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Date:	Tue, 28 Aug 2012 15:25:27 -0700 (PDT)
From:	Jiri Kosina <jkosina@...e.cz>
To:	Henrik Rydberg <rydberg@...omail.se>
Cc:	Benjamin Tissoires <benjamin.tissoires@...c.fr>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] HID: multitouch: Remove the redundant touch state

On Wed, 22 Aug 2012, Henrik Rydberg wrote:

> With the input_mt_sync_frame() function in place, there is no longer
> any need to keep the full touch state in the driver. This patch
> removes the slot state and replaces the lookup code with the input-mt
> equivalent. The initialization code is moved to mt_input_configured(),
> to make sure the full HID report has been seen.
> 
> Signed-off-by: Henrik Rydberg <rydberg@...omail.se>
> ---
> Hi Benjamin,
> 
> Maybe this patch works better? It has received limited testing so far.

What is the status of this patch please? Henrik, Benjamin?

> 
> Henrik
> 
>  drivers/hid/hid-multitouch.c | 133 +++++++++++++++----------------------------
>  1 file changed, 46 insertions(+), 87 deletions(-)
> 
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index c400d90..dc08a4e 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -56,7 +56,6 @@ struct mt_slot {
>  	__s32 x, y, p, w, h;
>  	__s32 contactid;	/* the device ContactID assigned to this slot */
>  	bool touch_state;	/* is the touch valid? */
> -	bool seen_in_this_frame;/* has this slot been updated */
>  };
>  
>  struct mt_class {
> @@ -93,7 +92,7 @@ struct mt_device {
>  				* 1 means we should use a serial protocol
>  				* > 1 means hybrid (multitouch) protocol */
>  	bool curvalid;		/* is the current contact valid? */
> -	struct mt_slot *slots;
> +	unsigned mt_flags;	/* flags to pass to input-mt */
>  };
>  
>  /* classes of device behavior */
> @@ -134,25 +133,6 @@ static int cypress_compute_slot(struct mt_device *td)
>  		return -1;
>  }
>  
> -static int find_slot_from_contactid(struct mt_device *td)
> -{
> -	int i;
> -	for (i = 0; i < td->maxcontacts; ++i) {
> -		if (td->slots[i].contactid == td->curdata.contactid &&
> -			td->slots[i].touch_state)
> -			return i;
> -	}
> -	for (i = 0; i < td->maxcontacts; ++i) {
> -		if (!td->slots[i].seen_in_this_frame &&
> -			!td->slots[i].touch_state)
> -			return i;
> -	}
> -	/* should not occurs. If this happens that means
> -	 * that the device sent more touches that it says
> -	 * in the report descriptor. It is ignored then. */
> -	return -1;
> -}
> -
>  static struct mt_class mt_classes[] = {
>  	{ .name = MT_CLS_DEFAULT,
>  		.quirks = MT_QUIRK_NOT_SEEN_MEANS_UP },
> @@ -319,24 +299,16 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>  	* We need to ignore fields that belong to other collections
>  	* such as Mouse that might have the same GenericDesktop usages. */
>  	if (field->application == HID_DG_TOUCHSCREEN)
> -		set_bit(INPUT_PROP_DIRECT, hi->input->propbit);
> +		td->mt_flags |= INPUT_MT_DIRECT;
>  	else if (field->application != HID_DG_TOUCHPAD)
>  		return 0;
>  
> -	/* In case of an indirect device (touchpad), we need to add
> -	 * specific BTN_TOOL_* to be handled by the synaptics xorg
> -	 * driver.
> -	 * We also consider that touchscreens providing buttons are touchpads.
> +	/*
> +	 * Model touchscreens providing buttons as touchpads.
>  	 */
>  	if (field->application == HID_DG_TOUCHPAD ||
> -	    (usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON ||
> -	    cls->is_indirect) {
> -		set_bit(INPUT_PROP_POINTER, hi->input->propbit);
> -		set_bit(BTN_TOOL_FINGER, hi->input->keybit);
> -		set_bit(BTN_TOOL_DOUBLETAP, hi->input->keybit);
> -		set_bit(BTN_TOOL_TRIPLETAP, hi->input->keybit);
> -		set_bit(BTN_TOOL_QUADTAP, hi->input->keybit);
> -	}
> +	    (usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON)
> +		td->mt_flags |= INPUT_MT_POINTER;
>  
>  	/* eGalax devices provide a Digitizer.Stylus input which overrides
>  	 * the correct Digitizers.Finger X/Y ranges.
> @@ -353,8 +325,6 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>  					EV_ABS, ABS_MT_POSITION_X);
>  			set_abs(hi->input, ABS_MT_POSITION_X, field,
>  				cls->sn_move);
> -			/* touchscreen emulation */
> -			set_abs(hi->input, ABS_X, field, cls->sn_move);
>  			mt_store_field(usage, td, hi);
>  			td->last_field_index = field->index;
>  			return 1;
> @@ -363,8 +333,6 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>  					EV_ABS, ABS_MT_POSITION_Y);
>  			set_abs(hi->input, ABS_MT_POSITION_Y, field,
>  				cls->sn_move);
> -			/* touchscreen emulation */
> -			set_abs(hi->input, ABS_Y, field, cls->sn_move);
>  			mt_store_field(usage, td, hi);
>  			td->last_field_index = field->index;
>  			return 1;
> @@ -390,7 +358,6 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>  		case HID_DG_CONTACTID:
>  			if (!td->maxcontacts)
>  				td->maxcontacts = MT_DEFAULT_MAXCONTACT;
> -			input_mt_init_slots(hi->input, td->maxcontacts, 0);
>  			mt_store_field(usage, td, hi);
>  			td->last_field_index = field->index;
>  			td->touches_by_report++;
> @@ -418,9 +385,6 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>  					EV_ABS, ABS_MT_PRESSURE);
>  			set_abs(hi->input, ABS_MT_PRESSURE, field,
>  				cls->sn_pressure);
> -			/* touchscreen emulation */
> -			set_abs(hi->input, ABS_PRESSURE, field,
> -				cls->sn_pressure);
>  			mt_store_field(usage, td, hi);
>  			td->last_field_index = field->index;
>  			return 1;
> @@ -464,7 +428,24 @@ static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
>  	return -1;
>  }
>  
> -static int mt_compute_slot(struct mt_device *td)
> +static void mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
> +
> +{
> +	struct mt_device *td = hid_get_drvdata(hdev);
> +	struct mt_class *cls = &td->mtclass;
> +
> +	if (cls->is_indirect)
> +		td->mt_flags |= INPUT_MT_POINTER;
> +
> +	if (cls->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
> +		td->mt_flags |= INPUT_MT_DROP_UNUSED;
> +
> +	input_mt_init_slots(hi->input, td->maxcontacts, td->mt_flags);
> +
> +	td->mt_flags = 0;
> +}
> +
> +static int mt_compute_slot(struct mt_device *td, struct input_dev *input)
>  {
>  	__s32 quirks = td->mtclass.quirks;
>  
> @@ -480,42 +461,23 @@ static int mt_compute_slot(struct mt_device *td)
>  	if (quirks & MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE)
>  		return td->curdata.contactid - 1;
>  
> -	return find_slot_from_contactid(td);
> +	return input_mt_assign_slot_by_id(input, td->curdata.contactid);
>  }
>  
>  /*
>   * this function is called when a whole contact has been processed,
>   * so that it can assign it to a slot and store the data there
>   */
> -static void mt_complete_slot(struct mt_device *td)
> +static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
>  {
> -	td->curdata.seen_in_this_frame = true;
>  	if (td->curvalid) {
> -		int slotnum = mt_compute_slot(td);
> -
> -		if (slotnum >= 0 && slotnum < td->maxcontacts)
> -			td->slots[slotnum] = td->curdata;
> -	}
> -	td->num_received++;
> -}
> +		int slotnum = mt_compute_slot(td, input);
> +		struct mt_slot *s = &td->curdata;
>  
> +		if (slotnum < 0 || slotnum >= td->maxcontacts)
> +			return;
>  
> -/*
> - * this function is called when a whole packet has been received and processed,
> - * so that it can decide what to send to the input layer.
> - */
> -static void mt_emit_event(struct mt_device *td, struct input_dev *input)
> -{
> -	int i;
> -
> -	for (i = 0; i < td->maxcontacts; ++i) {
> -		struct mt_slot *s = &(td->slots[i]);
> -		if ((td->mtclass.quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
> -			!s->seen_in_this_frame) {
> -			s->touch_state = false;
> -		}
> -
> -		input_mt_slot(input, i);
> +		input_mt_slot(input, slotnum);
>  		input_mt_report_slot_state(input, MT_TOOL_FINGER,
>  			s->touch_state);
>  		if (s->touch_state) {
> @@ -532,16 +494,22 @@ static void mt_emit_event(struct mt_device *td, struct input_dev *input)
>  			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
>  			input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
>  		}
> -		s->seen_in_this_frame = false;
> -
>  	}
>  
> -	input_mt_report_pointer_emulation(input, true);
> -	input_sync(input);
> -	td->num_received = 0;
> +	td->num_received++;
>  }
>  
>  
> +/*
> + * this function is called when a whole packet has been received and processed,
> + * so that it can decide what to send to the input layer.
> + */
> +static void mt_sync_frame(struct mt_device *td, struct input_dev *input)
> +{
> +	input_mt_sync_frame(input);
> +	input_sync(input);
> +	td->num_received = 0;
> +}
>  
>  static int mt_event(struct hid_device *hid, struct hid_field *field,
>  				struct hid_usage *usage, __s32 value)
> @@ -549,7 +517,7 @@ static int mt_event(struct hid_device *hid, struct hid_field *field,
>  	struct mt_device *td = hid_get_drvdata(hid);
>  	__s32 quirks = td->mtclass.quirks;
>  
> -	if (hid->claimed & HID_CLAIMED_INPUT && td->slots) {
> +	if (hid->claimed & HID_CLAIMED_INPUT) {
>  		switch (usage->hid) {
>  		case HID_DG_INRANGE:
>  			if (quirks & MT_QUIRK_ALWAYS_VALID)
> @@ -602,11 +570,11 @@ static int mt_event(struct hid_device *hid, struct hid_field *field,
>  		}
>  
>  		if (usage->hid == td->last_slot_field)
> -			mt_complete_slot(td);
> +			mt_complete_slot(td, field->hidinput->input);
>  
>  		if (field->index == td->last_field_index
>  			&& td->num_received >= td->num_expected)
> -			mt_emit_event(td, field->hidinput->input);
> +			mt_sync_frame(td, field->hidinput->input);
>  
>  	}
>  
> @@ -735,15 +703,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  	if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
>  		mt_post_parse_default_settings(td);
>  
> -	td->slots = kzalloc(td->maxcontacts * sizeof(struct mt_slot),
> -				GFP_KERNEL);
> -	if (!td->slots) {
> -		dev_err(&hdev->dev, "cannot allocate multitouch slots\n");
> -		hid_hw_stop(hdev);
> -		ret = -ENOMEM;
> -		goto fail;
> -	}
> -
>  	ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
>  
>  	mt_set_maxcontacts(hdev);
> @@ -774,7 +733,6 @@ static void mt_remove(struct hid_device *hdev)
>  	struct mt_device *td = hid_get_drvdata(hdev);
>  	sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group);
>  	hid_hw_stop(hdev);
> -	kfree(td->slots);
>  	kfree(td);
>  	hid_set_drvdata(hdev, NULL);
>  }
> @@ -1087,6 +1045,7 @@ static struct hid_driver mt_driver = {
>  	.remove = mt_remove,
>  	.input_mapping = mt_input_mapping,
>  	.input_mapped = mt_input_mapped,
> +	.input_configured = mt_input_configured,
>  	.feature_mapping = mt_feature_mapping,
>  	.usage_table = mt_grabbed_usages,
>  	.event = mt_event,
> -- 
> 1.7.11.5
> 

-- 
Jiri Kosina
SUSE Labs
--
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