On 12-10-20, 09:55, Jie Deng wrote: > Add an I2C bus driver for virtio para-virtualization. > > The controller can be emulated by the backend driver in > any device model software by following the virtio protocol. > > This driver communicates with the backend driver through a > virtio I2C message structure which includes following parts: > > - Header: i2c_msg addr, flags, len. > - Data buffer: the pointer to the I2C msg data. > - Status: the processing result from the backend. > > People may implement different backend drivers to emulate > different controllers according to their needs. A backend > example can be found in the device model of the open source > project ACRN. For more information, please refer to > https://projectacrn.org. > diff --git a/include/uapi/linux/virtio_i2c.h b/include/uapi/linux/virtio_i2c.h > new file mode 100644 > index 0000000..7413e45 > --- /dev/null > +++ b/include/uapi/linux/virtio_i2c.h > @@ -0,0 +1,31 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause */ > +/* > + * Definitions for virtio I2C Adpter > + * > + * Copyright (c) 2020 Intel Corporation. All rights reserved. > + */ > + > +#ifndef _UAPI_LINUX_VIRTIO_I2C_H > +#define _UAPI_LINUX_VIRTIO_I2C_H > + > +#include <linux/types.h> > +#include <linux/virtio_ids.h> > +#include <linux/virtio_config.h> > + > +/** > + * struct virtio_i2c_hdr - the virtio I2C message header structure > + * @addr: i2c_msg addr, the slave address > + * @flags: i2c_msg flags > + * @len: i2c_msg len > + */ > +struct virtio_i2c_hdr { > + __le16 addr; > + __le16 flags; > + __le16 len; > +}; Hi Jie, I am a bit confused about the header and the format in which data is being processed here. When I look at the specification present here: https://lists.oasis-open.org/archives/virtio-comment/202009/msg00021.html it talks about struct virtio_i2c_out_hdr { le16 addr; le16 padding; le32 flags; }; struct virtio_i2c_in_hdr { u8 status; }; struct virtio_i2c_req { struct virtio_i2c_out_hdr out_hdr; u8 write_buf []; u8 read_buf []; struct virtio_i2c_in_hdr in_hdr; }; while what we have above is completely different. What am I missing ? -- viresh
