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authorGerd Hoffmann <kraxel@redhat.com>2015-03-27 12:46:12 +1030
committerRusty Russell <rusty@rustcorp.com.au>2015-03-29 12:13:52 +1030
commit271c865161c57cfabca45b93eaa712b19da365bc (patch)
tree4bdb56ba5f7bd2c2e7c078187fa8841d3d81546b /drivers/virtio/virtio_input.c
parent2f921b5bb0511fb698681d8ef35c48be7a9116bf (diff)
Add virtio-input driver.
virtio-input is basically evdev-events-over-virtio, so this driver isn't much more than reading configuration from config space and forwarding incoming events to the linux input layer. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio/virtio_input.c')
-rw-r--r--drivers/virtio/virtio_input.c384
1 files changed, 384 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
new file mode 100644
index 000000000000..60e2a1677563
--- /dev/null
+++ b/drivers/virtio/virtio_input.c
@@ -0,0 +1,384 @@
+#include <linux/module.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/input.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(vi->vdev, struct virtio_input_config, select, &select);
+ virtio_cwrite(vi->vdev, struct virtio_input_config, subsel, &subsel);
+ virtio_cread(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(vi->vdev, struct virtio_input_config, u.abs.min, &mi);
+ virtio_cread(vi->vdev, struct virtio_input_config, u.abs.max, &ma);
+ virtio_cread(vi->vdev, struct virtio_input_config, u.abs.res, &re);
+ virtio_cread(vi->vdev, struct virtio_input_config, u.abs.fuzz, &fu);
+ virtio_cread(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 *names[] = { "events", "status" };
+ int err;
+
+ err = vi->vdev->config->find_vqs(vi->vdev, 2, vqs, cbs, names);
+ 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(vi->vdev, struct virtio_input_config,
+ u.ids.bustype, &vi->idev->id.bustype);
+ virtio_cread(vi->vdev, struct virtio_input_config,
+ u.ids.vendor, &vi->idev->id.vendor);
+ virtio_cread(vi->vdev, struct virtio_input_config,
+ u.ids.product, &vi->idev->id.product);
+ virtio_cread(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;
+ 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->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 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>");

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