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Commit 271c8651 authored by Gerd Hoffmann's avatar Gerd Hoffmann Committed by Rusty Russell
Browse files

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: default avatarGerd Hoffmann <kraxel@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 2f921b5b

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -10435,6 +10435,12 @@ S: Maintained 
F:	drivers/vhost/

F:	include/uapi/linux/vhost.h



VIRTIO INPUT DRIVER

M:	Gerd Hoffmann <kraxel@redhat.com>

S:	Maintained

F:	drivers/virtio/virtio_input.c

F:	include/uapi/linux/virtio_input.h



VIA RHINE NETWORK DRIVER

M:	Roger Luethi <rl@hellgate.ch>

S:	Maintained

drivers/virtio/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -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

drivers/virtio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/virtio/virtio_input.c

0 → 100644
+384 −0
Original line number Diff line number Diff line 
#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>");

include/uapi/linux/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -430,6 +430,7 @@ header-y += virtio_blk.h 
header-y += virtio_config.h

header-y += virtio_console.h

header-y += virtio_ids.h

header-y += virtio_input.h

header-y += virtio_net.h

header-y += virtio_pci.h

header-y += virtio_ring.h