diff options
Diffstat (limited to 'drivers/input/virtio_input.c')
| -rw-r--r-- | drivers/input/virtio_input.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/input/virtio_input.c b/drivers/input/virtio_input.c new file mode 100644 index 0000000000..406dc613dc --- /dev/null +++ b/drivers/input/virtio_input.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <common.h> +#include <bthread.h> +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ring.h> +#include <input/input.h> +#include <dt-bindings/input/linux-event-codes.h> + +#include <uapi/linux/virtio_ids.h> +#include <uapi/linux/virtio_input.h> + +struct virtio_input { + struct input_device idev; + struct virtio_device *vdev; + struct virtqueue *evt; + struct virtio_input_event evts[64]; + struct bthread *bthread; +}; + +static void virtinput_queue_evtbuf(struct virtio_input *vi, + struct virtio_input_event *evtbuf) +{ + struct virtio_sg sg[1]; + virtio_sg_init_one(sg, evtbuf, sizeof(*evtbuf)); + virtqueue_add_inbuf(vi->evt, sg, 1); +} + +static int virtinput_recv_events(struct virtio_input *vi) +{ + struct device_d *dev = &vi->vdev->dev; + struct virtio_input_event *event; + unsigned int len; + int i = 0; + + while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) { + if (le16_to_cpu(event->type) == EV_KEY) + input_report_key_event(&vi->idev, le16_to_cpu(event->code), + le32_to_cpu(event->value)); + + pr_debug("\n%s: input event #%td received (type=%u, code=%u, value=%u)\n", + dev_name(dev), + event - &vi->evts[0], + le16_to_cpu(event->type), le16_to_cpu(event->code), + le32_to_cpu(event->value)); + + virtinput_queue_evtbuf(vi, event); + i++; + } + + return i; +} + +static int virtinput_poll_vqs(void *_vi) +{ + struct virtio_input *vi = _vi; + + while (!bthread_should_stop()) { + int bufs = 0; + + bufs += virtinput_recv_events(vi); + + if (bufs) + virtqueue_kick(vi->evt); + } + + return 0; +} + +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_fill_evt(struct virtio_input *vi) +{ + int i, size; + + 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); +} + +static int virtinput_init_vqs(struct virtio_input *vi) +{ + struct virtqueue *vqs[1]; + int err; + + + err = virtio_find_vqs(vi->vdev, 1, vqs); + if (err) + return err; + + vi->evt = vqs[0]; + + return 0; +} + +static int virtinput_probe(struct virtio_device *vdev) +{ + struct virtio_input *vi; + char name[64]; + size_t size; + int err; + + 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; + + err = virtinput_init_vqs(vi); + if (err) + goto err_init_vq; + + size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0); + virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config, u.string), + name, min(size, sizeof(name))); + name[size] = '\0'; + + virtio_device_ready(vdev); + + err = input_device_register(&vi->idev); + if (err) + goto err_input_register; + + virtinput_fill_evt(vi); + + vi->bthread = bthread_run(virtinput_poll_vqs, vi, + "%s/input0", dev_name(&vdev->dev)); + if (!vi->bthread) { + err = -ENOMEM; + goto err_bthread_run; + } + + dev_info(&vdev->dev, "'%s' probed\n", name); + + return 0; + +err_bthread_run: + bthread_free(vi->bthread); +err_input_register: + 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; + + bthread_stop(vi->bthread); + bthread_free(vi->bthread); + + vdev->config->reset(vdev); + vdev->config->del_vqs(vdev); + kfree(vi); +} + +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 = "virtio_input", + .id_table = id_table, + .probe = virtinput_probe, + .remove = virtinput_remove, +}; +device_virtio_driver(virtio_input_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Virtio input device driver"); +MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>"); +MODULE_AUTHOR("Ahmad Fatoum <a.fatoum@pengutronix.de>"); |