[PATCH v6 0/3] adc-joystick: Add polled support

[PATCH v6 0/3] adc-joystick: Add polled support

[Chris Morgan]

Add support to the existing adc-joystick driver to support polling
rather than relying on triggered buffers. This is useful for devices
that do not offer triggered buffers in hardware. Code adapted from
changes made by Maya Matuszczyk <maccraft123mc@gmail.com>.

Changes from V5:
 - Corrected an error found by yamllint in the documentation.

Changes from V4:
 - Added unit property to devicetree attribute making it now
   "poll-interval-ms".
 - Simplified logic for setting polled value and made variable names
   more clear.

Changes from V3:
 - After lengthy discussion decided to support with existing attribute
   of "poll-interval". If present, the driver will use polling and if
   not present, it will use triggered buffers (as the driver does
   today).
 - Corrected some lines to honor the 80 character line-limit.
 - Check return value from polling method and return early if there
   is an error reading the data.

Changes from V2:
 - Changed parameter from "adc-joystick,polled" to
   "adc-joystick,no-hardware-trigger" as it is more representative of
   what the driver and hardware are doing.

Changes from V1:
 - Removed driver compatible string of "adc-joystick-polled".
 - Added new optional boolean value of "adc-joystick,polled".
 - Cleaned up if statements regarding polling behavior.


Chris Morgan (3):
  dt-bindings: adc-joystick: add poll-interval-ms
  Input: adc-joystick - Add polled input device support
  arm64: dts: rockchip: Update joystick to polled for OG2

 .../bindings/input/adc-joystick.yaml          |  5 ++
 .../boot/dts/rockchip/rk3326-odroid-go2.dts   |  1 +
 drivers/input/joystick/adc-joystick.c         | 51 +++++++++++++++----
 3 files changed, 46 insertions(+), 11 deletions(-)

-- 
2.34.1

[PATCH v6 1/3] dt-bindings: adc-joystick: add poll-interval-ms

[Chris Morgan]

New devicetree attribute of "poll-interval-ms".

Add poll-interval support for the adc-joystick documentation. This is
an optional value and if not provided the adc-joystick works as it
does today (with triggered buffers). If this value is provided, the
adc-joystick driver is polled at the specified interval. A new
attribute was added instead of using the existing attribute of
"poll-interval" to comply with rules detailed in property-units.yaml.

Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
---
 Documentation/devicetree/bindings/input/adc-joystick.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/adc-joystick.yaml b/Documentation/devicetree/bindings/input/adc-joystick.yaml
index 2ee04e03bc22..9a34b928b15b 100644
--- a/Documentation/devicetree/bindings/input/adc-joystick.yaml
+++ b/Documentation/devicetree/bindings/input/adc-joystick.yaml
@@ -18,6 +18,11 @@ properties:
   compatible:
     const: adc-joystick
 
+  poll-interval-ms:
+    description:
+      Poll interval time in milliseconds. If not specified, device will use
+      iio buffer.
+
   io-channels:
     minItems: 1
     maxItems: 1024
-- 
2.34.1

[PATCH v6 2/3] Input: adc-joystick - Add polled input device support

[Chris Morgan]

Add polled input device support to the adc-joystick driver. This is
useful for devices which do not have hardware capable triggers on
their SARADC. Code modified from adc-joystick.c changes made by Maya
Matuszczyk.

Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
---
 drivers/input/joystick/adc-joystick.c | 51 +++++++++++++++++++++------
 1 file changed, 40 insertions(+), 11 deletions(-)

diff --git a/drivers/input/joystick/adc-joystick.c b/drivers/input/joystick/adc-joystick.c
index 78ebca7d400a..e52f8b2b5563 100644
--- a/drivers/input/joystick/adc-joystick.c
+++ b/drivers/input/joystick/adc-joystick.c
@@ -26,8 +26,23 @@ struct adc_joystick {
 	struct adc_joystick_axis *axes;
 	struct iio_channel *chans;
 	int num_chans;
+	bool polled;
 };
 
+static void adc_joystick_poll(struct input_dev *input)
+{
+	struct adc_joystick *joy = input_get_drvdata(input);
+	int i, val, ret;
+
+	for (i = 0; i < joy->num_chans; i++) {
+		ret = iio_read_channel_raw(&joy->chans[i], &val);
+		if (ret < 0)
+			return;
+		input_report_abs(input, joy->axes[i].code, val);
+	}
+	input_sync(input);
+}
+
 static int adc_joystick_handle(const void *data, void *private)
 {
 	struct adc_joystick *joy = private;
@@ -179,6 +194,7 @@ static int adc_joystick_probe(struct platform_device *pdev)
 	int error;
 	int bits;
 	int i;
+	unsigned int poll_interval;
 
 	joy = devm_kzalloc(dev, sizeof(*joy), GFP_KERNEL);
 	if (!joy)
@@ -215,8 +231,17 @@ static int adc_joystick_probe(struct platform_device *pdev)
 	joy->input = input;
 	input->name = pdev->name;
 	input->id.bustype = BUS_HOST;
-	input->open = adc_joystick_open;
-	input->close = adc_joystick_close;
+
+	joy->polled = !device_property_read_u32(dev, "poll-interval-ms",
+						&poll_interval);
+
+	if (joy->polled) {
+		input_setup_polling(input, adc_joystick_poll);
+		input_set_poll_interval(input, poll_interval);
+	} else {
+		input->open = adc_joystick_open;
+		input->close = adc_joystick_close;
+	}
 
 	error = adc_joystick_set_axes(dev, joy);
 	if (error)
@@ -229,16 +254,20 @@ static int adc_joystick_probe(struct platform_device *pdev)
 		return error;
 	}
 
-	joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle, joy);
-	if (IS_ERR(joy->buffer)) {
-		dev_err(dev, "Unable to allocate callback buffer\n");
-		return PTR_ERR(joy->buffer);
-	}
+	if (!joy->polled) {
+		joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle,
+						     joy);
+		if (IS_ERR(joy->buffer)) {
+			dev_err(dev, "Unable to allocate callback buffer\n");
+			return PTR_ERR(joy->buffer);
+		}
 
-	error = devm_add_action_or_reset(dev, adc_joystick_cleanup, joy->buffer);
-	if (error)  {
-		dev_err(dev, "Unable to add action\n");
-		return error;
+		error = devm_add_action_or_reset(dev, adc_joystick_cleanup,
+						 joy->buffer);
+		if (error)  {
+			dev_err(dev, "Unable to add action\n");
+			return error;
+		}
 	}
 
 	return 0;
-- 
2.34.1

[PATCH v6 3/3] arm64: dts: rockchip: Update joystick to polled for OG2

[Chris Morgan]

Update the Odroid Go Advance to use "poll-interval-ms" from the
adc-joystick driver.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
---
 arch/arm64/boot/dts/rockchip/rk3326-odroid-go2.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3326-odroid-go2.dts b/arch/arm64/boot/dts/rockchip/rk3326-odroid-go2.dts
index ea0695b51ecd..5a4f81861e07 100644
--- a/arch/arm64/boot/dts/rockchip/rk3326-odroid-go2.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3326-odroid-go2.dts
@@ -26,6 +26,7 @@ adc-joystick {
 		compatible = "adc-joystick";
 		io-channels = <&saradc 1>,
 			      <&saradc 2>;
+		poll-interval-ms = <60>;
 		#address-cells = <1>;
 		#size-cells = <0>;
 
-- 
2.34.1

Re: [PATCH v6 2/3] Input: adc-joystick - Add polled input device support

[Artur Rojek]

On 2022-06-30 00:29, Chris Morgan wrote:
> Add polled input device support to the adc-joystick driver. This is
> useful for devices which do not have hardware capable triggers on
> their SARADC. Code modified from adc-joystick.c changes made by Maya
> Matuszczyk.
> 
> Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
> Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Hey Chris,

the patch is looking good, thanks for sticking through! :)

With the poll-interval property adjusted to whatever naming ends up 
decided on in patch 1/3:
Acked-by: Artur Rojek <contact@artur-rojek.eu>
> ---
>  drivers/input/joystick/adc-joystick.c | 51 +++++++++++++++++++++------
>  1 file changed, 40 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/input/joystick/adc-joystick.c
> b/drivers/input/joystick/adc-joystick.c
> index 78ebca7d400a..e52f8b2b5563 100644
> --- a/drivers/input/joystick/adc-joystick.c
> +++ b/drivers/input/joystick/adc-joystick.c
> @@ -26,8 +26,23 @@ struct adc_joystick {
>  	struct adc_joystick_axis *axes;
>  	struct iio_channel *chans;
>  	int num_chans;
> +	bool polled;
>  };
> 
> +static void adc_joystick_poll(struct input_dev *input)
> +{
> +	struct adc_joystick *joy = input_get_drvdata(input);
> +	int i, val, ret;
> +
> +	for (i = 0; i < joy->num_chans; i++) {
> +		ret = iio_read_channel_raw(&joy->chans[i], &val);
> +		if (ret < 0)
> +			return;
> +		input_report_abs(input, joy->axes[i].code, val);
> +	}
> +	input_sync(input);
> +}
> +
>  static int adc_joystick_handle(const void *data, void *private)
>  {
>  	struct adc_joystick *joy = private;
> @@ -179,6 +194,7 @@ static int adc_joystick_probe(struct 
> platform_device *pdev)
>  	int error;
>  	int bits;
>  	int i;
> +	unsigned int poll_interval;
> 
>  	joy = devm_kzalloc(dev, sizeof(*joy), GFP_KERNEL);
>  	if (!joy)
> @@ -215,8 +231,17 @@ static int adc_joystick_probe(struct 
> platform_device *pdev)
>  	joy->input = input;
>  	input->name = pdev->name;
>  	input->id.bustype = BUS_HOST;
> -	input->open = adc_joystick_open;
> -	input->close = adc_joystick_close;
> +
> +	joy->polled = !device_property_read_u32(dev, "poll-interval-ms",
> +						&poll_interval);
> +
> +	if (joy->polled) {
> +		input_setup_polling(input, adc_joystick_poll);
> +		input_set_poll_interval(input, poll_interval);
> +	} else {
> +		input->open = adc_joystick_open;
> +		input->close = adc_joystick_close;
> +	}
> 
>  	error = adc_joystick_set_axes(dev, joy);
>  	if (error)
> @@ -229,16 +254,20 @@ static int adc_joystick_probe(struct
> platform_device *pdev)
>  		return error;
>  	}
> 
> -	joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle, joy);
> -	if (IS_ERR(joy->buffer)) {
> -		dev_err(dev, "Unable to allocate callback buffer\n");
> -		return PTR_ERR(joy->buffer);
> -	}
> +	if (!joy->polled) {
> +		joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle,
> +						     joy);
> +		if (IS_ERR(joy->buffer)) {
> +			dev_err(dev, "Unable to allocate callback buffer\n");
> +			return PTR_ERR(joy->buffer);
> +		}
> 
> -	error = devm_add_action_or_reset(dev, adc_joystick_cleanup, 
> joy->buffer);
> -	if (error)  {
> -		dev_err(dev, "Unable to add action\n");
> -		return error;
> +		error = devm_add_action_or_reset(dev, adc_joystick_cleanup,
> +						 joy->buffer);
> +		if (error)  {
> +			dev_err(dev, "Unable to add action\n");
> +			return error;
> +		}
>  	}
> 
>  	return 0;

Re: [PATCH v6 1/3] dt-bindings: adc-joystick: add poll-interval-ms

[Krzysztof Kozlowski]

On 30/06/2022 00:29, Chris Morgan wrote:
> New devicetree attribute of "poll-interval-ms".
> 
> Add poll-interval support for the adc-joystick documentation. This is
> an optional value and if not provided the adc-joystick works as it
> does today (with triggered buffers). If this value is provided, the
> adc-joystick driver is polled at the specified interval. A new
> attribute was added instead of using the existing attribute of
> "poll-interval" to comply with rules detailed in property-units.yaml.
> 
> Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
> Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
> ---
>  Documentation/devicetree/bindings/input/adc-joystick.yaml | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/adc-joystick.yaml b/Documentation/devicetree/bindings/input/adc-joystick.yaml
> index 2ee04e03bc22..9a34b928b15b 100644
> --- a/Documentation/devicetree/bindings/input/adc-joystick.yaml
> +++ b/Documentation/devicetree/bindings/input/adc-joystick.yaml
> @@ -18,6 +18,11 @@ properties:
>    compatible:
>      const: adc-joystick
>  
> +  poll-interval-ms:
> +    description:
> +      Poll interval time in milliseconds. If not specified, device will use
> +      iio buffer.

Rob's comments from v5 apply.

Best regards,
Krzysztof