// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <uapi/linux/virtio_ids.h>
#include <uapi/linux/virtio_input.h>
#include <linux/input/mt.h>
struct virtio_input {
struct virtio_device *vdev;
struct input_dev *idev;
char name[64];
char serial[64];
char phys[64];
struct virtqueue *evt, *sts;
struct virtio_input_event evts[64];
spinlock_t lock;
bool ready;
};
static void virtinput_queue_evtbuf(struct virtio_input *vi,
struct virtio_input_event *evtbuf)
{
struct scatterlist sg[1];
sg_init_one(sg, evtbuf, sizeof(*evtbuf));
virtqueue_add_inbuf(vi->evt, sg, 1, evtbuf, GFP_ATOMIC);
}
static void virtinput_recv_events(struct virtqueue *vq)
{
struct virtio_input *vi = vq->vdev->priv;
struct virtio_input_event *event;
unsigned long flags;
unsigned int len;
spin_lock_irqsave(&vi->lock, flags);
if (vi->ready) {
while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) {
spin_unlock_irqrestore(&vi->lock, flags);
input_event(vi->idev,
le16_to_cpu(event->type),
le16_to_cpu(event->code),
le32_to_cpu(event->value));
spin_lock_irqsave(&vi->lock, flags);
virtinput_queue_evtbuf(vi, event);
}
virtqueue_kick(vq);
}
spin_unlock_irqrestore(&vi->lock, flags);
}
/*
* On error we are losing the status update, which isn't critical as
* this is typically used for stuff like keyboard leds.
*/
static int virtinput_send_status(struct virtio_input *vi,
u16 type, u16 code, s32 value)
{
struct virtio_input_event *stsbuf;
struct scatterlist sg[1];
unsigned long flags;
int rc;
/*
* Since 29cc309d8bf1 (HID: hid-multitouch: forward MSC_TIMESTAMP),
* EV_MSC/MSC_TIMESTAMP is added to each before EV_SYN event.
* EV_MSC is configured as INPUT_PASS_TO_ALL.
* In case of touch device:
* BE pass EV_MSC/MSC_TIMESTAMP to FE on receiving event from evdev.
* FE pass EV_MSC/MSC_TIMESTAMP back to BE.
* BE writes EV_MSC/MSC_TIMESTAMP to evdev due to INPUT_PASS_TO_ALL.
* BE receives extra EV_MSC/MSC_TIMESTAMP and pass to FE.
* >>> Each new frame becomes larger and larger.
* Disable EV_MSC/MSC_TIMESTAMP forwarding for MT.
*/
if (vi->idev->mt && type == EV_MSC && code == MSC_TIMESTAMP)
return 0;
stsbuf = kzalloc(sizeof(*stsbuf), GFP_ATOMIC);
if (!stsbuf)
return -ENOMEM;
stsbuf->type = cpu_to_le16(type);
stsbuf->code = cpu_to_le16(code);
stsbuf->value = cpu_to_le32(value);
sg_init_one(sg, stsbuf, sizeof(*stsbuf));
spin_lock_irqsave(&vi->lock, flags);
if (vi->ready) {
rc = virtqueue_add_outbuf(vi->sts, sg, 1, stsbuf, GFP_ATOMIC);
virtqueue_kick(vi->sts);
} else {
rc = -ENODEV;
}
spin_unlock_irqrestore(&vi->lock, flags);
if (rc != 0)
kfree(stsbuf);
return rc;
}
static void virtinput_recv_status(struct virtqueue *vq)
{
struct virtio_input *vi = vq->vdev->priv;
struct virtio_input_event *stsbuf;
unsigned long flags;
unsigned int len;
spin_lock_irqsave(&vi->lock, flags);
while ((stsbuf = virtqueue_get_buf(vi->sts, &len)) != NULL)
kfree(stsbuf);
spin_unlock_irqrestore(&vi->lock, flags);
}
static int virtinput_status(struct input_dev *idev, unsigned int type,
unsigned int code, int value)
{
struct virtio_input *vi = input_get_drvdata(idev);
return virtinput_send_status(vi, type, code, value);
}
static u8 virtinput_cfg_select(struct virtio_input *vi,
u8 select, u8 subsel)
{
u8 size;
virtio_cwrite_le(vi->vdev, struct virtio_input_config, select, &select);
virtio_cwrite_le(vi->vdev, struct virtio_input_config, subsel, &subsel);
virtio_cread_le(vi->vdev, struct virtio_input_config, size, &size);
return size;
}
static void virtinput_cfg_bits(struct virtio_input *vi, int select, int subsel,
unsigned long *bits, unsigned int bitcount)
{
unsigned int bit;
u8 *virtio_bits;
u8 bytes;
bytes = virtinput_cfg_select(vi, select, subsel);
if (!bytes)
return;
if (bitcount > bytes * 8)
bitcount = bytes * 8;
/*
* Bitmap in virtio config space is a simple stream of bytes,
* with the first byte carrying bits 0-7, second bits 8-15 and
* so on.
*/
virtio_bits = kzalloc(bytes, GFP_KERNEL);
if (!virtio_bits)
return;
virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
u.bitmap),
virtio_bits, bytes);
for (bit = 0; bit < bitcount; bit++) {
if (virtio_bits[bit / 8] & (1 << (bit % 8)))
__set_bit(bit, bits);
}
kfree(virtio_bits);
if (select == VIRTIO_INPUT_CFG_EV_BITS)
__set_bit(subsel, vi->idev->evbit);
}
static void virtinput_cfg_abs(struct virtio_input *vi, int abs)
{
u32 mi, ma, re, fu, fl;
virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ABS_INFO, abs);
virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.min, &mi);
virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.max, &ma);
virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.res, &re);
virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.fuzz, &fu);
virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.flat, &fl);
input_set_abs_params(vi->idev, abs, mi, ma, fu, fl);
input_abs_set_res(vi->idev, abs, re);
}
static int virtinput_init_vqs(struct virtio_input *vi)
{
struct virtqueue_info vqs_info[] = {
{ "events", virtinput_recv_events },
{ "status", virtinput_recv_status },
};
struct virtqueue *vqs[2];
int err;
err = virtio_find_vqs(vi->vdev, 2, vqs, vqs_info, NULL);
if (err)
return err;
vi->evt = vqs[0];
vi->sts = vqs[1];
return 0;
}
static void virtinput_fill_evt(struct virtio_input *vi)
{
unsigned long flags;
int i, size;
spin_lock_irqsave(&vi->lock, flags);
size = virtqueue_get_vring_size(vi->evt);
if (size > ARRAY_SIZE(vi->evts))
size = ARRAY_SIZE(vi->evts);
for (i = 0; i < size; i++)
virtinput_queue_evtbuf(vi, &vi->evts[i]);
virtqueue_kick(vi->evt);
spin_unlock_irqrestore(&vi->lock, flags);
}
static int virtinput_probe(struct virtio_device *vdev)
{
struct virtio_input *vi;
unsigned long flags;
size_t size;
int abs, err, nslots;
if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
return -ENODEV;
vi = kzalloc(sizeof(*vi), GFP_KERNEL);
if (!vi)
return -ENOMEM;
vdev->priv = vi;
vi->vdev = vdev;
spin_lock_init(&vi->lock);
err = virtinput_init_vqs(vi);
if (err)
goto err_init_vq;
vi->idev = input_allocate_device();
if (!vi->idev) {
err = -ENOMEM;
goto err_input_alloc;
}
input_set_drvdata(vi->idev, vi);
size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0);
virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
u.string),
vi->name, min(size, sizeof(vi->name)));
size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_SERIAL, 0);
virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
u.string),
vi->serial, min(size, sizeof(vi->serial)));
snprintf(vi->phys, sizeof(vi->phys),
"virtio%d/input0", vdev->index);
vi->idev->name = vi->name;
vi->idev->phys = vi->phys;
vi->idev->uniq = vi->serial;
size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_DEVIDS, 0);
if (size >= sizeof(struct virtio_input_devids)) {
virtio_cread_le(vi->vdev, struct virtio_input_config,
u.ids.bustype, &vi->idev->id.bustype);
virtio_cread_le(vi->vdev, struct virtio_input_config,
u.ids.vendor, &vi->idev->id.vendor);
virtio_cread_le(vi->vdev, struct virtio_input_config,
u.ids.product, &vi->idev->id.product);
virtio_cread_le(vi->vdev, struct virtio_input_config,
u.ids.version, &vi->idev->id.version);
} else {
vi->idev->id.bustype = BUS_VIRTUAL;
}
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_PROP_BITS, 0,
vi->idev->propbit, INPUT_PROP_CNT);
size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REP);
if (size)
__set_bit(EV_REP, vi->idev->evbit);
vi->idev->dev.parent = &vdev->dev;
vi->idev->event = virtinput_status;
/* device -> kernel */
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_KEY,
vi->idev->keybit, KEY_CNT);
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REL,
vi->idev->relbit, REL_CNT);
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_ABS,
vi->idev->absbit, ABS_CNT);
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_MSC,
vi->idev->mscbit, MSC_CNT);
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SW,
vi->idev->swbit, SW_CNT);
/* kernel -> device */
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_LED,
vi->idev->ledbit, LED_CNT);
virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SND,
vi->idev->sndbit, SND_CNT);
if (test_bit(EV_ABS, vi->idev->evbit)) {
for (abs = 0; abs < ABS_CNT; abs++) {
if (!test_bit(abs, vi->idev->absbit))
continue;
virtinput_cfg_abs(vi, abs);
}
if (test_bit(ABS_MT_SLOT, vi->idev->absbit)) {
nslots = input_abs_get_max(vi->idev, ABS_MT_SLOT) + 1;
err = input_mt_init_slots(vi->idev, nslots, 0);
if (err)
goto err_mt_init_slots;
}
}
virtio_device_ready(vdev);
vi->ready = true;
err = input_register_device(vi->idev);
if (err)
goto err_input_register;
virtinput_fill_evt(vi);
return 0;
err_input_register:
spin_lock_irqsave(&vi->lock, flags);
vi->ready = false;
spin_unlock_irqrestore(&vi->lock, flags);
err_mt_init_slots:
input_free_device(vi->idev);
err_input_alloc:
vdev->config->del_vqs(vdev);
err_init_vq:
kfree(vi);
return err;
}
static void virtinput_remove(struct virtio_device *vdev)
{
struct virtio_input *vi = vdev->priv;
void *buf;
unsigned long flags;
spin_lock_irqsave(&vi->lock, flags);
vi->ready = false;
spin_unlock_irqrestore(&vi->lock, flags);
input_unregister_device(vi->idev);
virtio_reset_device(vdev);
while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)
kfree(buf);
vdev->config->del_vqs(vdev);
kfree(vi);
}
#ifdef CONFIG_PM_SLEEP
static int virtinput_freeze(struct virtio_device *vdev)
{
struct virtio_input *vi = vdev->priv;
unsigned long flags;
spin_lock_irqsave(&vi->lock, flags);
vi->ready = false;
spin_unlock_irqrestore(&vi->lock, flags);
vdev->config->del_vqs(vdev);
return 0;
}
static int virtinput_restore(struct virtio_device *vdev)
{
struct virtio_input *vi = vdev->priv;
int err;
err = virtinput_init_vqs(vi);
if (err)
return err;
virtio_device_ready(vdev);
vi->ready = true;
virtinput_fill_evt(vi);
return 0;
}
#endif
static unsigned int features[] = {
/* none */
};
static const struct virtio_device_id id_table[] = {
{ VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static struct virtio_driver virtio_input_driver = {
.driver.name = KBUILD_MODNAME,
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.id_table = id_table,
.probe = virtinput_probe,
.remove = virtinput_remove,
#ifdef CONFIG_PM_SLEEP
.freeze = virtinput_freeze,
.restore = virtinput_restore,
#endif
};
module_virtio_driver(virtio_input_driver);
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Virtio input device driver");
MODULE_AUTHOR("Gerd Hoffmann <[email protected]>");
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