Input: bcm5974 - Drop the logical dimensions

The logical scale is used to produce special finger width values to
userspace, but has become an unnecessary restriction for everything
else.  Also, the bcm5974 trackpads are very accurate and work well
without hysteresis.

This patch simplifies the driver and device data by removing the
logical scale, and by moving the special synaptics code out of the
main path.  Also add the orientation range, needed in a subsequent
patch, to the device configuration.

Tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 111 insertions, 144 deletions

diff --git a/drivers/input/mouse/bcm5974.c b/drivers/input/mouse/bcm5974.c
index 2de974c..e8cfb38 100644
--- a/drivers/input/mouse/bcm5974.c
+++ b/drivers/input/mouse/bcm5974.c
@@ -200,10 +200,9 @@ struct tp_finger {
 
 /* device-specific parameters */
 struct bcm5974_param {
-	int dim;		/* logical dimension */
-	int fuzz;		/* logical noise value */
-	int devmin;		/* device minimum reading */
-	int devmax;		/* device maximum reading */
+	int snratio;		/* signal-to-noise ratio */
+	int min;		/* device minimum reading */
+	int max;		/* device maximum reading */
 };
 
 /* device-specific configuration */
@@ -220,6 +219,7 @@ struct bcm5974_config {
 	struct bcm5974_param w;	/* finger width limits */
 	struct bcm5974_param x;	/* horizontal limits */
 	struct bcm5974_param y;	/* vertical limits */
+	struct bcm5974_param o;	/* orientation limits */
 };
 
 /* logical device structure */
@@ -235,23 +235,13 @@ struct bcm5974 {
 	struct bt_data *bt_data;	/* button transferred data */
 	struct urb *tp_urb;		/* trackpad usb request block */
 	u8 *tp_data;			/* trackpad transferred data */
-	int fingers;			/* number of fingers on trackpad */
 };
 
-/* logical dimensions */
-#define DIM_PRESSURE	256		/* maximum finger pressure */
-#define DIM_WIDTH	16		/* maximum finger width */
-#define DIM_X		1280		/* maximum trackpad x value */
-#define DIM_Y		800		/* maximum trackpad y value */
-
 /* logical signal quality */
 #define SN_PRESSURE	45		/* pressure signal-to-noise ratio */
 #define SN_WIDTH	100		/* width signal-to-noise ratio */
 #define SN_COORD	250		/* coordinate signal-to-noise ratio */
-
-/* pressure thresholds */
-#define PRESSURE_LOW	(2 * DIM_PRESSURE / SN_PRESSURE)
-#define PRESSURE_HIGH	(3 * PRESSURE_LOW)
+#define SN_ORIENT	10		/* orientation signal-to-noise ratio */
 
 /* device constants */
 static const struct bcm5974_config bcm5974_config_table[] = {
@@ -262,10 +252,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		0,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4824, 5342 },
-		{ DIM_Y, DIM_Y / SN_COORD, -172, 5820 }
+		{ SN_PRESSURE, 0, 256 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4824, 5342 },
+		{ SN_COORD, -172, 5820 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI,
@@ -274,10 +265,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		0,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4824, 4824 },
-		{ DIM_Y, DIM_Y / SN_COORD, -172, 4290 }
+		{ SN_PRESSURE, 0, 256 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4824, 4824 },
+		{ SN_COORD, -172, 4290 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI,
@@ -286,10 +278,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4460, 5166 },
-		{ DIM_Y, DIM_Y / SN_COORD, -75, 6700 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4460, 5166 },
+		{ SN_COORD, -75, 6700 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI,
@@ -298,10 +291,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4620, 5140 },
-		{ DIM_Y, DIM_Y / SN_COORD, -150, 6600 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4620, 5140 },
+		{ SN_COORD, -150, 6600 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI,
@@ -310,10 +304,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4616, 5112 },
-		{ DIM_Y, DIM_Y / SN_COORD, -142, 5234 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4616, 5112 },
+		{ SN_COORD, -142, 5234 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI,
@@ -322,10 +317,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4415, 5050 },
-		{ DIM_Y, DIM_Y / SN_COORD, -55, 6680 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4415, 5050 },
+		{ SN_COORD, -55, 6680 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI,
@@ -334,10 +330,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4620, 5140 },
-		{ DIM_Y, DIM_Y / SN_COORD, -150, 6600 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4620, 5140 },
+		{ SN_COORD, -150, 6600 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI,
@@ -346,10 +343,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4750, 5280 },
-		{ DIM_Y, DIM_Y / SN_COORD, -150, 6730 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4750, 5280 },
+		{ SN_COORD, -150, 6730 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING6A_ANSI,
@@ -358,10 +356,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4620, 5140 },
-		{ DIM_Y, DIM_Y / SN_COORD, -150, 6600 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4620, 5140 },
+		{ SN_COORD, -150, 6600 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{
 		USB_DEVICE_ID_APPLE_WELLSPRING7_ANSI,
@@ -370,10 +369,11 @@ static const struct bcm5974_config bcm5974_config_table[] = {
 		HAS_INTEGRATED_BUTTON,
 		0x84, sizeof(struct bt_data),
 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
-		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
-		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
-		{ DIM_X, DIM_X / SN_COORD, -4750, 5280 },
-		{ DIM_Y, DIM_Y / SN_COORD, -150, 6730 }
+		{ SN_PRESSURE, 0, 300 },
+		{ SN_WIDTH, 0, 2048 },
+		{ SN_COORD, -4750, 5280 },
+		{ SN_COORD, -150, 6730 },
+		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
 	},
 	{}
 };
@@ -397,18 +397,11 @@ static inline int raw2int(__le16 x)
 	return (signed short)le16_to_cpu(x);
 }
 
-/* scale device data to logical dimensions (asserts devmin < devmax) */
-static inline int int2scale(const struct bcm5974_param *p, int x)
+static void set_abs(struct input_dev *input, unsigned int code,
+		    const struct bcm5974_param *p)
 {
-	return x * p->dim / (p->devmax - p->devmin);
-}
-
-/* all logical value ranges are [0,dim). */
-static inline int int2bound(const struct bcm5974_param *p, int x)
-{
-	int s = int2scale(p, x);
-
-	return clamp_val(s, 0, p->dim - 1);
+	int fuzz = p->snratio ? (p->max - p->min) / p->snratio : 0;
+	input_set_abs_params(input, code, p->min, p->max, fuzz, 0);
 }
 
 /* setup which logical events to report */
@@ -417,34 +410,25 @@ static void setup_events_to_report(struct input_dev *input_dev,
 {
 	__set_bit(EV_ABS, input_dev->evbit);
 
-	input_set_abs_params(input_dev, ABS_PRESSURE,
-				0, cfg->p.dim, cfg->p.fuzz, 0);
-	input_set_abs_params(input_dev, ABS_TOOL_WIDTH,
-				0, cfg->w.dim, cfg->w.fuzz, 0);
-	input_set_abs_params(input_dev, ABS_X,
-				0, cfg->x.dim, cfg->x.fuzz, 0);
-	input_set_abs_params(input_dev, ABS_Y,
-				0, cfg->y.dim, cfg->y.fuzz, 0);
+	/* for synaptics only */
+	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 256, 5, 0);
+	input_set_abs_params(input_dev, ABS_TOOL_WIDTH, 0, 16, 0, 0);
+
+	/* pointer emulation */
+	set_abs(input_dev, ABS_X, &cfg->x);
+	set_abs(input_dev, ABS_Y, &cfg->y);
 
 	/* finger touch area */
-	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
-			     cfg->w.devmin, cfg->w.devmax, 0, 0);
-	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
-			     cfg->w.devmin, cfg->w.devmax, 0, 0);
+	set_abs(input_dev, ABS_MT_TOUCH_MAJOR, &cfg->w);
+	set_abs(input_dev, ABS_MT_TOUCH_MINOR, &cfg->w);
 	/* finger approach area */
-	input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR,
-			     cfg->w.devmin, cfg->w.devmax, 0, 0);
-	input_set_abs_params(input_dev, ABS_MT_WIDTH_MINOR,
-			     cfg->w.devmin, cfg->w.devmax, 0, 0);
+	set_abs(input_dev, ABS_MT_WIDTH_MAJOR, &cfg->w);
+	set_abs(input_dev, ABS_MT_WIDTH_MINOR, &cfg->w);
 	/* finger orientation */
-	input_set_abs_params(input_dev, ABS_MT_ORIENTATION,
-			     -MAX_FINGER_ORIENTATION,
-			     MAX_FINGER_ORIENTATION, 0, 0);
+	set_abs(input_dev, ABS_MT_ORIENTATION, &cfg->o);
 	/* finger position */
-	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
-			     cfg->x.devmin, cfg->x.devmax, 0, 0);
-	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
-			     cfg->y.devmin, cfg->y.devmax, 0, 0);
+	set_abs(input_dev, ABS_MT_POSITION_X, &cfg->x);
+	set_abs(input_dev, ABS_MT_POSITION_Y, &cfg->y);
 
 	__set_bit(EV_KEY, input_dev->evbit);
 	__set_bit(BTN_TOUCH, input_dev->keybit);
@@ -494,19 +478,37 @@ static void report_finger_data(struct input_dev *input,
 			 MAX_FINGER_ORIENTATION - raw2int(f->orientation));
 	input_report_abs(input, ABS_MT_POSITION_X, raw2int(f->abs_x));
 	input_report_abs(input, ABS_MT_POSITION_Y,
-			 cfg->y.devmin + cfg->y.devmax - raw2int(f->abs_y));
+			 cfg->y.min + cfg->y.max - raw2int(f->abs_y));
 	input_mt_sync(input);
 }
 
+static void report_synaptics_data(struct input_dev *input,
+				  const struct bcm5974_config *cfg,
+				  const struct tp_finger *f, int raw_n)
+{
+	int abs_p = 0, abs_w = 0;
+
+	if (raw_n) {
+		int p = raw2int(f->touch_major);
+		int w = raw2int(f->tool_major);
+		if (p > 0 && raw2int(f->origin)) {
+			abs_p = clamp_val(256 * p / cfg->p.max, 0, 255);
+			abs_w = clamp_val(16 * w / cfg->w.max, 0, 15);
+		}
+	}
+
+	input_report_abs(input, ABS_PRESSURE, abs_p);
+	input_report_abs(input, ABS_TOOL_WIDTH, abs_w);
+}
+
 /* report trackpad data as logical trackpad state */
 static int report_tp_state(struct bcm5974 *dev, int size)
 {
 	const struct bcm5974_config *c = &dev->cfg;
 	const struct tp_finger *f;
 	struct input_dev *input = dev->input;
-	int raw_p, raw_w, raw_x, raw_y, raw_n, i;
-	int ptest, origin, ibt = 0, nmin = 0, nmax = 0;
-	int abs_p = 0, abs_w = 0, abs_x = 0, abs_y = 0;
+	int raw_n, i;
+	int abs_x = 0, abs_y = 0, n = 0;
 
 	if (size < c->tp_offset || (size - c->tp_offset) % SIZEOF_FINGER != 0)
 		return -EIO;
@@ -522,69 +524,34 @@ static int report_tp_state(struct bcm5974 *dev, int size)
 		for (i = 0; i < raw_n; i++)
 			report_finger_data(input, c, &f[i]);
 
-		raw_p = raw2int(f->touch_major);
-		raw_w = raw2int(f->tool_major);
-		raw_x = raw2int(f->abs_x);
-		raw_y = raw2int(f->abs_y);
-
-		dprintk(9,
-			"bcm5974: "
-			"raw: p: %+05d w: %+05d x: %+05d y: %+05d n: %d\n",
-			raw_p, raw_w, raw_x, raw_y, raw_n);
-
-		ptest = int2bound(&c->p, raw_p);
-		origin = raw2int(f->origin);
-
 		/* while tracking finger still valid, count all fingers */
-		if (ptest > PRESSURE_LOW && origin) {
-			abs_p = ptest;
-			abs_w = int2bound(&c->w, raw_w);
-			abs_x = int2bound(&c->x, raw_x - c->x.devmin);
-			abs_y = int2bound(&c->y, c->y.devmax - raw_y);
-			while (raw_n--) {
-				ptest = int2bound(&c->p,
-						  raw2int(f->touch_major));
-				if (ptest > PRESSURE_LOW)
-					nmax++;
-				if (ptest > PRESSURE_HIGH)
-					nmin++;
-				f++;
-			}
+		if (raw2int(f->touch_major) > 0 && raw2int(f->origin)) {
+			abs_x = raw2int(f->abs_x);
+			abs_y = c->y.min + c->y.max - raw2int(f->abs_y);
+			for (i = 0; i < raw_n; i++)
+				if (raw2int(f[i].touch_major) > 0)
+					n++;
 		}
 	}
 
-	/* set the integrated button if applicable */
-	if (c->tp_type == TYPE2)
-		ibt = raw2int(dev->tp_data[BUTTON_TYPE2]);
-
-	if (dev->fingers < nmin)
-		dev->fingers = nmin;
-	if (dev->fingers > nmax)
-		dev->fingers = nmax;
+	input_report_key(input, BTN_TOUCH, n > 0);
+	input_report_key(input, BTN_TOOL_FINGER, n == 1);
+	input_report_key(input, BTN_TOOL_DOUBLETAP, n == 2);
+	input_report_key(input, BTN_TOOL_TRIPLETAP, n == 3);
+	input_report_key(input, BTN_TOOL_QUADTAP, n > 3);
 
-	input_report_key(input, BTN_TOUCH, dev->fingers > 0);
-	input_report_key(input, BTN_TOOL_FINGER, dev->fingers == 1);
-	input_report_key(input, BTN_TOOL_DOUBLETAP, dev->fingers == 2);
-	input_report_key(input, BTN_TOOL_TRIPLETAP, dev->fingers == 3);
-	input_report_key(input, BTN_TOOL_QUADTAP, dev->fingers > 3);
+	report_synaptics_data(input, c, f, raw_n);
 
-	input_report_abs(input, ABS_PRESSURE, abs_p);
-	input_report_abs(input, ABS_TOOL_WIDTH, abs_w);
-
-	if (abs_p) {
+	if (n > 0) {
 		input_report_abs(input, ABS_X, abs_x);
 		input_report_abs(input, ABS_Y, abs_y);
-
-		dprintk(8,
-			"bcm5974: abs: p: %+05d w: %+05d x: %+05d y: %+05d "
-			"nmin: %d nmax: %d n: %d ibt: %d\n", abs_p, abs_w,
-			abs_x, abs_y, nmin, nmax, dev->fingers, ibt);
-
 	}
 
 	/* type 2 reports button events via ibt only */
-	if (c->tp_type == TYPE2)
+	if (c->tp_type == TYPE2) {
+		int ibt = raw2int(dev->tp_data[BUTTON_TYPE2]);
 		input_report_key(input, BTN_LEFT, ibt);
+	}
 
 	input_sync(input);