err(dev, "Synchronization failed\n");
+		return ret;
+	}
+
+	iowrite32(rtcval, priv->rtc_base + RTCVAL_OFFSET);
+
+	return 0;
+}
+
+static int s32g_rtc_set_time(struct device *dev,
+			     struct rtc_time *time)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+
+	if (!time)
+		return -EINVAL;
+
+	priv->base.rollovers = priv->rollovers;
+	priv->base.cycles = ioread32(priv->rtc_base + RTCCNT_OFFSET);
+	priv->base.sec = rtc_tm_to_time64(time);
+
+	return 0;
+}
+
+/*
+ * Disable the 32-bit free running counter.
+ * This allows Clock Source and Divisors selection
+ * to be performed without causing synchronization issues.
+ */
+static void s32g_rtc_disable(struct rtc_priv *priv)
+{
+	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
+
+	rtcc &= ~RTCC_CNTEN;
+	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
+}
+
+static void s32g_rtc_enable(struct rtc_priv *priv)
+{
+	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
+
+	rtcc |= RTCC_CNTEN;
+	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
+}
+
+static void adjust_dividers(struct rtc_priv *priv,
+			    u32 div_val, u32 *reg)
+{
+	switch (div_val) {
+	case DIV512_32:
+		*reg |= RTCC_DIV512EN;
+		*reg |= RTCC_DIV32EN;
+		break;
+	case DIV512:
+		*reg |= RTCC_DIV512EN;
+		break;
+	case DIV32:
+		*reg |= RTCC_DIV32EN;
+		break;
+	default:
+		return;
+	}
+
+	priv->rtc_hz /= div_val;
+}
+
+static int rtc_get_clk_src(struct rtc_priv *priv)
+{
+	return (ioread32(priv->rtc_base + RTCC_OFFSET) &
+			RTCC_CLKSEL_MASK) >> RTCC_CLKSEL_OFFSET;
+}
+
+static int rtc_clk_src_switch(struct rtc_priv *priv, u32 src)
+{
+	struct device *dev = priv->rdev->dev.parent;
+	u32 rtcc = 0;
+
+	switch (src % RTC_CLK_MUX_SIZE) {
+	case RTC_CLK_SRC0:
+		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC0);
+		break;
+	case RTC_CLK_SRC1:
+		if (is_src1_reserved(priv))
+			return -EOPNOTSUPP;
+		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC1);
+		break;
+	case RTC_CLK_SRC2:
+		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC2);
+		break;
+	case RTC_CLK_SRC3:
+		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC3);
+		break;
+	default:
+		dev_err(dev, "Invalid clock mux parent: %d\n", src);
+		return -EINVAL;
+	}
+
+	if (src < RTC_CLK_MUX_SIZE) {
+		priv->rtc_hz = clk_get_rate(priv->runtime_clk);
+		if (!priv->rtc_hz) {
+			dev_err(dev, "Failed to get RTC frequency\n");
+			return -EINVAL;
+		}
+		adjust_dividers(priv, priv->rtc_data->runtime_div, &rtcc);
+	} else {
+		priv->rtc_hz = clk_get_rate(priv->suspend_clk);
+		if (!priv->rtc_hz) {
+			dev_err(dev, "Failed to get RTC frequency\n");
+			return -EINVAL;
+		}
+		adjust_dividers(priv, priv->rtc_data->suspend_div, &rtcc);
+	}
+
+	rtcc |= RTCC_RTCIE | RTCC_ROVREN;
+	/*
+	 * Make sure the CNTEN is 0 before we configure
+	 * the clock source and dividers.
+	 */
+	s32g_rtc_disable(priv);
+	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
+	s32g_rtc_enable(priv);
+
+	return 0;
+}
+
+static const struct rtc_class_ops rtc_ops = {
+	.read_time = s32g_rtc_read_time,
+	.set_time = s32g_rtc_set_time,
+	.read_alarm = s32g_rtc_read_alarm,
+	.set_alarm = s32g_rtc_set_alarm,
+	.alarm_irq_enable = s32g_rtc_alarm_irq_enable,
+};
+
+static int rtc_clk_dts_setup(struct rtc_priv *priv,
+			     struct device *dev)
+{
+	int i;
+
+	priv->runtime_src_idx = -EINVAL;
+	priv->suspend_src_idx = -EINVAL;
+
+	priv->ipg = devm_clk_get_enabled(dev, "ipg");
+	if (IS_ERR(priv->ipg)) {
+		dev_err(dev, "Failed to get 'ipg' clock\n");
+		return PTR_ERR(priv->ipg);
+	}
+
+	/* Get RTC runtime clock source */
+	for (i = 0; i < RTC_CLK_MUX_SIZE; i++) {
+		priv->runtime_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
+		if (!IS_ERR(priv->runtime_clk)) {
+			priv->runtime_src_idx = i;
+			break;
+		}
+	}
+
+	if (IS_ERR(priv->runtime_clk)) {
+		dev_err(dev, "Failed to get runtime rtc clock\n");
+		return PTR_ERR(priv->runtime_clk);
+	}
+
+	/* If present, get RTC suspend clock source */
+	for (i = RTC_CLK_MUX_SIZE; i < RTC_CLK_MUX_SIZE * 2; i++) {
+		priv->suspend_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
+		if (!IS_ERR(priv->suspend_clk)) {
+			priv->suspend_src_idx = i;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int rtc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rtc_priv *priv;
+	int ret = 0;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->rtc_data = of_device_get_match_data(dev);
+	if (!priv->rtc_data)
+		return -ENODEV;
+
+	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->rtc_base))
+		return dev_err_probe(dev, PTR_ERR(priv->rtc_base),
+				"Failed to map registers\n");
+
+	device_init_wakeup(dev, true);
+
+	ret = rtc_clk_dts_setup(priv, dev);
+	if (ret)
+		return ret;
+
+	priv->rdev = devm_rtc_allocate_device(dev);
+	if (IS_ERR(priv->rdev))
+		return dev_err_probe(dev, PTR_ERR(priv->rdev),
+				"Failed to allocate RTC device\n");
+
+	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				"Failed clk source switch, err: %d\n", ret);
+
+	platform_set_drvdata(pdev, priv);
+	priv->rdev->ops = &rtc_ops;
+
+	ret = devm_rtc_register_device(priv->rdev);
+	if (ret) {
+		dev_err(dev, "Failed to register RTC device\n");
+		goto disable_rtc;
+	}
+
+	priv->dt_irq_id = platform_get_irq(pdev, 0);
+	if (priv->dt_irq_id < 0)
+		return dev_err_probe(dev, priv->dt_irq_id,
+				"Error reading interrupt # from dts\n");
+
+	ret = devm_request_irq(dev, priv->dt_irq_id,
+			       rtc_handler, 0, dev_name(dev), pdev);
+	if (ret) {
+		dev_err(dev, "Request interrupt %d failed, error: %d\n",
+			priv->dt_irq_id, ret);
+		goto disable_rtc;
+	}
+
+	return 0;
+
+disable_rtc:
+	s32g_rtc_disable(priv);
+	return ret;
+}
+
+static void rtc_remove(struct platform_device *pdev)
+{
+	struct rtc_priv *priv = platform_get_drvdata(pdev);
+
+	s32g_rtc_disable(priv);
+}
+
+static void  __maybe_unused enable_api_irq(struct device *dev, unsigned int enabled)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+	u32 api_irq = RTCC_APIEN | RTCC_APIIE;
+	u32 rtcc;
+
+	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
+	if (enabled)
+		rtcc |= api_irq;
+	else
+		rtcc &= ~api_irq;
+	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
+}
+
+static int __maybe_unused rtc_suspend(struct device *dev)
+{
+	struct rtc_priv *init_priv = dev_get_drvdata(dev);
+	struct rtc_priv priv;
+	long long base_sec;
+	int ret = 0;
+	u32 rtcval;
+	u32 sec;
+
+	if (!device_may_wakeup(dev))
+		return 0;
+
+	if (init_priv->suspend_src_idx < 0)
+		return 0;
+
+	if (rtc_get_clk_src(init_priv) + RTC_CLK_MUX_SIZE ==
+			init_priv->suspend_src_idx)
+		return 0;
+
+	/* Save last known timestamp before we switch clocks and reinit RTC */
+	ret = s32g_rtc_read_time(dev, &init_priv->base.tm);
+	if (ret)
+		return ret;
+
+	/*
+	 * Use a local copy of the RTC control block to
+	 * avoid restoring it on resume path.
+	 */
+	memcpy(&priv, init_priv, sizeof(priv));
+
+	ret = get_time_left(dev, init_priv, &sec);
+	if (ret)
+		return ret;
+
+	/* Adjust for the number of seconds we'll be asleep */
+	base_sec = rtc_tm_to_time64(&init_priv->base.tm);
+	base_sec += sec;
+	rtc_time64_to_tm(base_sec, &init_priv->base.tm);
+
+	ret = rtc_clk_src_switch(&priv, priv.suspend_src_idx);
+	if (ret) {
+		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
+		return ret;
+	}
+
+	ret = sec_to_rtcval(&priv, sec, &rtcval);
+	if (ret) {
+		dev_warn(dev, "Alarm is too far in the future\n");
+		return ret;
+	}
+
+	s32g_rtc_alarm_irq_enable(dev, 0);
+	enable_api_irq(dev, 1);
+	iowrite32(rtcval, priv.rtc_base + APIVAL_OFFSET);
+	iowrite32(0, priv.rtc_base + RTCVAL_OFFSET);
+
+	return ret;
+}
+
+static int __maybe_unused rtc_resume(struct device *dev)
+{
+	struct rtc_priv *priv = dev_get_drvdata(dev);
+	int ret;
+
+	if (!device_may_wakeup(dev))
+		return 0;
+
+	if (rtc_get_clk_src(priv) == priv->runtime_src_idx)
+		return 0;
+
+	/* Disable wake-up interrupts */
+	enable_api_irq(dev, 0);
+
+	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
+	if (ret) {
+		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Now RTCCNT has just been reset, and is out of sync with priv->base;
+	 * reapply the saved time settings
+	 */
+	return s32g_rtc_set_time(dev, &priv->base.tm);
+}
+
+static const struct of_device_id rtc_dt_ids[] = {
+	{ .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data},
+	{ /* sentinel */ },
+};
+
+static SIMPLE_DEV_PM_OPS(rtc_pm_ops,
+			 rtc_suspend, rtc_resume);
+
+static struct platform_driver rtc_driver = {
+	.driver		= {
+		.name			= "s32g-rtc",
+		.pm				= &rtc_pm_ops,
+		.of_match_table = rtc_dt_ids,
+	},
+	.probe		= rtc_probe,
+	.remove	= rtc_remove,
+};
+module_platform_driver(rtc_driver);
+
+MODULE_AUTHOR("NXP");
+MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
+MODULE_LICENSE("GPL");
-- 
2.45.2

Re: [PATCH v4 2/4] rtc: s32g: add NXP S32G2/S32G3 SoC support

[Frank Li]

On Mon, Nov 11, 2024 at 03:59:38PM +0200, Ciprian Costea wrote:
> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>
> Add a RTC driver for NXP S32G2/S32G3 SoCs.
>
> The RTC module is used to enable Suspend to RAM (STR) support on NXP
> S32G2/S32G3 SoC based boards.

Why suspend to RAM related RTC module?

>
> RTC tracks clock time during system suspend.
>
> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
> during system reset.
>
> Co-developed-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> Co-developed-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> ---
>  drivers/rtc/Kconfig    |  11 +
>  drivers/rtc/Makefile   |   1 +
>  drivers/rtc/rtc-s32g.c | 692 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 704 insertions(+)
>  create mode 100644 drivers/rtc/rtc-s32g.c
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index e87c3d74565c..18fc3577f6cd 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -2054,4 +2054,15 @@ config RTC_DRV_SSD202D
>  	  This driver can also be built as a module, if so, the module
>  	  will be called "rtc-ssd20xd".
>
> +config RTC_DRV_S32G
> +	tristate "RTC driver for S32G2/S32G3 SoCs"
> +	depends on ARCH_S32 || COMPILE_TEST
> +	depends on COMMON_CLK
> +	help
> +	  Say yes to enable RTC driver for platforms based on the
> +	  S32G2/S32G3 SoC family.
> +
> +	  This RTC module can be used as a wakeup source.
> +	  Please note that it is not battery-powered.
> +
>  endif # RTC_CLASS
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 8ee79cb18322..a63d010a753c 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
>  obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
>  obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
>  obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
> +obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
>  obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
>  obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
>  obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
> diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
> new file mode 100644
> index 000000000000..c3792b674a18
> --- /dev/null
> +++ b/drivers/rtc/rtc-s32g.c
> @@ -0,0 +1,692 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/iopoll.h>
> +#include <linux/math64.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/rtc.h>
> +
> +#define RTCC_OFFSET	0x4ul
> +#define RTCS_OFFSET	0x8ul
> +#define RTCCNT_OFFSET	0xCul
> +#define APIVAL_OFFSET	0x10ul
> +#define RTCVAL_OFFSET	0x14ul
> +
> +/* RTCC fields */
> +#define RTCC_CNTEN				BIT(31)
> +#define RTCC_RTCIE_SHIFT		30
> +#define RTCC_RTCIE				BIT(RTCC_RTCIE_SHIFT)
> +#define RTCC_ROVREN				BIT(28)
> +#define RTCC_APIEN				BIT(15)
> +#define RTCC_APIIE				BIT(14)
> +#define RTCC_CLKSEL_OFFSET		12
> +#define RTCC_CLKSEL_MASK		GENMASK(13, 12)
> +#define RTCC_CLKSEL(n)			(((n) << 12) & RTCC_CLKSEL_MASK)
> +#define RTCC_DIV512EN			BIT(11)
> +#define RTCC_DIV32EN			BIT(10)
> +
> +/* RTCS fields */
> +#define RTCS_RTCF		BIT(29)
> +#define RTCS_INV_RTC		BIT(18)
> +#define RTCS_APIF		BIT(13)
> +#define RTCS_ROVRF		BIT(10)
> +
> +#define ROLLOVER_VAL		GENMASK(31, 0)
> +#define RTC_SYNCH_TIMEOUT	(100 * USEC_PER_MSEC)
> +
> +#define RTC_CLK_MUX_SIZE	4
> +
> +/*
> + * S32G2 and S32G3 SoCs have RTC clock source 1 reserved and
> + * should not be used.
> + */
> +#define RTC_QUIRK_SRC1_RESERVED			BIT(2)
> +
> +enum {
> +	RTC_CLK_SRC0,
> +	RTC_CLK_SRC1,
> +	RTC_CLK_SRC2,
> +	RTC_CLK_SRC3
> +};
> +
> +enum {
> +	DIV1 = 1,
> +	DIV32 = 32,
> +	DIV512 = 512,
> +	DIV512_32 = 16384
> +};
> +
> +static const char *rtc_clk_src[RTC_CLK_MUX_SIZE * 2] = {
> +	"rtc_runtime_s0",
> +	"rtc_runtime_s1",
> +	"rtc_runtime_s2",
> +	"rtc_runtime_s3",
> +	"rtc_standby_s0",
> +	"rtc_standby_s1",
> +	"rtc_standby_s2",
> +	"rtc_standby_s3"
> +};
> +
> +struct rtc_time_base {
> +	s64 sec;
> +	u64 cycles;
> +	u64 rollovers;
> +	struct rtc_time tm;
> +};
> +
> +struct rtc_priv {
> +	struct rtc_device *rdev;
> +	void __iomem *rtc_base;
> +	struct clk *ipg;
> +	struct clk *runtime_clk;
> +	struct clk *suspend_clk;
> +	const struct rtc_soc_data *rtc_data;
> +	struct rtc_time_base base;
> +	u64 rtc_hz;
> +	u64 rollovers;
> +	int dt_irq_id;
> +	int runtime_src_idx;
> +	int suspend_src_idx;
> +};
> +
> +struct rtc_soc_data {
> +	u32 runtime_div;
> +	u32 suspend_div;
> +	u32 quirks;
> +};
> +
> +static const struct rtc_soc_data rtc_s32g2_data = {
> +	.runtime_div = DIV512,
> +	.suspend_div = DIV512,
> +	.quirks = RTC_QUIRK_SRC1_RESERVED,
> +};
> +
> +static int is_src1_reserved(struct rtc_priv *priv)
> +{
> +	return priv->rtc_data->quirks & RTC_QUIRK_SRC1_RESERVED;
> +}
> +
> +static u64 cycles_to_sec(u64 hz, u64 cycles)
> +{
> +	return div_u64(cycles, hz);
> +}
> +
> +/**
> + * Convert a number of seconds to a value suitable for RTCVAL in our clock's
> + * current configuration.
> + * @rtcval: The value to go into RTCVAL[RTCVAL]
> + * Returns: 0 for success, -EINVAL if @seconds push the counter at least
> + *          twice the rollover interval
> + */
> +static int sec_to_rtcval(const struct rtc_priv *priv,
> +			 unsigned long seconds, u32 *rtcval)
> +{
> +	u32 rtccnt, delta_cnt;
> +	u32 target_cnt = 0;
> +
> +	/* For now, support at most one rollover of the counter */
> +	if (!seconds || seconds > cycles_to_sec(priv->rtc_hz, ROLLOVER_VAL))
> +		return -EINVAL;
> +
> +	/*
> +	 * RTCCNT is read-only; we must return a value relative to the
> +	 * current value of the counter (and hope we don't linger around
> +	 * too much before we get to enable the interrupt)
> +	 */
> +	delta_cnt = seconds * priv->rtc_hz;
> +	rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> +
> +	if (~rtccnt < delta_cnt)
> +		target_cnt = (delta_cnt - ~rtccnt);
> +	else
> +		target_cnt = rtccnt + delta_cnt;
> +
> +	/*
> +	 * According to RTCVAL register description,
> +	 * its minimum value should be 4.
> +	 */
> +	if (unlikely(target_cnt < 4))
> +		target_cnt = 4;
> +
> +	*rtcval = target_cnt;
> +
> +	return 0;
> +}
> +
> +static irqreturn_t rtc_handler(int irq, void *dev)
> +{
> +	struct rtc_priv *priv = platform_get_drvdata(dev);
> +	u32 status;
> +
> +	status = ioread32(priv->rtc_base + RTCS_OFFSET);
> +	if (status & RTCS_ROVRF) {
> +		if (priv->rollovers == ULONG_MAX)
> +			priv->rollovers = 0;
> +		else
> +			priv->rollovers++;
> +	}
> +
> +	if (status & RTCS_RTCF) {
> +		iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
> +		rtc_update_irq(priv->rdev, 1, RTC_AF);
> +	}
> +
> +	if (status & RTCS_APIF)
> +		rtc_update_irq(priv->rdev, 1, RTC_PF);
> +
> +	iowrite32(status, priv->rtc_base + RTCS_OFFSET);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int get_time_left(struct device *dev, struct rtc_priv *priv,
> +			 u32 *sec)
> +{
> +	u32 rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> +	u32 rtcval = ioread32(priv->rtc_base + RTCVAL_OFFSET);
> +
> +	if (rtcval < rtccnt) {
> +		dev_err(dev, "RTC timer expired before entering suspend\n");
> +		return -EIO;
> +	}
> +
> +	*sec = cycles_to_sec(priv->rtc_hz, rtcval - rtccnt);
> +
> +	return 0;
> +}
> +
> +static s64 s32g_rtc_get_time_or_alrm(struct rtc_priv *priv,
> +				     u32 offset)
> +{
> +	u64 cycles, base_cycles;
> +	u32 counter;
> +	s64 sec;
> +
> +	counter = ioread32(priv->rtc_base + offset);
> +	cycles = priv->rollovers * ROLLOVER_VAL + counter;
> +	base_cycles = priv->base.cycles + priv->base.rollovers * ROLLOVER_VAL;
> +
> +	if (cycles < base_cycles)
> +		return -EINVAL;
> +
> +	cycles -= base_cycles;
> +	sec = priv->base.sec + cycles_to_sec(priv->rtc_hz, cycles);
> +
> +	return sec;
> +}
> +
> +static int s32g_rtc_read_time(struct device *dev,
> +			      struct rtc_time *tm)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	s64 sec;
> +
> +	if (!tm)
> +		return -EINVAL;
> +
> +	sec = s32g_rtc_get_time_or_alrm(priv, RTCCNT_OFFSET);
> +	if (sec < 0)
> +		return -EINVAL;
> +
> +	rtc_time64_to_tm(sec, tm);
> +
> +	return 0;
> +}
> +
> +static int s32g_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	u32 rtcc, sec_left;
> +	s64 sec;
> +
> +	if (!alrm)
> +		return -EINVAL;
> +
> +	sec = s32g_rtc_get_time_or_alrm(priv, RTCVAL_OFFSET);
> +	if (sec < 0)
> +		return -EINVAL;
> +
> +	rtc_time64_to_tm(sec, &alrm->time);
> +
> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +	alrm->enabled = sec && (rtcc & RTCC_RTCIE);
> +
> +	alrm->pending = 0;
> +	if (alrm->enabled && !get_time_left(dev, priv, &sec_left))
> +		alrm->pending = !!sec_left;
> +
> +	return 0;
> +}
> +
> +static int s32g_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	u32 rtcc;
> +
> +	if (!priv->dt_irq_id)
> +		return -EIO;
> +
> +	/*
> +	 * RTCIE cannot be deasserted because it will also disable the
> +	 * rollover interrupt.
> +	 */
> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +	if (enabled)
> +		rtcc |= RTCC_RTCIE;
> +
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +
> +	return 0;
> +}
> +
> +static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	struct rtc_time time_crt;
> +	long long t_crt, t_alrm;
> +	u32 rtcval, rtcs;
> +	int ret = 0;
> +
> +	iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
> +
> +	t_alrm = rtc_tm_to_time64(&alrm->time);
> +
> +	/*
> +	 * Assuming the alarm is being set relative to the same time
> +	 * returned by our s32g_rtc_read_time callback
> +	 */
> +	ret = s32g_rtc_read_time(dev, &time_crt);
> +	if (ret)
> +		return ret;
> +
> +	t_crt = rtc_tm_to_time64(&time_crt);
> +	if (t_alrm <= t_crt) {
> +		dev_warn(dev, "Alarm is set in the past\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = sec_to_rtcval(priv, t_alrm - t_crt, &rtcval);
> +	if (ret) {
> +		/*
> +		 * Rollover support enables RTC alarm
> +		 * for a maximum timespan of ~3 months.
> +		 */
> +		dev_warn(dev, "Alarm is set too far in the future\n");
> +		return ret;
> +	}
> +
> +	ret = read_poll_timeout(ioread32, rtcs, !(rtcs & RTCS_INV_RTC),
> +				0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
> +	if (ret) {
> +		dev_err(dev, "Synchronization failed\n");
> +		return ret;
> +	}
> +
> +	iowrite32(rtcval, priv->rtc_base + RTCVAL_OFFSET);
> +
> +	return 0;
> +}
> +
> +static int s32g_rtc_set_time(struct device *dev,
> +			     struct rtc_time *time)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +
> +	if (!time)
> +		return -EINVAL;
> +
> +	priv->base.rollovers = priv->rollovers;
> +	priv->base.cycles = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> +	priv->base.sec = rtc_tm_to_time64(time);
> +
> +	return 0;
> +}
> +
> +/*
> + * Disable the 32-bit free running counter.
> + * This allows Clock Source and Divisors selection
> + * to be performed without causing synchronization issues.
> + */
> +static void s32g_rtc_disable(struct rtc_priv *priv)
> +{
> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +
> +	rtcc &= ~RTCC_CNTEN;
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +}
> +
> +static void s32g_rtc_enable(struct rtc_priv *priv)
> +{
> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +
> +	rtcc |= RTCC_CNTEN;
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +}
> +
> +static void adjust_dividers(struct rtc_priv *priv,
> +			    u32 div_val, u32 *reg)
> +{
> +	switch (div_val) {
> +	case DIV512_32:
> +		*reg |= RTCC_DIV512EN;
> +		*reg |= RTCC_DIV32EN;
> +		break;
> +	case DIV512:
> +		*reg |= RTCC_DIV512EN;
> +		break;
> +	case DIV32:
> +		*reg |= RTCC_DIV32EN;
> +		break;
> +	default:
> +		return;
> +	}
> +
> +	priv->rtc_hz /= div_val;
> +}
> +
> +static int rtc_get_clk_src(struct rtc_priv *priv)
> +{
> +	return (ioread32(priv->rtc_base + RTCC_OFFSET) &
> +			RTCC_CLKSEL_MASK) >> RTCC_CLKSEL_OFFSET;
> +}
> +
> +static int rtc_clk_src_switch(struct rtc_priv *priv, u32 src)
> +{
> +	struct device *dev = priv->rdev->dev.parent;
> +	u32 rtcc = 0;
> +
> +	switch (src % RTC_CLK_MUX_SIZE) {
> +	case RTC_CLK_SRC0:
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC0);
> +		break;
> +	case RTC_CLK_SRC1:
> +		if (is_src1_reserved(priv))
> +			return -EOPNOTSUPP;
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC1);
> +		break;
> +	case RTC_CLK_SRC2:
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC2);
> +		break;
> +	case RTC_CLK_SRC3:
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC3);
> +		break;
> +	default:
> +		dev_err(dev, "Invalid clock mux parent: %d\n", src);
> +		return -EINVAL;
> +	}
> +
> +	if (src < RTC_CLK_MUX_SIZE) {
> +		priv->rtc_hz = clk_get_rate(priv->runtime_clk);
> +		if (!priv->rtc_hz) {
> +			dev_err(dev, "Failed to get RTC frequency\n");
> +			return -EINVAL;
> +		}
> +		adjust_dividers(priv, priv->rtc_data->runtime_div, &rtcc);
> +	} else {
> +		priv->rtc_hz = clk_get_rate(priv->suspend_clk);
> +		if (!priv->rtc_hz) {
> +			dev_err(dev, "Failed to get RTC frequency\n");
> +			return -EINVAL;
> +		}
> +		adjust_dividers(priv, priv->rtc_data->suspend_div, &rtcc);
> +	}
> +
> +	rtcc |= RTCC_RTCIE | RTCC_ROVREN;
> +	/*
> +	 * Make sure the CNTEN is 0 before we configure
> +	 * the clock source and dividers.
> +	 */
> +	s32g_rtc_disable(priv);
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +	s32g_rtc_enable(priv);
> +
> +	return 0;
> +}
> +
> +static const struct rtc_class_ops rtc_ops = {
> +	.read_time = s32g_rtc_read_time,
> +	.set_time = s32g_rtc_set_time,
> +	.read_alarm = s32g_rtc_read_alarm,
> +	.set_alarm = s32g_rtc_set_alarm,
> +	.alarm_irq_enable = s32g_rtc_alarm_irq_enable,
> +};
> +
> +static int rtc_clk_dts_setup(struct rtc_priv *priv,
> +			     struct device *dev)
> +{
> +	int i;
> +
> +	priv->runtime_src_idx = -EINVAL;
> +	priv->suspend_src_idx = -EINVAL;
> +
> +	priv->ipg = devm_clk_get_enabled(dev, "ipg");

binding doc need document 'ipg'

> +	if (IS_ERR(priv->ipg)) {
> +		dev_err(dev, "Failed to get 'ipg' clock\n");
> +		return PTR_ERR(priv->ipg);
> +	}
> +
> +	/* Get RTC runtime clock source */
> +	for (i = 0; i < RTC_CLK_MUX_SIZE; i++) {
> +		priv->runtime_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
> +		if (!IS_ERR(priv->runtime_clk)) {
> +			priv->runtime_src_idx = i;
> +			break;
> +		}
> +	}
> +
> +	if (IS_ERR(priv->runtime_clk)) {
> +		dev_err(dev, "Failed to get runtime rtc clock\n");
> +		return PTR_ERR(priv->runtime_clk);

return  dev_err_proble()

> +	}
> +
> +	/* If present, get RTC suspend clock source */
> +	for (i = RTC_CLK_MUX_SIZE; i < RTC_CLK_MUX_SIZE * 2; i++) {
> +		priv->suspend_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
> +		if (!IS_ERR(priv->suspend_clk)) {
> +			priv->suspend_src_idx = i;
> +			break;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int rtc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct rtc_priv *priv;
> +	int ret = 0;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->rtc_data = of_device_get_match_data(dev);
> +	if (!priv->rtc_data)
> +		return -ENODEV;
> +
> +	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(priv->rtc_base))
> +		return dev_err_probe(dev, PTR_ERR(priv->rtc_base),
> +				"Failed to map registers\n");
> +
> +	device_init_wakeup(dev, true);
> +
> +	ret = rtc_clk_dts_setup(priv, dev);
> +	if (ret)
> +		return ret;
> +
> +	priv->rdev = devm_rtc_allocate_device(dev);
> +	if (IS_ERR(priv->rdev))
> +		return dev_err_probe(dev, PTR_ERR(priv->rdev),
> +				"Failed to allocate RTC device\n");
> +
> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
> +	if (ret)
> +		return dev_err_probe(dev, ret,
> +				"Failed clk source switch, err: %d\n", ret);
> +
> +	platform_set_drvdata(pdev, priv);
> +	priv->rdev->ops = &rtc_ops;
> +
> +	ret = devm_rtc_register_device(priv->rdev);
> +	if (ret) {
> +		dev_err(dev, "Failed to register RTC device\n");
> +		goto disable_rtc;
> +	}
> +
> +	priv->dt_irq_id = platform_get_irq(pdev, 0);
> +	if (priv->dt_irq_id < 0)
> +		return dev_err_probe(dev, priv->dt_irq_id,
> +				"Error reading interrupt # from dts\n");
> +
> +	ret = devm_request_irq(dev, priv->dt_irq_id,
> +			       rtc_handler, 0, dev_name(dev), pdev);
> +	if (ret) {
> +		dev_err(dev, "Request interrupt %d failed, error: %d\n",
> +			priv->dt_irq_id, ret);
> +		goto disable_rtc;
> +	}
> +
> +	return 0;
> +
> +disable_rtc:
> +	s32g_rtc_disable(priv);
> +	return ret;
> +}
> +
> +static void rtc_remove(struct platform_device *pdev)
> +{
> +	struct rtc_priv *priv = platform_get_drvdata(pdev);
> +
> +	s32g_rtc_disable(priv);
> +}
> +
> +static void  __maybe_unused enable_api_irq(struct device *dev, unsigned int enabled)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	u32 api_irq = RTCC_APIEN | RTCC_APIIE;
> +	u32 rtcc;
> +
> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +	if (enabled)
> +		rtcc |= api_irq;
> +	else
> +		rtcc &= ~api_irq;
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +}
> +
> +static int __maybe_unused rtc_suspend(struct device *dev)
> +{
> +	struct rtc_priv *init_priv = dev_get_drvdata(dev);
> +	struct rtc_priv priv;
> +	long long base_sec;
> +	int ret = 0;
> +	u32 rtcval;
> +	u32 sec;
> +
> +	if (!device_may_wakeup(dev))
> +		return 0;
> +
> +	if (init_priv->suspend_src_idx < 0)
> +		return 0;
> +
> +	if (rtc_get_clk_src(init_priv) + RTC_CLK_MUX_SIZE ==
> +			init_priv->suspend_src_idx)
> +		return 0;
> +
> +	/* Save last known timestamp before we switch clocks and reinit RTC */
> +	ret = s32g_rtc_read_time(dev, &init_priv->base.tm);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Use a local copy of the RTC control block to
> +	 * avoid restoring it on resume path.
> +	 */
> +	memcpy(&priv, init_priv, sizeof(priv));
> +
> +	ret = get_time_left(dev, init_priv, &sec);
> +	if (ret)
> +		return ret;
> +
> +	/* Adjust for the number of seconds we'll be asleep */
> +	base_sec = rtc_tm_to_time64(&init_priv->base.tm);
> +	base_sec += sec;
> +	rtc_time64_to_tm(base_sec, &init_priv->base.tm);
> +
> +	ret = rtc_clk_src_switch(&priv, priv.suspend_src_idx);
> +	if (ret) {
> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = sec_to_rtcval(&priv, sec, &rtcval);
> +	if (ret) {
> +		dev_warn(dev, "Alarm is too far in the future\n");
> +		return ret;
> +	}
> +
> +	s32g_rtc_alarm_irq_enable(dev, 0);
> +	enable_api_irq(dev, 1);
> +	iowrite32(rtcval, priv.rtc_base + APIVAL_OFFSET);
> +	iowrite32(0, priv.rtc_base + RTCVAL_OFFSET);
> +
> +	return ret;
> +}
> +
> +static int __maybe_unused rtc_resume(struct device *dev)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	int ret;
> +
> +	if (!device_may_wakeup(dev))
> +		return 0;
> +
> +	if (rtc_get_clk_src(priv) == priv->runtime_src_idx)
> +		return 0;
> +
> +	/* Disable wake-up interrupts */
> +	enable_api_irq(dev, 0);
> +
> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
> +	if (ret) {
> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/*
> +	 * Now RTCCNT has just been reset, and is out of sync with priv->base;
> +	 * reapply the saved time settings
> +	 */
> +	return s32g_rtc_set_time(dev, &priv->base.tm);
> +}
> +
> +static const struct of_device_id rtc_dt_ids[] = {
> +	{ .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data},
> +	{ /* sentinel */ },
> +};
> +
> +static SIMPLE_DEV_PM_OPS(rtc_pm_ops,
> +			 rtc_suspend, rtc_resume);
> +
> +static struct platform_driver rtc_driver = {
> +	.driver		= {
> +		.name			= "s32g-rtc",
> +		.pm				= &rtc_pm_ops,

pm_ptr(&rtc_pm_ops),

> +		.of_match_table = rtc_dt_ids,
> +	},
> +	.probe		= rtc_probe,
> +	.remove	= rtc_remove,
> +};
> +module_platform_driver(rtc_driver);
> +
> +MODULE_AUTHOR("NXP");
> +MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
> +MODULE_LICENSE("GPL");
> --
> 2.45.2
>

Re: [PATCH v4 2/4] rtc: s32g: add NXP S32G2/S32G3 SoC support

[Ciprian Marian Costea]

On 11/11/2024 6:07 PM, Frank Li wrote:
> On Mon, Nov 11, 2024 at 03:59:38PM +0200, Ciprian Costea wrote:
>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>
>> Add a RTC driver for NXP S32G2/S32G3 SoCs.
>>
>> The RTC module is used to enable Suspend to RAM (STR) support on NXP
>> S32G2/S32G3 SoC based boards.
> 
> Why suspend to RAM related RTC module?
> 

Hello Frank,

Here I was referring to the fact that the RTC module is used as a wakeup 
source from suspend state on S32G, thus enabling easy Suspend to RAM 
testing.

I will update the commit body accordingly for this patchset to remove 
this confusion in V5.

>>
>> RTC tracks clock time during system suspend.
>>
>> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
>> during system reset.
>>
>> Co-developed-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
>> Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
>> Co-developed-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
>> Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>> ---
>>   drivers/rtc/Kconfig    |  11 +
>>   drivers/rtc/Makefile   |   1 +
>>   drivers/rtc/rtc-s32g.c | 692 +++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 704 insertions(+)
>>   create mode 100644 drivers/rtc/rtc-s32g.c
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index e87c3d74565c..18fc3577f6cd 100644
>> --- a/drivers/rtc/Kconfig
>> +++ b/drivers/rtc/Kconfig
>> @@ -2054,4 +2054,15 @@ config RTC_DRV_SSD202D
>>   	  This driver can also be built as a module, if so, the module
>>   	  will be called "rtc-ssd20xd".
>>
>> +config RTC_DRV_S32G
>> +	tristate "RTC driver for S32G2/S32G3 SoCs"
>> +	depends on ARCH_S32 || COMPILE_TEST
>> +	depends on COMMON_CLK
>> +	help
>> +	  Say yes to enable RTC driver for platforms based on the
>> +	  S32G2/S32G3 SoC family.
>> +
>> +	  This RTC module can be used as a wakeup source.
>> +	  Please note that it is not battery-powered.
>> +
>>   endif # RTC_CLASS
>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>> index 8ee79cb18322..a63d010a753c 100644
>> --- a/drivers/rtc/Makefile
>> +++ b/drivers/rtc/Makefile
>> @@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
>>   obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
>>   obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
>>   obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
>> +obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
>>   obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
>>   obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
>>   obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
>> diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
>> new file mode 100644
>> index 000000000000..c3792b674a18
>> --- /dev/null
>> +++ b/drivers/rtc/rtc-s32g.c
>> @@ -0,0 +1,692 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright 2024 NXP
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/clk-provider.h>
>> +#include <linux/err.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/math64.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/rtc.h>
>> +
>> +#define RTCC_OFFSET	0x4ul
>> +#define RTCS_OFFSET	0x8ul
>> +#define RTCCNT_OFFSET	0xCul
>> +#define APIVAL_OFFSET	0x10ul
>> +#define RTCVAL_OFFSET	0x14ul
>> +
>> +/* RTCC fields */
>> +#define RTCC_CNTEN				BIT(31)
>> +#define RTCC_RTCIE_SHIFT		30
>> +#define RTCC_RTCIE				BIT(RTCC_RTCIE_SHIFT)
>> +#define RTCC_ROVREN				BIT(28)
>> +#define RTCC_APIEN				BIT(15)
>> +#define RTCC_APIIE				BIT(14)
>> +#define RTCC_CLKSEL_OFFSET		12
>> +#define RTCC_CLKSEL_MASK		GENMASK(13, 12)
>> +#define RTCC_CLKSEL(n)			(((n) << 12) & RTCC_CLKSEL_MASK)
>> +#define RTCC_DIV512EN			BIT(11)
>> +#define RTCC_DIV32EN			BIT(10)
>> +
>> +/* RTCS fields */
>> +#define RTCS_RTCF		BIT(29)
>> +#define RTCS_INV_RTC		BIT(18)
>> +#define RTCS_APIF		BIT(13)
>> +#define RTCS_ROVRF		BIT(10)
>> +
>> +#define ROLLOVER_VAL		GENMASK(31, 0)
>> +#define RTC_SYNCH_TIMEOUT	(100 * USEC_PER_MSEC)
>> +
>> +#define RTC_CLK_MUX_SIZE	4
>> +
>> +/*
>> + * S32G2 and S32G3 SoCs have RTC clock source 1 reserved and
>> + * should not be used.
>> + */
>> +#define RTC_QUIRK_SRC1_RESERVED			BIT(2)
>> +
>> +enum {
>> +	RTC_CLK_SRC0,
>> +	RTC_CLK_SRC1,
>> +	RTC_CLK_SRC2,
>> +	RTC_CLK_SRC3
>> +};
>> +
>> +enum {
>> +	DIV1 = 1,
>> +	DIV32 = 32,
>> +	DIV512 = 512,
>> +	DIV512_32 = 16384
>> +};
>> +
>> +static const char *rtc_clk_src[RTC_CLK_MUX_SIZE * 2] = {
>> +	"rtc_runtime_s0",
>> +	"rtc_runtime_s1",
>> +	"rtc_runtime_s2",
>> +	"rtc_runtime_s3",
>> +	"rtc_standby_s0",
>> +	"rtc_standby_s1",
>> +	"rtc_standby_s2",
>> +	"rtc_standby_s3"
>> +};
>> +
>> +struct rtc_time_base {
>> +	s64 sec;
>> +	u64 cycles;
>> +	u64 rollovers;
>> +	struct rtc_time tm;
>> +};
>> +
>> +struct rtc_priv {
>> +	struct rtc_device *rdev;
>> +	void __iomem *rtc_base;
>> +	struct clk *ipg;
>> +	struct clk *runtime_clk;
>> +	struct clk *suspend_clk;
>> +	const struct rtc_soc_data *rtc_data;
>> +	struct rtc_time_base base;
>> +	u64 rtc_hz;
>> +	u64 rollovers;
>> +	int dt_irq_id;
>> +	int runtime_src_idx;
>> +	int suspend_src_idx;
>> +};
>> +
>> +struct rtc_soc_data {
>> +	u32 runtime_div;
>> +	u32 suspend_div;
>> +	u32 quirks;
>> +};
>> +
>> +static const struct rtc_soc_data rtc_s32g2_data = {
>> +	.runtime_div = DIV512,
>> +	.suspend_div = DIV512,
>> +	.quirks = RTC_QUIRK_SRC1_RESERVED,
>> +};
>> +
>> +static int is_src1_reserved(struct rtc_priv *priv)
>> +{
>> +	return priv->rtc_data->quirks & RTC_QUIRK_SRC1_RESERVED;
>> +}
>> +
>> +static u64 cycles_to_sec(u64 hz, u64 cycles)
>> +{
>> +	return div_u64(cycles, hz);
>> +}
>> +
>> +/**
>> + * Convert a number of seconds to a value suitable for RTCVAL in our clock's
>> + * current configuration.
>> + * @rtcval: The value to go into RTCVAL[RTCVAL]
>> + * Returns: 0 for success, -EINVAL if @seconds push the counter at least
>> + *          twice the rollover interval
>> + */
>> +static int sec_to_rtcval(const struct rtc_priv *priv,
>> +			 unsigned long seconds, u32 *rtcval)
>> +{
>> +	u32 rtccnt, delta_cnt;
>> +	u32 target_cnt = 0;
>> +
>> +	/* For now, support at most one rollover of the counter */
>> +	if (!seconds || seconds > cycles_to_sec(priv->rtc_hz, ROLLOVER_VAL))
>> +		return -EINVAL;
>> +
>> +	/*
>> +	 * RTCCNT is read-only; we must return a value relative to the
>> +	 * current value of the counter (and hope we don't linger around
>> +	 * too much before we get to enable the interrupt)
>> +	 */
>> +	delta_cnt = seconds * priv->rtc_hz;
>> +	rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
>> +
>> +	if (~rtccnt < delta_cnt)
>> +		target_cnt = (delta_cnt - ~rtccnt);
>> +	else
>> +		target_cnt = rtccnt + delta_cnt;
>> +
>> +	/*
>> +	 * According to RTCVAL register description,
>> +	 * its minimum value should be 4.
>> +	 */
>> +	if (unlikely(target_cnt < 4))
>> +		target_cnt = 4;
>> +
>> +	*rtcval = target_cnt;
>> +
>> +	return 0;
>> +}
>> +
>> +static irqreturn_t rtc_handler(int irq, void *dev)
>> +{
>> +	struct rtc_priv *priv = platform_get_drvdata(dev);
>> +	u32 status;
>> +
>> +	status = ioread32(priv->rtc_base + RTCS_OFFSET);
>> +	if (status & RTCS_ROVRF) {
>> +		if (priv->rollovers == ULONG_MAX)
>> +			priv->rollovers = 0;
>> +		else
>> +			priv->rollovers++;
>> +	}
>> +
>> +	if (status & RTCS_RTCF) {
>> +		iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
>> +		rtc_update_irq(priv->rdev, 1, RTC_AF);
>> +	}
>> +
>> +	if (status & RTCS_APIF)
>> +		rtc_update_irq(priv->rdev, 1, RTC_PF);
>> +
>> +	iowrite32(status, priv->rtc_base + RTCS_OFFSET);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int get_time_left(struct device *dev, struct rtc_priv *priv,
>> +			 u32 *sec)
>> +{
>> +	u32 rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
>> +	u32 rtcval = ioread32(priv->rtc_base + RTCVAL_OFFSET);
>> +
>> +	if (rtcval < rtccnt) {
>> +		dev_err(dev, "RTC timer expired before entering suspend\n");
>> +		return -EIO;
>> +	}
>> +
>> +	*sec = cycles_to_sec(priv->rtc_hz, rtcval - rtccnt);
>> +
>> +	return 0;
>> +}
>> +
>> +static s64 s32g_rtc_get_time_or_alrm(struct rtc_priv *priv,
>> +				     u32 offset)
>> +{
>> +	u64 cycles, base_cycles;
>> +	u32 counter;
>> +	s64 sec;
>> +
>> +	counter = ioread32(priv->rtc_base + offset);
>> +	cycles = priv->rollovers * ROLLOVER_VAL + counter;
>> +	base_cycles = priv->base.cycles + priv->base.rollovers * ROLLOVER_VAL;
>> +
>> +	if (cycles < base_cycles)
>> +		return -EINVAL;
>> +
>> +	cycles -= base_cycles;
>> +	sec = priv->base.sec + cycles_to_sec(priv->rtc_hz, cycles);
>> +
>> +	return sec;
>> +}
>> +
>> +static int s32g_rtc_read_time(struct device *dev,
>> +			      struct rtc_time *tm)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	s64 sec;
>> +
>> +	if (!tm)
>> +		return -EINVAL;
>> +
>> +	sec = s32g_rtc_get_time_or_alrm(priv, RTCCNT_OFFSET);
>> +	if (sec < 0)
>> +		return -EINVAL;
>> +
>> +	rtc_time64_to_tm(sec, tm);
>> +
>> +	return 0;
>> +}
>> +
>> +static int s32g_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	u32 rtcc, sec_left;
>> +	s64 sec;
>> +
>> +	if (!alrm)
>> +		return -EINVAL;
>> +
>> +	sec = s32g_rtc_get_time_or_alrm(priv, RTCVAL_OFFSET);
>> +	if (sec < 0)
>> +		return -EINVAL;
>> +
>> +	rtc_time64_to_tm(sec, &alrm->time);
>> +
>> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +	alrm->enabled = sec && (rtcc & RTCC_RTCIE);
>> +
>> +	alrm->pending = 0;
>> +	if (alrm->enabled && !get_time_left(dev, priv, &sec_left))
>> +		alrm->pending = !!sec_left;
>> +
>> +	return 0;
>> +}
>> +
>> +static int s32g_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	u32 rtcc;
>> +
>> +	if (!priv->dt_irq_id)
>> +		return -EIO;
>> +
>> +	/*
>> +	 * RTCIE cannot be deasserted because it will also disable the
>> +	 * rollover interrupt.
>> +	 */
>> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +	if (enabled)
>> +		rtcc |= RTCC_RTCIE;
>> +
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +
>> +	return 0;
>> +}
>> +
>> +static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	struct rtc_time time_crt;
>> +	long long t_crt, t_alrm;
>> +	u32 rtcval, rtcs;
>> +	int ret = 0;
>> +
>> +	iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
>> +
>> +	t_alrm = rtc_tm_to_time64(&alrm->time);
>> +
>> +	/*
>> +	 * Assuming the alarm is being set relative to the same time
>> +	 * returned by our s32g_rtc_read_time callback
>> +	 */
>> +	ret = s32g_rtc_read_time(dev, &time_crt);
>> +	if (ret)
>> +		return ret;
>> +
>> +	t_crt = rtc_tm_to_time64(&time_crt);
>> +	if (t_alrm <= t_crt) {
>> +		dev_warn(dev, "Alarm is set in the past\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = sec_to_rtcval(priv, t_alrm - t_crt, &rtcval);
>> +	if (ret) {
>> +		/*
>> +		 * Rollover support enables RTC alarm
>> +		 * for a maximum timespan of ~3 months.
>> +		 */
>> +		dev_warn(dev, "Alarm is set too far in the future\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = read_poll_timeout(ioread32, rtcs, !(rtcs & RTCS_INV_RTC),
>> +				0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
>> +	if (ret) {
>> +		dev_err(dev, "Synchronization failed\n");
>> +		return ret;
>> +	}
>> +
>> +	iowrite32(rtcval, priv->rtc_base + RTCVAL_OFFSET);
>> +
>> +	return 0;
>> +}
>> +
>> +static int s32g_rtc_set_time(struct device *dev,
>> +			     struct rtc_time *time)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +
>> +	if (!time)
>> +		return -EINVAL;
>> +
>> +	priv->base.rollovers = priv->rollovers;
>> +	priv->base.cycles = ioread32(priv->rtc_base + RTCCNT_OFFSET);
>> +	priv->base.sec = rtc_tm_to_time64(time);
>> +
>> +	return 0;
>> +}
>> +
>> +/*
>> + * Disable the 32-bit free running counter.
>> + * This allows Clock Source and Divisors selection
>> + * to be performed without causing synchronization issues.
>> + */
>> +static void s32g_rtc_disable(struct rtc_priv *priv)
>> +{
>> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +
>> +	rtcc &= ~RTCC_CNTEN;
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +}
>> +
>> +static void s32g_rtc_enable(struct rtc_priv *priv)
>> +{
>> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +
>> +	rtcc |= RTCC_CNTEN;
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +}
>> +
>> +static void adjust_dividers(struct rtc_priv *priv,
>> +			    u32 div_val, u32 *reg)
>> +{
>> +	switch (div_val) {
>> +	case DIV512_32:
>> +		*reg |= RTCC_DIV512EN;
>> +		*reg |= RTCC_DIV32EN;
>> +		break;
>> +	case DIV512:
>> +		*reg |= RTCC_DIV512EN;
>> +		break;
>> +	case DIV32:
>> +		*reg |= RTCC_DIV32EN;
>> +		break;
>> +	default:
>> +		return;
>> +	}
>> +
>> +	priv->rtc_hz /= div_val;
>> +}
>> +
>> +static int rtc_get_clk_src(struct rtc_priv *priv)
>> +{
>> +	return (ioread32(priv->rtc_base + RTCC_OFFSET) &
>> +			RTCC_CLKSEL_MASK) >> RTCC_CLKSEL_OFFSET;
>> +}
>> +
>> +static int rtc_clk_src_switch(struct rtc_priv *priv, u32 src)
>> +{
>> +	struct device *dev = priv->rdev->dev.parent;
>> +	u32 rtcc = 0;
>> +
>> +	switch (src % RTC_CLK_MUX_SIZE) {
>> +	case RTC_CLK_SRC0:
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC0);
>> +		break;
>> +	case RTC_CLK_SRC1:
>> +		if (is_src1_reserved(priv))
>> +			return -EOPNOTSUPP;
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC1);
>> +		break;
>> +	case RTC_CLK_SRC2:
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC2);
>> +		break;
>> +	case RTC_CLK_SRC3:
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC3);
>> +		break;
>> +	default:
>> +		dev_err(dev, "Invalid clock mux parent: %d\n", src);
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (src < RTC_CLK_MUX_SIZE) {
>> +		priv->rtc_hz = clk_get_rate(priv->runtime_clk);
>> +		if (!priv->rtc_hz) {
>> +			dev_err(dev, "Failed to get RTC frequency\n");
>> +			return -EINVAL;
>> +		}
>> +		adjust_dividers(priv, priv->rtc_data->runtime_div, &rtcc);
>> +	} else {
>> +		priv->rtc_hz = clk_get_rate(priv->suspend_clk);
>> +		if (!priv->rtc_hz) {
>> +			dev_err(dev, "Failed to get RTC frequency\n");
>> +			return -EINVAL;
>> +		}
>> +		adjust_dividers(priv, priv->rtc_data->suspend_div, &rtcc);
>> +	}
>> +
>> +	rtcc |= RTCC_RTCIE | RTCC_ROVREN;
>> +	/*
>> +	 * Make sure the CNTEN is 0 before we configure
>> +	 * the clock source and dividers.
>> +	 */
>> +	s32g_rtc_disable(priv);
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +	s32g_rtc_enable(priv);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct rtc_class_ops rtc_ops = {
>> +	.read_time = s32g_rtc_read_time,
>> +	.set_time = s32g_rtc_set_time,
>> +	.read_alarm = s32g_rtc_read_alarm,
>> +	.set_alarm = s32g_rtc_set_alarm,
>> +	.alarm_irq_enable = s32g_rtc_alarm_irq_enable,
>> +};
>> +
>> +static int rtc_clk_dts_setup(struct rtc_priv *priv,
>> +			     struct device *dev)
>> +{
>> +	int i;
>> +
>> +	priv->runtime_src_idx = -EINVAL;
>> +	priv->suspend_src_idx = -EINVAL;
>> +
>> +	priv->ipg = devm_clk_get_enabled(dev, "ipg");
> 
> binding doc need document 'ipg'
> 

Is the current documentation from 'clocks' [1] in the bindings not enough ?

clocks:
...
   items:
     - description: ipg clock drives the access to the RTC iomapped 
registers
...


[1] 
https://lore.kernel.org/all/20241111135940.2534034-2-ciprianmarian.costea@oss.nxp.com/

>> +	if (IS_ERR(priv->ipg)) {
>> +		dev_err(dev, "Failed to get 'ipg' clock\n");
>> +		return PTR_ERR(priv->ipg);
>> +	}
>> +
>> +	/* Get RTC runtime clock source */
>> +	for (i = 0; i < RTC_CLK_MUX_SIZE; i++) {
>> +		priv->runtime_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
>> +		if (!IS_ERR(priv->runtime_clk)) {
>> +			priv->runtime_src_idx = i;
>> +			break;
>> +		}
>> +	}
>> +
>> +	if (IS_ERR(priv->runtime_clk)) {
>> +		dev_err(dev, "Failed to get runtime rtc clock\n");
>> +		return PTR_ERR(priv->runtime_clk);
> 
> return  dev_err_proble()
> 
>> +	}
>> +
>> +	/* If present, get RTC suspend clock source */
>> +	for (i = RTC_CLK_MUX_SIZE; i < RTC_CLK_MUX_SIZE * 2; i++) {
>> +		priv->suspend_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
>> +		if (!IS_ERR(priv->suspend_clk)) {
>> +			priv->suspend_src_idx = i;
>> +			break;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int rtc_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct rtc_priv *priv;
>> +	int ret = 0;
>> +
>> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	priv->rtc_data = of_device_get_match_data(dev);
>> +	if (!priv->rtc_data)
>> +		return -ENODEV;
>> +
>> +	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
>> +	if (IS_ERR(priv->rtc_base))
>> +		return dev_err_probe(dev, PTR_ERR(priv->rtc_base),
>> +				"Failed to map registers\n");
>> +
>> +	device_init_wakeup(dev, true);
>> +
>> +	ret = rtc_clk_dts_setup(priv, dev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	priv->rdev = devm_rtc_allocate_device(dev);
>> +	if (IS_ERR(priv->rdev))
>> +		return dev_err_probe(dev, PTR_ERR(priv->rdev),
>> +				"Failed to allocate RTC device\n");
>> +
>> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
>> +	if (ret)
>> +		return dev_err_probe(dev, ret,
>> +				"Failed clk source switch, err: %d\n", ret);
>> +
>> +	platform_set_drvdata(pdev, priv);
>> +	priv->rdev->ops = &rtc_ops;
>> +
>> +	ret = devm_rtc_register_device(priv->rdev);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to register RTC device\n");
>> +		goto disable_rtc;
>> +	}
>> +
>> +	priv->dt_irq_id = platform_get_irq(pdev, 0);
>> +	if (priv->dt_irq_id < 0)
>> +		return dev_err_probe(dev, priv->dt_irq_id,
>> +				"Error reading interrupt # from dts\n");
>> +
>> +	ret = devm_request_irq(dev, priv->dt_irq_id,
>> +			       rtc_handler, 0, dev_name(dev), pdev);
>> +	if (ret) {
>> +		dev_err(dev, "Request interrupt %d failed, error: %d\n",
>> +			priv->dt_irq_id, ret);
>> +		goto disable_rtc;
>> +	}
>> +
>> +	return 0;
>> +
>> +disable_rtc:
>> +	s32g_rtc_disable(priv);
>> +	return ret;
>> +}
>> +
>> +static void rtc_remove(struct platform_device *pdev)
>> +{
>> +	struct rtc_priv *priv = platform_get_drvdata(pdev);
>> +
>> +	s32g_rtc_disable(priv);
>> +}
>> +
>> +static void  __maybe_unused enable_api_irq(struct device *dev, unsigned int enabled)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	u32 api_irq = RTCC_APIEN | RTCC_APIIE;
>> +	u32 rtcc;
>> +
>> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +	if (enabled)
>> +		rtcc |= api_irq;
>> +	else
>> +		rtcc &= ~api_irq;
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +}
>> +
>> +static int __maybe_unused rtc_suspend(struct device *dev)
>> +{
>> +	struct rtc_priv *init_priv = dev_get_drvdata(dev);
>> +	struct rtc_priv priv;
>> +	long long base_sec;
>> +	int ret = 0;
>> +	u32 rtcval;
>> +	u32 sec;
>> +
>> +	if (!device_may_wakeup(dev))
>> +		return 0;
>> +
>> +	if (init_priv->suspend_src_idx < 0)
>> +		return 0;
>> +
>> +	if (rtc_get_clk_src(init_priv) + RTC_CLK_MUX_SIZE ==
>> +			init_priv->suspend_src_idx)
>> +		return 0;
>> +
>> +	/* Save last known timestamp before we switch clocks and reinit RTC */
>> +	ret = s32g_rtc_read_time(dev, &init_priv->base.tm);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/*
>> +	 * Use a local copy of the RTC control block to
>> +	 * avoid restoring it on resume path.
>> +	 */
>> +	memcpy(&priv, init_priv, sizeof(priv));
>> +
>> +	ret = get_time_left(dev, init_priv, &sec);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Adjust for the number of seconds we'll be asleep */
>> +	base_sec = rtc_tm_to_time64(&init_priv->base.tm);
>> +	base_sec += sec;
>> +	rtc_time64_to_tm(base_sec, &init_priv->base.tm);
>> +
>> +	ret = rtc_clk_src_switch(&priv, priv.suspend_src_idx);
>> +	if (ret) {
>> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = sec_to_rtcval(&priv, sec, &rtcval);
>> +	if (ret) {
>> +		dev_warn(dev, "Alarm is too far in the future\n");
>> +		return ret;
>> +	}
>> +
>> +	s32g_rtc_alarm_irq_enable(dev, 0);
>> +	enable_api_irq(dev, 1);
>> +	iowrite32(rtcval, priv.rtc_base + APIVAL_OFFSET);
>> +	iowrite32(0, priv.rtc_base + RTCVAL_OFFSET);
>> +
>> +	return ret;
>> +}
>> +
>> +static int __maybe_unused rtc_resume(struct device *dev)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	int ret;
>> +
>> +	if (!device_may_wakeup(dev))
>> +		return 0;
>> +
>> +	if (rtc_get_clk_src(priv) == priv->runtime_src_idx)
>> +		return 0;
>> +
>> +	/* Disable wake-up interrupts */
>> +	enable_api_irq(dev, 0);
>> +
>> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
>> +	if (ret) {
>> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	/*
>> +	 * Now RTCCNT has just been reset, and is out of sync with priv->base;
>> +	 * reapply the saved time settings
>> +	 */
>> +	return s32g_rtc_set_time(dev, &priv->base.tm);
>> +}
>> +
>> +static const struct of_device_id rtc_dt_ids[] = {
>> +	{ .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data},
>> +	{ /* sentinel */ },
>> +};
>> +
>> +static SIMPLE_DEV_PM_OPS(rtc_pm_ops,
>> +			 rtc_suspend, rtc_resume);
>> +
>> +static struct platform_driver rtc_driver = {
>> +	.driver		= {
>> +		.name			= "s32g-rtc",
>> +		.pm				= &rtc_pm_ops,
> 
> pm_ptr(&rtc_pm_ops),
> 

Thanks. I will update as suggested in V5.


Best Regards,
Ciprian

>> +		.of_match_table = rtc_dt_ids,
>> +	},
>> +	.probe		= rtc_probe,
>> +	.remove	= rtc_remove,
>> +};
>> +module_platform_driver(rtc_driver);
>> +
>> +MODULE_AUTHOR("NXP");
>> +MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.45.2
>>

Re: [PATCH v4 2/4] rtc: s32g: add NXP S32G2/S32G3 SoC support

[Frank Li]

On Mon, Nov 11, 2024 at 06:18:37PM +0200, Ciprian Marian Costea wrote:
> On 11/11/2024 6:07 PM, Frank Li wrote:
> > On Mon, Nov 11, 2024 at 03:59:38PM +0200, Ciprian Costea wrote:
> > > From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > >
> > > Add a RTC driver for NXP S32G2/S32G3 SoCs.
> > >
> > > The RTC module is used to enable Suspend to RAM (STR) support on NXP
> > > S32G2/S32G3 SoC based boards.
> >
> > Why suspend to RAM related RTC module?
> >
>
> Hello Frank,
>
> Here I was referring to the fact that the RTC module is used as a wakeup
> source from suspend state on S32G, thus enabling easy Suspend to RAM
> testing.

You can mention it can be a wakeup source.

>
> I will update the commit body accordingly for this patchset to remove this
> confusion in V5.
>
> > >
> > > RTC tracks clock time during system suspend.
> > >
> > > RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
> > > during system reset.
> > >
> > > Co-developed-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> > > Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> > > Co-developed-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
> > > Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
> > > Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > ---
> > >   drivers/rtc/Kconfig    |  11 +
> > >   drivers/rtc/Makefile   |   1 +
> > >   drivers/rtc/rtc-s32g.c | 692 +++++++++++++++++++++++++++++++++++++++++
> > >   3 files changed, 704 insertions(+)
> > >   create mode 100644 drivers/rtc/rtc-s32g.c
> > >
> > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> > > index e87c3d74565c..18fc3577f6cd 100644
> > > --- a/drivers/rtc/Kconfig
> > > +++ b/drivers/rtc/Kconfig
> > > @@ -2054,4 +2054,15 @@ config RTC_DRV_SSD202D
> > >   	  This driver can also be built as a module, if so, the module
> > >   	  will be called "rtc-ssd20xd".
> > >
> > > +config RTC_DRV_S32G
> > > +	tristate "RTC driver for S32G2/S32G3 SoCs"
> > > +	depends on ARCH_S32 || COMPILE_TEST
> > > +	depends on COMMON_CLK
> > > +	help
> > > +	  Say yes to enable RTC driver for platforms based on the
> > > +	  S32G2/S32G3 SoC family.
> > > +
> > > +	  This RTC module can be used as a wakeup source.
> > > +	  Please note that it is not battery-powered.
> > > +
> > >   endif # RTC_CLASS
> > > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> > > index 8ee79cb18322..a63d010a753c 100644
> > > --- a/drivers/rtc/Makefile
> > > +++ b/drivers/rtc/Makefile
> > > @@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
> > >   obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
> > >   obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
> > >   obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
> > > +obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
> > >   obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
> > >   obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
> > >   obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
> > > diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
> > > new file mode 100644
> > > index 000000000000..c3792b674a18
> > > --- /dev/null
> > > +++ b/drivers/rtc/rtc-s32g.c
> > > @@ -0,0 +1,692 @@
> > > +// SPDX-License-Identifier: GPL-2.0-or-later
> > > +/*
> > > + * Copyright 2024 NXP
> > > + */
> > > +
> > > +#include <linux/clk.h>
> > > +#include <linux/clk-provider.h>
> > > +#include <linux/err.h>
> > > +#include <linux/iopoll.h>
> > > +#include <linux/math64.h>
> > > +#include <linux/of_irq.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/rtc.h>
> > > +
> > > +#define RTCC_OFFSET	0x4ul
> > > +#define RTCS_OFFSET	0x8ul
> > > +#define RTCCNT_OFFSET	0xCul
> > > +#define APIVAL_OFFSET	0x10ul
> > > +#define RTCVAL_OFFSET	0x14ul
> > > +
> > > +/* RTCC fields */
> > > +#define RTCC_CNTEN				BIT(31)
> > > +#define RTCC_RTCIE_SHIFT		30
> > > +#define RTCC_RTCIE				BIT(RTCC_RTCIE_SHIFT)
> > > +#define RTCC_ROVREN				BIT(28)
> > > +#define RTCC_APIEN				BIT(15)
> > > +#define RTCC_APIIE				BIT(14)
> > > +#define RTCC_CLKSEL_OFFSET		12
> > > +#define RTCC_CLKSEL_MASK		GENMASK(13, 12)
> > > +#define RTCC_CLKSEL(n)			(((n) << 12) & RTCC_CLKSEL_MASK)
> > > +#define RTCC_DIV512EN			BIT(11)
> > > +#define RTCC_DIV32EN			BIT(10)
> > > +
> > > +/* RTCS fields */
> > > +#define RTCS_RTCF		BIT(29)
> > > +#define RTCS_INV_RTC		BIT(18)
> > > +#define RTCS_APIF		BIT(13)
> > > +#define RTCS_ROVRF		BIT(10)
> > > +
> > > +#define ROLLOVER_VAL		GENMASK(31, 0)
> > > +#define RTC_SYNCH_TIMEOUT	(100 * USEC_PER_MSEC)
> > > +
> > > +#define RTC_CLK_MUX_SIZE	4
> > > +
> > > +/*
> > > + * S32G2 and S32G3 SoCs have RTC clock source 1 reserved and
> > > + * should not be used.
> > > + */
> > > +#define RTC_QUIRK_SRC1_RESERVED			BIT(2)
> > > +
> > > +enum {
> > > +	RTC_CLK_SRC0,
> > > +	RTC_CLK_SRC1,
> > > +	RTC_CLK_SRC2,
> > > +	RTC_CLK_SRC3
> > > +};
> > > +
> > > +enum {
> > > +	DIV1 = 1,
> > > +	DIV32 = 32,
> > > +	DIV512 = 512,
> > > +	DIV512_32 = 16384
> > > +};
> > > +
> > > +static const char *rtc_clk_src[RTC_CLK_MUX_SIZE * 2] = {
> > > +	"rtc_runtime_s0",
> > > +	"rtc_runtime_s1",
> > > +	"rtc_runtime_s2",
> > > +	"rtc_runtime_s3",
> > > +	"rtc_standby_s0",
> > > +	"rtc_standby_s1",
> > > +	"rtc_standby_s2",
> > > +	"rtc_standby_s3"
> > > +};
> > > +
> > > +struct rtc_time_base {
> > > +	s64 sec;
> > > +	u64 cycles;
> > > +	u64 rollovers;
> > > +	struct rtc_time tm;
> > > +};
> > > +
> > > +struct rtc_priv {
> > > +	struct rtc_device *rdev;
> > > +	void __iomem *rtc_base;
> > > +	struct clk *ipg;
> > > +	struct clk *runtime_clk;
> > > +	struct clk *suspend_clk;
> > > +	const struct rtc_soc_data *rtc_data;
> > > +	struct rtc_time_base base;
> > > +	u64 rtc_hz;
> > > +	u64 rollovers;
> > > +	int dt_irq_id;
> > > +	int runtime_src_idx;
> > > +	int suspend_src_idx;
> > > +};
> > > +
> > > +struct rtc_soc_data {
> > > +	u32 runtime_div;
> > > +	u32 suspend_div;
> > > +	u32 quirks;
> > > +};
> > > +
> > > +static const struct rtc_soc_data rtc_s32g2_data = {
> > > +	.runtime_div = DIV512,
> > > +	.suspend_div = DIV512,
> > > +	.quirks = RTC_QUIRK_SRC1_RESERVED,
> > > +};
> > > +
> > > +static int is_src1_reserved(struct rtc_priv *priv)
> > > +{
> > > +	return priv->rtc_data->quirks & RTC_QUIRK_SRC1_RESERVED;
> > > +}
> > > +
> > > +static u64 cycles_to_sec(u64 hz, u64 cycles)
> > > +{
> > > +	return div_u64(cycles, hz);
> > > +}
> > > +
> > > +/**
> > > + * Convert a number of seconds to a value suitable for RTCVAL in our clock's
> > > + * current configuration.
> > > + * @rtcval: The value to go into RTCVAL[RTCVAL]
> > > + * Returns: 0 for success, -EINVAL if @seconds push the counter at least
> > > + *          twice the rollover interval
> > > + */
> > > +static int sec_to_rtcval(const struct rtc_priv *priv,
> > > +			 unsigned long seconds, u32 *rtcval)
> > > +{
> > > +	u32 rtccnt, delta_cnt;
> > > +	u32 target_cnt = 0;
> > > +
> > > +	/* For now, support at most one rollover of the counter */
> > > +	if (!seconds || seconds > cycles_to_sec(priv->rtc_hz, ROLLOVER_VAL))
> > > +		return -EINVAL;
> > > +
> > > +	/*
> > > +	 * RTCCNT is read-only; we must return a value relative to the
> > > +	 * current value of the counter (and hope we don't linger around
> > > +	 * too much before we get to enable the interrupt)
> > > +	 */
> > > +	delta_cnt = seconds * priv->rtc_hz;
> > > +	rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> > > +
> > > +	if (~rtccnt < delta_cnt)
> > > +		target_cnt = (delta_cnt - ~rtccnt);
> > > +	else
> > > +		target_cnt = rtccnt + delta_cnt;
> > > +
> > > +	/*
> > > +	 * According to RTCVAL register description,
> > > +	 * its minimum value should be 4.
> > > +	 */
> > > +	if (unlikely(target_cnt < 4))
> > > +		target_cnt = 4;
> > > +
> > > +	*rtcval = target_cnt;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static irqreturn_t rtc_handler(int irq, void *dev)
> > > +{
> > > +	struct rtc_priv *priv = platform_get_drvdata(dev);
> > > +	u32 status;
> > > +
> > > +	status = ioread32(priv->rtc_base + RTCS_OFFSET);
> > > +	if (status & RTCS_ROVRF) {
> > > +		if (priv->rollovers == ULONG_MAX)
> > > +			priv->rollovers = 0;
> > > +		else
> > > +			priv->rollovers++;
> > > +	}
> > > +
> > > +	if (status & RTCS_RTCF) {
> > > +		iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
> > > +		rtc_update_irq(priv->rdev, 1, RTC_AF);
> > > +	}
> > > +
> > > +	if (status & RTCS_APIF)
> > > +		rtc_update_irq(priv->rdev, 1, RTC_PF);
> > > +
> > > +	iowrite32(status, priv->rtc_base + RTCS_OFFSET);
> > > +
> > > +	return IRQ_HANDLED;
> > > +}
> > > +
> > > +static int get_time_left(struct device *dev, struct rtc_priv *priv,
> > > +			 u32 *sec)
> > > +{
> > > +	u32 rtccnt = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> > > +	u32 rtcval = ioread32(priv->rtc_base + RTCVAL_OFFSET);
> > > +
> > > +	if (rtcval < rtccnt) {
> > > +		dev_err(dev, "RTC timer expired before entering suspend\n");
> > > +		return -EIO;
> > > +	}
> > > +
> > > +	*sec = cycles_to_sec(priv->rtc_hz, rtcval - rtccnt);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static s64 s32g_rtc_get_time_or_alrm(struct rtc_priv *priv,
> > > +				     u32 offset)
> > > +{
> > > +	u64 cycles, base_cycles;
> > > +	u32 counter;
> > > +	s64 sec;
> > > +
> > > +	counter = ioread32(priv->rtc_base + offset);
> > > +	cycles = priv->rollovers * ROLLOVER_VAL + counter;
> > > +	base_cycles = priv->base.cycles + priv->base.rollovers * ROLLOVER_VAL;
> > > +
> > > +	if (cycles < base_cycles)
> > > +		return -EINVAL;
> > > +
> > > +	cycles -= base_cycles;
> > > +	sec = priv->base.sec + cycles_to_sec(priv->rtc_hz, cycles);
> > > +
> > > +	return sec;
> > > +}
> > > +
> > > +static int s32g_rtc_read_time(struct device *dev,
> > > +			      struct rtc_time *tm)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +	s64 sec;
> > > +
> > > +	if (!tm)
> > > +		return -EINVAL;
> > > +
> > > +	sec = s32g_rtc_get_time_or_alrm(priv, RTCCNT_OFFSET);
> > > +	if (sec < 0)
> > > +		return -EINVAL;
> > > +
> > > +	rtc_time64_to_tm(sec, tm);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int s32g_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +	u32 rtcc, sec_left;
> > > +	s64 sec;
> > > +
> > > +	if (!alrm)
> > > +		return -EINVAL;
> > > +
> > > +	sec = s32g_rtc_get_time_or_alrm(priv, RTCVAL_OFFSET);
> > > +	if (sec < 0)
> > > +		return -EINVAL;
> > > +
> > > +	rtc_time64_to_tm(sec, &alrm->time);
> > > +
> > > +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> > > +	alrm->enabled = sec && (rtcc & RTCC_RTCIE);
> > > +
> > > +	alrm->pending = 0;
> > > +	if (alrm->enabled && !get_time_left(dev, priv, &sec_left))
> > > +		alrm->pending = !!sec_left;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int s32g_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +	u32 rtcc;
> > > +
> > > +	if (!priv->dt_irq_id)
> > > +		return -EIO;
> > > +
> > > +	/*
> > > +	 * RTCIE cannot be deasserted because it will also disable the
> > > +	 * rollover interrupt.
> > > +	 */
> > > +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> > > +	if (enabled)
> > > +		rtcc |= RTCC_RTCIE;
> > > +
> > > +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +	struct rtc_time time_crt;
> > > +	long long t_crt, t_alrm;
> > > +	u32 rtcval, rtcs;
> > > +	int ret = 0;
> > > +
> > > +	iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
> > > +
> > > +	t_alrm = rtc_tm_to_time64(&alrm->time);
> > > +
> > > +	/*
> > > +	 * Assuming the alarm is being set relative to the same time
> > > +	 * returned by our s32g_rtc_read_time callback
> > > +	 */
> > > +	ret = s32g_rtc_read_time(dev, &time_crt);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	t_crt = rtc_tm_to_time64(&time_crt);
> > > +	if (t_alrm <= t_crt) {
> > > +		dev_warn(dev, "Alarm is set in the past\n");
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	ret = sec_to_rtcval(priv, t_alrm - t_crt, &rtcval);
> > > +	if (ret) {
> > > +		/*
> > > +		 * Rollover support enables RTC alarm
> > > +		 * for a maximum timespan of ~3 months.
> > > +		 */
> > > +		dev_warn(dev, "Alarm is set too far in the future\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	ret = read_poll_timeout(ioread32, rtcs, !(rtcs & RTCS_INV_RTC),
> > > +				0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
> > > +	if (ret) {
> > > +		dev_err(dev, "Synchronization failed\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	iowrite32(rtcval, priv->rtc_base + RTCVAL_OFFSET);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int s32g_rtc_set_time(struct device *dev,
> > > +			     struct rtc_time *time)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +
> > > +	if (!time)
> > > +		return -EINVAL;
> > > +
> > > +	priv->base.rollovers = priv->rollovers;
> > > +	priv->base.cycles = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> > > +	priv->base.sec = rtc_tm_to_time64(time);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +/*
> > > + * Disable the 32-bit free running counter.
> > > + * This allows Clock Source and Divisors selection
> > > + * to be performed without causing synchronization issues.
> > > + */
> > > +static void s32g_rtc_disable(struct rtc_priv *priv)
> > > +{
> > > +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> > > +
> > > +	rtcc &= ~RTCC_CNTEN;
> > > +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> > > +}
> > > +
> > > +static void s32g_rtc_enable(struct rtc_priv *priv)
> > > +{
> > > +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> > > +
> > > +	rtcc |= RTCC_CNTEN;
> > > +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> > > +}
> > > +
> > > +static void adjust_dividers(struct rtc_priv *priv,
> > > +			    u32 div_val, u32 *reg)
> > > +{
> > > +	switch (div_val) {
> > > +	case DIV512_32:
> > > +		*reg |= RTCC_DIV512EN;
> > > +		*reg |= RTCC_DIV32EN;
> > > +		break;
> > > +	case DIV512:
> > > +		*reg |= RTCC_DIV512EN;
> > > +		break;
> > > +	case DIV32:
> > > +		*reg |= RTCC_DIV32EN;
> > > +		break;
> > > +	default:
> > > +		return;
> > > +	}
> > > +
> > > +	priv->rtc_hz /= div_val;
> > > +}
> > > +
> > > +static int rtc_get_clk_src(struct rtc_priv *priv)
> > > +{
> > > +	return (ioread32(priv->rtc_base + RTCC_OFFSET) &
> > > +			RTCC_CLKSEL_MASK) >> RTCC_CLKSEL_OFFSET;
> > > +}
> > > +
> > > +static int rtc_clk_src_switch(struct rtc_priv *priv, u32 src)
> > > +{
> > > +	struct device *dev = priv->rdev->dev.parent;
> > > +	u32 rtcc = 0;
> > > +
> > > +	switch (src % RTC_CLK_MUX_SIZE) {
> > > +	case RTC_CLK_SRC0:
> > > +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC0);
> > > +		break;
> > > +	case RTC_CLK_SRC1:
> > > +		if (is_src1_reserved(priv))
> > > +			return -EOPNOTSUPP;
> > > +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC1);
> > > +		break;
> > > +	case RTC_CLK_SRC2:
> > > +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC2);
> > > +		break;
> > > +	case RTC_CLK_SRC3:
> > > +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC3);
> > > +		break;
> > > +	default:
> > > +		dev_err(dev, "Invalid clock mux parent: %d\n", src);
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	if (src < RTC_CLK_MUX_SIZE) {
> > > +		priv->rtc_hz = clk_get_rate(priv->runtime_clk);
> > > +		if (!priv->rtc_hz) {
> > > +			dev_err(dev, "Failed to get RTC frequency\n");
> > > +			return -EINVAL;
> > > +		}
> > > +		adjust_dividers(priv, priv->rtc_data->runtime_div, &rtcc);
> > > +	} else {
> > > +		priv->rtc_hz = clk_get_rate(priv->suspend_clk);
> > > +		if (!priv->rtc_hz) {
> > > +			dev_err(dev, "Failed to get RTC frequency\n");
> > > +			return -EINVAL;
> > > +		}
> > > +		adjust_dividers(priv, priv->rtc_data->suspend_div, &rtcc);
> > > +	}
> > > +
> > > +	rtcc |= RTCC_RTCIE | RTCC_ROVREN;
> > > +	/*
> > > +	 * Make sure the CNTEN is 0 before we configure
> > > +	 * the clock source and dividers.
> > > +	 */
> > > +	s32g_rtc_disable(priv);
> > > +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> > > +	s32g_rtc_enable(priv);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct rtc_class_ops rtc_ops = {
> > > +	.read_time = s32g_rtc_read_time,
> > > +	.set_time = s32g_rtc_set_time,
> > > +	.read_alarm = s32g_rtc_read_alarm,
> > > +	.set_alarm = s32g_rtc_set_alarm,
> > > +	.alarm_irq_enable = s32g_rtc_alarm_irq_enable,
> > > +};
> > > +
> > > +static int rtc_clk_dts_setup(struct rtc_priv *priv,
> > > +			     struct device *dev)
> > > +{
> > > +	int i;
> > > +
> > > +	priv->runtime_src_idx = -EINVAL;
> > > +	priv->suspend_src_idx = -EINVAL;
> > > +
> > > +	priv->ipg = devm_clk_get_enabled(dev, "ipg");
> >
> > binding doc need document 'ipg'
> >
>
> Is the current documentation from 'clocks' [1] in the bindings not enough ?
>
> clocks:
> ...
>   items:
>     - description: ipg clock drives the access to the RTC iomapped registers
> ...

clock-names
  items:
    - ipg


"clocks" supposed you will use index instead of 'name' to get clock.

Frank
>
>
> [1] https://lore.kernel.org/all/20241111135940.2534034-2-ciprianmarian.costea@oss.nxp.com/
>
> > > +	if (IS_ERR(priv->ipg)) {
> > > +		dev_err(dev, "Failed to get 'ipg' clock\n");
> > > +		return PTR_ERR(priv->ipg);
> > > +	}
> > > +
> > > +	/* Get RTC runtime clock source */
> > > +	for (i = 0; i < RTC_CLK_MUX_SIZE; i++) {
> > > +		priv->runtime_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
> > > +		if (!IS_ERR(priv->runtime_clk)) {
> > > +			priv->runtime_src_idx = i;
> > > +			break;
> > > +		}
> > > +	}
> > > +
> > > +	if (IS_ERR(priv->runtime_clk)) {
> > > +		dev_err(dev, "Failed to get runtime rtc clock\n");
> > > +		return PTR_ERR(priv->runtime_clk);
> >
> > return  dev_err_proble()
> >
> > > +	}
> > > +
> > > +	/* If present, get RTC suspend clock source */
> > > +	for (i = RTC_CLK_MUX_SIZE; i < RTC_CLK_MUX_SIZE * 2; i++) {
> > > +		priv->suspend_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
> > > +		if (!IS_ERR(priv->suspend_clk)) {
> > > +			priv->suspend_src_idx = i;
> > > +			break;
> > > +		}
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int rtc_probe(struct platform_device *pdev)
> > > +{
> > > +	struct device *dev = &pdev->dev;
> > > +	struct rtc_priv *priv;
> > > +	int ret = 0;
> > > +
> > > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > > +	if (!priv)
> > > +		return -ENOMEM;
> > > +
> > > +	priv->rtc_data = of_device_get_match_data(dev);
> > > +	if (!priv->rtc_data)
> > > +		return -ENODEV;
> > > +
> > > +	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
> > > +	if (IS_ERR(priv->rtc_base))
> > > +		return dev_err_probe(dev, PTR_ERR(priv->rtc_base),
> > > +				"Failed to map registers\n");
> > > +
> > > +	device_init_wakeup(dev, true);
> > > +
> > > +	ret = rtc_clk_dts_setup(priv, dev);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	priv->rdev = devm_rtc_allocate_device(dev);
> > > +	if (IS_ERR(priv->rdev))
> > > +		return dev_err_probe(dev, PTR_ERR(priv->rdev),
> > > +				"Failed to allocate RTC device\n");
> > > +
> > > +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
> > > +	if (ret)
> > > +		return dev_err_probe(dev, ret,
> > > +				"Failed clk source switch, err: %d\n", ret);
> > > +
> > > +	platform_set_drvdata(pdev, priv);
> > > +	priv->rdev->ops = &rtc_ops;
> > > +
> > > +	ret = devm_rtc_register_device(priv->rdev);
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed to register RTC device\n");
> > > +		goto disable_rtc;
> > > +	}
> > > +
> > > +	priv->dt_irq_id = platform_get_irq(pdev, 0);
> > > +	if (priv->dt_irq_id < 0)
> > > +		return dev_err_probe(dev, priv->dt_irq_id,
> > > +				"Error reading interrupt # from dts\n");
> > > +
> > > +	ret = devm_request_irq(dev, priv->dt_irq_id,
> > > +			       rtc_handler, 0, dev_name(dev), pdev);
> > > +	if (ret) {
> > > +		dev_err(dev, "Request interrupt %d failed, error: %d\n",
> > > +			priv->dt_irq_id, ret);
> > > +		goto disable_rtc;
> > > +	}
> > > +
> > > +	return 0;
> > > +
> > > +disable_rtc:
> > > +	s32g_rtc_disable(priv);
> > > +	return ret;
> > > +}
> > > +
> > > +static void rtc_remove(struct platform_device *pdev)
> > > +{
> > > +	struct rtc_priv *priv = platform_get_drvdata(pdev);
> > > +
> > > +	s32g_rtc_disable(priv);
> > > +}
> > > +
> > > +static void  __maybe_unused enable_api_irq(struct device *dev, unsigned int enabled)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +	u32 api_irq = RTCC_APIEN | RTCC_APIIE;
> > > +	u32 rtcc;
> > > +
> > > +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> > > +	if (enabled)
> > > +		rtcc |= api_irq;
> > > +	else
> > > +		rtcc &= ~api_irq;
> > > +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> > > +}
> > > +
> > > +static int __maybe_unused rtc_suspend(struct device *dev)
> > > +{
> > > +	struct rtc_priv *init_priv = dev_get_drvdata(dev);
> > > +	struct rtc_priv priv;
> > > +	long long base_sec;
> > > +	int ret = 0;
> > > +	u32 rtcval;
> > > +	u32 sec;
> > > +
> > > +	if (!device_may_wakeup(dev))
> > > +		return 0;
> > > +
> > > +	if (init_priv->suspend_src_idx < 0)
> > > +		return 0;
> > > +
> > > +	if (rtc_get_clk_src(init_priv) + RTC_CLK_MUX_SIZE ==
> > > +			init_priv->suspend_src_idx)
> > > +		return 0;
> > > +
> > > +	/* Save last known timestamp before we switch clocks and reinit RTC */
> > > +	ret = s32g_rtc_read_time(dev, &init_priv->base.tm);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	/*
> > > +	 * Use a local copy of the RTC control block to
> > > +	 * avoid restoring it on resume path.
> > > +	 */
> > > +	memcpy(&priv, init_priv, sizeof(priv));
> > > +
> > > +	ret = get_time_left(dev, init_priv, &sec);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	/* Adjust for the number of seconds we'll be asleep */
> > > +	base_sec = rtc_tm_to_time64(&init_priv->base.tm);
> > > +	base_sec += sec;
> > > +	rtc_time64_to_tm(base_sec, &init_priv->base.tm);
> > > +
> > > +	ret = rtc_clk_src_switch(&priv, priv.suspend_src_idx);
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	ret = sec_to_rtcval(&priv, sec, &rtcval);
> > > +	if (ret) {
> > > +		dev_warn(dev, "Alarm is too far in the future\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	s32g_rtc_alarm_irq_enable(dev, 0);
> > > +	enable_api_irq(dev, 1);
> > > +	iowrite32(rtcval, priv.rtc_base + APIVAL_OFFSET);
> > > +	iowrite32(0, priv.rtc_base + RTCVAL_OFFSET);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int __maybe_unused rtc_resume(struct device *dev)
> > > +{
> > > +	struct rtc_priv *priv = dev_get_drvdata(dev);
> > > +	int ret;
> > > +
> > > +	if (!device_may_wakeup(dev))
> > > +		return 0;
> > > +
> > > +	if (rtc_get_clk_src(priv) == priv->runtime_src_idx)
> > > +		return 0;
> > > +
> > > +	/* Disable wake-up interrupts */
> > > +	enable_api_irq(dev, 0);
> > > +
> > > +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	/*
> > > +	 * Now RTCCNT has just been reset, and is out of sync with priv->base;
> > > +	 * reapply the saved time settings
> > > +	 */
> > > +	return s32g_rtc_set_time(dev, &priv->base.tm);
> > > +}
> > > +
> > > +static const struct of_device_id rtc_dt_ids[] = {
> > > +	{ .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data},
> > > +	{ /* sentinel */ },
> > > +};
> > > +
> > > +static SIMPLE_DEV_PM_OPS(rtc_pm_ops,
> > > +			 rtc_suspend, rtc_resume);
> > > +
> > > +static struct platform_driver rtc_driver = {
> > > +	.driver		= {
> > > +		.name			= "s32g-rtc",
> > > +		.pm				= &rtc_pm_ops,
> >
> > pm_ptr(&rtc_pm_ops),
> >
>
> Thanks. I will update as suggested in V5.
>
>
> Best Regards,
> Ciprian
>
> > > +		.of_match_table = rtc_dt_ids,
> > > +	},
> > > +	.probe		= rtc_probe,
> > > +	.remove	= rtc_remove,
> > > +};
> > > +module_platform_driver(rtc_driver);
> > > +
> > > +MODULE_AUTHOR("NXP");
> > > +MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
> > > +MODULE_LICENSE("GPL");
> > > --
> > > 2.45.2
> > >
>

Re: [PATCH v4 2/4] rtc: s32g: add NXP S32G2/S32G3 SoC support

[Alexandre Belloni]

Hello,

On 11/11/2024 15:59:38+0200, Ciprian Costea wrote:
> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> 
> Add a RTC driver for NXP S32G2/S32G3 SoCs.
> 
> The RTC module is used to enable Suspend to RAM (STR) support on NXP
> S32G2/S32G3 SoC based boards.
> 
> RTC tracks clock time during system suspend.
> 
> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
> during system reset.
> 
> Co-developed-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
> Co-developed-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> ---
>  drivers/rtc/Kconfig    |  11 +
>  drivers/rtc/Makefile   |   1 +
>  drivers/rtc/rtc-s32g.c | 692 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 704 insertions(+)
>  create mode 100644 drivers/rtc/rtc-s32g.c
> 
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index e87c3d74565c..18fc3577f6cd 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -2054,4 +2054,15 @@ config RTC_DRV_SSD202D
>  	  This driver can also be built as a module, if so, the module
>  	  will be called "rtc-ssd20xd".
>  
> +config RTC_DRV_S32G
> +	tristate "RTC driver for S32G2/S32G3 SoCs"
> +	depends on ARCH_S32 || COMPILE_TEST
> +	depends on COMMON_CLK
> +	help
> +	  Say yes to enable RTC driver for platforms based on the
> +	  S32G2/S32G3 SoC family.
> +
> +	  This RTC module can be used as a wakeup source.
> +	  Please note that it is not battery-powered.
> +
>  endif # RTC_CLASS
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 8ee79cb18322..a63d010a753c 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
>  obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
>  obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
>  obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
> +obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
>  obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
>  obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
>  obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
> diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
> new file mode 100644
> index 000000000000..c3792b674a18
> --- /dev/null
> +++ b/drivers/rtc/rtc-s32g.c
> @@ -0,0 +1,692 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/iopoll.h>
> +#include <linux/math64.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/rtc.h>
> +
> +#define RTCC_OFFSET	0x4ul
> +#define RTCS_OFFSET	0x8ul
> +#define RTCCNT_OFFSET	0xCul
> +#define APIVAL_OFFSET	0x10ul
> +#define RTCVAL_OFFSET	0x14ul
> +
> +/* RTCC fields */
> +#define RTCC_CNTEN				BIT(31)
> +#define RTCC_RTCIE_SHIFT		30
> +#define RTCC_RTCIE				BIT(RTCC_RTCIE_SHIFT)
> +#define RTCC_ROVREN				BIT(28)
> +#define RTCC_APIEN				BIT(15)
> +#define RTCC_APIIE				BIT(14)
> +#define RTCC_CLKSEL_OFFSET		12
> +#define RTCC_CLKSEL_MASK		GENMASK(13, 12)
> +#define RTCC_CLKSEL(n)			(((n) << 12) & RTCC_CLKSEL_MASK)
> +#define RTCC_DIV512EN			BIT(11)
> +#define RTCC_DIV32EN			BIT(10)
> +
> +/* RTCS fields */
> +#define RTCS_RTCF		BIT(29)
> +#define RTCS_INV_RTC		BIT(18)
> +#define RTCS_APIF		BIT(13)
> +#define RTCS_ROVRF		BIT(10)
> +
> +#define ROLLOVER_VAL		GENMASK(31, 0)
> +#define RTC_SYNCH_TIMEOUT	(100 * USEC_PER_MSEC)
> +
> +#define RTC_CLK_MUX_SIZE	4
> +
> +/*
> + * S32G2 and S32G3 SoCs have RTC clock source 1 reserved and
> + * should not be used.
> + */
> +#define RTC_QUIRK_SRC1_RESERVED			BIT(2)
> +
> +enum {
> +	RTC_CLK_SRC0,
> +	RTC_CLK_SRC1,
> +	RTC_CLK_SRC2,
> +	RTC_CLK_SRC3
> +};
> +
> +enum {
> +	DIV1 = 1,
> +	DIV32 = 32,
> +	DIV512 = 512,
> +	DIV512_32 = 16384
> +};
> +
> +static const char *rtc_clk_src[RTC_CLK_MUX_SIZE * 2] = {
> +	"rtc_runtime_s0",
> +	"rtc_runtime_s1",
> +	"rtc_runtime_s2",
> +	"rtc_runtime_s3",
> +	"rtc_standby_s0",
> +	"rtc_standby_s1",
> +	"rtc_standby_s2",
> +	"rtc_standby_s3"
> +};
> +
> +struct rtc_time_base {
> +	s64 sec;
> +	u64 cycles;
> +	u64 rollovers;
> +	struct rtc_time tm;
> +};
> +
> +struct rtc_priv {
> +	struct rtc_device *rdev;
> +	void __iomem *rtc_base;
> +	struct clk *ipg;
> +	struct clk *runtime_clk;
> +	struct clk *suspend_clk;
> +	const struct rtc_soc_data *rtc_data;
> +	struct rtc_time_base base;
> +	u64 rtc_hz;
> +	u64 rollovers;
> +	int dt_irq_id;
> +	int runtime_src_idx;
> +	int suspend_src_idx;
> +};
> +
> +struct rtc_soc_data {
> +	u32 runtime_div;
> +	u32 suspend_div;
> +	u32 quirks;
> +};
> +
> +static const struct rtc_soc_data rtc_s32g2_data = {
> +	.runtime_div = DIV512,
> +	.suspend_div = DIV512,
> +	.quirks = RTC_QUIRK_SRC1_RESERVED,
> +};
> +
> +static int is_src1_reserved(struct rtc_priv *priv)
> +{
> +	return priv->rtc_data->quirks & RTC_QUIRK_SRC1_RESERVED;
> +}
> +
> +static u64 cycles_to_sec(u64 hz, u64 cycles)
> +{
> +	return div_u64(cycles, hz);
> +}
> +
> +/**
> + * Convert a number of seconds to a value suitable for RTCVAL in our clock's
> + * current configuration.
> + * @rtcval: The value to go into RTCVAL[RTCVAL]
> + * Returns: 0 for success, -EINVAL if @seconds push the counter at least
> + *          twice the rollover interval
> + */
> +static int sec_to_rtcval(const struct rtc_priv *priv,
> +			 unsigned long seconds, u32 *rtcval)
> +{
> +	u32 rtccnt, delta_cnt;
> +	u32 target_cnt = 0;
> +
> +	/* For now, support at most one rollover of the counter */
> +	if (!seconds || seconds > cycles_to_sec(priv->rtc_hz, ROLLOVER_VAL))
> +		return -EINVAL;

Honestly, I still feel the whole rollover handling is useless as it
doesn't bring any significant benefits. The workflow seems like it will
always be something like:
 - set time
 - set alarm
 - wait for wakeup

Without rollover support, you already have the whole 32bit range for the
counter. Obviously get_time_left is then useless.

The whole clock switching code also seem over complicated. What are the
actual benefits? The accuracy of the wakeup will always be the one of
the clock selected while in suspend and this RTC will probably not be
your system clock because of its limitations.

> +static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	struct rtc_time time_crt;
> +	long long t_crt, t_alrm;
> +	u32 rtcval, rtcs;
> +	int ret = 0;
> +
> +	iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
> +
> +	t_alrm = rtc_tm_to_time64(&alrm->time);
> +
> +	/*
> +	 * Assuming the alarm is being set relative to the same time
> +	 * returned by our s32g_rtc_read_time callback
> +	 */
> +	ret = s32g_rtc_read_time(dev, &time_crt);
> +	if (ret)
> +		return ret;
> +
> +	t_crt = rtc_tm_to_time64(&time_crt);
> +	if (t_alrm <= t_crt) {
> +		dev_warn(dev, "Alarm is set in the past\n");

This is never going to happen.

> +		return -EINVAL;
> +	}
> +
> +	ret = sec_to_rtcval(priv, t_alrm - t_crt, &rtcval);
> +	if (ret) {
> +		/*
> +		 * Rollover support enables RTC alarm
> +		 * for a maximum timespan of ~3 months.
> +		 */
> +		dev_warn(dev, "Alarm is set too far in the future\n");
> +		return ret;

-ERANGE is probably appriopriate.

> +	}
> +
> +	ret = read_poll_timeout(ioread32, rtcs, !(rtcs & RTCS_INV_RTC),
> +				0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
> +	if (ret) {
> +		dev_err(dev, "Synchronization failed\n");

The driver is very verbose. Most of the strings will never be seen by
anyone because this is an embedded system however, the strings will take
space which make the system slower to boot an use more memory than
necessary.

> +		return ret;
> +	}
> +
> +	iowrite32(rtcval, priv->rtc_base + RTCVAL_OFFSET);
> +
> +	return 0;
> +}
> +
> +static int s32g_rtc_set_time(struct device *dev,
> +			     struct rtc_time *time)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +
> +	if (!time)

How will this ever happen?

> +		return -EINVAL;
> +
> +	priv->base.rollovers = priv->rollovers;
> +	priv->base.cycles = ioread32(priv->rtc_base + RTCCNT_OFFSET);
> +	priv->base.sec = rtc_tm_to_time64(time);
> +
> +	return 0;
> +}
> +
> +/*
> + * Disable the 32-bit free running counter.
> + * This allows Clock Source and Divisors selection
> + * to be performed without causing synchronization issues.
> + */
> +static void s32g_rtc_disable(struct rtc_priv *priv)
> +{
> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +
> +	rtcc &= ~RTCC_CNTEN;
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +}
> +
> +static void s32g_rtc_enable(struct rtc_priv *priv)
> +{
> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +
> +	rtcc |= RTCC_CNTEN;
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +}
> +
> +static void adjust_dividers(struct rtc_priv *priv,
> +			    u32 div_val, u32 *reg)
> +{
> +	switch (div_val) {
> +	case DIV512_32:
> +		*reg |= RTCC_DIV512EN;
> +		*reg |= RTCC_DIV32EN;
> +		break;
> +	case DIV512:
> +		*reg |= RTCC_DIV512EN;
> +		break;
> +	case DIV32:
> +		*reg |= RTCC_DIV32EN;
> +		break;
> +	default:
> +		return;
> +	}
> +
> +	priv->rtc_hz /= div_val;
> +}
> +
> +static int rtc_get_clk_src(struct rtc_priv *priv)
> +{
> +	return (ioread32(priv->rtc_base + RTCC_OFFSET) &
> +			RTCC_CLKSEL_MASK) >> RTCC_CLKSEL_OFFSET;
> +}
> +
> +static int rtc_clk_src_switch(struct rtc_priv *priv, u32 src)
> +{
> +	struct device *dev = priv->rdev->dev.parent;
> +	u32 rtcc = 0;
> +
> +	switch (src % RTC_CLK_MUX_SIZE) {
> +	case RTC_CLK_SRC0:
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC0);
> +		break;
> +	case RTC_CLK_SRC1:
> +		if (is_src1_reserved(priv))
> +			return -EOPNOTSUPP;
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC1);
> +		break;
> +	case RTC_CLK_SRC2:
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC2);
> +		break;
> +	case RTC_CLK_SRC3:
> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC3);
> +		break;
> +	default:
> +		dev_err(dev, "Invalid clock mux parent: %d\n", src);
> +		return -EINVAL;
> +	}
> +
> +	if (src < RTC_CLK_MUX_SIZE) {
> +		priv->rtc_hz = clk_get_rate(priv->runtime_clk);
> +		if (!priv->rtc_hz) {
> +			dev_err(dev, "Failed to get RTC frequency\n");
> +			return -EINVAL;
> +		}
> +		adjust_dividers(priv, priv->rtc_data->runtime_div, &rtcc);
> +	} else {
> +		priv->rtc_hz = clk_get_rate(priv->suspend_clk);
> +		if (!priv->rtc_hz) {
> +			dev_err(dev, "Failed to get RTC frequency\n");
> +			return -EINVAL;
> +		}
> +		adjust_dividers(priv, priv->rtc_data->suspend_div, &rtcc);
> +	}
> +
> +	rtcc |= RTCC_RTCIE | RTCC_ROVREN;
> +	/*
> +	 * Make sure the CNTEN is 0 before we configure
> +	 * the clock source and dividers.
> +	 */
> +	s32g_rtc_disable(priv);
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +	s32g_rtc_enable(priv);
> +
> +	return 0;
> +}
> +
> +static const struct rtc_class_ops rtc_ops = {
> +	.read_time = s32g_rtc_read_time,
> +	.set_time = s32g_rtc_set_time,
> +	.read_alarm = s32g_rtc_read_alarm,
> +	.set_alarm = s32g_rtc_set_alarm,
> +	.alarm_irq_enable = s32g_rtc_alarm_irq_enable,
> +};
> +
> +static int rtc_clk_dts_setup(struct rtc_priv *priv,
> +			     struct device *dev)
> +{
> +	int i;
> +
> +	priv->runtime_src_idx = -EINVAL;
> +	priv->suspend_src_idx = -EINVAL;
> +
> +	priv->ipg = devm_clk_get_enabled(dev, "ipg");
> +	if (IS_ERR(priv->ipg)) {
> +		dev_err(dev, "Failed to get 'ipg' clock\n");
> +		return PTR_ERR(priv->ipg);
> +	}
> +
> +	/* Get RTC runtime clock source */
> +	for (i = 0; i < RTC_CLK_MUX_SIZE; i++) {
> +		priv->runtime_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
> +		if (!IS_ERR(priv->runtime_clk)) {
> +			priv->runtime_src_idx = i;
> +			break;
> +		}
> +	}
> +
> +	if (IS_ERR(priv->runtime_clk)) {
> +		dev_err(dev, "Failed to get runtime rtc clock\n");
> +		return PTR_ERR(priv->runtime_clk);
> +	}
> +
> +	/* If present, get RTC suspend clock source */
> +	for (i = RTC_CLK_MUX_SIZE; i < RTC_CLK_MUX_SIZE * 2; i++) {
> +		priv->suspend_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
> +		if (!IS_ERR(priv->suspend_clk)) {
> +			priv->suspend_src_idx = i;
> +			break;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int rtc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct rtc_priv *priv;
> +	int ret = 0;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->rtc_data = of_device_get_match_data(dev);
> +	if (!priv->rtc_data)
> +		return -ENODEV;
> +
> +	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(priv->rtc_base))
> +		return dev_err_probe(dev, PTR_ERR(priv->rtc_base),
> +				"Failed to map registers\n");
> +
> +	device_init_wakeup(dev, true);
> +
> +	ret = rtc_clk_dts_setup(priv, dev);
> +	if (ret)
> +		return ret;
> +
> +	priv->rdev = devm_rtc_allocate_device(dev);
> +	if (IS_ERR(priv->rdev))
> +		return dev_err_probe(dev, PTR_ERR(priv->rdev),
> +				"Failed to allocate RTC device\n");
> +
> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
> +	if (ret)
> +		return dev_err_probe(dev, ret,
> +				"Failed clk source switch, err: %d\n", ret);
> +
> +	platform_set_drvdata(pdev, priv);
> +	priv->rdev->ops = &rtc_ops;
> +
> +	ret = devm_rtc_register_device(priv->rdev);
> +	if (ret) {
> +		dev_err(dev, "Failed to register RTC device\n");
> +		goto disable_rtc;
> +	}
> +
> +	priv->dt_irq_id = platform_get_irq(pdev, 0);
> +	if (priv->dt_irq_id < 0)
> +		return dev_err_probe(dev, priv->dt_irq_id,
> +				"Error reading interrupt # from dts\n");
> +
> +	ret = devm_request_irq(dev, priv->dt_irq_id,
> +			       rtc_handler, 0, dev_name(dev), pdev);
> +	if (ret) {
> +		dev_err(dev, "Request interrupt %d failed, error: %d\n",
> +			priv->dt_irq_id, ret);
> +		goto disable_rtc;
> +	}
> +
> +	return 0;
> +
> +disable_rtc:
> +	s32g_rtc_disable(priv);
> +	return ret;
> +}
> +
> +static void rtc_remove(struct platform_device *pdev)
> +{
> +	struct rtc_priv *priv = platform_get_drvdata(pdev);
> +

You really need a comment here stating why you feel this is necessary to
stop the RTC when removing the driver. Also, you need to prefix your
function names with s32g.

> +	s32g_rtc_disable(priv);
> +}
> +
> +static void  __maybe_unused enable_api_irq(struct device *dev, unsigned int enabled)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	u32 api_irq = RTCC_APIEN | RTCC_APIIE;
> +	u32 rtcc;
> +
> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
> +	if (enabled)
> +		rtcc |= api_irq;
> +	else
> +		rtcc &= ~api_irq;
> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
> +}
> +
> +static int __maybe_unused rtc_suspend(struct device *dev)
> +{
> +	struct rtc_priv *init_priv = dev_get_drvdata(dev);
> +	struct rtc_priv priv;
> +	long long base_sec;
> +	int ret = 0;
> +	u32 rtcval;
> +	u32 sec;
> +
> +	if (!device_may_wakeup(dev))
> +		return 0;
> +
> +	if (init_priv->suspend_src_idx < 0)
> +		return 0;
> +
> +	if (rtc_get_clk_src(init_priv) + RTC_CLK_MUX_SIZE ==
> +			init_priv->suspend_src_idx)
> +		return 0;
> +
> +	/* Save last known timestamp before we switch clocks and reinit RTC */
> +	ret = s32g_rtc_read_time(dev, &init_priv->base.tm);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Use a local copy of the RTC control block to
> +	 * avoid restoring it on resume path.
> +	 */
> +	memcpy(&priv, init_priv, sizeof(priv));
> +
> +	ret = get_time_left(dev, init_priv, &sec);
> +	if (ret)
> +		return ret;
> +
> +	/* Adjust for the number of seconds we'll be asleep */
> +	base_sec = rtc_tm_to_time64(&init_priv->base.tm);
> +	base_sec += sec;
> +	rtc_time64_to_tm(base_sec, &init_priv->base.tm);
> +
> +	ret = rtc_clk_src_switch(&priv, priv.suspend_src_idx);
> +	if (ret) {
> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = sec_to_rtcval(&priv, sec, &rtcval);
> +	if (ret) {
> +		dev_warn(dev, "Alarm is too far in the future\n");
> +		return ret;
> +	}
> +
> +	s32g_rtc_alarm_irq_enable(dev, 0);
> +	enable_api_irq(dev, 1);
> +	iowrite32(rtcval, priv.rtc_base + APIVAL_OFFSET);
> +	iowrite32(0, priv.rtc_base + RTCVAL_OFFSET);
> +
> +	return ret;
> +}
> +
> +static int __maybe_unused rtc_resume(struct device *dev)
> +{
> +	struct rtc_priv *priv = dev_get_drvdata(dev);
> +	int ret;
> +
> +	if (!device_may_wakeup(dev))
> +		return 0;
> +
> +	if (rtc_get_clk_src(priv) == priv->runtime_src_idx)
> +		return 0;
> +
> +	/* Disable wake-up interrupts */
> +	enable_api_irq(dev, 0);
> +
> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
> +	if (ret) {
> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/*
> +	 * Now RTCCNT has just been reset, and is out of sync with priv->base;
> +	 * reapply the saved time settings
> +	 */
> +	return s32g_rtc_set_time(dev, &priv->base.tm);
> +}
> +
> +static const struct of_device_id rtc_dt_ids[] = {
> +	{ .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data},
> +	{ /* sentinel */ },
> +};
> +
> +static SIMPLE_DEV_PM_OPS(rtc_pm_ops,
> +			 rtc_suspend, rtc_resume);
> +
> +static struct platform_driver rtc_driver = {
> +	.driver		= {
> +		.name			= "s32g-rtc",
> +		.pm				= &rtc_pm_ops,
> +		.of_match_table = rtc_dt_ids,
> +	},
> +	.probe		= rtc_probe,
> +	.remove	= rtc_remove,
> +};
> +module_platform_driver(rtc_driver);
> +
> +MODULE_AUTHOR("NXP");
> +MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
> +MODULE_LICENSE("GPL");
> -- 
> 2.45.2
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v4 2/4] rtc: s32g: add NXP S32G2/S32G3 SoC support

[Ciprian Marian Costea]

On 11/14/2024 4:42 PM, Alexandre Belloni wrote:

Hello,

Thank you for reviewing this driver.

> Hello,
> 
> On 11/11/2024 15:59:38+0200, Ciprian Costea wrote:
>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>
>> Add a RTC driver for NXP S32G2/S32G3 SoCs.
>>
>> The RTC module is used to enable Suspend to RAM (STR) support on NXP
>> S32G2/S32G3 SoC based boards.
>>
>> RTC tracks clock time during system suspend.
>>
>> RTC from S32G2/S32G3 is not battery-powered and it is not kept alive
>> during system reset.
>>
>> Co-developed-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
>> Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
>> Co-developed-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
>> Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>> ---
>>   drivers/rtc/Kconfig    |  11 +
>>   drivers/rtc/Makefile   |   1 +
>>   drivers/rtc/rtc-s32g.c | 692 +++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 704 insertions(+)
>>   create mode 100644 drivers/rtc/rtc-s32g.c
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index e87c3d74565c..18fc3577f6cd 100644
>> --- a/drivers/rtc/Kconfig
>> +++ b/drivers/rtc/Kconfig
>> @@ -2054,4 +2054,15 @@ config RTC_DRV_SSD202D
>>   	  This driver can also be built as a module, if so, the module
>>   	  will be called "rtc-ssd20xd".
>>   
>> +config RTC_DRV_S32G
>> +	tristate "RTC driver for S32G2/S32G3 SoCs"
>> +	depends on ARCH_S32 || COMPILE_TEST
>> +	depends on COMMON_CLK
>> +	help
>> +	  Say yes to enable RTC driver for platforms based on the
>> +	  S32G2/S32G3 SoC family.
>> +
>> +	  This RTC module can be used as a wakeup source.
>> +	  Please note that it is not battery-powered.
>> +
>>   endif # RTC_CLASS
>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>> index 8ee79cb18322..a63d010a753c 100644
>> --- a/drivers/rtc/Makefile
>> +++ b/drivers/rtc/Makefile
>> @@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
>>   obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
>>   obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
>>   obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
>> +obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
>>   obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
>>   obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
>>   obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
>> diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
>> new file mode 100644
>> index 000000000000..c3792b674a18
>> --- /dev/null
>> +++ b/drivers/rtc/rtc-s32g.c
>> @@ -0,0 +1,692 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright 2024 NXP
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/clk-provider.h>
>> +#include <linux/err.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/math64.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/rtc.h>
>> +
>> +#define RTCC_OFFSET	0x4ul
>> +#define RTCS_OFFSET	0x8ul
>> +#define RTCCNT_OFFSET	0xCul
>> +#define APIVAL_OFFSET	0x10ul
>> +#define RTCVAL_OFFSET	0x14ul
>> +
>> +/* RTCC fields */
>> +#define RTCC_CNTEN				BIT(31)
>> +#define RTCC_RTCIE_SHIFT		30
>> +#define RTCC_RTCIE				BIT(RTCC_RTCIE_SHIFT)
>> +#define RTCC_ROVREN				BIT(28)
>> +#define RTCC_APIEN				BIT(15)
>> +#define RTCC_APIIE				BIT(14)
>> +#define RTCC_CLKSEL_OFFSET		12
>> +#define RTCC_CLKSEL_MASK		GENMASK(13, 12)
>> +#define RTCC_CLKSEL(n)			(((n) << 12) & RTCC_CLKSEL_MASK)
>> +#define RTCC_DIV512EN			BIT(11)
>> +#define RTCC_DIV32EN			BIT(10)
>> +
>> +/* RTCS fields */
>> +#define RTCS_RTCF		BIT(29)
>> +#define RTCS_INV_RTC		BIT(18)
>> +#define RTCS_APIF		BIT(13)
>> +#define RTCS_ROVRF		BIT(10)
>> +
>> +#define ROLLOVER_VAL		GENMASK(31, 0)
>> +#define RTC_SYNCH_TIMEOUT	(100 * USEC_PER_MSEC)
>> +
>> +#define RTC_CLK_MUX_SIZE	4
>> +
>> +/*
>> + * S32G2 and S32G3 SoCs have RTC clock source 1 reserved and
>> + * should not be used.
>> + */
>> +#define RTC_QUIRK_SRC1_RESERVED			BIT(2)
>> +
>> +enum {
>> +	RTC_CLK_SRC0,
>> +	RTC_CLK_SRC1,
>> +	RTC_CLK_SRC2,
>> +	RTC_CLK_SRC3
>> +};
>> +
>> +enum {
>> +	DIV1 = 1,
>> +	DIV32 = 32,
>> +	DIV512 = 512,
>> +	DIV512_32 = 16384
>> +};
>> +
>> +static const char *rtc_clk_src[RTC_CLK_MUX_SIZE * 2] = {
>> +	"rtc_runtime_s0",
>> +	"rtc_runtime_s1",
>> +	"rtc_runtime_s2",
>> +	"rtc_runtime_s3",
>> +	"rtc_standby_s0",
>> +	"rtc_standby_s1",
>> +	"rtc_standby_s2",
>> +	"rtc_standby_s3"
>> +};
>> +
>> +struct rtc_time_base {
>> +	s64 sec;
>> +	u64 cycles;
>> +	u64 rollovers;
>> +	struct rtc_time tm;
>> +};
>> +
>> +struct rtc_priv {
>> +	struct rtc_device *rdev;
>> +	void __iomem *rtc_base;
>> +	struct clk *ipg;
>> +	struct clk *runtime_clk;
>> +	struct clk *suspend_clk;
>> +	const struct rtc_soc_data *rtc_data;
>> +	struct rtc_time_base base;
>> +	u64 rtc_hz;
>> +	u64 rollovers;
>> +	int dt_irq_id;
>> +	int runtime_src_idx;
>> +	int suspend_src_idx;
>> +};
>> +
>> +struct rtc_soc_data {
>> +	u32 runtime_div;
>> +	u32 suspend_div;
>> +	u32 quirks;
>> +};
>> +
>> +static const struct rtc_soc_data rtc_s32g2_data = {
>> +	.runtime_div = DIV512,
>> +	.suspend_div = DIV512,
>> +	.quirks = RTC_QUIRK_SRC1_RESERVED,
>> +};
>> +
>> +static int is_src1_reserved(struct rtc_priv *priv)
>> +{
>> +	return priv->rtc_data->quirks & RTC_QUIRK_SRC1_RESERVED;
>> +}
>> +
>> +static u64 cycles_to_sec(u64 hz, u64 cycles)
>> +{
>> +	return div_u64(cycles, hz);
>> +}
>> +
>> +/**
>> + * Convert a number of seconds to a value suitable for RTCVAL in our clock's
>> + * current configuration.
>> + * @rtcval: The value to go into RTCVAL[RTCVAL]
>> + * Returns: 0 for success, -EINVAL if @seconds push the counter at least
>> + *          twice the rollover interval
>> + */
>> +static int sec_to_rtcval(const struct rtc_priv *priv,
>> +			 unsigned long seconds, u32 *rtcval)
>> +{
>> +	u32 rtccnt, delta_cnt;
>> +	u32 target_cnt = 0;
>> +
>> +	/* For now, support at most one rollover of the counter */
>> +	if (!seconds || seconds > cycles_to_sec(priv->rtc_hz, ROLLOVER_VAL))
>> +		return -EINVAL;
> 
> Honestly, I still feel the whole rollover handling is useless as it
> doesn't bring any significant benefits. The workflow seems like it will
> always be something like:
>   - set time
>   - set alarm
>   - wait for wakeup
> 
> Without rollover support, you already have the whole 32bit range for the
> counter. Obviously get_time_left is then useless.

I understand how rollover support would not bring much benefit. We can 
live with the 32bit range available for the RTC counter. I will remove 
the rollover support in V5.

> 
> The whole clock switching code also seem over complicated. What are the
> actual benefits? The accuracy of the wakeup will always be the one of
> the clock selected while in suspend and this RTC will probably not be
> your system clock because of its limitations.

I see how the driver complexity which this entire clock switching 
mechanism brings just to use a higher resolution clock during runtime is 
not worth it. I agree, I will drop it in V5 and use just one clock for 
the RTC module.

> 
>> +static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	struct rtc_time time_crt;
>> +	long long t_crt, t_alrm;
>> +	u32 rtcval, rtcs;
>> +	int ret = 0;
>> +
>> +	iowrite32(0x0, priv->rtc_base + RTCVAL_OFFSET);
>> +
>> +	t_alrm = rtc_tm_to_time64(&alrm->time);
>> +
>> +	/*
>> +	 * Assuming the alarm is being set relative to the same time
>> +	 * returned by our s32g_rtc_read_time callback
>> +	 */
>> +	ret = s32g_rtc_read_time(dev, &time_crt);
>> +	if (ret)
>> +		return ret;
>> +
>> +	t_crt = rtc_tm_to_time64(&time_crt);
>> +	if (t_alrm <= t_crt) {
>> +		dev_warn(dev, "Alarm is set in the past\n");
> 
> This is never going to happen.
> 

I see, I will drop this check in V5.

>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = sec_to_rtcval(priv, t_alrm - t_crt, &rtcval);
>> +	if (ret) {
>> +		/*
>> +		 * Rollover support enables RTC alarm
>> +		 * for a maximum timespan of ~3 months.
>> +		 */
>> +		dev_warn(dev, "Alarm is set too far in the future\n");
>> +		return ret;
> 
> -ERANGE is probably appriopriate.
> 

Correct, I will update in V5.

>> +	}
>> +
>> +	ret = read_poll_timeout(ioread32, rtcs, !(rtcs & RTCS_INV_RTC),
>> +				0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
>> +	if (ret) {
>> +		dev_err(dev, "Synchronization failed\n");
> 
> The driver is very verbose. Most of the strings will never be seen by
> anyone because this is an embedded system however, the strings will take
> space which make the system slower to boot an use more memory than
> necessary.
> 

I understand, I will try to refine and limit the error path messages. 
However, usually the S32G2/S32G3 SoCs have 4GB of DDR memory.

>> +		return ret;
>> +	}
>> +
>> +	iowrite32(rtcval, priv->rtc_base + RTCVAL_OFFSET);
>> +
>> +	return 0;
>> +}
>> +
>> +static int s32g_rtc_set_time(struct device *dev,
>> +			     struct rtc_time *time)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +
>> +	if (!time)
> 
> How will this ever happen?
> 

It cannot. I will remove this check in V5.

>> +		return -EINVAL;
>> +
>> +	priv->base.rollovers = priv->rollovers;
>> +	priv->base.cycles = ioread32(priv->rtc_base + RTCCNT_OFFSET);
>> +	priv->base.sec = rtc_tm_to_time64(time);
>> +
>> +	return 0;
>> +}
>> +
>> +/*
>> + * Disable the 32-bit free running counter.
>> + * This allows Clock Source and Divisors selection
>> + * to be performed without causing synchronization issues.
>> + */
>> +static void s32g_rtc_disable(struct rtc_priv *priv)
>> +{
>> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +
>> +	rtcc &= ~RTCC_CNTEN;
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +}
>> +
>> +static void s32g_rtc_enable(struct rtc_priv *priv)
>> +{
>> +	u32 rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +
>> +	rtcc |= RTCC_CNTEN;
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +}
>> +
>> +static void adjust_dividers(struct rtc_priv *priv,
>> +			    u32 div_val, u32 *reg)
>> +{
>> +	switch (div_val) {
>> +	case DIV512_32:
>> +		*reg |= RTCC_DIV512EN;
>> +		*reg |= RTCC_DIV32EN;
>> +		break;
>> +	case DIV512:
>> +		*reg |= RTCC_DIV512EN;
>> +		break;
>> +	case DIV32:
>> +		*reg |= RTCC_DIV32EN;
>> +		break;
>> +	default:
>> +		return;
>> +	}
>> +
>> +	priv->rtc_hz /= div_val;
>> +}
>> +
>> +static int rtc_get_clk_src(struct rtc_priv *priv)
>> +{
>> +	return (ioread32(priv->rtc_base + RTCC_OFFSET) &
>> +			RTCC_CLKSEL_MASK) >> RTCC_CLKSEL_OFFSET;
>> +}
>> +
>> +static int rtc_clk_src_switch(struct rtc_priv *priv, u32 src)
>> +{
>> +	struct device *dev = priv->rdev->dev.parent;
>> +	u32 rtcc = 0;
>> +
>> +	switch (src % RTC_CLK_MUX_SIZE) {
>> +	case RTC_CLK_SRC0:
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC0);
>> +		break;
>> +	case RTC_CLK_SRC1:
>> +		if (is_src1_reserved(priv))
>> +			return -EOPNOTSUPP;
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC1);
>> +		break;
>> +	case RTC_CLK_SRC2:
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC2);
>> +		break;
>> +	case RTC_CLK_SRC3:
>> +		rtcc |= RTCC_CLKSEL(RTC_CLK_SRC3);
>> +		break;
>> +	default:
>> +		dev_err(dev, "Invalid clock mux parent: %d\n", src);
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (src < RTC_CLK_MUX_SIZE) {
>> +		priv->rtc_hz = clk_get_rate(priv->runtime_clk);
>> +		if (!priv->rtc_hz) {
>> +			dev_err(dev, "Failed to get RTC frequency\n");
>> +			return -EINVAL;
>> +		}
>> +		adjust_dividers(priv, priv->rtc_data->runtime_div, &rtcc);
>> +	} else {
>> +		priv->rtc_hz = clk_get_rate(priv->suspend_clk);
>> +		if (!priv->rtc_hz) {
>> +			dev_err(dev, "Failed to get RTC frequency\n");
>> +			return -EINVAL;
>> +		}
>> +		adjust_dividers(priv, priv->rtc_data->suspend_div, &rtcc);
>> +	}
>> +
>> +	rtcc |= RTCC_RTCIE | RTCC_ROVREN;
>> +	/*
>> +	 * Make sure the CNTEN is 0 before we configure
>> +	 * the clock source and dividers.
>> +	 */
>> +	s32g_rtc_disable(priv);
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +	s32g_rtc_enable(priv);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct rtc_class_ops rtc_ops = {
>> +	.read_time = s32g_rtc_read_time,
>> +	.set_time = s32g_rtc_set_time,
>> +	.read_alarm = s32g_rtc_read_alarm,
>> +	.set_alarm = s32g_rtc_set_alarm,
>> +	.alarm_irq_enable = s32g_rtc_alarm_irq_enable,
>> +};
>> +
>> +static int rtc_clk_dts_setup(struct rtc_priv *priv,
>> +			     struct device *dev)
>> +{
>> +	int i;
>> +
>> +	priv->runtime_src_idx = -EINVAL;
>> +	priv->suspend_src_idx = -EINVAL;
>> +
>> +	priv->ipg = devm_clk_get_enabled(dev, "ipg");
>> +	if (IS_ERR(priv->ipg)) {
>> +		dev_err(dev, "Failed to get 'ipg' clock\n");
>> +		return PTR_ERR(priv->ipg);
>> +	}
>> +
>> +	/* Get RTC runtime clock source */
>> +	for (i = 0; i < RTC_CLK_MUX_SIZE; i++) {
>> +		priv->runtime_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
>> +		if (!IS_ERR(priv->runtime_clk)) {
>> +			priv->runtime_src_idx = i;
>> +			break;
>> +		}
>> +	}
>> +
>> +	if (IS_ERR(priv->runtime_clk)) {
>> +		dev_err(dev, "Failed to get runtime rtc clock\n");
>> +		return PTR_ERR(priv->runtime_clk);
>> +	}
>> +
>> +	/* If present, get RTC suspend clock source */
>> +	for (i = RTC_CLK_MUX_SIZE; i < RTC_CLK_MUX_SIZE * 2; i++) {
>> +		priv->suspend_clk = devm_clk_get_enabled(dev, rtc_clk_src[i]);
>> +		if (!IS_ERR(priv->suspend_clk)) {
>> +			priv->suspend_src_idx = i;
>> +			break;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int rtc_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct rtc_priv *priv;
>> +	int ret = 0;
>> +
>> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	priv->rtc_data = of_device_get_match_data(dev);
>> +	if (!priv->rtc_data)
>> +		return -ENODEV;
>> +
>> +	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
>> +	if (IS_ERR(priv->rtc_base))
>> +		return dev_err_probe(dev, PTR_ERR(priv->rtc_base),
>> +				"Failed to map registers\n");
>> +
>> +	device_init_wakeup(dev, true);
>> +
>> +	ret = rtc_clk_dts_setup(priv, dev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	priv->rdev = devm_rtc_allocate_device(dev);
>> +	if (IS_ERR(priv->rdev))
>> +		return dev_err_probe(dev, PTR_ERR(priv->rdev),
>> +				"Failed to allocate RTC device\n");
>> +
>> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
>> +	if (ret)
>> +		return dev_err_probe(dev, ret,
>> +				"Failed clk source switch, err: %d\n", ret);
>> +
>> +	platform_set_drvdata(pdev, priv);
>> +	priv->rdev->ops = &rtc_ops;
>> +
>> +	ret = devm_rtc_register_device(priv->rdev);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to register RTC device\n");
>> +		goto disable_rtc;
>> +	}
>> +
>> +	priv->dt_irq_id = platform_get_irq(pdev, 0);
>> +	if (priv->dt_irq_id < 0)
>> +		return dev_err_probe(dev, priv->dt_irq_id,
>> +				"Error reading interrupt # from dts\n");
>> +
>> +	ret = devm_request_irq(dev, priv->dt_irq_id,
>> +			       rtc_handler, 0, dev_name(dev), pdev);
>> +	if (ret) {
>> +		dev_err(dev, "Request interrupt %d failed, error: %d\n",
>> +			priv->dt_irq_id, ret);
>> +		goto disable_rtc;
>> +	}
>> +
>> +	return 0;
>> +
>> +disable_rtc:
>> +	s32g_rtc_disable(priv);
>> +	return ret;
>> +}
>> +
>> +static void rtc_remove(struct platform_device *pdev)
>> +{
>> +	struct rtc_priv *priv = platform_get_drvdata(pdev);
>> +
> 
> You really need a comment here stating why you feel this is necessary to
> stop the RTC when removing the driver. Also, you need to prefix your
> function names with s32g.
> 

I will update accordingly in V5.


Best Regards,
Ciprian

>> +	s32g_rtc_disable(priv);
>> +}
>> +
>> +static void  __maybe_unused enable_api_irq(struct device *dev, unsigned int enabled)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	u32 api_irq = RTCC_APIEN | RTCC_APIIE;
>> +	u32 rtcc;
>> +
>> +	rtcc = ioread32(priv->rtc_base + RTCC_OFFSET);
>> +	if (enabled)
>> +		rtcc |= api_irq;
>> +	else
>> +		rtcc &= ~api_irq;
>> +	iowrite32(rtcc, priv->rtc_base + RTCC_OFFSET);
>> +}
>> +
>> +static int __maybe_unused rtc_suspend(struct device *dev)
>> +{
>> +	struct rtc_priv *init_priv = dev_get_drvdata(dev);
>> +	struct rtc_priv priv;
>> +	long long base_sec;
>> +	int ret = 0;
>> +	u32 rtcval;
>> +	u32 sec;
>> +
>> +	if (!device_may_wakeup(dev))
>> +		return 0;
>> +
>> +	if (init_priv->suspend_src_idx < 0)
>> +		return 0;
>> +
>> +	if (rtc_get_clk_src(init_priv) + RTC_CLK_MUX_SIZE ==
>> +			init_priv->suspend_src_idx)
>> +		return 0;
>> +
>> +	/* Save last known timestamp before we switch clocks and reinit RTC */
>> +	ret = s32g_rtc_read_time(dev, &init_priv->base.tm);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/*
>> +	 * Use a local copy of the RTC control block to
>> +	 * avoid restoring it on resume path.
>> +	 */
>> +	memcpy(&priv, init_priv, sizeof(priv));
>> +
>> +	ret = get_time_left(dev, init_priv, &sec);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Adjust for the number of seconds we'll be asleep */
>> +	base_sec = rtc_tm_to_time64(&init_priv->base.tm);
>> +	base_sec += sec;
>> +	rtc_time64_to_tm(base_sec, &init_priv->base.tm);
>> +
>> +	ret = rtc_clk_src_switch(&priv, priv.suspend_src_idx);
>> +	if (ret) {
>> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = sec_to_rtcval(&priv, sec, &rtcval);
>> +	if (ret) {
>> +		dev_warn(dev, "Alarm is too far in the future\n");
>> +		return ret;
>> +	}
>> +
>> +	s32g_rtc_alarm_irq_enable(dev, 0);
>> +	enable_api_irq(dev, 1);
>> +	iowrite32(rtcval, priv.rtc_base + APIVAL_OFFSET);
>> +	iowrite32(0, priv.rtc_base + RTCVAL_OFFSET);
>> +
>> +	return ret;
>> +}
>> +
>> +static int __maybe_unused rtc_resume(struct device *dev)
>> +{
>> +	struct rtc_priv *priv = dev_get_drvdata(dev);
>> +	int ret;
>> +
>> +	if (!device_may_wakeup(dev))
>> +		return 0;
>> +
>> +	if (rtc_get_clk_src(priv) == priv->runtime_src_idx)
>> +		return 0;
>> +
>> +	/* Disable wake-up interrupts */
>> +	enable_api_irq(dev, 0);
>> +
>> +	ret = rtc_clk_src_switch(priv, priv->runtime_src_idx);
>> +	if (ret) {
>> +		dev_err(dev, "Failed clk source switch, err: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	/*
>> +	 * Now RTCCNT has just been reset, and is out of sync with priv->base;
>> +	 * reapply the saved time settings
>> +	 */
>> +	return s32g_rtc_set_time(dev, &priv->base.tm);
>> +}
>> +
>> +static const struct of_device_id rtc_dt_ids[] = {
>> +	{ .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data},
>> +	{ /* sentinel */ },
>> +};
>> +
>> +static SIMPLE_DEV_PM_OPS(rtc_pm_ops,
>> +			 rtc_suspend, rtc_resume);
>> +
>> +static struct platform_driver rtc_driver = {
>> +	.driver		= {
>> +		.name			= "s32g-rtc",
>> +		.pm				= &rtc_pm_ops,
>> +		.of_match_table = rtc_dt_ids,
>> +	},
>> +	.probe		= rtc_probe,
>> +	.remove	= rtc_remove,
>> +};
>> +module_platform_driver(rtc_driver);
>> +
>> +MODULE_AUTHOR("NXP");
>> +MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
>> +MODULE_LICENSE("GPL");
>> -- 
>> 2.45.2
>>
> 

[PATCH v4 3/4] arm64: defconfig: add S32G RTC module support

[Ciprian Costea]

From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

The RTC module enables Suspend to RAM (STR) support on NXP S32G2/S32G3
SoC based boards.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 5fdbfea7a5b2..584cef78c984 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -1209,6 +1209,7 @@ CONFIG_RTC_DRV_DA9063=m
 CONFIG_RTC_DRV_EFI=y
 CONFIG_RTC_DRV_CROS_EC=y
 CONFIG_RTC_DRV_FSL_FTM_ALARM=m
+CONFIG_RTC_DRV_S32G=m
 CONFIG_RTC_DRV_S3C=y
 CONFIG_RTC_DRV_PL031=y
 CONFIG_RTC_DRV_SUN6I=y
-- 
2.45.2

[PATCH v4 4/4] MAINTAINERS: add NXP S32G RTC driver

[Ciprian Costea]

From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

Add the NXP S32G RTC driver as maintained so further patches on this
driver can be reviewed under this architecture.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 7bfef98226d9..991a9df6819d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2763,8 +2763,10 @@ R:	Ghennadi Procopciuc <ghennadi.procopciuc@oss.nxp.com>
 L:	NXP S32 Linux Team <s32@nxp.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
+F:	Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
 F:	arch/arm64/boot/dts/freescale/s32g*.dts*
 F:	drivers/pinctrl/nxp/
+F:	drivers/rtc/rtc-s32g.c
 
 ARM/Orion SoC/Technologic Systems TS-78xx platform support
 M:	Alexander Clouter <alex@digriz.org.uk>
-- 
2.45.2