[PATCH v6 00/11] Turris Omnia MCU driver

[PATCH v6 00/11] Turris Omnia MCU driver

[Marek Behún]

Hello Andy, Dan, Linus, Arnd, Gregory, and others,

I am sending v6 of the series adding Turris Omnia MCU driver.

This series depends on the immutable branch between LEDs and locking,
introducing devm_mutex_init(), see the PR
  https://lore.kernel.org/linux-leds/20240412084616.GR2399047@google.com/

See the cover letters for v1, v2, v3, v4 and v5:
  https://patchwork.kernel.org/project/linux-soc/cover/20230823161012.6986-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20230919103815.16818-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20231023143130.11602-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20231026161803.16750-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240323164359.21642-1-kabel@kernel.org/

Changes since v5:
- use dev_get_drvdata(dev) instead of
  i2c_get_clientdata(to_i2c_client(dev))
- uses devm_mutex_init() from the above mentioned branch
- addressed Andy's suggestions for patch 2 (excluding the one suggesting
  100 column lines, I still prefer 80 columns)
- addressed Dan's suggestion for devm_irq_create_mapping() (return
  -ENXIO if mapping could not be created, not 0 as irq_create_mapping()
  does)
- I threw away the changes for other drivers that came with the new
  devm_ helpers, notably conversion to devm_debugfs_create_dir(), as
  there were some problems

Marek Behún (11):
  dt-bindings: arm: add cznic,turris-omnia-mcu binding
  platform: cznic: Add preliminary support for Turris Omnia MCU
  platform: cznic: turris-omnia-mcu: Add support for MCU connected GPIOs
  platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup
  platform: cznic: turris-omnia-mcu: Add support for MCU watchdog
  devm-helpers: Add resource managed version of irq_create_mapping()
  platform: cznic: turris-omnia-mcu: Add support for MCU provided TRNG
  devm-helpers: Add resource managed version of debugfs directory create
    function
  platform: cznic: turris-omnia-mcu: Add support for digital message
    signing via debugfs
  ARM: dts: turris-omnia: Add MCU system-controller node
  ARM: dts: turris-omnia: Add GPIO key node for front button

 .../ABI/testing/debugfs-turris-omnia-mcu      |   13 +
 .../sysfs-bus-i2c-devices-turris-omnia-mcu    |  126 ++
 .../bindings/arm/cznic,turris-omnia-mcu.yaml  |   86 ++
 MAINTAINERS                                   |    5 +
 .../dts/marvell/armada-385-turris-omnia.dts   |   35 +-
 drivers/platform/Kconfig                      |    2 +
 drivers/platform/Makefile                     |    1 +
 drivers/platform/cznic/Kconfig                |   51 +
 drivers/platform/cznic/Makefile               |    9 +
 .../platform/cznic/turris-omnia-mcu-base.c    |  439 +++++++
 .../platform/cznic/turris-omnia-mcu-debugfs.c |  209 ++++
 .../platform/cznic/turris-omnia-mcu-gpio.c    | 1047 +++++++++++++++++
 .../cznic/turris-omnia-mcu-sys-off-wakeup.c   |  258 ++++
 .../platform/cznic/turris-omnia-mcu-trng.c    |   89 ++
 .../cznic/turris-omnia-mcu-watchdog.c         |  123 ++
 drivers/platform/cznic/turris-omnia-mcu.h     |  188 +++
 include/linux/devm-helpers.h                  |   94 ++
 include/linux/turris-omnia-mcu-interface.h    |  249 ++++
 18 files changed, 3023 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/debugfs-turris-omnia-mcu
 create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
 create mode 100644 Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
 create mode 100644 drivers/platform/cznic/Kconfig
 create mode 100644 drivers/platform/cznic/Makefile
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-base.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-debugfs.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-gpio.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-trng.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-watchdog.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu.h
 create mode 100644 include/linux/turris-omnia-mcu-interface.h

-- 
2.43.2

[PATCH v6 01/11] dt-bindings: arm: add cznic,turris-omnia-mcu binding

[Marek Behún]

Add binding for cznic,turris-omnia-mcu, the device-tree node
representing the system-controller features provided by the MCU on the
Turris Omnia router.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../bindings/arm/cznic,turris-omnia-mcu.yaml  | 86 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 87 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml

diff --git a/Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml b/Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
new file mode 100644
index 000000000000..dd9ee21ee24d
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/cznic,turris-omnia-mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: CZ.NIC's Turris Omnia MCU
+
+maintainers:
+  - Marek Behún <kabel@kernel.org>
+
+description:
+  The MCU on Turris Omnia acts as a system controller providing additional
+  GPIOs, interrupts, watchdog, system power off and wakeup configuration.
+
+properties:
+  compatible:
+    const: cznic,turris-omnia-mcu
+
+  reg:
+    description: MCU I2C slave address
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+    description: |
+      The first cell specifies the interrupt number (0 to 63), the second cell
+      specifies interrupt type (which can be one of IRQ_TYPE_EDGE_RISING,
+      IRQ_TYPE_EDGE_FALLING or IRQ_TYPE_EDGE_BOTH).
+      The interrupt numbers correspond sequentially to GPIO numbers, taking the
+      GPIO banks into account:
+        IRQ number   GPIO bank   GPIO pin within bank
+           0 - 15      0           0 - 15
+          16 - 47      1           0 - 31
+          48 - 63      2           0 - 15
+      There are several exceptions:
+        IRQ number   meaning
+          11           LED panel brightness changed by button press
+          13           TRNG entropy ready
+          14           ECDSA message signature computation done
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 3
+    description:
+      The first cell is bank number (0, 1 or 2), the second cell is pin number
+      within the bank (0 to 15 for banks 0 and 2, 0 to 31 for bank 1), and the
+      third cell specifies consumer flags.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+  - gpio-controller
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        system-controller@2a {
+            compatible = "cznic,turris-omnia-mcu";
+            reg = <0x2a>;
+
+            interrupt-parent = <&gpio1>;
+            interrupts = <11 IRQ_TYPE_NONE>;
+
+            gpio-controller;
+            #gpio-cells = <3>;
+
+            interrupt-controller;
+            #interrupt-cells = <2>;
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index c23fda1aa1f0..23637ff1e0bc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2141,6 +2141,7 @@ W:	https://www.turris.cz/
 F:	Documentation/ABI/testing/debugfs-moxtet
 F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/ABI/testing/sysfs-firmware-turris-mox-rwtm
+F:	Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	Documentation/devicetree/bindings/firmware/cznic,turris-mox-rwtm.txt
 F:	Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
-- 
2.43.2

[PATCH v6 10/11] ARM: dts: turris-omnia: Add MCU system-controller node

[Marek Behún]

Turris Omnia's MCU provides various features that can be configured over
I2C at address 0x2a. Add device-tree node.

Fixes: 26ca8b52d6e1 ("ARM: dts: add support for Turris Omnia")
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 .../dts/marvell/armada-385-turris-omnia.dts   | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts b/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts
index 7b755bb4e4e7..59079d63fe27 100644
--- a/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts
+++ b/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts
@@ -218,7 +218,22 @@ i2c@0 {
 			#size-cells = <0>;
 			reg = <0>;
 
-			/* STM32F0 command interface at address 0x2a */
+			mcu: system-controller@2a {
+				compatible = "cznic,turris-omnia-mcu";
+				reg = <0x2a>;
+
+				pinctrl-names = "default";
+				pinctrl-0 = <&mcu_pins>;
+
+				interrupt-parent = <&gpio1>;
+				interrupts = <11 IRQ_TYPE_NONE>;
+
+				gpio-controller;
+				#gpio-cells = <3>;
+
+				interrupt-controller;
+				#interrupt-cells = <2>;
+			};
 
 			led-controller@2b {
 				compatible = "cznic,turris-omnia-leds";
@@ -501,6 +516,11 @@ fixed-link {
 };
 
 &pinctrl {
+	mcu_pins: mcu-pins {
+		marvell,pins = "mpp43";
+		marvell,function = "gpio";
+	};
+
 	pcawan_pins: pcawan-pins {
 		marvell,pins = "mpp46";
 		marvell,function = "gpio";
-- 
2.43.2

[PATCH v6 11/11] ARM: dts: turris-omnia: Add GPIO key node for front button

[Marek Behún]

Now that we have the MCU device-tree node, which acts as a GPIO
controller, add GPIO key node for the front button.

Fixes: 26ca8b52d6e1 ("ARM: dts: add support for Turris Omnia")
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 .../boot/dts/marvell/armada-385-turris-omnia.dts    | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts b/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts
index 59079d63fe27..43202890c959 100644
--- a/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts
+++ b/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts
@@ -112,6 +112,19 @@ sfp: sfp {
 		status = "disabled";
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		front-button {
+			label = "Front Button";
+			linux,code = <KEY_VENDOR>;
+			linux,can-disable;
+			gpios = <&mcu 0 12 GPIO_ACTIVE_HIGH>;
+			/* debouncing is done by the microcontroller */
+			debounce-interval = <0>;
+		};
+	};
+
 	sound {
 		compatible = "simple-audio-card";
 		simple-audio-card,name = "SPDIF";
-- 
2.43.2

Re: [PATCH v6 01/11] dt-bindings: arm: add cznic,turris-omnia-mcu binding

[Conor Dooley]

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On Thu, Apr 18, 2024 at 02:11:06PM +0200, Marek Behún wrote:
> Add binding for cznic,turris-omnia-mcu, the device-tree node
> representing the system-controller features provided by the MCU on the
> Turris Omnia router.
> 
> Signed-off-by: Marek Behún <kabel@kernel.org>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  .../bindings/arm/cznic,turris-omnia-mcu.yaml  | 86 +++++++++++++++++++

Why's this in bindings/arm btw? Seems like it is some remote firmware if
it is running off-SoC on an MCU, so either remoteproc or firmware would
make more sense? Tying it to arm at least needs an explanation IMO.

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Re: [PATCH v6 01/11] dt-bindings: arm: add cznic,turris-omnia-mcu binding

[Marek Behún]

On Thu, Apr 18, 2024 at 04:43:54PM +0100, Conor Dooley wrote:
> On Thu, Apr 18, 2024 at 02:11:06PM +0200, Marek Behún wrote:
> > Add binding for cznic,turris-omnia-mcu, the device-tree node
> > representing the system-controller features provided by the MCU on the
> > Turris Omnia router.
> > 
> > Signed-off-by: Marek Behún <kabel@kernel.org>
> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > ---
> >  .../bindings/arm/cznic,turris-omnia-mcu.yaml  | 86 +++++++++++++++++++
> 
> Why's this in bindings/arm btw? Seems like it is some remote firmware if
> it is running off-SoC on an MCU, so either remoteproc or firmware would
> make more sense? Tying it to arm at least needs an explanation IMO.

This was discussed with Krzysztof in v1, you can look it up at
  https://lore.kernel.org/soc/20230824131736.067c40e2@dellmb/

Basically the SoC is an ARM board, and the MCU is also always ARM.

I'm guessing firmware would also make sense...

Re: [PATCH v6 01/11] dt-bindings: arm: add cznic,turris-omnia-mcu binding

[Marek Behún]

On Fri, Apr 19, 2024 at 10:23:37AM +0200, Marek Behún wrote:
> On Thu, Apr 18, 2024 at 04:43:54PM +0100, Conor Dooley wrote:
> > On Thu, Apr 18, 2024 at 02:11:06PM +0200, Marek Behún wrote:
> > > Add binding for cznic,turris-omnia-mcu, the device-tree node
> > > representing the system-controller features provided by the MCU on the
> > > Turris Omnia router.
> > > 
> > > Signed-off-by: Marek Behún <kabel@kernel.org>
> > > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > > ---
> > >  .../bindings/arm/cznic,turris-omnia-mcu.yaml  | 86 +++++++++++++++++++
> > 
> > Why's this in bindings/arm btw? Seems like it is some remote firmware if
> > it is running off-SoC on an MCU, so either remoteproc or firmware would
> > make more sense? Tying it to arm at least needs an explanation IMO.
> 
> This was discussed with Krzysztof in v1, you can look it up at
>   https://lore.kernel.org/soc/20230824131736.067c40e2@dellmb/
> 
> Basically the SoC is an ARM board, and the MCU is also always ARM.

What I wrote does not make sense. I wanted to say is that the driver
drives the peripherals implemented by the Turris Omnia MCU firmware, and
the Turris Omnia router is based on an ARM SoC, and that the MCU is also
an ARM-based MCU.

> 
> I'm guessing firmware would also make sense...
> 

Re: [PATCH v6 01/11] dt-bindings: arm: add cznic,turris-omnia-mcu binding

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1603 bytes --]

On Fri, Apr 19, 2024 at 01:14:45PM +0200, Marek Behún wrote:
> On Fri, Apr 19, 2024 at 10:23:37AM +0200, Marek Behún wrote:
> > On Thu, Apr 18, 2024 at 04:43:54PM +0100, Conor Dooley wrote:
> > > On Thu, Apr 18, 2024 at 02:11:06PM +0200, Marek Behún wrote:
> > > > Add binding for cznic,turris-omnia-mcu, the device-tree node
> > > > representing the system-controller features provided by the MCU on the
> > > > Turris Omnia router.
> > > > 
> > > > Signed-off-by: Marek Behún <kabel@kernel.org>
> > > > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > > > ---
> > > >  .../bindings/arm/cznic,turris-omnia-mcu.yaml  | 86 +++++++++++++++++++
> > > 
> > > Why's this in bindings/arm btw? Seems like it is some remote firmware if
> > > it is running off-SoC on an MCU, so either remoteproc or firmware would
> > > make more sense? Tying it to arm at least needs an explanation IMO.
> > 
> > This was discussed with Krzysztof in v1, you can look it up at
> >   https://lore.kernel.org/soc/20230824131736.067c40e2@dellmb/
> > 
> > Basically the SoC is an ARM board, and the MCU is also always ARM.
> 
> What I wrote does not make sense. I wanted to say is that the driver
> drives the peripherals implemented by the Turris Omnia MCU firmware, and
> the Turris Omnia router is based on an ARM SoC, and that the MCU is also
> an ARM-based MCU.

Yeah, it didn't really make sense, but I read between the lines.
FWIW, I still don't really think that bindings/arm is the right place
for it.

> 
> > 
> > I'm guessing firmware would also make sense...
> > 

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Re: [PATCH v6 00/11] Turris Omnia MCU driver

[Andy Shevchenko]

On Thu, Apr 18, 2024 at 02:11:05PM +0200, Marek Behún wrote:
> Hello Andy, Dan, Linus, Arnd, Gregory, and others,
> 
> I am sending v6 of the series adding Turris Omnia MCU driver.
> 
> This series depends on the immutable branch between LEDs and locking,
> introducing devm_mutex_init(), see the PR
>   https://lore.kernel.org/linux-leds/20240412084616.GR2399047@google.com/

...

>   devm-helpers: Add resource managed version of irq_create_mapping()
>   devm-helpers: Add resource managed version of debugfs directory create
>     function

IIUC you created them as static inline, the header will become yet another
cumbersome and messy "kernel.h". Can we prevent that?

-- 
With Best Regards,
Andy Shevchenko