For detachable or lock-able joysticks the ADC lanes might
be biased to GND or AVDD when the joystick is detached/locked.
One such kind of joystick is found in the Ritmix RZX-50 device.
The joystick is non-detachable, although ADC lane biased to power
supply when the "Hold" switch is activated.
To avoid reporting old/broken measurements valid-range is used.
When measured value is outside valid-range the driver reports
safe center position for corresponding axis.
Signed-off-by: Siarhei Volkau <[email protected]>
---
drivers/input/joystick/adc-joystick.c | 58 ++++++++++++++++++++++++++-
1 file changed, 57 insertions(+), 1 deletion(-)
diff --git a/drivers/input/joystick/adc-joystick.c b/drivers/input/joystick/adc-joystick.c
index c0deff5d4..6a143dc38 100644
--- a/drivers/input/joystick/adc-joystick.c
+++ b/drivers/input/joystick/adc-joystick.c
@@ -18,6 +18,8 @@ struct adc_joystick_axis {
s32 range[2];
s32 fuzz;
s32 flat;
+ s32 valid[2];
+ s32 center;
};
struct adc_joystick {
@@ -29,6 +31,14 @@ struct adc_joystick {
bool polled;
};
+static inline bool is_in_range(const s32 *range, int val)
+{
+ s32 min = range[0];
+ s32 max = range[1];
+
+ return (min == 0 && max == 0) || (val >= min && val <= max);
+}
+
static void adc_joystick_poll(struct input_dev *input)
{
struct adc_joystick *joy = input_get_drvdata(input);
@@ -38,6 +48,10 @@ static void adc_joystick_poll(struct input_dev *input)
ret = iio_read_channel_raw(&joy->chans[i], &val);
if (ret < 0)
return;
+
+ if (!is_in_range(joy->axes[i].valid, val))
+ val = joy->axes[i].center;
+
input_report_abs(input, joy->axes[i].code, val);
}
input_sync(input);
@@ -86,6 +100,10 @@ static int adc_joystick_handle(const void *data, void *private)
val = sign_extend32(val, msb);
else
val &= GENMASK(msb, 0);
+
+ if (!is_in_range(joy->axes[i].valid, val))
+ val = joy->axes[i].center;
+
input_report_abs(joy->input, joy->axes[i].code, val);
}
@@ -119,6 +137,21 @@ static void adc_joystick_cleanup(void *data)
iio_channel_release_all_cb(data);
}
+static bool valid_range_covers_abs_range(struct adc_joystick_axis *axis)
+{
+ s32 abs_min, abs_max;
+
+ if (axis->range[0] > axis->range[1]) {
+ abs_min = axis->range[1];
+ abs_max = axis->range[0];
+ } else {
+ abs_min = axis->range[0];
+ abs_max = axis->range[1];
+ }
+
+ return axis->valid[0] <= abs_min && axis->valid[1] >= abs_max;
+}
+
static int adc_joystick_set_axes(struct device *dev, struct adc_joystick *joy)
{
struct adc_joystick_axis *axes;
@@ -137,7 +170,7 @@ static int adc_joystick_set_axes(struct device *dev, struct adc_joystick *joy)
return -EINVAL;
}
- axes = devm_kmalloc_array(dev, num_axes, sizeof(*axes), GFP_KERNEL);
+ axes = devm_kcalloc(dev, num_axes, sizeof(*axes), GFP_KERNEL);
if (!axes)
return -ENOMEM;
@@ -167,10 +200,33 @@ static int adc_joystick_set_axes(struct device *dev, struct adc_joystick *joy)
dev_err(dev, "abs-range invalid or missing\n");
goto err_fwnode_put;
}
+ axes[i].center = (axes[i].range[0] + axes[i].range[1]) / 2;
fwnode_property_read_u32(child, "abs-fuzz", &axes[i].fuzz);
fwnode_property_read_u32(child, "abs-flat", &axes[i].flat);
+ if (fwnode_property_present(child, "valid-range")) {
+ error = fwnode_property_read_u32_array(child,
+ "valid-range",
+ axes[i].valid, 2);
+ if (error) {
+ dev_err(dev, "valid-range invalid\n");
+ goto err_fwnode_put;
+ }
+
+ if (axes[i].valid[0] > axes[i].valid[1]) {
+ dev_err(dev,
+ "valid-range invalid (min > max)\n");
+ goto err_fwnode_put;
+ }
+
+ if (!valid_range_covers_abs_range(&axes[i])) {
+ dev_err(dev,
+ "valid-range must cover abs-range\n");
+ goto err_fwnode_put;
+ }
+ }
+
input_set_abs_params(joy->input, axes[i].code,
axes[i].range[0], axes[i].range[1],
axes[i].fuzz, axes[i].flat);
--
2.36.1