diff options
Diffstat (limited to 'drivers/virtio/virtio_input.c')
| -rw-r--r-- | drivers/virtio/virtio_input.c | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c new file mode 100644 index 000000000..f1f6208ed --- /dev/null +++ b/drivers/virtio/virtio_input.c @@ -0,0 +1,390 @@ +// 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> + +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; + + 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 *vqs[2]; + vq_callback_t *cbs[] = { virtinput_recv_events, + virtinput_recv_status }; + static const char * const names[] = { "events", "status" }; + int err; + + err = virtio_find_vqs(vi->vdev, 2, vqs, cbs, names, 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; + + 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); + } + } + + 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); + 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); + vdev->config->reset(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, + .driver.owner = THIS_MODULE, + .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 <kraxel@redhat.com>"); |