Add Serial Wire Debug Port interface driver API and bit-bang driver.

The driver requires a simple Hardware Interface Circuits (HICs),
where signals CLK, DOUT, DIN, ENn, OE_ENn, RESETn
are connected to board GPIOs and buffered signals SWD_CLK and SWD_DIO
to the target.

Signal OE_ENn controls the direction of the Serial Wire (SWD_DIO),
ENn the buffers SWD_CLK possibly others and enables/disables HIC.

Signed-off-by: Johann Fischer <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

Add CMSIS-DAP compatible controller which is a handler between
the host interface and SWD driver. The controller follows CMSIS-DAP
reference implementation. It expects a request buffer from the host
interface, splits it to simple transfers and forwards to the DP driver,
and finally returns a response buffer to the host.
Interface to the host can be implemented with USB HID device support.

Controller implements only SW-DP support and is tested
with pyOCD and ADIv5.x.

Signed-off-by: Johann Fischer <[email protected]>

This also fixes a bug where the packet size returned was only 17 byte.

Signed-off-by: Johan Carlsson <[email protected]>

If a host client crashes or fails to disconnect, the probe will
hang. Allow a new connection without raising errors.

Signed-off-by: Johan Carlsson <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

Move low-level GPIO functions to a separate file and use GPIO driver
API if low-level GPIO support is not available for the platform.
Allows alternative pin configuration using only two pins, clk and dio.
Improve binding description.

Signed-off-by: Maximilian Deubel <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

Add API to read count bits from SWDIO into data LSB first.

Signed-off-by: Maximilian Deubel <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

Implement wait for SWJ pins command.

Signed-off-by: Maximilian Deubel <[email protected]>

Add support for DAP_INFO string elements.

Signed-off-by: Maximilian Deubel <[email protected]>

Add ID_DAP_UART_* command definitions and react properly to
unsupported UART commands.

Signed-off-by: Maximilian Deubel <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

DAP SWD sequence command is a requirement to support CMSIS-DAPv2.
Raise supported version to "2.1.0".

Signed-off-by: Maximilian Deubel <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

Add CMSIS DAP sample using USB as interface.

Signed-off-by: Maximilian Deubel <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>

Use k_timepoint_t for timeout handling in the swj_pins function.

Signed-off-by: Maximilian Deubel <[email protected]>

Hardcode the lookup table for SWDP requests.
This is an optimization to save some space.
Documentation was added to understand the values.

Signed-off-by: Maximilian Deubel <[email protected]>

This patch adds documentation for the SWDP API.

Signed-off-by: Maximilian Deubel <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>