[PATCH v5 0/2] Add the driver for Intel Keem Bay SoC timer block

[PATCH v5 0/2] Add the driver for Intel Keem Bay SoC timer block

[shruthi.sanil]

From: Shruthi Sanil <shruthi.sanil@intel.com>

The timer block supports 1 64-bit free running counter
and 8 32-bit general purpose timers.

Patch 1 holds the device tree binding documentation.
Patch 2 holds the device driver.

This driver is tested on the Keem Bay evaluation module board.

Changes since v4:
- Updated the description in the device tree bindings.
- Updated the unit address of all the timers and counter in the device tree binding.

Changes since v3:
- Update in KConfig file to support COMPILE_TEST for Keem Bay timer.
- Update in device tree bindings to remove status field.
- Update in device tree bindings to remove 64-bit address space for
  the child nodes by using non-empty ranges.

Changes since v2:
- Add multi timer support.
- Update in the device tree binding to support multi timers.
- Code optimization.

Changes since v1:
- Add support for KEEMBAY_TIMER to get selected through Kconfig.platforms.
- Add CLOCK_EVT_FEAT_DYNIRQ as part of clockevent feature.
- Avoid overlapping reg regions across 2 device nodes.
- Simplify 2 device nodes as 1 because both are from same IP block.
- Adapt the driver code according to the new simplified devicetree.

Shruthi Sanil (2):
  dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer
  clocksource: Add Intel Keem Bay timer support

 .../bindings/timer/intel,keembay-timer.yaml   | 166 ++++++++++++
 MAINTAINERS                                   |   5 +
 drivers/clocksource/Kconfig                   |  11 +
 drivers/clocksource/Makefile                  |   1 +
 drivers/clocksource/timer-keembay.c           | 255 ++++++++++++++++++
 5 files changed, 438 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
 create mode 100644 drivers/clocksource/timer-keembay.c


base-commit: 4010a528219e01dd02e768b22168f7f0e78365ce
-- 
2.17.1

[PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

[shruthi.sanil]

From: Shruthi Sanil <shruthi.sanil@intel.com>

Add Device Tree bindings for the Timer IP, which can be used as
clocksource and clockevent device in the Intel Keem Bay SoC.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Shruthi Sanil <shruthi.sanil@intel.com>
---
 .../bindings/timer/intel,keembay-timer.yaml   | 166 ++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml

diff --git a/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml b/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
new file mode 100644
index 000000000000..b2eb2459d09b
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
@@ -0,0 +1,166 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/intel,keembay-timer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel Keem Bay SoC Timers
+
+maintainers:
+  - Shruthi Sanil <shruthi.sanil@intel.com>
+
+description: |
+  The Intel Keem Bay timer driver supports 1 free running counter and 8 timers.
+  Each timer is capable of generating inividual interrupt.
+  Both the features are enabled through the timer general config register.
+
+  The parent node represents the common general configuration details and
+  the child nodes represents the counter and timers.
+
+properties:
+  reg:
+    description: General configuration register address and length.
+    maxItems: 1
+
+  ranges: true
+
+  "#address-cells":
+    const: 2
+
+  "#size-cells":
+    const: 2
+
+required:
+  - reg
+  - ranges
+  - "#address-cells"
+  - "#size-cells"
+
+patternProperties:
+  "^counter@[0-9a-f]+$":
+    type: object
+    description: Properties for Intel Keem Bay counter
+
+    properties:
+      compatible:
+        enum:
+          - intel,keembay-counter
+
+      reg:
+        maxItems: 1
+
+      clocks:
+        maxItems: 1
+
+    required:
+      - compatible
+      - reg
+      - clocks
+
+  "^timer@[0-9a-f]+$":
+    type: object
+    description: Properties for Intel Keem Bay timer
+
+    properties:
+      compatible:
+        enum:
+          - intel,keembay-timer
+
+      reg:
+        maxItems: 1
+
+      interrupts:
+        maxItems: 1
+
+      clocks:
+        maxItems: 1
+
+    required:
+      - compatible
+      - reg
+      - interrupts
+      - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #define KEEM_BAY_A53_TIM
+
+    soc {
+        #address-cells = <0x2>;
+        #size-cells = <0x2>;
+
+        gpt@20331000 {
+            reg = <0x0 0x20331000 0x0 0xc>;
+            ranges = <0x0 0x0 0x20330000 0xF0>;
+            #address-cells = <0x1>;
+            #size-cells = <0x1>;
+
+            counter@e8 {
+                compatible = "intel,keembay-counter";
+                reg = <0xe8 0x8>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@10 {
+                compatible = "intel,keembay-timer";
+                reg = <0x10 0xc>;
+                interrupts = <GIC_SPI 0x3 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@20 {
+                compatible = "intel,keembay-timer";
+                reg = <0x20 0xc>;
+                interrupts = <GIC_SPI 0x4 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@30 {
+                compatible = "intel,keembay-timer";
+                reg = <0x30 0xc>;
+                interrupts = <GIC_SPI 0x5 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@40 {
+                compatible = "intel,keembay-timer";
+                reg = <0x40 0xc>;
+                interrupts = <GIC_SPI 0x6 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@50 {
+                compatible = "intel,keembay-timer";
+                reg = <0x50 0xc>;
+                interrupts = <GIC_SPI 0x7 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@60 {
+                compatible = "intel,keembay-timer";
+                reg = <0x60 0xc>;
+                interrupts = <GIC_SPI 0x8 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@70 {
+                compatible = "intel,keembay-timer";
+                reg = <0x70 0xc>;
+                interrupts = <GIC_SPI 0x9 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+
+            timer@80 {
+                compatible = "intel,keembay-timer";
+                reg = <0x80 0xc>;
+                interrupts = <GIC_SPI 0xa IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
+            };
+        };
+    };
+
+...
-- 
2.17.1

Re: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

[Rob Herring]

On Thu, Jul 29, 2021 at 11:09:36AM +0530, shruthi.sanil@intel.com wrote:
> From: Shruthi Sanil <shruthi.sanil@intel.com>
> 
> Add Device Tree bindings for the Timer IP, which can be used as
> clocksource and clockevent device in the Intel Keem Bay SoC.
> 
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
> Signed-off-by: Shruthi Sanil <shruthi.sanil@intel.com>
> ---
>  .../bindings/timer/intel,keembay-timer.yaml   | 166 ++++++++++++++++++
>  1 file changed, 166 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> 
> diff --git a/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml b/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> new file mode 100644
> index 000000000000..b2eb2459d09b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> @@ -0,0 +1,166 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/timer/intel,keembay-timer.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Intel Keem Bay SoC Timers
> +
> +maintainers:
> +  - Shruthi Sanil <shruthi.sanil@intel.com>
> +
> +description: |
> +  The Intel Keem Bay timer driver supports 1 free running counter and 8 timers.
> +  Each timer is capable of generating inividual interrupt.
> +  Both the features are enabled through the timer general config register.
> +
> +  The parent node represents the common general configuration details and
> +  the child nodes represents the counter and timers.
> +
> +properties:

You need a 'compatible' here. Otherwise, how does one know what 
'reg' contains. Also, without it, this schema will never be applied.

> +  reg:
> +    description: General configuration register address and length.
> +    maxItems: 1
> +
> +  ranges: true
> +
> +  "#address-cells":
> +    const: 2
> +
> +  "#size-cells":
> +    const: 2
> +
> +required:
> +  - reg
> +  - ranges
> +  - "#address-cells"
> +  - "#size-cells"
> +
> +patternProperties:
> +  "^counter@[0-9a-f]+$":
> +    type: object
> +    description: Properties for Intel Keem Bay counter
> +
> +    properties:
> +      compatible:
> +        enum:
> +          - intel,keembay-counter
> +
> +      reg:
> +        maxItems: 1
> +
> +      clocks:
> +        maxItems: 1
> +
> +    required:
> +      - compatible
> +      - reg
> +      - clocks
> +
> +  "^timer@[0-9a-f]+$":
> +    type: object
> +    description: Properties for Intel Keem Bay timer
> +
> +    properties:
> +      compatible:
> +        enum:
> +          - intel,keembay-timer
> +
> +      reg:
> +        maxItems: 1
> +
> +      interrupts:
> +        maxItems: 1
> +
> +      clocks:
> +        maxItems: 1
> +
> +    required:
> +      - compatible
> +      - reg
> +      - interrupts
> +      - clocks
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #define KEEM_BAY_A53_TIM
> +
> +    soc {
> +        #address-cells = <0x2>;
> +        #size-cells = <0x2>;
> +
> +        gpt@20331000 {
> +            reg = <0x0 0x20331000 0x0 0xc>;
> +            ranges = <0x0 0x0 0x20330000 0xF0>;
> +            #address-cells = <0x1>;
> +            #size-cells = <0x1>;
> +
> +            counter@e8 {
> +                compatible = "intel,keembay-counter";
> +                reg = <0xe8 0x8>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@10 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x10 0xc>;
> +                interrupts = <GIC_SPI 0x3 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@20 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x20 0xc>;
> +                interrupts = <GIC_SPI 0x4 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@30 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x30 0xc>;
> +                interrupts = <GIC_SPI 0x5 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@40 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x40 0xc>;
> +                interrupts = <GIC_SPI 0x6 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@50 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x50 0xc>;
> +                interrupts = <GIC_SPI 0x7 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@60 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x60 0xc>;
> +                interrupts = <GIC_SPI 0x8 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@70 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x70 0xc>;
> +                interrupts = <GIC_SPI 0x9 IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +
> +            timer@80 {
> +                compatible = "intel,keembay-timer";
> +                reg = <0x80 0xc>;
> +                interrupts = <GIC_SPI 0xa IRQ_TYPE_LEVEL_HIGH>;
> +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> +            };
> +        };
> +    };
> +
> +...
> -- 
> 2.17.1
> 
> 

RE: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

[Sanil, Shruthi]

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: Tuesday, August 3, 2021 4:14 AM
> To: Sanil, Shruthi <shruthi.sanil@intel.com>
> Cc: daniel.lezcano@linaro.org; tglx@linutronix.de; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org;
> andriy.shevchenko@linux.intel.com; kris.pan@linux.intel.com;
> mgross@linux.intel.com; Thokala, Srikanth <srikanth.thokala@intel.com>;
> Raja Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@intel.com>;
> Sangannavar, Mallikarjunappa <mallikarjunappa.sangannavar@intel.com>
> Subject: Re: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem
> Bay SoC Timer
> 
> On Thu, Jul 29, 2021 at 11:09:36AM +0530, shruthi.sanil@intel.com wrote:
> > From: Shruthi Sanil <shruthi.sanil@intel.com>
> >
> > Add Device Tree bindings for the Timer IP, which can be used as
> > clocksource and clockevent device in the Intel Keem Bay SoC.
> >
> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
> > Signed-off-by: Shruthi Sanil <shruthi.sanil@intel.com>
> > ---
> >  .../bindings/timer/intel,keembay-timer.yaml   | 166 ++++++++++++++++++
> >  1 file changed, 166 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> > b/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> > new file mode 100644
> > index 000000000000..b2eb2459d09b
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/timer/intel,keembay-
> timer.yaml
> > @@ -0,0 +1,166 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/timer/intel,keembay-timer.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Intel Keem Bay SoC Timers
> > +
> > +maintainers:
> > +  - Shruthi Sanil <shruthi.sanil@intel.com>
> > +
> > +description: |
> > +  The Intel Keem Bay timer driver supports 1 free running counter and 8
> timers.
> > +  Each timer is capable of generating inividual interrupt.
> > +  Both the features are enabled through the timer general config register.
> > +
> > +  The parent node represents the common general configuration details
> > + and  the child nodes represents the counter and timers.
> > +
> > +properties:
> 
> You need a 'compatible' here. Otherwise, how does one know what 'reg'
> contains. Also, without it, this schema will never be applied.
> 

This is a parent block that has the common configuration register address defined which we would need during the initialization of the child nodes. This block in itself is not doing anything. We have this because, we have a common register that is required to be accessed during all the timers and counter initialization.
The child nodes have the compatible string, which is used in the driver. I have validated this on the Keem Bay HW and see that the timer probes are being called and the timers are functional as expected.

> > +  reg:
> > +    description: General configuration register address and length.
> > +    maxItems: 1
> > +
> > +  ranges: true
> > +
> > +  "#address-cells":
> > +    const: 2
> > +
> > +  "#size-cells":
> > +    const: 2
> > +
> > +required:
> > +  - reg
> > +  - ranges
> > +  - "#address-cells"
> > +  - "#size-cells"
> > +
> > +patternProperties:
> > +  "^counter@[0-9a-f]+$":
> > +    type: object
> > +    description: Properties for Intel Keem Bay counter
> > +
> > +    properties:
> > +      compatible:
> > +        enum:
> > +          - intel,keembay-counter
> > +
> > +      reg:
> > +        maxItems: 1
> > +
> > +      clocks:
> > +        maxItems: 1
> > +
> > +    required:
> > +      - compatible
> > +      - reg
> > +      - clocks
> > +
> > +  "^timer@[0-9a-f]+$":
> > +    type: object
> > +    description: Properties for Intel Keem Bay timer
> > +
> > +    properties:
> > +      compatible:
> > +        enum:
> > +          - intel,keembay-timer
> > +
> > +      reg:
> > +        maxItems: 1
> > +
> > +      interrupts:
> > +        maxItems: 1
> > +
> > +      clocks:
> > +        maxItems: 1
> > +
> > +    required:
> > +      - compatible
> > +      - reg
> > +      - interrupts
> > +      - clocks
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    #define KEEM_BAY_A53_TIM
> > +
> > +    soc {
> > +        #address-cells = <0x2>;
> > +        #size-cells = <0x2>;
> > +
> > +        gpt@20331000 {
> > +            reg = <0x0 0x20331000 0x0 0xc>;
> > +            ranges = <0x0 0x0 0x20330000 0xF0>;
> > +            #address-cells = <0x1>;
> > +            #size-cells = <0x1>;
> > +
> > +            counter@e8 {
> > +                compatible = "intel,keembay-counter";
> > +                reg = <0xe8 0x8>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@10 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x10 0xc>;
> > +                interrupts = <GIC_SPI 0x3 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@20 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x20 0xc>;
> > +                interrupts = <GIC_SPI 0x4 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@30 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x30 0xc>;
> > +                interrupts = <GIC_SPI 0x5 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@40 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x40 0xc>;
> > +                interrupts = <GIC_SPI 0x6 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@50 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x50 0xc>;
> > +                interrupts = <GIC_SPI 0x7 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@60 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x60 0xc>;
> > +                interrupts = <GIC_SPI 0x8 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@70 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x70 0xc>;
> > +                interrupts = <GIC_SPI 0x9 IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +
> > +            timer@80 {
> > +                compatible = "intel,keembay-timer";
> > +                reg = <0x80 0xc>;
> > +                interrupts = <GIC_SPI 0xa IRQ_TYPE_LEVEL_HIGH>;
> > +                clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > +            };
> > +        };
> > +    };
> > +
> > +...
> > --
> > 2.17.1
> >
> >

Re: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

[Andy Shevchenko]

On Wed, Aug 4, 2021 at 8:35 AM Sanil, Shruthi <shruthi.sanil@intel.com> wrote:
> > From: Rob Herring <robh@kernel.org>
> > Sent: Tuesday, August 3, 2021 4:14 AM

...

> > > +properties:
> >
> > You need a 'compatible' here. Otherwise, how does one know what 'reg'
> > contains. Also, without it, this schema will never be applied.
> >
>
> This is a parent block that has the common configuration register address defined which we would need during the initialization of the child nodes. This block in itself is not doing anything. We have this because, we have a common register that is required to be accessed during all the timers and counter initialization.
> The child nodes have the compatible string, which is used in the driver. I have validated this on the Keem Bay HW and see that the timer probes are being called and the timers are functional as expected.

I think I understand now. The problem is that the current state of
affairs with this block is incorrect software representation. What you
need is to create an MFD device driver (for which the compatible will
exactly the one Rob is telling about) and from it you register the
rest of your drivers. The existing drivers for this block should be
converted to MFD schema.

-- 
With Best Regards,
Andy Shevchenko

RE: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

[Sanil, Shruthi]

> -----Original Message-----
> From: Andy Shevchenko <andy.shevchenko@gmail.com>
> Sent: Wednesday, August 4, 2021 1:08 PM
> To: Sanil, Shruthi <shruthi.sanil@intel.com>
> Cc: Rob Herring <robh@kernel.org>; daniel.lezcano@linaro.org;
> tglx@linutronix.de; linux-kernel@vger.kernel.org;
> devicetree@vger.kernel.org; andriy.shevchenko@linux.intel.com;
> kris.pan@linux.intel.com; mgross@linux.intel.com; Thokala, Srikanth
> <srikanth.thokala@intel.com>; Raja Subramanian, Lakshmi Bai
> <lakshmi.bai.raja.subramanian@intel.com>; Sangannavar, Mallikarjunappa
> <mallikarjunappa.sangannavar@intel.com>
> Subject: Re: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem
> Bay SoC Timer
> 
> On Wed, Aug 4, 2021 at 8:35 AM Sanil, Shruthi <shruthi.sanil@intel.com>
> wrote:
> > > From: Rob Herring <robh@kernel.org>
> > > Sent: Tuesday, August 3, 2021 4:14 AM
> 
> ...
> 
> > > > +properties:
> > >
> > > You need a 'compatible' here. Otherwise, how does one know what 'reg'
> > > contains. Also, without it, this schema will never be applied.
> > >
> >
> > This is a parent block that has the common configuration register address
> defined which we would need during the initialization of the child nodes. This
> block in itself is not doing anything. We have this because, we have a
> common register that is required to be accessed during all the timers and
> counter initialization.
> > The child nodes have the compatible string, which is used in the driver. I
> have validated this on the Keem Bay HW and see that the timer probes are
> being called and the timers are functional as expected.
> 
> I think I understand now. The problem is that the current state of affairs with
> this block is incorrect software representation. What you need is to create an
> MFD device driver (for which the compatible will exactly the one Rob is telling
> about) and from it you register the rest of your drivers. The existing drivers
> for this block should be converted to MFD schema.

Sure Andy, I shall check on this and get back.
Thank You!

> 
> --
> With Best Regards,
> Andy Shevchenko

RE: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

[Sanil, Shruthi]

> -----Original Message-----
> From: Sanil, Shruthi
> Sent: Thursday, August 12, 2021 10:19 PM
> To: Andy Shevchenko <andy.shevchenko@gmail.com>
> Cc: Rob Herring <robh@kernel.org>; daniel.lezcano@linaro.org;
> tglx@linutronix.de; linux-kernel@vger.kernel.org;
> devicetree@vger.kernel.org; andriy.shevchenko@linux.intel.com;
> kris.pan@linux.intel.com; mgross@linux.intel.com; Thokala, Srikanth
> <Srikanth.Thokala@intel.com>; Raja Subramanian, Lakshmi Bai
> <lakshmi.bai.raja.subramanian@intel.com>; Sangannavar, Mallikarjunappa
> <mallikarjunappa.sangannavar@intel.com>
> Subject: RE: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel Keem
> Bay SoC Timer
> 
> > -----Original Message-----
> > From: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Sent: Wednesday, August 4, 2021 1:08 PM
> > To: Sanil, Shruthi <shruthi.sanil@intel.com>
> > Cc: Rob Herring <robh@kernel.org>; daniel.lezcano@linaro.org;
> > tglx@linutronix.de; linux-kernel@vger.kernel.org;
> > devicetree@vger.kernel.org; andriy.shevchenko@linux.intel.com;
> > kris.pan@linux.intel.com; mgross@linux.intel.com; Thokala, Srikanth
> > <srikanth.thokala@intel.com>; Raja Subramanian, Lakshmi Bai
> > <lakshmi.bai.raja.subramanian@intel.com>; Sangannavar, Mallikarjunappa
> > <mallikarjunappa.sangannavar@intel.com>
> > Subject: Re: [PATCH v5 1/2] dt-bindings: timer: Add bindings for Intel
> > Keem Bay SoC Timer
> >
> > On Wed, Aug 4, 2021 at 8:35 AM Sanil, Shruthi
> > <shruthi.sanil@intel.com>
> > wrote:
> > > > From: Rob Herring <robh@kernel.org>
> > > > Sent: Tuesday, August 3, 2021 4:14 AM
> >
> > ...
> >
> > > > > +properties:
> > > >
> > > > You need a 'compatible' here. Otherwise, how does one know what
> 'reg'
> > > > contains. Also, without it, this schema will never be applied.
> > > >
> > >
> > > This is a parent block that has the common configuration register
> > > address
> > defined which we would need during the initialization of the child
> > nodes. This block in itself is not doing anything. We have this
> > because, we have a common register that is required to be accessed
> > during all the timers and counter initialization.
> > > The child nodes have the compatible string, which is used in the
> > > driver. I
> > have validated this on the Keem Bay HW and see that the timer probes
> > are being called and the timers are functional as expected.
> >
> > I think I understand now. The problem is that the current state of
> > affairs with this block is incorrect software representation. What you
> > need is to create an MFD device driver (for which the compatible will
> > exactly the one Rob is telling
> > about) and from it you register the rest of your drivers. The existing
> > drivers for this block should be converted to MFD schema.
> 
> Sure Andy, I shall check on this and get back.
> Thank You!
> 

Hi Rob,
Do you agree with the above proposal of creating a MFD device with compatible string "simple-mfd"? 

> >
> > --
> > With Best Regards,
> > Andy Shevchenko

[PATCH v5 2/2] clocksource: Add Intel Keem Bay timer support

[shruthi.sanil]

From: Shruthi Sanil <shruthi.sanil@intel.com>

The Intel Keem Bay timer driver supports clocksource and clockevent
features for the timer IP used in Intel Keem Bay SoC.
The timer block supports 1 free running counter and 8 timers.
The free running counter can be used as a clocksource and
the timers can be used as clockevent. Each timer is capable of
generating individual interrupt.
Both the features are enabled through the timer general config register.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Shruthi Sanil <shruthi.sanil@intel.com>
---
 MAINTAINERS                         |   5 +
 drivers/clocksource/Kconfig         |  11 ++
 drivers/clocksource/Makefile        |   1 +
 drivers/clocksource/timer-keembay.c | 255 ++++++++++++++++++++++++++++
 4 files changed, 272 insertions(+)
 create mode 100644 drivers/clocksource/timer-keembay.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 19135a9d778e..a1ad37cd5350 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9436,6 +9436,11 @@ F:	drivers/crypto/keembay/keembay-ocs-hcu-core.c
 F:	drivers/crypto/keembay/ocs-hcu.c
 F:	drivers/crypto/keembay/ocs-hcu.h
 
+INTEL KEEM BAY TIMER SUPPORT
+M:	Shruthi Sanil <shruthi.sanil@intel.com>
+S:	Maintained
+F:	drivers/clocksource/timer-keembay.c
+
 INTEL MANAGEMENT ENGINE (mei)
 M:	Tomas Winkler <tomas.winkler@intel.com>
 L:	linux-kernel@vger.kernel.org
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index eb661b539a3e..4878784dba94 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -707,4 +707,15 @@ config MICROCHIP_PIT64B
 	  modes and high resolution. It is used as a clocksource
 	  and a clockevent.
 
+config KEEMBAY_TIMER
+	bool "Intel Keem Bay timer"
+	depends on ARCH_KEEMBAY || COMPILE_TEST
+	select TIMER_OF
+	help
+	  This option enables the support for the Intel Keem Bay
+	  general purpose timer and free running counter driver.
+	  Each timer can generate an individual interrupt and
+	  supports oneshot and periodic modes.
+	  The 64-bit counter can be used as a clock source.
+
 endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index c17ee32a7151..ea319063ba47 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -88,3 +88,4 @@ obj-$(CONFIG_CSKY_MP_TIMER)		+= timer-mp-csky.o
 obj-$(CONFIG_GX6605S_TIMER)		+= timer-gx6605s.o
 obj-$(CONFIG_HYPERV_TIMER)		+= hyperv_timer.o
 obj-$(CONFIG_MICROCHIP_PIT64B)		+= timer-microchip-pit64b.o
+obj-$(CONFIG_KEEMBAY_TIMER)		+= timer-keembay.o
diff --git a/drivers/clocksource/timer-keembay.c b/drivers/clocksource/timer-keembay.c
new file mode 100644
index 000000000000..e62187eeb4f6
--- /dev/null
+++ b/drivers/clocksource/timer-keembay.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Keem Bay Timer driver
+ *
+ * Copyright (C) 2020 Intel Corporation
+ */
+
+#include <linux/bitops.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include "timer-of.h"
+
+/* Timer register offset */
+#define TIM_CNT_VAL_OFFSET		0x0
+#define TIM_RELOAD_VAL_OFFSET		0x4
+#define TIM_CONFIG_OFFSET		0x8
+
+/* Bit fields of timer general config register */
+#define TIM_CONFIG_PRESCALER_ENABLE	BIT(2)
+#define TIM_CONFIG_COUNTER_ENABLE	BIT(0)
+
+/* Bit fields of timer config register */
+#define TIM_CONFIG_INTERRUPT_PENDING	BIT(4)
+#define TIM_CONFIG_INTERRUPT_ENABLE	BIT(2)
+#define TIM_CONFIG_RESTART		BIT(1)
+#define TIM_CONFIG_ENABLE		BIT(0)
+
+#define TIM_GEN_MASK			GENMASK(31, 12)
+#define TIM_RATING			200
+#define TIM_CLKSRC_MASK_BITS		64
+
+#define TIMER_NAME_SIZE			25
+
+/* Provides a unique ID for each timer */
+static DEFINE_IDA(keembay_timer_ida);
+
+static inline void keembay_timer_enable(void __iomem *base, u32 flags)
+{
+	writel(TIM_CONFIG_ENABLE | flags, base + TIM_CONFIG_OFFSET);
+}
+
+static inline void keembay_timer_disable(void __iomem *base)
+{
+	writel(0x0, base + TIM_CONFIG_OFFSET);
+}
+
+static inline void keembay_timer_update_counter(void __iomem *base, u32 val)
+{
+	writel(val, base + TIM_CNT_VAL_OFFSET);
+	writel(val, base + TIM_RELOAD_VAL_OFFSET);
+}
+
+static inline void keembay_timer_clear_pending_int(void __iomem *base)
+{
+	u32 val;
+
+	val = readl(base + TIM_CONFIG_OFFSET);
+	val &= ~TIM_CONFIG_INTERRUPT_PENDING;
+	writel(val, base + TIM_CONFIG_OFFSET);
+}
+
+static int keembay_timer_set_next_event(unsigned long evt, struct clock_event_device *ce)
+{
+	u32 flags = TIM_CONFIG_INTERRUPT_ENABLE;
+	struct timer_of *to = to_timer_of(ce);
+	void __iomem *tim_base = timer_of_base(to);
+
+	keembay_timer_disable(tim_base);
+	keembay_timer_update_counter(tim_base, evt);
+	keembay_timer_enable(tim_base, flags);
+
+	return 0;
+}
+
+static int keembay_timer_periodic(struct clock_event_device *ce)
+{
+	u32 flags = TIM_CONFIG_INTERRUPT_ENABLE | TIM_CONFIG_RESTART;
+	struct timer_of *to = to_timer_of(ce);
+	void __iomem *tim_base = timer_of_base(to);
+
+	keembay_timer_disable(tim_base);
+	keembay_timer_update_counter(tim_base, timer_of_period(to));
+	keembay_timer_enable(tim_base, flags);
+
+	return 0;
+}
+
+static int keembay_timer_shutdown(struct clock_event_device *ce)
+{
+	struct timer_of *to = to_timer_of(ce);
+
+	keembay_timer_disable(timer_of_base(to));
+
+	return 0;
+}
+
+static irqreturn_t keembay_timer_isr(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+	struct timer_of *to = to_timer_of(evt);
+	void __iomem *tim_base = timer_of_base(to);
+	u32 val;
+
+	val = readl(tim_base + TIM_CONFIG_OFFSET);
+
+	if (val & TIM_CONFIG_RESTART) {
+		/* Clear interrupt for periodic timer*/
+		keembay_timer_clear_pending_int(tim_base);
+	} else {
+		/* Disable the timer for one shot timer */
+		keembay_timer_disable(tim_base);
+	}
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static int __init keembay_clockevent_init(struct device_node *np)
+{
+	struct device_node *gpt_node = np->parent;
+	struct timer_of *keembay_ce_to;
+	void __iomem *gpt_base;
+	char *timer_name;
+	int timer_id;
+	int ret;
+	u32 val;
+
+	gpt_base = of_iomap(gpt_node, 0);
+	if (!gpt_base) {
+		pr_err("%pOF: Failed to get general config base address\n", np);
+		return -ENXIO;
+	}
+
+	/* Prescaler must be enabled for the timer to operate */
+	val = readl(gpt_base + TIM_CONFIG_OFFSET);
+	if (!(val & TIM_CONFIG_PRESCALER_ENABLE)) {
+		pr_err("%pOF: Prescaler is not enabled\n", np);
+		ret = -ENODEV;
+		goto err_iounmap;
+	}
+
+	keembay_ce_to = kzalloc(sizeof(*keembay_ce_to), GFP_KERNEL);
+	if (!keembay_ce_to) {
+		ret = -ENOMEM;
+		goto err_iounmap;
+	}
+
+	timer_id = ida_alloc(&keembay_timer_ida, GFP_KERNEL);
+	if (timer_id < 0) {
+		ret = timer_id;
+		goto err_keembay_ce_to_free;
+	}
+
+	timer_name = kasprintf(GFP_KERNEL, "keembay_timer%d", timer_id);
+	if (!timer_name) {
+		ret = -ENOMEM;
+		goto err_free_ida;
+	}
+
+	keembay_ce_to->flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK;
+	keembay_ce_to->clkevt.name = timer_name;
+	keembay_ce_to->clkevt.cpumask = cpumask_of(0);
+	keembay_ce_to->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
+					 CLOCK_EVT_FEAT_ONESHOT  |
+					 CLOCK_EVT_FEAT_DYNIRQ;
+	keembay_ce_to->clkevt.rating = TIM_RATING;
+	keembay_ce_to->clkevt.set_next_event = keembay_timer_set_next_event;
+	keembay_ce_to->clkevt.set_state_periodic = keembay_timer_periodic;
+	keembay_ce_to->clkevt.set_state_shutdown = keembay_timer_shutdown;
+	keembay_ce_to->of_irq.handler = keembay_timer_isr;
+	keembay_ce_to->of_irq.flags = IRQF_TIMER;
+
+	ret = timer_of_init(np, keembay_ce_to);
+	if (ret)
+		goto err_timer_name_free;
+
+	val = readl(gpt_base + TIM_RELOAD_VAL_OFFSET);
+	iounmap(gpt_base);
+
+	keembay_ce_to->of_clk.rate = keembay_ce_to->of_clk.rate / (val + 1);
+
+	clockevents_config_and_register(&keembay_ce_to->clkevt,
+					timer_of_rate(keembay_ce_to),
+					1,
+					U32_MAX);
+
+	return 0;
+
+err_timer_name_free:
+	kfree(timer_name);
+err_free_ida:
+	ida_free(&keembay_timer_ida, timer_id);
+err_keembay_ce_to_free:
+	kfree(keembay_ce_to);
+err_iounmap:
+	iounmap(gpt_base);
+
+	return ret;
+}
+
+static struct timer_of keembay_cs_to = {
+	.flags	= TIMER_OF_BASE | TIMER_OF_CLOCK,
+};
+
+static u64 notrace keembay_clocksource_read(struct clocksource *cs)
+{
+	return lo_hi_readq(timer_of_base(&keembay_cs_to));
+}
+
+static struct clocksource keembay_counter = {
+	.name	= "keembay_sys_counter",
+	.rating	= TIM_RATING,
+	.read	= keembay_clocksource_read,
+	.mask	= CLOCKSOURCE_MASK(TIM_CLKSRC_MASK_BITS),
+	.flags	= CLOCK_SOURCE_IS_CONTINUOUS |
+		  CLOCK_SOURCE_SUSPEND_NONSTOP,
+};
+
+static int __init keembay_clocksource_init(struct device_node *np)
+{
+	struct device_node *gpt_node = np->parent;
+	void __iomem *gpt_base;
+	u32 val;
+	int ret;
+
+	gpt_base = of_iomap(gpt_node, 0);
+	if (!gpt_base) {
+		pr_err("%pOF: Failed to get general config base address\n", np);
+		return -ENXIO;
+	}
+
+	/* Free Running Counter must be enabled */
+	val = readl(gpt_base + TIM_CONFIG_OFFSET);
+	iounmap(gpt_base);
+	if (!(val & TIM_CONFIG_COUNTER_ENABLE)) {
+		pr_err("%pOF: free running counter is not enabled\n", np);
+		return -ENODEV;
+	}
+
+	ret = timer_of_init(np, &keembay_cs_to);
+	if (ret)
+		return ret;
+
+	return clocksource_register_hz(&keembay_counter, timer_of_rate(&keembay_cs_to));
+}
+
+TIMER_OF_DECLARE(keembay_clockevent, "intel,keembay-timer", keembay_clockevent_init);
+TIMER_OF_DECLARE(keembay_clocksource, "intel,keembay-counter", keembay_clocksource_init);
-- 
2.17.1