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Date: Wed, 21 Aug 2013 20:26:54 +0200
From: Henrik Rydberg <rydberg@...omail.se>
To: Benjamin Tissoires <benjamin.tissoires@...hat.com>
Cc: Benjamin Tissoires <benjamin.tissoires@...il.com>,
Jiri Kosina <jkosina@...e.cz>,
Stephane Chatty <chatty@...c.fr>,
Alexander Holler <holler@...oftware.de>,
Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/3] HID: detect Win 8 multitouch devices in core
Hi Benjamin,
> Detecting Win 8 multitouch devices in core allows us to set quirks
> before the device is parsed through hid_hw_start().
> It also simplifies the detection of those devices in hid-multitouch and
> makes the handling of those devices cleaner.
>
> As Win 8 multitouch panels are in the group multitouch and rely on a
> special feature to be detected, this patch also temporary convert
> hid->group into a bitfield, before reverting it to the actual
> group information. If we ever have more than 16 groups to detect,
> we can then add a .flags field in hid_parser for instance, and then
> use this to get the actual group.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@...hat.com>
> ---
>
> changes in v2:
> - moved "flags" processing here
> - do not introduce parser->flags, but use hid->group as a temporary flag placeholder
> - #define and #undef HID_FLAG_* in hid-core.c instead of hid.h
> - amended commit message
>
> drivers/hid/hid-core.c | 41 +++++++++++++++++++++++++++++++++++++++--
> drivers/hid/hid-multitouch.c | 24 +++++++++++-------------
> include/linux/hid.h | 1 +
> 3 files changed, 51 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index e072b15..c749966 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -677,12 +677,25 @@ static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
> return NULL;
> }
>
> +#define HID_FLAG_MULTITOUCH (1 << HID_GROUP_MULTITOUCH)
> +#define HID_FLAG_WIN_8_CERTIFIED (1 << HID_GROUP_MULTITOUCH_WIN_8)
> +#define HID_FLAG_SENSOR_HUB (1 << HID_GROUP_SENSOR_HUB)
> +
Why not use the existing defines directly? If you worry about being
able to combine bit positions in a simple mask rather than using the
existing bitmask (which could be good), how about a priority list for
the groups instead? My own preference would be to leave structure for
the future to the future, and use a single state in the parser for the
case you are adding.
> static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
> {
> struct hid_device *hid = parser->device;
>
> if (usage == HID_DG_CONTACTID)
> - hid->group = HID_GROUP_MULTITOUCH;
> + hid->group |= HID_FLAG_MULTITOUCH;
> +}
Dynamic semantics, please no :-) My suggestion: leave this line be...
> +
> +static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
> +{
> + struct hid_device *hid = parser->device;
> +
> + if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
> + parser->global.report_size == 8)
> + hid->group |= HID_FLAG_WIN_8_CERTIFIED;
And set 'parser->is_win8 = true' here.
> }
>
> static void hid_scan_collection(struct hid_parser *parser, unsigned type)
> @@ -691,7 +704,7 @@ static void hid_scan_collection(struct hid_parser *parser, unsigned type)
>
> if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
> type == HID_COLLECTION_PHYSICAL)
> - hid->group = HID_GROUP_SENSOR_HUB;
> + hid->group |= HID_FLAG_SENSOR_HUB;
Leave this...
> }
>
> static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
> @@ -714,6 +727,8 @@ static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
> case HID_MAIN_ITEM_TAG_OUTPUT:
> break;
> case HID_MAIN_ITEM_TAG_FEATURE:
> + for (i = 0; i < parser->local.usage_index; i++)
> + hid_scan_feature_usage(parser, parser->local.usage[i]);
> break;
> default:
> hid_err(parser->device, "unknown main item tag 0x%x\n",
> @@ -759,10 +774,32 @@ static int hid_scan_report(struct hid_device *hid)
> while ((start = fetch_item(start, end, &item)) != NULL)
> dispatch_type[item.type](parser, &item);
>
> + /*
> + * Re-interprete the group field to keep the same group definitions than
> + * we had in previous kernels.
> + */
> + switch (hid->group) {
> + case HID_FLAG_MULTITOUCH:
> + hid->group = HID_GROUP_MULTITOUCH;
> + break;
> + case HID_FLAG_MULTITOUCH | HID_FLAG_WIN_8_CERTIFIED:
> + hid->group = HID_GROUP_MULTITOUCH_WIN_8;
> + break;
> + case HID_FLAG_SENSOR_HUB:
> + hid->group = HID_GROUP_SENSOR_HUB;
> + break;
> + default:
> + hid->group = HID_GROUP_GENERIC;
> + }
> +
... and replace this with 'if (parser->is_win8) hid->group = HID_GROUP_MULTITOUCH_WIN_8'.
> vfree(parser);
> return 0;
> }
>
> +#undef HID_FLAG_MULTITOUCH
> +#undef HID_FLAG_WIN_8_CERTIFIED
> +#undef HID_FLAG_SENSOR_HUB
> +
No comment ;-)
> /**
> * hid_parse_report - parse device report
> *
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index 0fe00e2..c28ef86 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -133,6 +133,7 @@ static void mt_post_parse(struct mt_device *td);
> #define MT_CLS_NSMU 0x000a
> #define MT_CLS_DUAL_CONTACT_NUMBER 0x0010
> #define MT_CLS_DUAL_CONTACT_ID 0x0011
> +#define MT_CLS_WIN_8 0x0012
>
> /* vendor specific classes */
> #define MT_CLS_3M 0x0101
> @@ -205,6 +206,11 @@ static struct mt_class mt_classes[] = {
> MT_QUIRK_CONTACT_CNT_ACCURATE |
> MT_QUIRK_SLOT_IS_CONTACTID,
> .maxcontacts = 2 },
> + { .name = MT_CLS_WIN_8,
> + .quirks = MT_QUIRK_ALWAYS_VALID |
> + MT_QUIRK_IGNORE_DUPLICATES |
> + MT_QUIRK_HOVERING |
> + MT_QUIRK_CONTACT_CNT_ACCURATE },
>
> /*
> * vendor specific classes
> @@ -332,19 +338,6 @@ static void mt_feature_mapping(struct hid_device *hdev,
> td->maxcontacts = td->mtclass.maxcontacts;
>
> break;
> - case 0xff0000c5:
> - if (field->report_count == 256 && field->report_size == 8) {
> - /* Win 8 devices need special quirks */
> - __s32 *quirks = &td->mtclass.quirks;
> - *quirks |= MT_QUIRK_ALWAYS_VALID;
> - *quirks |= MT_QUIRK_IGNORE_DUPLICATES;
> - *quirks |= MT_QUIRK_HOVERING;
> - *quirks |= MT_QUIRK_CONTACT_CNT_ACCURATE;
> - *quirks &= ~MT_QUIRK_NOT_SEEN_MEANS_UP;
> - *quirks &= ~MT_QUIRK_VALID_IS_INRANGE;
> - *quirks &= ~MT_QUIRK_VALID_IS_CONFIDENCE;
> - }
> - break;
> }
> }
>
> @@ -1346,6 +1339,11 @@ static const struct hid_device_id mt_devices[] = {
>
> /* Generic MT device */
> { HID_DEVICE(HID_BUS_ANY, HID_GROUP_MULTITOUCH, HID_ANY_ID, HID_ANY_ID) },
> +
> + /* Generic Win 8 certified MT device */
> + { .driver_data = MT_CLS_WIN_8,
> + HID_DEVICE(HID_BUS_ANY, HID_GROUP_MULTITOUCH_WIN_8,
> + HID_ANY_ID, HID_ANY_ID) },
> { }
> };
> MODULE_DEVICE_TABLE(hid, mt_devices);
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index 5a4e789..45b7f3f 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -295,6 +295,7 @@ struct hid_item {
> #define HID_GROUP_GENERIC 0x0001
> #define HID_GROUP_MULTITOUCH 0x0002
> #define HID_GROUP_SENSOR_HUB 0x0003
> +#define HID_GROUP_MULTITOUCH_WIN_8 0x0004
>
> /*
> * This is the global environment of the parser. This information is
> --
> 1.8.3.1
>
Thanks,
Henrik
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