[PATCH v1] xen/input: add multi-touch support

From: Oleksandr Andrushchenko
Date: Fri Jun 23 2017 - 02:11:17 EST


From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Extend xen_kbdfront to provide multi-touch support
to unprivileged domains.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

---
Changes since initial:
- use input_set_capability instead of setting flags directly
- input_mt_init_slots: let userspace better chance of figuring
how to handle the device: use INPUT_MT_DIRECT,
drop INPUT_MT_DROP_UNUSED
- add error handling for input_mt_init_slots
- remove module paramters
- remove odd unlikely
---
drivers/input/misc/xen-kbdfront.c | 135 +++++++++++++++++++++++++++++++++++++-
1 file changed, 133 insertions(+), 2 deletions(-)

diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index eb770613a9bd..9fa005038773 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -17,6 +17,7 @@
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/input.h>
+#include <linux/input/mt.h>
#include <linux/slab.h>

#include <asm/xen/hypervisor.h>
@@ -34,11 +35,14 @@
struct xenkbd_info {
struct input_dev *kbd;
struct input_dev *ptr;
+ struct input_dev *mtouch;
struct xenkbd_page *page;
int gref;
int irq;
struct xenbus_device *xbdev;
char phys[32];
+ /* current MT slot/contact ID we are injecting events in */
+ int mtouch_cur_contact_id;
};

enum { KPARAM_X, KPARAM_Y, KPARAM_CNT };
@@ -100,6 +104,60 @@ static irqreturn_t input_handler(int rq, void *dev_id)
input_report_rel(dev, REL_WHEEL,
-event->pos.rel_z);
break;
+ case XENKBD_TYPE_MTOUCH:
+ dev = info->mtouch;
+ if (unlikely(!dev))
+ break;
+ if (event->mtouch.contact_id !=
+ info->mtouch_cur_contact_id) {
+ info->mtouch_cur_contact_id =
+ event->mtouch.contact_id;
+ input_mt_slot(dev, event->mtouch.contact_id);
+ }
+ switch (event->mtouch.event_type) {
+ case XENKBD_MT_EV_DOWN:
+ input_mt_report_slot_state(dev, MT_TOOL_FINGER,
+ true);
+ input_event(dev, EV_ABS, ABS_MT_POSITION_X,
+ event->mtouch.u.pos.abs_x);
+ input_event(dev, EV_ABS, ABS_MT_POSITION_Y,
+ event->mtouch.u.pos.abs_y);
+ input_event(dev, EV_ABS, ABS_X,
+ event->mtouch.u.pos.abs_x);
+ input_event(dev, EV_ABS, ABS_Y,
+ event->mtouch.u.pos.abs_y);
+ break;
+ case XENKBD_MT_EV_UP:
+ input_mt_report_slot_state(dev, MT_TOOL_FINGER,
+ false);
+ break;
+ case XENKBD_MT_EV_MOTION:
+ input_event(dev, EV_ABS, ABS_MT_POSITION_X,
+ event->mtouch.u.pos.abs_x);
+ input_event(dev, EV_ABS, ABS_MT_POSITION_Y,
+ event->mtouch.u.pos.abs_y);
+ input_event(dev, EV_ABS, ABS_X,
+ event->mtouch.u.pos.abs_x);
+ input_event(dev, EV_ABS, ABS_Y,
+ event->mtouch.u.pos.abs_y);
+ break;
+ case XENKBD_MT_EV_SYN:
+ input_mt_sync_frame(dev);
+ break;
+ case XENKBD_MT_EV_SHAPE:
+ input_event(dev, EV_ABS, ABS_MT_TOUCH_MAJOR,
+ event->mtouch.u.shape.major);
+ input_event(dev, EV_ABS, ABS_MT_TOUCH_MINOR,
+ event->mtouch.u.shape.minor);
+ break;
+ case XENKBD_MT_EV_ORIENT:
+ input_event(dev, EV_ABS, ABS_MT_ORIENTATION,
+ event->mtouch.u.orientation);
+ break;
+ }
+ /* only report syn when requested */
+ if (event->mtouch.event_type != XENKBD_MT_EV_SYN)
+ dev = NULL;
}
if (dev)
input_sync(dev);
@@ -115,9 +173,9 @@ static int xenkbd_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
int ret, i;
- unsigned int abs;
+ unsigned int abs, touch;
struct xenkbd_info *info;
- struct input_dev *kbd, *ptr;
+ struct input_dev *kbd, *ptr, *mtouch;

info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info) {
@@ -152,6 +210,17 @@ static int xenkbd_probe(struct xenbus_device *dev,
}
}

+ touch = xenbus_read_unsigned(dev->nodename,
+ XENKBD_FIELD_FEAT_MTOUCH, 0);
+ if (touch) {
+ ret = xenbus_write(XBT_NIL, dev->nodename,
+ XENKBD_FIELD_REQ_MTOUCH, "1");
+ if (ret) {
+ pr_warning("xenkbd: can't request multi-touch");
+ touch = 0;
+ }
+ }
+
/* keyboard */
kbd = input_allocate_device();
if (!kbd)
@@ -208,6 +277,66 @@ static int xenkbd_probe(struct xenbus_device *dev,
}
info->ptr = ptr;

+ /* multi-touch device */
+ if (touch) {
+ int num_cont, width, height;
+
+ mtouch = input_allocate_device();
+ if (!mtouch)
+ goto error_nomem;
+
+ num_cont = xenbus_read_unsigned(info->xbdev->nodename,
+ XENKBD_FIELD_MT_NUM_CONTACTS,
+ 1);
+ width = xenbus_read_unsigned(info->xbdev->nodename,
+ XENKBD_FIELD_MT_WIDTH,
+ XENFB_WIDTH);
+ height = xenbus_read_unsigned(info->xbdev->nodename,
+ XENKBD_FIELD_MT_HEIGHT,
+ XENFB_HEIGHT);
+
+ mtouch->name = "Xen Virtual Multi-touch";
+ mtouch->phys = info->phys;
+ mtouch->id.bustype = BUS_PCI;
+ mtouch->id.vendor = 0x5853;
+ mtouch->id.product = 0xfffd;
+
+ input_set_capability(mtouch, EV_KEY, BTN_TOUCH);
+ input_set_abs_params(mtouch, ABS_X,
+ 0, width, 0, 0);
+ input_set_abs_params(mtouch, ABS_Y,
+ 0, height, 0, 0);
+ input_set_abs_params(mtouch, ABS_PRESSURE,
+ 0, 255, 0, 0);
+
+ input_set_abs_params(mtouch, ABS_MT_TOUCH_MAJOR,
+ 0, 255, 0, 0);
+ input_set_abs_params(mtouch, ABS_MT_POSITION_X,
+ 0, width, 0, 0);
+ input_set_abs_params(mtouch, ABS_MT_POSITION_Y,
+ 0, height, 0, 0);
+ input_set_abs_params(mtouch, ABS_MT_PRESSURE,
+ 0, 255, 0, 0);
+
+ ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
+ if (ret) {
+ input_free_device(mtouch);
+ xenbus_dev_fatal(info->xbdev, ret,
+ "input_mt_init_slots");
+ goto error;
+ }
+
+ ret = input_register_device(mtouch);
+ if (ret) {
+ input_free_device(mtouch);
+ xenbus_dev_fatal(info->xbdev, ret,
+ "input_register_device(mtouch)");
+ goto error;
+ }
+ info->mtouch_cur_contact_id = -1;
+ info->mtouch = mtouch;
+ }
+
ret = xenkbd_connect_backend(dev, info);
if (ret < 0)
goto error;
@@ -240,6 +369,8 @@ static int xenkbd_remove(struct xenbus_device *dev)
input_unregister_device(info->kbd);
if (info->ptr)
input_unregister_device(info->ptr);
+ if (info->mtouch)
+ input_unregister_device(info->mtouch);
free_page((unsigned long)info->page);
kfree(info);
return 0;
--
2.7.4