SN32: Add UART support

keyboards/handwired/splittest/sn32f240b/config.h

@@ -0,0 +1,10 @@
+// Copyright 2024 Dimitris Mantzouranis (@dexter93)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#define SPLIT_HAND_PIN A7
+
+#if !(defined(USE_SDI0) || defined(USE_SDI1) || defined(USE_SDI2))
+    #define USE_SDI0
+#endif

keyboards/handwired/splittest/sn32f240b/halconf.h

@@ -0,0 +1,13 @@
+// Copyright 2024 Dimitris Mantzouranis (@dexter93)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+/* Needed for serial bitbang, half-duplex and full-duplex */
+#define HAL_USE_PAL TRUE
+// Needed for serial bitbang
+//#define PAL_USE_WAIT TRUE
+//#define PAL_USE_CALLBACKS TRUE
+#include_next <halconf.h>
+#undef HAL_USE_PWM
+#define HAL_USE_PWM FALSE

keyboards/handwired/splittest/sn32f240b/keyboard.json

@@ -0,0 +1,15 @@
+{
+    "matrix_pins": {
+        "cols": ["B1"],
+        "rows": ["B10"]
+    },
+    "diode_direction": "COL2ROW",
+    "processor": "SN32F248BF",
+    "bootloader": "sn32-dfu",
+    "features": {
+        "bootmagic": false,
+        "mousekey": false,
+        "extrakey": false,
+        "console": true
+    }
+}

keyboards/handwired/splittest/sn32f240b/mcuconf.h

@@ -0,0 +1,18 @@
+// Copyright 2024 Dimitris Mantzouranis (@dexter93)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include_next <mcuconf.h>
+
+// These are needed if the communication is on the SD0 UART, either with standard or alternate pins
+#undef SN32_SERIAL_USE_UART0
+#define SN32_SERIAL_USE_UART0 TRUE
+
+// These are needed if the communication is on the SD1 UART, either with standard or alternate pins
+//#undef SN32_SERIAL_USE_UART1
+//#define SN32_SERIAL_USE_UART1 TRUE
+
+// These are needed if the communication is on the SD2 UART, either with standard or alternate pins
+//#undef SN32_SERIAL_USE_UART2
+//#define SN32_SERIAL_USE_UART2 TRUE

keyboards/handwired/splittest/sn32f240b/post_config.h

@@ -0,0 +1,26 @@
+// Copyright 2024 Dimitris Mantzouranis (@dexter93)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#if defined(SPLIT_SERIAL_FULLDUPLEX)
+#    define SERIAL_USART_FULL_DUPLEX // Enable full duplex operation mode.
+#endif
+#if defined(SPLIT_SERIAL_HALFDUPLEX) || defined(SPLIT_SERIAL_FULLDUPLEX)
+#    if defined(USE_SDI0)
+#        define SOFT_SERIAL_PIN A10
+#        define SERIAL_USART_RX_PIN A11 // USART RX pin
+#        define SERIAL_USART_DRIVER SD0
+#    elif defined(USE_SDI1)
+#        define SOFT_SERIAL_PIN B9
+#        define SERIAL_USART_RX_PIN B8 // USART RX pin
+#    elif defined(USE_SDI2)
+#        define SOFT_SERIAL_PIN A1
+#        define SERIAL_USART_RX_PIN A0  // USART RX pin
+#        define SERIAL_USART_DRIVER SD2 // USART driver of TX and RX pin. default: SD1
+#    else
+#        error "splittest serial keymap is missing a configuration"
+#    endif
+#else // defined(SPLIT_BITBANG)
+#    define SOFT_SERIAL_PIN B8
+#endif

keyboards/handwired/splittest/sn32f240b/readme.md

@@ -0,0 +1,66 @@
+# sn32f240b splittest
+
+This is the splittest example for the sn32f240b MCU.
+To trigger keypress, short together pins _B10_ and _B1_.
+
+## Keyboard Configuration
+
+The type of communication (bitbang, serial (half/full duplex)) is set by the keymap `config.h` file with variables with `SPLIT_` prefix.
+So this example uses:
+
+-   `config.h` to set which SDI to use for serial. Either define `USE_SDI0`, `USE_SDI1` or `USE_SDI2` before the `#ifdef` that configures the default case when none of these variable is defined.
+-   `post_config.h` for defining the communication pins between the halves once the keymap is configured.
+
+On your keyboard, you most likely will only use `config.h` because you'd have already chosen your communication scheme: serial type, SDI, pins.
+
+## Wiring
+
+### Switches
+
+-   Add switches to both sn32f240b across B10 and B1 pins
+
+### Handedness
+
+Have a look at the [handedness documentation](https://docs.qmk.fm/#/feature_split_keyboard?id=setting-handedness)
+
+-   Add pull-up resistor to left side between VCC and A7
+-   Add pull-down resistors to right side between GND and A7
+
+### Send power to the other half
+
+-   Connect the following pins on both sides together: GND, VCC
+
+### Halves data connection
+
+Choose one of the connection type
+
+#### serial - bitbang
+
+-   Connect the B8 pins on both sides together
+-   Note that bitbang functionality requires strict timings. Currently not supported.
+
+#### serial - usart half duplex
+
+Check the [documentation](https://docs.qmk.fm/#/serial_driver?id=usart-half-duplex) to determine the pull-up resistor.
+
+-   To use the default usart (UART0),
+    -   Connect the A10, A11 pins on both sides together and to add a pull-up resistor on one of these pins
+    -   Define USE_SDI0 in config.h
+-   To use the second usart (UART1),
+    -   Connect the B8, B9 pins on both sides together and to add a pull-up resistor on one of these pins
+    -   Define USE_SDI1 in config.h
+-   To use the third usart (UART2),
+    -   Connect the A0, A1 pins on both sides together and to add a pull-up resistor on one of these pins
+    -   Define USE_SDI1 in config.h
+
+#### serial - usart full duplex
+
+-   To use the default usart (UART0),
+    -   Connect the pins on A10, A11 one to the other on each side
+    -   Define USE_SDI0 in config.h
+-   To use the second usart (UART1),
+    -   Connect the pins B8, B9 one to the other on each side
+    -   Define USE_SDI1 in config.h
+-   To use the third usart2 (UART2) pins,
+    -   Connect the pins A0, A1 one to the other on each side
+    -   Define USE_SDI2 in config.h

platforms/chibios/drivers/serial_usart.c

@@ -1,4 +1,4 @@
 // Copyright 2021 QMK
 // Copyright 2022 Stefan Kerkmann
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -35,6 +35,23 @@
     .UARTDMACR = 0U
 };
 // clang-format on
+#elif defined(MCU_SN32) /* SN32F2 MCUs */
+// clang-format off
+static QMKSerialConfig serial_config = {
+    .speed = (SERIAL_USART_SPEED),
+    .UART_WordLength = (UART_WordLength_8b),
+    .UART_StopBits = (UART_StopBits_Two),
+    .UART_Parity = (UART_Parity_Enable|UART_Parity_Even),
+    .UART_FIFOControl = (UART_RxFIFOThreshold_1),
+    .UART_AutoBaudControl = (UART_AutoBaudControl_None),
+    .UART_Oversampling = (UART_Oversample_8),
+#    if !defined(SERIAL_USART_FULL_DUPLEX)
+    .UART_HalfDuplexMode = (UART_HalfDuplexEnable)
+#    else
+    .UART_HalfDuplexMode = (UART_FullDuplexEnable)
+#    endif
+};
+// clang-format on
 #else
 #    error MCU Familiy not supported by default, supply your own serial_config by defining SERIAL_USART_CONFIG in your keyboard files.
 #endif
@@ -172,6 +189,10 @@
 #        endif
 #    elif defined(MCU_RP) /* Raspberry Pi MCUs */
 #        error Half-duplex with the SIO driver is not supported due to hardware limitations on the RP2040, switch to the PIO driver which has half-duplex support.
+#    elif defined(MCU_SN32) /* SN32F2 MCUs */
+    // Hardware limitations, we can use one wire, but both TX and RX pins should be connected
+    // SN32 family autoconfigures the TX pin
+    palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_INPUT);
 #    else
 #        pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files."
 #    endif
@@ -198,6 +219,9 @@
 #    elif defined(MCU_RP) /* Raspberry Pi MCUs */
     palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE_UART);
     palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_ALTERNATE_UART);
+#    elif defined(MCU_SN32) /* SN32F2 MCUs */
+    // SN32 family autoconfigures the TX pin
+    palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_INPUT);
 #    else
 #        pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files."
 #    endif