diff options
| -rw-r--r-- | drivers/virtio/virtio_console.c | 94 |
1 files changed, 90 insertions, 4 deletions
diff --git a/drivers/virtio/virtio_console.c b/drivers/virtio/virtio_console.c index 75c5e1a4230..74bf371c629 100644 --- a/drivers/virtio/virtio_console.c +++ b/drivers/virtio/virtio_console.c @@ -2,6 +2,10 @@ /* * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com> + * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation + * Copyright (C) 2009, 2010, 2011 Red Hat, Inc. + * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com> + * Copyright (C) 2021 Ahmad Fatoum * Copyright (C) 2021, Google LLC, schuffelen@google.com (A. Cody Schuffelen) */ @@ -16,6 +20,9 @@ #include "virtio_blk.h" struct virtio_console_priv { + struct virtqueue *receiveq_port0; + struct virtqueue *transmitq_port0; + unsigned char inbuf[1] __aligned(4); }; static int virtio_console_bind(struct udevice *dev) @@ -28,8 +35,46 @@ static int virtio_console_bind(struct udevice *dev) return 0; } +/* + * Create a scatter-gather list representing our input buffer and put + * it in the queue. + */ +static void add_inbuf(struct virtio_console_priv *priv) +{ + struct virtio_sg sg; + struct virtio_sg *sgs[1]; + + sgs[0] = &sg; + sg.addr = priv->inbuf; + sg.length = sizeof(priv->inbuf); + + /* We should always be able to add one buffer to an empty queue. */ + if (virtqueue_add(priv->receiveq_port0, sgs, 0, 1) < 0) { + debug("%s: virtqueue_add failed\n", __func__); + BUG(); + } + virtqueue_kick(priv->receiveq_port0); +} + static int virtio_console_probe(struct udevice *dev) { + struct virtio_console_priv *priv = dev_get_priv(dev); + int ret; + + struct virtqueue *virtqueues[2]; + + ret = virtio_find_vqs(dev, 2, virtqueues); + if (ret < 0) { + debug("%s: virtio_find_vqs failed\n", __func__); + return ret; + } + + priv->receiveq_port0 = virtqueues[0]; + priv->transmitq_port0 = virtqueues[1]; + + /* Register the input buffer the first time. */ + add_inbuf(priv); + return 0; } @@ -38,18 +83,59 @@ static int virtio_console_serial_setbrg(struct udevice *dev, int baudrate) return 0; } -static int virtio_console_serial_getc(struct udevice *dev) +static int virtio_console_serial_pending(struct udevice *dev, bool input) { - return -EAGAIN; + struct virtio_console_priv *priv = dev_get_priv(dev); + return virtqueue_poll(priv->receiveq_port0, + priv->receiveq_port0->last_used_idx); } -static int virtio_console_serial_pending(struct udevice *dev, bool input) +static int virtio_console_serial_getc(struct udevice *dev) { - return 0; + struct virtio_console_priv *priv = dev_get_priv(dev); + unsigned char *in; + int ch; + unsigned int len = 0; + + in = virtqueue_get_buf(priv->receiveq_port0, &len); + if (!in) { + return -EAGAIN; + } else if (len != 1) { + debug("%s: too much data: %d\n", __func__, len); + BUG(); + } + + ch = *in; + + add_inbuf(priv); + + return ch; } static int virtio_console_serial_putc(struct udevice *dev, const char ch) { + struct virtio_console_priv *priv = dev_get_priv(dev); + struct virtio_sg sg; + struct virtio_sg *sgs[1]; + unsigned char buf[1] __aligned(4); + int ret = 0; + + sg.addr = buf; + sg.length = sizeof(buf); + sgs[0] = &sg; + buf[0] = ch; + + ret = virtqueue_add(priv->transmitq_port0, sgs, 1, 0); + if (ret) { + debug("%s: virtqueue_add failed\n", __func__); + return ret; + } + + virtqueue_kick(priv->transmitq_port0); + + while (!virtqueue_get_buf(priv->transmitq_port0, NULL)) { + } + return 0; } |