Re: [PATCH] Input: ALPS - Add semi-MT support for v4 protocol

[Seth Forshee]

On Wed, Apr 18, 2012 at 02:02:14AM +0300, George Pantalos wrote:
> This patch adds semi-MT support for ALPS v4 protocol touchpads.
> It is based on the work by Seth Forshee for ALPS v3 and v4 protocol
> support. Three packets are required to assemble and process the MT
> data. ST events are reported at once to avoid latency. If there
> were two contacts or more, report MT data instead of ST events.
> 
> Thanks to Seth Forshee for providing most of the code, guidance
> and insight for producing this patch.
> 
> Signed-off-by: George Pantalos <gpantalos@xxxxxxxxx>

Acked-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>

> ---
>  drivers/input/mouse/alps.c |   79 +++++++++++++++++++++++++++++++---
>  drivers/input/mouse/alps.h |    2 +
>  2 files changed, 75 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
> index 4c6a72d..6028e02 100644
> --- a/drivers/input/mouse/alps.c
> +++ b/drivers/input/mouse/alps.c
> @@ -604,10 +604,54 @@ static void alps_process_packet_v3(struct 
> psmouse *psmouse)
>  
>  static void alps_process_packet_v4(struct psmouse *psmouse)
>  {
> +	struct alps_data *priv = psmouse->private;
>  	unsigned char *packet = psmouse->packet;
>  	struct input_dev *dev = psmouse->dev;
> +	int offset;
>  	int x, y, z;
>  	int left, right;
> +	int x1, y1, x2, y2;
> +	int fingers = 0;
> +	unsigned int x_bitmap, y_bitmap;
> +
> +	/*
> +	 * v4 has a 6-byte encoding for bitmap data, but this data is
> +	 * broken up between 3 normal packets. Use priv->multi_packet to
> +	 * track our position in the bitmap packet.
> +	 */
> +	if (packet[6] & 0x40) {
> +		/* sync, reset position */
> +		priv->multi_packet = 0;
> +	}
> +
> +	if (WARN_ON_ONCE(priv->multi_packet > 2))
> +		return;
> +
> +	offset = 2 * priv->multi_packet;
> +	priv->multi_data[offset] = packet[6];
> +	priv->multi_data[offset + 1] = packet[7];
> +
> +	if (++priv->multi_packet > 2) {
> +		priv->multi_packet = 0;
> +
> +		x_bitmap = ((priv->multi_data[2] & 0x1f) << 10) |
> +			   ((priv->multi_data[3] & 0x60) << 3) |
> +			   ((priv->multi_data[0] & 0x3f) << 2) |
> +			   ((priv->multi_data[1] & 0x60) >> 5);
> +		y_bitmap = ((priv->multi_data[5] & 0x01) << 10) |
> +			   ((priv->multi_data[3] & 0x1f) << 5) |
> +			   (priv->multi_data[1] & 0x1f);
> +
> +		fingers = alps_process_bitmap(x_bitmap, y_bitmap,
> +					      &x1, &y1, &x2, &y2);
> +
> +		/* Store MT data.*/
> +		priv->fingers = fingers;
> +		priv->x1 = x1;
> +		priv->x2 = x2;
> +		priv->y1 = y1;
> +		priv->y2 = y2;
> +	}
>  
>  	left = packet[4] & 0x01;
>  	right = packet[4] & 0x02;
> @@ -617,21 +661,44 @@ static void alps_process_packet_v4(struct psmouse 
> *psmouse)
>  	y = ((packet[2] & 0x7f) << 4) | (packet[3] & 0x0f);
>  	z = packet[5] & 0x7f;
>  
> +	/*
> +	 * If there were no contacts in the bitmap, use ST
> +	 * points in MT reports.
> +	 * If there were two contacts or more, report MT data.
> +	 */
> +	if (priv->fingers < 2) {
> +		x1 = x;
> +		y1 = y;
> +		fingers = z > 0 ? 1 : 0;
> +	} else {
> +		fingers = priv->fingers;
> +		x1 = priv->x1;
> +		x2 = priv->x2;
> +		y1 = priv->y1;
> +		y2 = priv->y2;
> +	}
> +
>  	if (z >= 64)
>  		input_report_key(dev, BTN_TOUCH, 1);
>  	else
>  		input_report_key(dev, BTN_TOUCH, 0);
>  
> +	alps_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
> +
> +	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
> +	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
> +	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
> +	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
> +
> +	input_report_key(dev, BTN_LEFT, left);
> +	input_report_key(dev, BTN_RIGHT, right);
> +
>  	if (z > 0) {
>  		input_report_abs(dev, ABS_X, x);
>  		input_report_abs(dev, ABS_Y, y);
>  	}
>  	input_report_abs(dev, ABS_PRESSURE, z);
>  
> -	input_report_key(dev, BTN_TOOL_FINGER, z > 0);
> -	input_report_key(dev, BTN_LEFT, left);
> -	input_report_key(dev, BTN_RIGHT, right);
> -
>  	input_sync(dev);
>  }
>  
> @@ -1557,6 +1624,7 @@ int alps_init(struct psmouse *psmouse)
>  		input_set_abs_params(dev1, ABS_Y, 0, 767, 0, 0);
>  		break;
>  	case ALPS_PROTO_V3:
> +	case ALPS_PROTO_V4:
>  		set_bit(INPUT_PROP_SEMI_MT, dev1->propbit);
>  		input_mt_init_slots(dev1, 2);
>  		input_set_abs_params(dev1, ABS_MT_POSITION_X, 0, 
> ALPS_V3_X_MAX, 0, 0);
> @@ -1565,8 +1633,7 @@ int alps_init(struct psmouse *psmouse)
>  		set_bit(BTN_TOOL_DOUBLETAP, dev1->keybit);
>  		set_bit(BTN_TOOL_TRIPLETAP, dev1->keybit);
>  		set_bit(BTN_TOOL_QUADTAP, dev1->keybit);
> -		/* fall through */
> -	case ALPS_PROTO_V4:
> +
>  		input_set_abs_params(dev1, ABS_X, 0, ALPS_V3_X_MAX, 0, 0);
>  		input_set_abs_params(dev1, ABS_Y, 0, ALPS_V3_Y_MAX, 0, 0);
>  		break;
> diff --git a/drivers/input/mouse/alps.h b/drivers/input/mouse/alps.h
> index a00a4ab..ae1ac35 100644
> --- a/drivers/input/mouse/alps.h
> +++ b/drivers/input/mouse/alps.h
> @@ -39,6 +39,8 @@ struct alps_data {
>  	int prev_fin;			/* Finger bit from previous packet */
>  	int multi_packet;		/* Multi-packet data in progress */
>  	unsigned char multi_data[6];	/* Saved multi-packet data */
> +	int x1, x2, y1, y2;		/* Coordinates from last MT report */
> +	int fingers;			/* Number of fingers from MT report */
>  	u8 quirks;
>  	struct timer_list timer;
>  };
> --
> 1.7.10
> 
> 
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