Re: [PATCH v5] i2c: virtio: add a virtio i2c frontend driver

[Arnd Bergmann]

On Mon, Mar 1, 2021 at 7:41 AM Jie Deng <jie.deng@xxxxxxxxx> wrote:

> --- /dev/null
> +++ b/include/uapi/linux/virtio_i2c.h
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later WITH Linux-syscall-note */
> +/*
> + * Definitions for virtio I2C Adpter
> + *
> + * Copyright (c) 2021 Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef _UAPI_LINUX_VIRTIO_I2C_H
> +#define _UAPI_LINUX_VIRTIO_I2C_H

Why is this a uapi header? Can't this all be moved into the driver
itself?

> +/**
> + * struct virtio_i2c_req - the virtio I2C request structure
> + * @out_hdr: the OUT header of the virtio I2C message
> + * @write_buf: contains one I2C segment being written to the device
> + * @read_buf: contains one I2C segment being read from the device
> + * @in_hdr: the IN header of the virtio I2C message
> + */
> +struct virtio_i2c_req {
> +       struct virtio_i2c_out_hdr out_hdr;
> +       u8 *write_buf;
> +       u8 *read_buf;
> +       struct virtio_i2c_in_hdr in_hdr;
> +};

In particular, this structure looks like it is only ever usable between
the transfer functions in the driver itself, it is shared with neither
user space nor the virtio host side.

       Arnd