Re: [PATCH v2] uwb: nxp: sr1xx: UWB driver support for sr1xx series chip

[Greg KH]

On Tue, Mar 15, 2022 at 04:22:05PM +0530, Manjunatha Venkatesh wrote:
> Ultra Wide Band(UWB) is a fast, secure and low power radio protocol used
> to determine location with accuracy unmatched by any other wireless
> technology.
> Its a short-range wireless communication protocol. It uses radio waves to
> enable devices to talk to each other.
> 
> This is a new driver that supports the integrated UWB for
> Nxp SoCs, especially the sr1xx series and depends on the SPI module.
> 
> This driver works with Nxp UWB Subsystem(UWBS) which is FiRa Compliance.
> Corresponding UCI details available in Fira Consortuim website.
> 
> sr1xx is flash less UWBS  and it requires firmware download on every
> device boot.
> 
> Internally driver will handle two modes of operation.
> 1.HBCI mode (sr1xx BootROM Code Interface)
>   Firmware download uses HBCI ptotocol packet structure which is
>   Nxp proprietary,Firmware File(.bin) stored in user space context
>   and during device init sequence pick the firmware packet in chunk
>   and send it to the driver with write() api call.
>   Complete firmware download protocol logic implemented in user space,
>   Driver used here is kind of pipe to send data to SPI line.
>   Firmware acknowledge for every chunk packet sent and same thing
>   is monitored,in user space code(HAL layer).
>   If any error Firmware download sequence will fail and reset the device.
>   If firmware download packet sent successfully at the end device will
>   send device status notification and its indication of device entered
>   UCI mode.Here after any command/response/notification will follow
>   UCI packet structure.
> 
> 2.UCI mode (UWB Command interface)
>   Once Firmware download finishes sr1xx will switch to UCI mode packet
>   structure.Here this driver acts as pipe between user space and sr1xx.
>   Any response or notification received from sr1xx through SPI line
>   will convey to user space.User space(UCI lib) will take care of
>   UCI parsing logic.
> 
>   Its IRQ based driver and sr1xx specific irq handshake mechanism logic
>   implemented to avoid any race condition between write and read
>   during ranging sequence.
> 
>   UCI mode Write is same as HBCI mode sequence whatever command received
>   from user space will send to the sr1xx via SPI line.
>   In UCI mode read api called first and waiting on the IRQ line status
>   in order to avoid missing of interrupts after write sequence.
> 
>   This driver needs dts config update as per the sr1xx data sheet.
>   Corresponding document added in Documentation/devicetree/bindings/uwb
> 
> Signed-off-by: Manjunatha Venkatesh <manjunatha.venkatesh@xxxxxxx>
> 
> Changes since v1:
> https://lkml.org/lkml/2022/3/7/1254

Always use lore.kernel.org links.  Also the changelog goes below the ---
line.  This does not describe what changed, you are just pointing to a
random place on the internet, which does not explain anything.

greg k-h