[PATCH 1/1] Add virtio-input driver.
From: Gerd Hoffmann
Date: Thu Mar 19 2015 - 05:14:26 EST
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@xxxxxxxxxx>
---
drivers/virtio/Kconfig | 10 ++
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_input.c | 313 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/virtio_ids.h | 1 +
include/uapi/linux/virtio_input.h | 65 ++++++++
5 files changed, 390 insertions(+)
create mode 100644 drivers/virtio/virtio_input.c
create mode 100644 include/uapi/linux/virtio_input.h
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index b546da5..cab9f3f 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -48,6 +48,16 @@ config VIRTIO_BALLOON
If unsure, say M.
+config VIRTIO_INPUT
+ tristate "Virtio input driver"
+ depends on VIRTIO
+ depends on INPUT
+ ---help---
+ This driver supports virtio input devices such as
+ keyboards, mice and tablets.
+
+ If unsure, say M.
+
config VIRTIO_MMIO
tristate "Platform bus driver for memory mapped virtio devices"
depends on HAS_IOMEM
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index d85565b..41e30e3 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
+obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o
diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
new file mode 100644
index 0000000..2d425cf
--- /dev/null
+++ b/drivers/virtio/virtio_input.c
@@ -0,0 +1,313 @@
+#include <linux/module.h>
+#include <linux/virtio.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];
+};
+
+static ssize_t serial_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct input_dev *idev = to_input_dev(dev);
+ struct virtio_input *vi = input_get_drvdata(idev);
+ return sprintf(buf, "%s\n", vi->serial);
+}
+static DEVICE_ATTR_RO(serial);
+
+static struct attribute *dev_attrs[] = {
+ &dev_attr_serial.attr,
+ NULL
+};
+
+static umode_t dev_attrs_are_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct input_dev *idev = to_input_dev(dev);
+ struct virtio_input *vi = input_get_drvdata(idev);
+
+ if (a == &dev_attr_serial.attr && !strlen(vi->serial))
+ return 0;
+
+ return a->mode;
+}
+
+static struct attribute_group dev_attr_grp = {
+ .attrs = dev_attrs,
+ .is_visible = dev_attrs_are_visible,
+};
+
+static const struct attribute_group *dev_attr_groups[] = {
+ &dev_attr_grp,
+ NULL
+};
+
+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 int len;
+
+ while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) {
+ input_event(vi->idev,
+ le16_to_cpu(event->type),
+ le16_to_cpu(event->code),
+ le32_to_cpu(event->value));
+ virtinput_queue_evtbuf(vi, event);
+ }
+ virtqueue_kick(vq);
+}
+
+static int virtinput_send_status(struct virtio_input *vi,
+ u16 type, u16 code, s32 value)
+{
+ struct virtio_input_event *stsbuf;
+ struct scatterlist sg[1];
+
+ 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));
+ virtqueue_add_outbuf(vi->sts, sg, 1, stsbuf, GFP_ATOMIC);
+ virtqueue_kick(vi->sts);
+ return 0;
+}
+
+static void virtinput_recv_status(struct virtqueue *vq)
+{
+ struct virtio_input *vi = vq->vdev->priv;
+ struct virtio_input_event *stsbuf;
+ unsigned int len;
+
+ while ((stsbuf = virtqueue_get_buf(vi->sts, &len)) != NULL)
+ kfree(stsbuf);
+ virtqueue_kick(vq);
+}
+
+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 size_t 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;
+ size_t bytes;
+ u8 cfg = 0;
+
+ bytes = virtinput_cfg_select(vi, select, subsel);
+ if (!bytes)
+ return;
+ if (bitcount > bytes*8)
+ bitcount = bytes*8;
+ if (select == VIRTIO_INPUT_CFG_EV_BITS)
+ set_bit(subsel, vi->idev->evbit);
+ for (bit = 0; bit < bitcount; bit++) {
+ if ((bit % 8) == 0)
+ virtio_cread(vi->vdev, struct virtio_input_config,
+ u.bitmap[bit/8], &cfg);
+ if (cfg & (1 << (bit % 8)))
+ set_bit(bit, bits);
+ }
+}
+
+static void virtinput_cfg_abs(struct virtio_input *vi, int abs)
+{
+ u32 size, mi, ma, fu, fl;
+
+ size = 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.fuzz, &fu);
+ virtio_cread(vi->vdev, struct virtio_input_config, u.abs.flat, &fl);
+ input_set_abs_params(vi->idev, abs,
+ le32_to_cpu(mi), le32_to_cpu(ma),
+ le32_to_cpu(fu), le32_to_cpu(fl));
+}
+
+static int virtinput_init_vqs(struct virtio_input *vi)
+{
+ struct virtqueue *vqs[2];
+ vq_callback_t *cbs[] = { virtinput_recv_events,
+ virtinput_recv_status };
+ const char *names[] = { "events", "status" };
+ int i, err, size;
+
+ err = vi->vdev->config->find_vqs(vi->vdev, 2, vqs, cbs, names);
+ if (err)
+ return err;
+ vi->evt = vqs[0];
+ vi->sts = vqs[1];
+
+ 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]);
+
+ return 0;
+}
+
+static int virtinput_probe(struct virtio_device *vdev)
+{
+ struct virtio_input *vi;
+ size_t size;
+ int abs, err;
+
+ vi = kzalloc(sizeof(*vi), GFP_KERNEL);
+ if (!vi) {
+ err = -ENOMEM;
+ goto out1;
+ }
+ vdev->priv = vi;
+ vi->vdev = vdev;
+
+ err = virtinput_init_vqs(vi);
+ if (err)
+ goto out2;
+
+ vi->idev = input_allocate_device();
+ if (!vi->idev) {
+ err = -ENOMEM;
+ goto out3;
+ }
+ 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),
+ 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),
+ vi->serial, min(size, sizeof(vi->serial)));
+ snprintf(vi->phys, sizeof(vi->phys),
+ "virtio%d/input0", vdev->index);
+
+ 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->name = vi->name;
+ vi->idev->phys = vi->phys;
+ vi->idev->id.bustype = BUS_VIRTUAL;
+ vi->idev->id.vendor = 0x0001;
+ vi->idev->id.product = 0x0001;
+ vi->idev->id.version = 0x0100;
+ vi->idev->dev.parent = &vdev->dev;
+ vi->idev->dev.groups = dev_attr_groups;
+ 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);
+ }
+ }
+
+ err = input_register_device(vi->idev);
+ if (err)
+ goto out4;
+
+ return 0;
+
+out4:
+ input_free_device(vi->idev);
+out3:
+ vdev->config->del_vqs(vdev);
+out2:
+ kfree(vi);
+out1:
+ return err;
+}
+
+static void virtinput_remove(struct virtio_device *vdev)
+{
+ struct virtio_input *vi = vdev->priv;
+
+ input_unregister_device(vi->idev);
+ vdev->config->reset(vdev);
+ vdev->config->del_vqs(vdev);
+ kfree(vi);
+}
+
+static unsigned int features[] = {
+};
+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,
+};
+
+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@xxxxxxxxxx>");
diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
index 284fc3a..5f60aa4 100644
--- a/include/uapi/linux/virtio_ids.h
+++ b/include/uapi/linux/virtio_ids.h
@@ -39,5 +39,6 @@
#define VIRTIO_ID_9P 9 /* 9p virtio console */
#define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */
#define VIRTIO_ID_CAIF 12 /* Virtio caif */
+#define VIRTIO_ID_INPUT 18 /* virtio input */
#endif /* _LINUX_VIRTIO_IDS_H */
diff --git a/include/uapi/linux/virtio_input.h b/include/uapi/linux/virtio_input.h
new file mode 100644
index 0000000..190d04a
--- /dev/null
+++ b/include/uapi/linux/virtio_input.h
@@ -0,0 +1,65 @@
+#ifndef _LINUX_VIRTIO_INPUT_H
+#define _LINUX_VIRTIO_INPUT_H
+/* This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE. */
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+
+enum virtio_input_config_select {
+ VIRTIO_INPUT_CFG_UNSET = 0x00,
+ VIRTIO_INPUT_CFG_ID_NAME = 0x01,
+ VIRTIO_INPUT_CFG_ID_SERIAL = 0x02,
+ VIRTIO_INPUT_CFG_PROP_BITS = 0x10,
+ VIRTIO_INPUT_CFG_EV_BITS = 0x11,
+ VIRTIO_INPUT_CFG_ABS_INFO = 0x12,
+};
+
+struct virtio_input_absinfo {
+ __le32 min;
+ __le32 max;
+ __le32 fuzz;
+ __le32 flat;
+};
+
+struct virtio_input_config {
+ __u8 select;
+ __u8 subsel;
+ __u8 size;
+ __u8 reserved;
+ union {
+ char string[128];
+ __u8 bitmap[128];
+ struct virtio_input_absinfo abs;
+ } u;
+};
+
+struct virtio_input_event {
+ __le16 type;
+ __le16 code;
+ __le32 value;
+};
+
+#endif /* _LINUX_VIRTIO_INPUT_H */
--
1.8.3.1
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