stm32: usb_hid_touchpad: add confidence

`confidence` is expected from a PTP-compliant touchpad

BRANCH=none
BUG=b:70482333
BUG=chromium:904711
TEST=manual
Signed-off-by: Wei-Han Chen <stimim@chromium.org>

Change-Id: Ibe7166f43cae5fb36bbcc4e6dfd9ae6525a7225e
Reviewed-on: https://chromium-review.googlesource.com/1188170
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/1333949
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>

5 files changed, 54 insertions, 43 deletions

diff --git a/board/hammer/board.h b/board/hammer/board.h
index a1b2f3175b..2f9e74a527 100644
--- a/board/hammer/board.h
+++ b/board/hammer/board.h
@@ -189,14 +189,14 @@
 #if defined(BOARD_HAMMER) || defined(BOARD_WAND)
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_X 3207
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_Y 1783
-#define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_PRESSURE 1023
+#define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_PRESSURE 511
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_X 1018 /* tenth of mm */
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_Y 566 /* tenth of mm */
 #define CONFIG_TOUCHPAD_VIRTUAL_SIZE (48*1024)
 #elif defined(BOARD_STAFF)
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_X 3206
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_Y 1832
-#define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_PRESSURE 1023
+#define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_PRESSURE 511
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_X 1017 /* tenth of mm */
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_Y 581 /* tenth of mm */
 #define CONFIG_TOUCHPAD_VIRTUAL_SIZE (56*1024)
diff --git a/chip/stm32/usb_hid_touchpad.c b/chip/stm32/usb_hid_touchpad.c
index 06082fdb1f..ebb8bd9ef4 100644
--- a/chip/stm32/usb_hid_touchpad.c
+++ b/chip/stm32/usb_hid_touchpad.c
@@ -69,23 +69,24 @@ const struct usb_endpoint_descriptor USB_EP_DESC(USB_IFACE_HID_TOUCHPAD, 81) = {
 	0x05, 0x0D,        /*   Usage Page (Digitizer) */ \
 	0x09, 0x22,        /*   Usage (Finger) */ \
 	0xA1, 0x02,        /*   Collection (Logical) */ \
+	0x09, 0x47,        /*     Usage (Confidence) */ \
 	0x09, 0x42,        /*     Usage (Tip Switch) */ \
+	0x09, 0x32,        /*     Usage (In Range) */ \
 	0x15, 0x00,        /*     Logical Minimum (0) */ \
 	0x25, 0x01,        /*     Logical Maximum (1) */ \
 	0x75, 0x01,        /*     Report Size (1) */ \
-	0x95, 0x01,        /*     Report Count (1) */ \
-	0x81, 0x02,        /*     Input (Data,Var,Abs) */ \
-	0x09, 0x32,        /*     Usage (In Range) */ \
+	0x95, 0x03,        /*     Report Count (3) */ \
 	0x81, 0x02,        /*     Input (Data,Var,Abs) */ \
-	0x75, 0x04,        /*     Report Size (4) */ \
 	0x09, 0x51,        /*     Usage (0x51) Contact identifier */ \
+	0x75, 0x04,        /*     Report Size (4) */ \
+	0x95, 0x01,        /*     Report Count (1) */ \
 	0x25, 0x0F,        /*     Logical Maximum (15) */ \
 	0x81, 0x02,        /*     Input (Data,Var,Abs) */ \
 	0x05, 0x0D,        /*     Usage Page (Digitizer) */ \
 			   /*     Logical Maximum of Pressure */ \
 	0x26, (CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_PRESSURE & 0xFF), \
 	      (CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_PRESSURE >> 8), \
-	0x75, 0x0A,        /*     Report Size (10) */ \
+	0x75, 0x09,        /*     Report Size (9) */ \
 	0x09, 0x30,        /*     Usage (Tip pressure) */ \
 	0x81, 0x02,        /*     Input (Data,Var,Abs) */ \
 	0x26, 0xFF, 0x00,  /*     Logical Maximum (255) */ \
@@ -123,10 +124,11 @@ const struct usb_endpoint_descriptor USB_EP_DESC(USB_IFACE_HID_TOUCHPAD, 81) = {
  * Finger Usage is repeated 5 times.
  */
 static const uint8_t report_desc[] = {
-	0x05, 0x0D,        /* Usage Page (Digitizer) */
-	0x09, 0x05,        /* Usage (Touch Pad) */
-	0xA1, 0x01,        /* Collection (Application) */
-	0x85, 0x01,        /*   Report ID (1, Touch) */
+	/* Touchpad Collection */
+	0x05, 0x0D,                    /* Usage Page (Digitizer) */
+	0x09, 0x05,                    /* Usage (Touch Pad) */
+	0xA1, 0x01,                    /* Collection (Application) */
+	0x85, REPORT_ID_TOUCHPAD,      /*   Report ID (1, Touch) */
 	/* Finger 0 */
 	FINGER_USAGE,
 	/* Finger 1 */
@@ -138,32 +140,33 @@ static const uint8_t report_desc[] = {
 	/* Finger 4 */
 	FINGER_USAGE,
 	/* Contact count */
-	0x05, 0x0D,        /*   Usage Page (Digitizer) */
-	0x09, 0x54,        /*   Usage (Contact count) */
-	0x75, 0x07,        /*   Report Size (7) */
-	0x95, 0x01,        /*   Report Count (1) */
-	0x81, 0x02,        /*   Input (Data,Var,Abs) */
+	0x05, 0x0D,                    /*   Usage Page (Digitizer) */
+	0x09, 0x54,                    /*   Usage (Contact count) */
+	0x25, MAX_FINGERS,             /*   Logical Maximum (MAX_FINGERS) */
+	0x75, 0x07,                    /*   Report Size (7) */
+	0x95, 0x01,                    /*   Report Count (1) */
+	0x81, 0x02,                    /*   Input (Data,Var,Abs) */
 	/* Button */
-	0x05, 0x01,        /*   Usage Page (Generic Desktop Ctrls) */
-	0x05, 0x09,        /*   Usage (Button) */
-	0x19, 0x01,        /*   Usage Minimum (0x01) */
-	0x29, 0x01,        /*   Usage Maximum (0x01) */
-	0x15, 0x00,        /*   Logical Minimum (0) */
-	0x25, 0x01,        /*   Logical Maximum (1) */
-	0x75, 0x01,        /*   Report Size (1) */
-	0x95, 0x01,        /*   Report Count (1) */
-	0x81, 0x02,        /*   Input (Data,Var,Abs) */
+	0x05, 0x01,                    /*   Usage Page(Generic Desktop Ctrls) */
+	0x05, 0x09,                    /*   Usage (Button) */
+	0x19, 0x01,                    /*   Usage Minimum (0x01) */
+	0x29, 0x01,                    /*   Usage Maximum (0x01) */
+	0x15, 0x00,                    /*   Logical Minimum (0) */
+	0x25, 0x01,                    /*   Logical Maximum (1) */
+	0x75, 0x01,                    /*   Report Size (1) */
+	0x95, 0x01,                    /*   Report Count (1) */
+	0x81, 0x02,                    /*   Input (Data,Var,Abs) */
 	/* Timestamp */
-	0x05, 0x0D,        /*   Usage Page (Digitizer) */
-	0x55, 0x0C,        /*   Unit Exponent (-4) */
-	0x66, 0x01, 0x10,  /*   Unit (System: SI Linear, Time: Seconds) */
+	0x05, 0x0D,                    /*   Usage Page (Digitizer) */
+	0x55, 0x0C,                    /*   Unit Exponent (-4) */
+	0x66, 0x01, 0x10,              /*   Unit (Seconds) */
 	0x47, 0xFF, 0xFF, 0x00, 0x00,  /*   Physical Maximum (65535) */
 	0x27, 0xFF, 0xFF, 0x00, 0x00,  /*   Logical Maximum (65535) */
-	0x75, 0x10,        /*   Report Size (16) */
-	0x95, 0x01,        /*   Report Count (1) */
-	0x09, 0x56,        /*   Usage (0x56, Relative Scan Time) */
-	0x81, 0x02,        /*   Input (Data,Var,Abs) */
-	0xC0,              /* End Collection */
+	0x75, 0x10,                    /*   Report Size (16) */
+	0x95, 0x01,                    /*   Report Count (1) */
+	0x09, 0x56,                    /*   Usage (0x56, Relative Scan Time) */
+	0x81, 0x02,                    /*   Input (Data,Var,Abs) */
+	0xC0,                          /* End Collection */
 };
 
 const struct usb_hid_descriptor USB_CUSTOM_DESC_VAR(USB_IFACE_HID_TOUCHPAD,
diff --git a/driver/touchpad_elan.c b/driver/touchpad_elan.c
index 9cc399ae6e..8988a99cf0 100644
--- a/driver/touchpad_elan.c
+++ b/driver/touchpad_elan.c
@@ -237,6 +237,7 @@ static int elan_tp_read_report(void)
 			height = MIN(4095, height * elan_tp_params.width_y);
 			pressure = MIN(1023, pressure);
 
+			report.finger[ri].confidence = 1;
 			report.finger[ri].tip = 1;
 			report.finger[ri].inrange = 1;
 			report.finger[ri].id = i;
diff --git a/driver/touchpad_st.c b/driver/touchpad_st.c
index 340923e587..7384e33af9 100644
--- a/driver/touchpad_st.c
+++ b/driver/touchpad_st.c
@@ -99,6 +99,8 @@ static int st_tp_parse_finger(struct usb_hid_touchpad_report *report,
 	switch (event->evt_id) {
 	case ST_TP_EVENT_ID_ENTER_POINTER:
 	case ST_TP_EVENT_ID_MOTION_POINTER:
+		/* Pressure == 255 is a palm. */
+		report->finger[i].confidence = (event->finger.z < 255);
 		report->finger[i].tip = 1;
 		report->finger[i].inrange = 1;
 		report->finger[i].id = event->finger.touch_id;
@@ -145,7 +147,7 @@ static int st_tp_write_hid_report(void)
 		return ret;
 
 	memset(&report, 0, sizeof(report));
-	report.id = 0x1;
+	report.id = REPORT_ID_TOUCHPAD;
 	num_finger = 0;
 
 	for (i = 0; i < ARRAY_SIZE(rx_buf.events); i++) {
diff --git a/include/usb_hid_touchpad.h b/include/usb_hid_touchpad.h
index 39b6277b96..3d6207b19e 100644
--- a/include/usb_hid_touchpad.h
+++ b/include/usb_hid_touchpad.h
@@ -10,18 +10,23 @@
 
 #define USB_HID_TOUCHPAD_TIMESTAMP_UNIT 100 /* usec */
 
+#define REPORT_ID_TOUCHPAD		0x01
+
+#define MAX_FINGERS			5
+
 struct usb_hid_touchpad_report {
 	uint8_t id; /* 0x01 */
 	struct {
-		unsigned tip:1;
-		unsigned inrange:1;
-		unsigned id:4;
-		unsigned pressure:10;
-		unsigned width:12;
-		unsigned height:12;
-		unsigned x:12;
-		unsigned y:12;
-	} __packed finger[5];
+		uint16_t confidence:1;
+		uint16_t tip:1;
+		uint16_t inrange:1;
+		uint16_t id:4;
+		uint16_t pressure:9;
+		uint16_t width:12;
+		uint16_t height:12;
+		uint16_t x:12;
+		uint16_t y:12;
+	} __packed finger[MAX_FINGERS];
 	uint8_t count:7;
 	uint8_t button:1;
 	uint16_t timestamp;