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

[Chris Morgan <macroalpha82@gmail.com>]

From: Chris Morgan <macromorgan@hotmail.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 | 53 +++++++++++++++++++++------
 1 file changed, 42 insertions(+), 11 deletions(-)

diff --git a/drivers/input/joystick/adc-joystick.c b/drivers/input/joystick/adc-joystick.c
index 78ebca7d400a..83a5a420141e 100644
--- a/drivers/input/joystick/adc-joystick.c
+++ b/drivers/input/joystick/adc-joystick.c
@@ -13,6 +13,10 @@
 
 #include <asm/unaligned.h>
 
+#define ADC_JSK_POLL_INTERVAL	16
+#define ADC_JSK_POLL_MIN	8
+#define ADC_JSK_POLL_MAX	32
+
 struct adc_joystick_axis {
 	u32 code;
 	s32 range[2];
@@ -26,8 +30,21 @@ 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;
+
+	for (i = 0; i < joy->num_chans; i++) {
+		iio_read_channel_raw(&joy->chans[i], &val);
+		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;
@@ -215,8 +232,19 @@ 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;
+
+	if (of_device_is_compatible(dev->of_node, "adc-joystick-polled"))
+		joy->polled = 1;
+
+	if (joy->polled == 1) {
+		input_setup_polling(input, adc_joystick_poll);
+		input_set_poll_interval(input, ADC_JSK_POLL_INTERVAL);
+		input_set_min_poll_interval(input, ADC_JSK_POLL_MIN);
+		input_set_max_poll_interval(input, ADC_JSK_POLL_MAX);
+	} else {
+		input->open = adc_joystick_open;
+		input->close = adc_joystick_close;
+	}
 
 	error = adc_joystick_set_axes(dev, joy);
 	if (error)
@@ -229,16 +257,18 @@ 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 == 0) {
+		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;
@@ -246,6 +276,7 @@ static int adc_joystick_probe(struct platform_device *pdev)
 
 static const struct of_device_id adc_joystick_of_match[] = {
 	{ .compatible = "adc-joystick", },
+	{ .compatible = "adc-joystick-polled", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, adc_joystick_of_match);
-- 
2.25.1