[PATCH v2 1/1] doc: riscv: Update documentation for Sipeed MAIX boards

[Sean Anderson <seanga2@gmail.com>]

On 7/28/20 2:05 PM, Heinrich Schuchardt wrote:
> The MAIXDUINO runs fine with the sipeed_maix_bitm_defconfig but a different
> board id parameter should be passed to kflash.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> ---
> v2:
> 	describe why we use the same defconfig for multiple boards
> 	describe how to reset the board via DTR/RTS
> ---
>  doc/board/sipeed/maix.rst | 75 ++++++++++++++++++++++++++++++++++-----
>  1 file changed, 66 insertions(+), 9 deletions(-)
> 
> diff --git a/doc/board/sipeed/maix.rst b/doc/board/sipeed/maix.rst
> index 06e0008b9f..c235cb44a8 100644
> --- a/doc/board/sipeed/maix.rst
> +++ b/doc/board/sipeed/maix.rst
> @@ -1,8 +1,8 @@
>  .. SPDX-License-Identifier: GPL-2.0+
>  .. Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
> 
> -Maix Bit
> -========
> +MAIX
> +====
> 
>  Several of the Sipeed Maix series of boards cotain the Kendryte K210 processor,
>  a 64-bit RISC-V CPU. This processor contains several peripherals to accelerate
> @@ -13,8 +13,10 @@ peripherals include 8M of SRAM (accessible with and without caching); remappable
>  pins, including 40 GPIOs; AES, FFT, and SHA256 accelerators; a DMA controller;
>  and I2C, I2S, and SPI controllers. Maix peripherals vary, but include spi flash;
>  on-board usb-serial bridges; ports for cameras, displays, and sd cards; and
> -ESP32 chips. Currently, only the Sipeed Maix Bit V2.0 (bitm) is supported, but
> -the boards are fairly similar.
> +ESP32 chips.
> +
> +Currently, only the Sipeed MAIX BiT V2.0 (bitm) and Sipeed MAIXDUINO are
> +supported, but the boards are fairly similar.
> 
>  Documentation for Maix boards is available from
>  `Sipeed's website <http://dl.sipeed.com/MAIX/HDK/>`_.
> @@ -26,20 +28,42 @@ details are rather lacking, so most technical reference has been taken from the
>  Build and boot steps
>  --------------------
> 
> -To build u-boot, run
> +To build U-Boot, run
> 
>  .. code-block:: none
> 
> -    make sipeed_maix_bitm_defconfig
> +    make <defconfig>
>      make CROSS_COMPILE=<your cross compile prefix>
> 
> -To flash u-boot to a maix bit, run
> +To flash U-Boot, run
> 
>  .. code-block:: none
> 
> -    kflash -tp /dev/<your tty here> -B bit_mic u-boot-dtb.bin
> +    kflash -tp /dev/<your tty here> -B <board_id> u-boot-dtb.bin
> +
> +The board provides two serial devices, e.g.
> +
> +* /dev/serial/by-id/usb-Kongou_Hikari_Sipeed-Debug_12345678AB-if00-port0
> +* /dev/serial/by-id/usb-Kongou_Hikari_Sipeed-Debug_12345678AB-if01-port0
> +
> +Which one is used for flashing depends on the board.
> 
> -Boot output should look like the following:
> +Currently only a small subset of the board features are supported. So we can
> +use the same default configuration and device tree. In the long run we may need
> +separate settings.
> +
> +======================== ========================== ========== ==========
> +Board                    defconfig                  board_id   TTY device
> +======================== ========================== ========== ==========
> +Sipeed MAIX BiT          sipeed_maix_bitm_defconfig bit        first
> +Sipeed MAIX BiT with Mic sipeed_maix_bitm_defconfig bit_mic    first
> +Sipeed MAIXDUINO         sipeed_maix_bitm_defconfig maixduino  first
> +Sipeed MAIX GO                                      goE        second
> +Sipeed MAIX ONE DOCK                                goD        first
> +======================== ========================== ========== ==========
> +
> +Flashing causes a reboot of the device. Parameter -t specifies that the serial
> +console shall be opened immediately. Boot output should look like the following:
> 
>  .. code-block:: none
> 
> @@ -238,6 +262,39 @@ Boot Sequence
>     stage.
>  8. The boot hart jumps to ``0x80000000``.
> 
> +Resetting the board
> +^^^^^^^^^^^^^^^^^^^
> +
> +The MAIX boards can be reset using the DTR and RTS lines of the serial console.
> +How the lines are used depends on the specific board. See the code of kflash.py
> +for details.
> +
> +This is the reset sequence for the MAXDUINO and MAIX BiT with Mic:
> +
> +.. code-block:: python
> +
> +   def reset(self):
> +        self.device.setDTR(False)
> +        self.device.setRTS(False)
> +        time.sleep(0.1)
> +        self.device.setDTR(True)
> +        time.sleep(0.1)
> +        self.device.setDTR(False)
> +        time.sleep(0.1)
> +
> +and this for the MAIX Bit:
> +
> +.. code-block:: python
> +
> +   def reset(self):
> +        self.device.setDTR(False)
> +        self.device.setRTS(False)
> +        time.sleep(0.1)
> +        self.device.setRTS(True)
> +        time.sleep(0.1)
> +        self.device.setRTS(False)
> +        time.sleep(0.1)
> +
>  Memory Map
>  ^^^^^^^^^^
> 
> --
> 2.27.0
> 

Reviewed-by: Sean Anderson <seanga2@gmail.com>