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Message-ID: <CAN+gG=FO7boJ7mQefL=JoggNiUS7ea6=W=+g=5fvMzpMB0x5+g@mail.gmail.com>
Date: Mon, 4 Feb 2013 10:36:58 +0100
From: Benjamin Tissoires <benjamin.tissoires@...il.com>
To: Henrik Rydberg <rydberg@...omail.se>
Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>,
Jiri Kosina <jkosina@...e.cz>,
Stephane Chatty <chatty@...c.fr>, linux-input@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/9] HID: multitouch: add support for Nexio 42" panel
Hi Henrik,
On Sun, Feb 3, 2013 at 2:00 PM, Henrik Rydberg <rydberg@...omail.se> wrote:
> Hi Benjamin,
>
>> This device is the worst device I saw. It keeps TipSwitch and InRange
>> at 1 for fingers that are not touching the panel.
>> The solution is to rely on the field ContactCount, which is accurate
>> as the correct information are packed at the begining of the frame.
>>
>> Unfortunately, CountactCount is most of the time at the end of the report.
>> The solution is to pick it when we have the whole report in raw_event.
>>
>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@...il.com>
>> ---
>> drivers/hid/hid-ids.h | 3 +++
>> drivers/hid/hid-multitouch.c | 36 ++++++++++++++++++++++++++++++------
>> 2 files changed, 33 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
>> index dad56aa..0935012 100644
>> --- a/drivers/hid/hid-ids.h
>> +++ b/drivers/hid/hid-ids.h
>> @@ -597,6 +597,9 @@
>> #define USB_VENDOR_ID_NEC 0x073e
>> #define USB_DEVICE_ID_NEC_USB_GAME_PAD 0x0301
>>
>> +#define USB_VENDOR_ID_NEXIO 0x1870
>> +#define USB_DEVICE_ID_NEXIO_MULTITOUCH_420 0x010d
>> +
>> #define USB_VENDOR_ID_NEXTWINDOW 0x1926
>> #define USB_DEVICE_ID_NEXTWINDOW_TOUCHSCREEN 0x0003
>>
>> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
>> index 092c09b..c9b8fe5 100644
>> --- a/drivers/hid/hid-multitouch.c
>> +++ b/drivers/hid/hid-multitouch.c
>> @@ -54,6 +54,7 @@ MODULE_LICENSE("GPL");
>> #define MT_QUIRK_NO_AREA (1 << 9)
>> #define MT_QUIRK_IGNORE_DUPLICATES (1 << 10)
>> #define MT_QUIRK_HOVERING (1 << 11)
>> +#define MT_QUIRK_CONTACT_CNT_ACCURATE (1 << 12)
>>
>> struct mt_slot {
>> __s32 x, y, cx, cy, p, w, h;
>> @@ -83,6 +84,7 @@ struct mt_device {
>> struct mt_class mtclass; /* our mt device class */
>> struct mt_fields *fields; /* temporary placeholder for storing the
>> multitouch fields */
>> + __s32 *contactcount; /* contact count value in the report */
>
> Why not an index here?
Just because an index is not sufficient. You need two things: an index
within the field, and the actual field (a pointer to a struct
hid_field). Each .value is local to a field, and even if in most of
the case, the contact count is alone in its field, it would mean to
take the risk that a new device does not follow this logic.
So the actual pointer to the contact count value seemed to be the
shortest way to do it. But it can be easily changed.
>
>> unsigned last_field_index; /* last field index of the report */
>> unsigned last_slot_field; /* the last field of a slot */
>> unsigned mt_report_id; /* the report ID of the multitouch device */
>> @@ -112,6 +114,7 @@ struct mt_device {
>> #define MT_CLS_DUAL_INRANGE_CONTACTNUMBER 0x0007
>> #define MT_CLS_DUAL_NSMU_CONTACTID 0x0008
>> #define MT_CLS_INRANGE_CONTACTNUMBER 0x0009
>> +#define MT_CLS_ALWAYS_TRUE 0x000a
>>
>> /* vendor specific classes */
>> #define MT_CLS_3M 0x0101
>> @@ -171,6 +174,9 @@ static struct mt_class mt_classes[] = {
>> { .name = MT_CLS_INRANGE_CONTACTNUMBER,
>> .quirks = MT_QUIRK_VALID_IS_INRANGE |
>> MT_QUIRK_SLOT_IS_CONTACTNUMBER },
>> + { .name = MT_CLS_ALWAYS_TRUE,
>> + .quirks = MT_QUIRK_ALWAYS_VALID |
>> + MT_QUIRK_CONTACT_CNT_ACCURATE },
>>
>> /*
>> * vendor specific classes
>> @@ -251,6 +257,9 @@ static ssize_t mt_set_quirks(struct device *dev,
>>
>> td->mtclass.quirks = val;
>>
>> + if (!td->contactcount)
>> + td->mtclass.quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE;
>> +
>
> Why override the overrider here?
This callback is called from the user-space through the sysfs
attribute. So, it is not called in the same time that the
mt_post_parse function. This is just to avoid a user setting this
quirk once the device is up and running leading to a potential oops.
>
>> return count;
>> }
>>
>> @@ -461,6 +470,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>> td->last_field_index = field->index;
>> return 1;
>> case HID_DG_CONTACTCOUNT:
>> + td->contactcount = field->value + usage->usage_index;
>
> An index into the the struct actually passed in mt_report() feels safer.
again, you need to store "field" and "usage->usage_index". Agree, it
would be safer but it will take more space... :)
>
>> td->last_field_index = field->index;
>> return 1;
>> case HID_DG_CONTACTMAX:
>> @@ -525,6 +535,10 @@ static int mt_compute_slot(struct mt_device *td, struct input_dev *input)
>> */
>> static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
>> {
>> + if ((td->mtclass.quirks & MT_QUIRK_CONTACT_CNT_ACCURATE) &&
>> + td->num_received >= td->num_expected)
>> + return;
>> +
>> if (td->curvalid || (td->mtclass.quirks & MT_QUIRK_ALWAYS_VALID)) {
>> int slotnum = mt_compute_slot(td, input);
>> struct mt_slot *s = &td->curdata;
>> @@ -635,12 +649,6 @@ static void mt_process_mt_event(struct hid_device *hid, struct hid_field *field,
>> td->curdata.h = value;
>> break;
>> case HID_DG_CONTACTCOUNT:
>> - /*
>> - * Includes multi-packet support where subsequent
>> - * packets are sent with zero contactcount.
>> - */
>> - if (value)
>> - td->num_expected = value;
>> break;
>> case HID_DG_TOUCH:
>> /* do nothing */
>> @@ -676,6 +684,13 @@ static void mt_report(struct hid_device *hid, struct hid_report *report)
>> if (!(hid->claimed & HID_CLAIMED_INPUT))
>> return;
>>
>> + /*
>> + * Includes multi-packet support where subsequent
>> + * packets are sent with zero contactcount.
>> + */
>> + if (td->contactcount && *td->contactcount)
>> + td->num_expected = *td->contactcount;
>> +
>
> Here, that is.
>
>> for (r = 0; r < report->maxfield; r++) {
>> field = report->field[r];
>> count = field->report_count;
>> @@ -750,11 +765,15 @@ static void mt_post_parse_default_settings(struct mt_device *td)
>> static void mt_post_parse(struct mt_device *td)
>> {
>> struct mt_fields *f = td->fields;
>> + struct mt_class *cls = &td->mtclass;
>>
>> if (td->touches_by_report > 0) {
>> int field_count_per_touch = f->length / td->touches_by_report;
>> td->last_slot_field = f->usages[field_count_per_touch - 1];
>> }
>> +
>> + if (!td->contactcount)
>> + cls->quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE;
>
> Since MT_QUIRK_CONTACT_CNT_ACCURATE is a quirk, modifiable by the
> user, it should probably not validate num_expected in the code. Better
> use the contact count index or something equivalent for that.
As when the user changes the quirk, we validate it, this is not required.
Cheers,
Benjamin
>
>> }
>>
>> static void mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
>> @@ -1087,6 +1106,11 @@ static const struct hid_device_id mt_devices[] = {
>> MT_USB_DEVICE(USB_VENDOR_ID_TURBOX,
>> USB_DEVICE_ID_TURBOX_TOUCHSCREEN_MOSART) },
>>
>> + /* Nexio panels */
>> + { .driver_data = MT_CLS_ALWAYS_TRUE,
>> + MT_USB_DEVICE(USB_VENDOR_ID_NEXIO,
>> + USB_DEVICE_ID_NEXIO_MULTITOUCH_420)},
>> +
>> /* Panasonic panels */
>> { .driver_data = MT_CLS_PANASONIC,
>> MT_USB_DEVICE(USB_VENDOR_ID_PANASONIC,
>> --
>> 1.8.1
>>
>
> Thanks,
> Henrik
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