From: "A. Cody Schuffelen" <schuffe...@google.com> This is an implementation of single-character virtio-console. Part of the patch is based on barebox implementations.
Signed-off-by: A. Cody Schuffelen <schuffe...@google.com> [ Paul: pick from the Android tree. Rebase to the upstream. Small fixes. ] Signed-off-by: Ying-Chun Liu (PaulLiu) <paul....@linaro.org> Link: https://android.googlesource.com/platform/external/u-boot/+/bc68da98ebf835a50d869cf01c535ac936bfcb11 Link: https://git.pengutronix.de/cgit/barebox/tree/drivers/serial/virtio_console.c?id=180a551d542844b70012d7b94a415aacdcf31d45 Link: https://android.googlesource.com/platform/external/u-boot/+/4581f7c6e96d7332b534ae20de356a4554594d08 Cc: Bin Meng <bmeng...@gmail.com> --- drivers/virtio/Kconfig | 8 ++ drivers/virtio/Makefile | 1 + drivers/virtio/virtio-uclass.c | 1 + drivers/virtio/virtio_console.c | 158 ++++++++++++++++++++++++++++++++ include/virtio.h | 2 + 5 files changed, 170 insertions(+) create mode 100644 drivers/virtio/virtio_console.c diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 852f6735b6..94aaf70ab9 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -68,6 +68,14 @@ config VIRTIO_BLK This is the virtual block driver for virtio. It can be used with QEMU based targets. +config VIRTIO_CONSOLE + bool "virtio console driver" + depends on VIRTIO + default y + help + This is the virtual console driver for virtio. It can be used + with QEMU based targets. + config VIRTIO_RNG bool "virtio rng driver" depends on DM_RNG diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 4c63a6c690..c816f66aa6 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -10,4 +10,5 @@ obj-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o obj-$(CONFIG_VIRTIO_NET) += virtio_net.o obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o +obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c index 31bb21c534..9c54c67572 100644 --- a/drivers/virtio/virtio-uclass.c +++ b/drivers/virtio/virtio-uclass.c @@ -30,6 +30,7 @@ static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = { [VIRTIO_ID_NET] = VIRTIO_NET_DRV_NAME, [VIRTIO_ID_BLOCK] = VIRTIO_BLK_DRV_NAME, + [VIRTIO_ID_CONSOLE] = VIRTIO_CONSOLE_DRV_NAME, [VIRTIO_ID_RNG] = VIRTIO_RNG_DRV_NAME, }; diff --git a/drivers/virtio/virtio_console.c b/drivers/virtio/virtio_console.c new file mode 100644 index 0000000000..1d4b319b08 --- /dev/null +++ b/drivers/virtio/virtio_console.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkky...@iki.fi> + * Copyright (C) 2018, Bin Meng <bmeng...@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.s...@redhat.com> + * Copyright (C) 2021 Ahmad Fatoum + * Copyright (C) 2021, Google LLC, schuffe...@google.com (A. Cody Schuffelen) + * Copyright (C) 2023, Linaro + */ + +#include <common.h> +#include <blk.h> +#include <dm.h> +#include <part.h> +#include <serial.h> +#include <virtio_types.h> +#include <virtio.h> +#include <virtio_ring.h> +#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) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent); + + /* Indicate what driver features we support */ + virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0); + + 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]; + int ret; + + sgs[0] = &sg; + sg.addr = priv->inbuf; + sg.length = sizeof(priv->inbuf); + + ret = virtqueue_add(priv->receiveq_port0, sgs, 0, 1); + /* We should always be able to add one buffer to an empty queue. */ + WARN(ret < 0, "%s: virtqueue_add failed\n", __func__); + + 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; +} + +static int virtio_console_serial_setbrg(struct udevice *dev, int baudrate) +{ + return 0; +} + +static int virtio_console_serial_pending(struct udevice *dev, bool input) +{ + 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_getc(struct udevice *dev) +{ + 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; + + WARN(len != 1, "%s: too much data: %d\n", __func__, len); + + 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; +} + +static const struct dm_serial_ops virtio_console_serial_ops = { + .putc = virtio_console_serial_putc, + .pending = virtio_console_serial_pending, + .getc = virtio_console_serial_getc, + .setbrg = virtio_console_serial_setbrg, +}; + +U_BOOT_DRIVER(virtio_console) = { + .name = VIRTIO_CONSOLE_DRV_NAME, + .id = UCLASS_SERIAL, + .ops = &virtio_console_serial_ops, + .bind = virtio_console_bind, + .probe = virtio_console_probe, + .remove = virtio_reset, + .priv_auto = sizeof(struct virtio_console_priv), + .flags = DM_FLAG_ACTIVE_DMA, +}; diff --git a/include/virtio.h b/include/virtio.h index 062a24630c..e36dd41fd1 100644 --- a/include/virtio.h +++ b/include/virtio.h @@ -25,11 +25,13 @@ #include <linux/bug.h> #define VIRTIO_ID_NET 1 /* virtio net */ #define VIRTIO_ID_BLOCK 2 /* virtio block */ +#define VIRTIO_ID_CONSOLE 3 /* virtio console */ #define VIRTIO_ID_RNG 4 /* virtio rng */ #define VIRTIO_ID_MAX_NUM 5 #define VIRTIO_NET_DRV_NAME "virtio-net" #define VIRTIO_BLK_DRV_NAME "virtio-blk" +#define VIRTIO_CONSOLE_DRV_NAME "virtio-console" #define VIRTIO_RNG_DRV_NAME "virtio-rng" /* Status byte for guest to report progress, and synchronize features */ -- 2.39.2
