RK3399 Android7.1 USB Touch坐标点颠倒的解决办法

Platform: RK3399
OS: Android 7.1
Kernel: v4.4.83

背景：

接了HDMI的副屏上的USB Touch，发现使用的时候坐标点是颠倒的，于是在驱动中根据USB的Vendor ID来进行判断，然后更正下上报坐标点的值。

解决方法：

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index f62a9d6..7167144 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
[url=home.php?mod=space&uid=1999721]@@[/url] -164,6 +164,11 @@ static void mt_post_parse(struct mt_device *td);
#define MT_USB_DEVICE(v, p) HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH, v, p)
#define MT_BT_DEVICE(v, p) HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_MULTITOUCH, v, p)

+//Kris, use vendor id to decide if mirroring touch point or not.
+static int vendor_id;
+
+
/*

these device-dependent functions determine what slot corresponds

to a valid contact that was just read.
@@ -639,6 +644,17 @@ static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
active = (s->touch_state || s->inrange_state) &&
s->confidence_state;

``
/* Kris, use vendor id to decide if mirroring touch point or not. { */

//hdmi touch

//vendor id: 0x222A

//max-x:16384

//max-y: 9600

if (vendor_id == 0x222a) {

s->x = 16384 - s->x;

s->y = 9600 - s->y;

}

/* Kris, use vendor id to decide if mirroring touch point or not. } */

input_mt_slot(input, slotnum);
input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
if (active) {

@@ -764,6 +780,10 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report)
unsigned count;
int r, n;

/* Kris, use vendor id to decide if mirroring touch point or not. { */
vendor_id = hid->vendor;
/* Kris, use vendor id to decide if mirroring touch point or not. } */
/*

Includes multi-packet support where subsequent
packets are sent with zero contactcount.

附hid touch注册流程：

设备注册:

worker_thread -> usb会开线程去监听hub插拔事件
process_one_work ->
hub_event -> 有usb设备插入,这里是usb touch
usb_new_device ->
device_add ->
usb_probe_device -> drvier.c
udriver->probe ->
generic_probe ->
usb_set_configuration ->
device_add ->
usb_probe_interface ->
driver->probe ->
usbhid_probe ->
hid_allocate_device -> //注意到这里是bus是hid_bus_type

驱动注册:

module_hid_driver(mt_driver) ->	
__hid_driver_init -> 	//上面宏定义的扩展
hid_register_driver ->
__hid_register_driver ->
driver_register ->  //bus是hid_bus_type
hid_bus_match -> hid-core.c
hid_match_device -> 这时候拿到的hdev就是前面hid_allocate_device分配的那个
hid_match_id -> 根据hdrv->id_table匹配也就是mt_driver@hid-multitouch.c中的id_table
hid_device_probe -> //匹配上之后继续执行bus probe
hdrv->probe ->
mt_probe ->
hid_parse
hid_hw_start ->
hid_connect ->
hidinput_connect -> 把hid和input子系统绑定关联起来
hidinput_allocate
input_register_device	 //注册一个input device
hdev->hiddev_connect ->	把hid和usb子系统绑定关联起来
hiddev_connect -> hiddev.c
usb_register_dev



原作者：KrisFei