Re: [PATCH v10 3/4] docs: Add documentation for userspace client interface

[Randy Dunlap]

Hi,

On 10/29/20 2:40 PM, Hemant Kumar wrote:
> MHI userspace client driver is creating device file node
> for user application to perform file operations. File
> operations are handled by MHI core driver. Currently
> Loopback MHI channel is supported by this driver.
> 
> Signed-off-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx>
> ---
>  Documentation/mhi/index.rst |  1 +
>  Documentation/mhi/uci.rst   | 83 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 84 insertions(+)
>  create mode 100644 Documentation/mhi/uci.rst


> diff --git a/Documentation/mhi/uci.rst b/Documentation/mhi/uci.rst
> new file mode 100644
> index 0000000..fe901c4
> --- /dev/null
> +++ b/Documentation/mhi/uci.rst
> @@ -0,0 +1,83 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=================================
> +Userspace Client Interface (UCI)
> +=================================
> +


Lots of TLAs.

> +
> +read
> +----
> +
> +When data transfer is completed on downlink channel, TRE buffer is copied to
> +pending list. Reader is unblocked and data is copied to userspace buffer. TRE
> +buffer is queued back to downlink channel transfer ring.

What is TRE?

> +
> +Usage
> +=====
> +
> +Device file node is created with format:-
> +
> +/dev/mhi_<controller_name>_<mhi_device_name>
> +
> +controller_name is the name of underlying bus used to transfer data. mhi_device
> +name is the name of the MHI channel being used by MHI client in userspace to
> +send or receive data using MHI protocol.
> +
> +There is a separate character device file node created for each channel
> +specified in mhi device id table. MHI channels are statically defined by MHI

                MHI
unless it is a variable name, like below: mhi_device_id

> +specification. The list of supported channels is in the channel list variable
> +of mhi_device_id table in UCI driver.
> +

> +Other Use Cases
> +---------------
> +
> +Getting MHI device specific diagnostics information to userspace MHI diag client

                                                                        diagnostic client

> +using DIAG channel 4 (Host to device) and 5 (Device to Host).
> 

thanks.
-- 
~Randy