fix force feedback arithmetic and wheel input filtering

src/hid-tmff2.c

@@ -43,11 +43,16 @@ MODULE_PARM_DESC(alt_mode,
 		"Alternate mode, eg. F1 mode");
 
 #define GAIN_MAX 65535
-int gain = 40000;
-module_param(gain, int, 0);
+u16 gain = 40000;
+module_param(gain, ushort, 0);
 MODULE_PARM_DESC(gain,
 		"Level of gain (0-65535)");
 
+static u16 tmff2_scale_gain(u16 value)
+{
+	return (u32)value * gain / GAIN_MAX;
+}
+
 static spinlock_t lock;
 
 static struct tmff2_device_entry *tmff2_from_hdev(struct hid_device *hdev)
@@ -230,28 +235,29 @@ static ssize_t gain_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct tmff2_device_entry *tmff2 = tmff2_from_hdev(to_hid_device(dev));
-	unsigned int value;
+	u16 value;
 	int ret;
 
 	if (!tmff2)
 		return -ENODEV;
 
-	if ((ret = kstrtouint(buf, 0, &value))) {
-		dev_err(dev, "kstrtouint failed at gain_store: %i", ret);
+	ret = kstrtou16(buf, 0, &value);
+	if (ret) {
+		dev_err(dev, "failed to parse gain: %d\n", ret);
 		return ret;
 	}
 
 	gain = value;
 	if (tmff2->set_gain) /* if we can, update gain immediately */
-		tmff2->set_gain(tmff2->data, (GAIN_MAX * gain) / GAIN_MAX);
+		tmff2->set_gain(tmff2->data, gain);
 
 	return count;
 }
 
 static ssize_t gain_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-	return scnprintf(buf, PAGE_SIZE, "%i\n", gain);
+	return scnprintf(buf, PAGE_SIZE, "%u\n", gain);
 }
 static DEVICE_ATTR_RW(gain);
 
@@ -267,7 +273,7 @@ static void tmff2_set_gain(struct input_dev *dev, uint16_t value)
 		return;
 	}
 
-	if (tmff2->set_gain(tmff2->data, (value * gain) / GAIN_MAX))
+	if (tmff2->set_gain(tmff2->data, tmff2_scale_gain(value)))
 		hid_warn(tmff2->hdev, "unable to set gain\n");
 }
 
@@ -643,7 +649,7 @@ static int tmff2_wheel_init(struct tmff2_device_entry *tmff2)
 	/* set defaults wherever possible */
 	if (tmff2->set_gain) {
 		ff->set_gain = tmff2_set_gain;
-		tmff2->set_gain(tmff2->data, (GAIN_MAX * gain) / GAIN_MAX);
+		tmff2->set_gain(tmff2->data, gain);
 	}
 
 	if (tmff2->set_autocenter)
@@ -801,6 +807,26 @@ static void tmff2_remove(struct hid_device *hdev)
 	kfree(tmff2);
 }
 
+static int tmff2_input_configured(struct hid_device *hdev,
+				  struct hid_input *hidinput)
+{
+	struct input_dev *input = hidinput->input;
+	int axis;
+
+	if (!input->absinfo)
+		return 0;
+
+	for (axis = ABS_X; axis <= ABS_BRAKE; axis++) {
+		if (!test_bit(axis, input->absbit))
+			continue;
+
+		input_abs_set_fuzz(input, axis, 0);
+		input_abs_set_flat(input, axis, 0);
+	}
+
+	return 0;
+}
+
 static const struct hid_device_id tmff2_devices[] = {
 	/* t300rs and variations */
 	{HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, TMT300RS_PS3_NORM_ID)},
@@ -825,6 +851,7 @@ static struct hid_driver tmff2_driver = {
 	.probe = tmff2_probe,
 	.remove = tmff2_remove,
 	.report_fixup = tmff2_report_fixup,
+	.input_configured = tmff2_input_configured,
 };
 module_hid_driver(tmff2_driver);
 

src/hid-tmff2.h

@@ -11,7 +11,7 @@ extern int spring_level;
 extern int damper_level;
 extern int friction_level;
 extern int range;
-extern int gain;
+extern u16 gain;
 extern int alt_mode;
 
 #define USB_VENDOR_ID_THRUSTMASTER 0x044f

src/tmt300rs/hid-tmt300rs.c

@@ -344,30 +344,35 @@ static uint16_t t300rs_calculate_length(uint16_t length)
 	return length;
 }
 
+static s32 t300rs_scale_direction(s16 level, u16 direction)
+{
+	return (s32)level * fixp_sin16(direction * 360 / 0x10000) / 0x7fff;
+}
+
 static int16_t t300rs_calculate_constant_level(int16_t level, uint16_t direction)
 {
-	level = (level * fixp_sin16(direction * 360 / 0x10000)) / 0x7fff;
+	s32 scaled_level = t300rs_scale_direction(level, direction);
 
 	/* the Windows driver uses the range [-16385;16381] */
-	level = level / 2;
-
-	return level;
+	return scaled_level / 2;
 }
 
 static void t300rs_calculate_periodic_values(struct ff_effect *effect)
 {
 	struct ff_periodic_effect *periodic = &effect->u.periodic;
-	int16_t headroom;
+	s32 magnitude, headroom;
 
-	periodic->magnitude = (periodic->magnitude * fixp_sin16(effect->direction * 360 / 0x10000)) / 0x7fff;
+	magnitude = t300rs_scale_direction(periodic->magnitude,
+					   effect->direction);
 
-	if (periodic->magnitude < 0){
+	if (magnitude < 0) {
 		/* the wheel handles positive magnitudes only */
-		periodic->magnitude = -periodic->magnitude;
+		magnitude = -magnitude;
 
 		/* to give the expected result 180 deg is added to the phase */
 		periodic->phase = (periodic->phase + (0x10000 / 2)) % 0x10000;
 	}
+	periodic->magnitude = min_t(s32, magnitude, S16_MAX);
 
 	/* the interval [0; 32677[ is used by the wheel for the [0; 360[ degree phase shift */
 	periodic->phase = periodic->phase * 32677 / 0x10000;
@@ -443,13 +448,16 @@ static void t300rs_calculate_ramp_parameters(uint16_t *out_slope,
 {
 	struct ff_ramp_effect *ramp = &effect->u.ramp;
 
-	int16_t start_level, end_level;
+	s32 start_level, end_level;
 
-	start_level = (ramp->start_level * fixp_sin16(effect->direction * 360 / 0x10000)) / 0x7fff;
-	end_level = (ramp->end_level * fixp_sin16(effect->direction * 360 / 0x10000)) / 0x7fff;
+	start_level = t300rs_scale_direction(ramp->start_level,
+					     effect->direction);
+	end_level = t300rs_scale_direction(ramp->end_level,
+					   effect->direction);
 
 	*out_slope = abs(start_level - end_level) / 2;
-	*out_center = (start_level + end_level) / 2;
+	*out_center = clamp_t(s32, (start_level + end_level) / 2,
+			      S16_MIN, S16_MAX);
 
 	*out_invert = (start_level < end_level) ? 0x04 : 0x05;
 }