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Commit 1eb00321 authored by Candle Sun's avatar Candle Sun Committed by Gerrit - the friendly Code Review server
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HID: core: add usage_page_preceding flag for hid_concatenate_usage_page() 



Upstream commit 58e75155009c ("HID: core: move Usage Page concatenation
to Main item") adds support for Usage Page item following Usage items
(such as keyboards manufactured by Primax).

Usage Page concatenation in Main item works well for following report
descriptor patterns:

    USAGE_PAGE (Keyboard)                   05 07
    USAGE_MINIMUM (Keyboard LeftControl)    19 E0
    USAGE_MAXIMUM (Keyboard Right GUI)      29 E7
    LOGICAL_MINIMUM (0)                     15 00
    LOGICAL_MAXIMUM (1)                     25 01
    REPORT_SIZE (1)                         75 01
    REPORT_COUNT (8)                        95 08
    INPUT (Data,Var,Abs)                    81 02

-------------

    USAGE_MINIMUM (Keyboard LeftControl)    19 E0
    USAGE_MAXIMUM (Keyboard Right GUI)      29 E7
    LOGICAL_MINIMUM (0)                     15 00
    LOGICAL_MAXIMUM (1)                     25 01
    REPORT_SIZE (1)                         75 01
    REPORT_COUNT (8)                        95 08
    USAGE_PAGE (Keyboard)                   05 07
    INPUT (Data,Var,Abs)                    81 02

But it makes the parser act wrong for the following report
descriptor pattern(such as some Gamepads):

    USAGE_PAGE (Button)                     05 09
    USAGE (Button 1)                        09 01
    USAGE (Button 2)                        09 02
    USAGE (Button 4)                        09 04
    USAGE (Button 5)                        09 05
    USAGE (Button 7)                        09 07
    USAGE (Button 8)                        09 08
    USAGE (Button 14)                       09 0E
    USAGE (Button 15)                       09 0F
    USAGE (Button 13)                       09 0D
    USAGE_PAGE (Consumer Devices)           05 0C
    USAGE (Back)                            0a 24 02
    USAGE (HomePage)                        0a 23 02
    LOGICAL_MINIMUM (0)                     15 00
    LOGICAL_MAXIMUM (1)                     25 01
    REPORT_SIZE (1)                         75 01
    REPORT_COUNT (11)                       95 0B
    INPUT (Data,Var,Abs)                    81 02

With Usage Page concatenation in Main item, parser recognizes all the
11 Usages as consumer keys, it is not the HID device's real intention.

This patch adds usage_page_preceding flag to detect the third pattern.
Usage Page concatenation is done in both Local and Main parsing.
If usage_page_preceding equals 3(the third pattern encountered),
hid_concatenate_usage_page() is jumped.

Change-Id: Ieba9bcae85c49619b0abbafb55ce26d72a24f086
Signed-off-by: default avatarCandle Sun <candle.sun@unisoc.com>
Signed-off-by: default avatarNianfu Bai <nianfu.bai@unisoc.com>
Fixes: 58e75155009c ("HID: core: move Usage Page concatenation to Main item")
Link: https://lore.kernel.org/lkml/1569830949-10771-1-git-send-email-candlesea@gmail.com/


Patch-mainline: linux-kernel @ 30/09/2019, 16:09
Signed-off-by: default avatarRahul Shahare <rshaha@codeaurora.org>
parent c5ac9792

drivers/hid/hid-core.c

+19 −2
Original line number Diff line number Diff line
@@ -205,6 +205,14 @@ static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size) 
		hid_err(parser->device, "usage index exceeded\n");

		return -1;

	}

	if (!parser->local.usage_index && parser->global.usage_page)

		parser->local.usage_page_preceding = 1;

	if (parser->local.usage_page_preceding == 2)

		parser->local.usage_page_preceding = 3;

	if (size <= 2 && parser->global.usage_page)

		parser->local.usage[parser->local.usage_index] =

			(usage & 0xffff) + (parser->global.usage_page << 16);

	else

		parser->local.usage[parser->local.usage_index] = usage;

	parser->local.usage_size[parser->local.usage_index] = size;

	parser->local.collection_index[parser->local.usage_index] =
@@ -345,6 +353,8 @@ static int hid_parser_global(struct hid_parser *parser, struct hid_item *item) 


	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:

		parser->global.usage_page = item_udata(item);

		if (parser->local.usage_page_preceding == 1)

			parser->local.usage_page_preceding = 2;

		return 0;



	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
@@ -526,9 +536,16 @@ static void hid_concatenate_usage_page(struct hid_parser *parser) 
{

	int i;



	if (parser->local.usage_page_preceding == 3) {

		dbg_hid("Using preceding usage page for final usage\n");

		return;

	}



	for (i = 0; i < parser->local.usage_index; i++)

		if (parser->local.usage_size[i] <= 2)

			parser->local.usage[i] += parser->global.usage_page << 16;

			parser->local.usage[i] =

				(parser->global.usage_page << 16)

				+ (parser->local.usage[i] & 0xffff);

}



/*

include/linux/hid.h

+1 −0
Original line number Diff line number Diff line
@@ -404,6 +404,7 @@ struct hid_local { 
	unsigned usage_minimum;

	unsigned delimiter_depth;

	unsigned delimiter_branch;

	unsigned int usage_page_preceding;

};



/*