[PATCH v7 2/3] Input: adc-joystick - Add polled input device support

From: Chris Morgan <macroalpha82@gmail.com>
To: linux-input@vger.kernel.org
Cc: devicetree@vger.kernel.org, contact@artur-rojek.eu,
	maccraft123mc@gmail.com, heiko@sntech.de,
	krzysztof.kozlowski+dt@linaro.org, robh+dt@kernel.org,
	dmitry.torokhov@gmail.com, paul@crapouillou.net,
	jic23@kernel.org, linux-iio@vger.kernel.org,
	Chris Morgan <macroalpha82@gmail.com>,
	Chris Morgan <macromorgan@hotmail.com>
Subject: [PATCH v7 2/3] Input: adc-joystick - Add polled input device support
Date: Tue,  5 Jul 2022 14:03:53 -0500	[thread overview]
Message-ID: <20220705190354.69263-3-macromorgan@hotmail.com> (raw)
In-Reply-To: <20220705190354.69263-1-macromorgan@hotmail.com>

From: Chris Morgan <macroalpha82@gmail.com>

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..2f4bd12d6344 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",
+						&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

