Re: [PATCH 2/2] HID: multitouch: Support Asus T304UA media keys

On Aug 02 2017 or thereabouts, Jiri Kosina wrote:

On Mon, 24 Jul 2017, João Paulo Rechi Vita wrote:

quoted

The Asus T304UA convertible sports a magnetic detachable keyboard with
touchpad, which is connected over USB. Most of the keyboard hotkeys are
exposed through the same USB interface as the touchpad, defined in the
report descriptor as follows:

0x06, 0x31, 0xFF,  // Usage Page (Vendor Defined 0xFF31)
0x09, 0x76,        // Usage (0x76)
0xA1, 0x01,        // Collection (Application)
0x05, 0xFF,        //   Usage Page (Reserved 0xFF)
0x85, 0x5A,        //   Report ID (90)
0x19, 0x00,        //   Usage Minimum (0x00)
0x2A, 0xFF, 0x00,  //   Usage Maximum (0xFF)
0x15, 0x00,        //   Logical Minimum (0)
0x26, 0xFF, 0x00,  //   Logical Maximum (255)
0x75, 0x08,        //   Report Size (8)
0x95, 0x0F,        //   Report Count (15)
0xB1, 0x02,        //   Feature (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
0x05, 0xFF,        //   Usage Page (Reserved 0xFF)
0x85, 0x5A,        //   Report ID (90)
0x19, 0x00,        //   Usage Minimum (0x00)
0x2A, 0xFF, 0x00,  //   Usage Maximum (0xFF)
0x15, 0x00,        //   Logical Minimum (0)
0x26, 0xFF, 0x00,  //   Logical Maximum (255)
0x75, 0x08,        //   Report Size (8)
0x95, 0x02,        //   Report Count (2)
0x81, 0x02,        //   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0xC0,              // End Collection

This UsagePage is declared as a variable, but we need to treat it as an
array to be able to map each Usage we care about to its corresponding
input key.

Signed-off-by: João Paulo Rechi Vita <redacted>
---
 drivers/hid/hid-ids.h        |  1 +
 drivers/hid/hid-multitouch.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
 include/linux/hid.h          |  2 ++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 3d911bfd91cf..6b7f9707076e 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h

@@ -176,6 +176,7 @@
 #define USB_DEVICE_ID_ASUSTEK_LCM	0x1726
 #define USB_DEVICE_ID_ASUSTEK_LCM2	0x175b
 #define USB_DEVICE_ID_ASUSTEK_T100_KEYBOARD	0x17e0
+#define USB_DEVICE_ID_ASUSTEK_T304_KEYBOARD	0x184a
 #define USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD	0x8585
 #define USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD	0x0101
 #define USB_DEVICE_ID_ASUSTEK_ROG_KEYBOARD1 0x1854

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 152d33120a55..6b3de7b01571 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c

@@ -72,6 +72,7 @@ MODULE_LICENSE("GPL");
 #define MT_QUIRK_FIX_CONST_CONTACT_ID	BIT(14)
 #define MT_QUIRK_TOUCH_SIZE_SCALING	BIT(15)
 #define MT_QUIRK_STICKY_FINGERS		BIT(16)
+#define MT_QUIRK_ASUS_CUSTOM_UP		BIT(17)
 
 #define MT_INPUTMODE_TOUCHSCREEN	0x02
 #define MT_INPUTMODE_TOUCHPAD		0x03

@@ -169,6 +170,7 @@ static void mt_post_parse(struct mt_device *td);
 #define MT_CLS_GENERALTOUCH_TWOFINGERS		0x0108
 #define MT_CLS_GENERALTOUCH_PWT_TENFINGERS	0x0109
 #define MT_CLS_LG				0x010a
+#define MT_CLS_ASUS				0x010b
 #define MT_CLS_VTL				0x0110
 #define MT_CLS_GOOGLE				0x0111
 

@@ -290,6 +292,10 @@ static struct mt_class mt_classes[] = {
 			MT_QUIRK_IGNORE_DUPLICATES |
 			MT_QUIRK_HOVERING |
 			MT_QUIRK_CONTACT_CNT_ACCURATE },
+	{ .name = MT_CLS_ASUS,
+		.quirks = MT_QUIRK_ALWAYS_VALID |
+			MT_QUIRK_CONTACT_CNT_ACCURATE |
+			MT_QUIRK_ASUS_CUSTOM_UP },
 	{ .name = MT_CLS_VTL,
 		.quirks = MT_QUIRK_ALWAYS_VALID |
 			MT_QUIRK_CONTACT_CNT_ACCURATE |

@@ -905,6 +911,8 @@ static int mt_touch_input_configured(struct hid_device *hdev,
 	return 0;
 }
 
+#define mt_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, \
+						    max, EV_KEY, (c))
 static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)

@@ -923,10 +931,35 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 	    field->application != HID_DG_TOUCHPAD &&
 	    field->application != HID_GD_KEYBOARD &&
 	    field->application != HID_CP_CONSUMER_CONTROL &&
-	    field->application != HID_GD_WIRELESS_RADIO_CTLS)
+	    field->application != HID_GD_WIRELESS_RADIO_CTLS &&
+	    !(field->application == HID_VD_ASUS_CUSTOM_MEDIA_KEYS &&
+	      td->mtclass.quirks & MT_QUIRK_ASUS_CUSTOM_UP))
 		return -1;
 
 	/*
+	 * Some Asus keyboard+touchpad devices have the hotkeys defined in the
+	 * touchpad report descriptor. We need to treat these as an array to
+	 * map usages to input keys.
+	 */
+	if (field->application == 0xff310076 &&

Could you please follow the convention and define a symbolic constant for 
this as well?

Otherwise the patch looks OK to me, so after this minor nit is fixed, I'll 
be queuing it for 4.14 unless Benjamin raises any objections.

Sorry for the delay. I was at GUADEC the whole past week and couldn't
get much kernel work done. I was thinking a little bit about this
series though. Patch 1 is fine, but patch 2 is a little bit more of an
issue.
Ideally, I'd like to keep hid-multitouch from having too many vendor
specific code, but it looks like this is the easier way to handle things
here.

I guess the proper way of solving this situation would be to merge the
generic windows 8 code from hid-multitouch into hid-input so that other
drivers can benefit from it, but this is going to be a lot of work and
-ETIME.

Jiri, I wouldn't scream too loud if you merge this, so do as you want :)

Cheers,
Benjamin

Thanks,

-- 
Jiri Kosina
SUSE Labs