From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-comment-return-1470-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: References: <61930337391bdfd23ed164288d998c04177bc839.1603435652.git.jie.deng@intel.com> <20201023115932-mutt-send-email-mst@kernel.org> From: Jie Deng Message-ID: Date: Mon, 26 Oct 2020 09:22:07 +0800 MIME-Version: 1.0 In-Reply-To: <20201023115932-mutt-send-email-mst@kernel.org> Subject: [virtio-comment] Re: [virtio-dev] Re: [PATCH v2] virtio-i2c: add the device specification Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US To: "Michael S. Tsirkin" Cc: virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org List-ID: On 2020/10/24 0:00, Michael S. Tsirkin wrote: > On Fri, Oct 23, 2020 at 02:51:25PM +0800, Jie Deng wrote: >> + >> +The driver queues requests to the virtqueues, and they are used by the >> +device. The request is the representation of one segment of an I2C >> +transaction. Each request is of form: >> + >> +\begin{lstlisting} >> +struct virtio_i2c_req { >> + le16 addr; >> + le16 flags; >> + le16 len; >> + u8 buf[]; >> + u8 status; >> +}; >> +\end{lstlisting} >> + >> +The \field{addr} is the address of the I2C slave device. >> + >> +The first bit of \field{flags} indicates whether it is a read or write request. >> +It means a read request if the first bit of \field{flags} is set, otherwise >> +it is a write request. The rest bits of \field{flags} are reserved. >> > > So how does one creates a multi-segment transaction then? > The I2C doesn't support segments numbering and sorting. So if one creates a multi-segment transaction, then he/she should keep the segments in order. Thanks. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org > This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/