tegrakernel/kernel/kernel-4.9/drivers/input/misc/xen-kbdfront.c

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2022-02-16 09:13:02 -06:00
/*
* Xen para-virtual input device
*
* Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
* Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
*
* Based on linux/drivers/input/mouse/sermouse.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <asm/xen/hypervisor.h>
#include <xen/xen.h>
#include <xen/events.h>
#include <xen/page.h>
#include <xen/grant_table.h>
#include <xen/interface/grant_table.h>
#include <xen/interface/io/fbif.h>
#include <xen/interface/io/kbdif.h>
#include <xen/xenbus.h>
#include <xen/platform_pci.h>
struct xenkbd_info {
struct input_dev *kbd;
struct input_dev *ptr;
struct xenkbd_page *page;
int gref;
int irq;
struct xenbus_device *xbdev;
char phys[32];
};
static int xenkbd_remove(struct xenbus_device *);
static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
static void xenkbd_disconnect_backend(struct xenkbd_info *);
/*
* Note: if you need to send out events, see xenfb_do_update() for how
* to do that.
*/
static irqreturn_t input_handler(int rq, void *dev_id)
{
struct xenkbd_info *info = dev_id;
struct xenkbd_page *page = info->page;
__u32 cons, prod;
prod = page->in_prod;
if (prod == page->in_cons)
return IRQ_HANDLED;
rmb(); /* ensure we see ring contents up to prod */
for (cons = page->in_cons; cons != prod; cons++) {
union xenkbd_in_event *event;
struct input_dev *dev;
event = &XENKBD_IN_RING_REF(page, cons);
dev = info->ptr;
switch (event->type) {
case XENKBD_TYPE_MOTION:
input_report_rel(dev, REL_X, event->motion.rel_x);
input_report_rel(dev, REL_Y, event->motion.rel_y);
if (event->motion.rel_z)
input_report_rel(dev, REL_WHEEL,
-event->motion.rel_z);
break;
case XENKBD_TYPE_KEY:
dev = NULL;
if (test_bit(event->key.keycode, info->kbd->keybit))
dev = info->kbd;
if (test_bit(event->key.keycode, info->ptr->keybit))
dev = info->ptr;
if (dev)
input_report_key(dev, event->key.keycode,
event->key.pressed);
else
pr_warning("unhandled keycode 0x%x\n",
event->key.keycode);
break;
case XENKBD_TYPE_POS:
input_report_abs(dev, ABS_X, event->pos.abs_x);
input_report_abs(dev, ABS_Y, event->pos.abs_y);
if (event->pos.rel_z)
input_report_rel(dev, REL_WHEEL,
-event->pos.rel_z);
break;
}
if (dev)
input_sync(dev);
}
mb(); /* ensure we got ring contents */
page->in_cons = cons;
notify_remote_via_irq(info->irq);
return IRQ_HANDLED;
}
static int xenkbd_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
int ret, i, abs;
struct xenkbd_info *info;
struct input_dev *kbd, *ptr;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
return -ENOMEM;
}
dev_set_drvdata(&dev->dev, info);
info->xbdev = dev;
info->irq = -1;
info->gref = -1;
snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
if (!info->page)
goto error_nomem;
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
abs = 0;
if (abs) {
ret = xenbus_write(XBT_NIL, dev->nodename,
"request-abs-pointer", "1");
if (ret) {
pr_warning("xenkbd: can't request abs-pointer");
abs = 0;
}
}
/* keyboard */
kbd = input_allocate_device();
if (!kbd)
goto error_nomem;
kbd->name = "Xen Virtual Keyboard";
kbd->phys = info->phys;
kbd->id.bustype = BUS_PCI;
kbd->id.vendor = 0x5853;
kbd->id.product = 0xffff;
__set_bit(EV_KEY, kbd->evbit);
for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
__set_bit(i, kbd->keybit);
for (i = KEY_OK; i < KEY_MAX; i++)
__set_bit(i, kbd->keybit);
ret = input_register_device(kbd);
if (ret) {
input_free_device(kbd);
xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
goto error;
}
info->kbd = kbd;
/* pointing device */
ptr = input_allocate_device();
if (!ptr)
goto error_nomem;
ptr->name = "Xen Virtual Pointer";
ptr->phys = info->phys;
ptr->id.bustype = BUS_PCI;
ptr->id.vendor = 0x5853;
ptr->id.product = 0xfffe;
if (abs) {
__set_bit(EV_ABS, ptr->evbit);
input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
} else {
input_set_capability(ptr, EV_REL, REL_X);
input_set_capability(ptr, EV_REL, REL_Y);
}
input_set_capability(ptr, EV_REL, REL_WHEEL);
__set_bit(EV_KEY, ptr->evbit);
for (i = BTN_LEFT; i <= BTN_TASK; i++)
__set_bit(i, ptr->keybit);
ret = input_register_device(ptr);
if (ret) {
input_free_device(ptr);
xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
goto error;
}
info->ptr = ptr;
ret = xenkbd_connect_backend(dev, info);
if (ret < 0)
goto error;
return 0;
error_nomem:
ret = -ENOMEM;
xenbus_dev_fatal(dev, ret, "allocating device memory");
error:
xenkbd_remove(dev);
return ret;
}
static int xenkbd_resume(struct xenbus_device *dev)
{
struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
xenkbd_disconnect_backend(info);
memset(info->page, 0, PAGE_SIZE);
return xenkbd_connect_backend(dev, info);
}
static int xenkbd_remove(struct xenbus_device *dev)
{
struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
xenkbd_disconnect_backend(info);
if (info->kbd)
input_unregister_device(info->kbd);
if (info->ptr)
input_unregister_device(info->ptr);
free_page((unsigned long)info->page);
kfree(info);
return 0;
}
static int xenkbd_connect_backend(struct xenbus_device *dev,
struct xenkbd_info *info)
{
int ret, evtchn;
struct xenbus_transaction xbt;
ret = gnttab_grant_foreign_access(dev->otherend_id,
virt_to_gfn(info->page), 0);
if (ret < 0)
return ret;
info->gref = ret;
ret = xenbus_alloc_evtchn(dev, &evtchn);
if (ret)
goto error_grant;
ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
0, dev->devicetype, info);
if (ret < 0) {
xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
goto error_evtchan;
}
info->irq = ret;
again:
ret = xenbus_transaction_start(&xbt);
if (ret) {
xenbus_dev_fatal(dev, ret, "starting transaction");
goto error_irqh;
}
ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
virt_to_gfn(info->page));
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
evtchn);
if (ret)
goto error_xenbus;
ret = xenbus_transaction_end(xbt, 0);
if (ret) {
if (ret == -EAGAIN)
goto again;
xenbus_dev_fatal(dev, ret, "completing transaction");
goto error_irqh;
}
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
error_irqh:
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
error_evtchan:
xenbus_free_evtchn(dev, evtchn);
error_grant:
gnttab_end_foreign_access(info->gref, 0, 0UL);
info->gref = -1;
return ret;
}
static void xenkbd_disconnect_backend(struct xenkbd_info *info)
{
if (info->irq >= 0)
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
if (info->gref >= 0)
gnttab_end_foreign_access(info->gref, 0, 0UL);
info->gref = -1;
}
static void xenkbd_backend_changed(struct xenbus_device *dev,
enum xenbus_state backend_state)
{
struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
int ret, val;
switch (backend_state) {
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateReconfiguring:
case XenbusStateReconfigured:
case XenbusStateUnknown:
break;
case XenbusStateInitWait:
InitWait:
ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
"feature-abs-pointer", "%d", &val);
if (ret < 0)
val = 0;
if (val) {
ret = xenbus_write(XBT_NIL, info->xbdev->nodename,
"request-abs-pointer", "1");
if (ret)
pr_warning("xenkbd: can't request abs-pointer");
}
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateConnected:
/*
* Work around xenbus race condition: If backend goes
* through InitWait to Connected fast enough, we can
* get Connected twice here.
*/
if (dev->state != XenbusStateConnected)
goto InitWait; /* no InitWait seen yet, fudge it */
/* Set input abs params to match backend screen res */
if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
"width", "%d", &val) > 0)
input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
"height", "%d", &val) > 0)
input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
break;
case XenbusStateClosed:
if (dev->state == XenbusStateClosed)
break;
/* Missed the backend's CLOSING state -- fallthrough */
case XenbusStateClosing:
xenbus_frontend_closed(dev);
break;
}
}
static const struct xenbus_device_id xenkbd_ids[] = {
{ "vkbd" },
{ "" }
};
static struct xenbus_driver xenkbd_driver = {
.ids = xenkbd_ids,
.probe = xenkbd_probe,
.remove = xenkbd_remove,
.resume = xenkbd_resume,
.otherend_changed = xenkbd_backend_changed,
};
static int __init xenkbd_init(void)
{
if (!xen_domain())
return -ENODEV;
/* Nothing to do if running in dom0. */
if (xen_initial_domain())
return -ENODEV;
if (!xen_has_pv_devices())
return -ENODEV;
return xenbus_register_frontend(&xenkbd_driver);
}
static void __exit xenkbd_cleanup(void)
{
xenbus_unregister_driver(&xenkbd_driver);
}
module_init(xenkbd_init);
module_exit(xenkbd_cleanup);
MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
MODULE_LICENSE("GPL");
MODULE_ALIAS("xen:vkbd");