Add preliminary busio.UART support

- Enabled BUSIO in mpconfigport.mk
- Stubs added for busio.I2C & busio.SPI
- Implemented busio.UART to basic working functionality
- Added MCU-specific UART data in peripherals/<mcu>/max32_uart.c & max32_uart.h
- Still have a couple issues where UART generates garbage characters or
  does not respond to timeouts / generate asynchronous IRQs

Author: Brandon-Hurst

ports/analog/common-hal/busio/I2C.c

@@ -30,7 +30,6 @@
 #include "shared-bindings/microcontroller/__init__.h"
 #include "shared-bindings/microcontroller/Pin.h"
 
-static I2CSPM_Init_TypeDef i2cspm_init;
 static bool in_used = false;
 
 // Construct I2C protocol, this function init i2c peripheral
@@ -39,37 +38,7 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
     const mcu_pin_obj_t *sda,
     uint32_t frequency, uint32_t timeout) {
 
-    // Ensure the object starts in its deinit state.
-    common_hal_busio_i2c_mark_deinit(self);
-
-    if ((scl != NULL) && (sda != NULL)) {
-        if (scl->function_list[ DEFAULT_I2C_PERIPHERAL == I2C1?
-                                FN_I2C1_SCL : FN_I2C0_SCL] == 1 &&
-            scl->function_list[DEFAULT_I2C_PERIPHERAL == I2C1?
-                               FN_I2C1_SDA : FN_I2C0_SDA] == 1) {
-            self->scl = scl;
-            self->sda = sda;
-            self->has_lock = false;
-            i2cspm_init.sclPort = self->scl->port;
-            i2cspm_init.sclPin = self->scl->number;
-            i2cspm_init.sdaPort = self->sda->port;
-            i2cspm_init.sdaPin = self->sda->number;
-            i2cspm_init.port = DEFAULT_I2C_PERIPHERAL;
-            i2cspm_init.i2cRefFreq = 0;
-            i2cspm_init.i2cMaxFreq = I2C_FREQ_STANDARD_MAX;
-            i2cspm_init.i2cClhr = i2cClockHLRStandard;
-
-            self->i2cspm = i2cspm_init.port;
-            I2CSPM_Init(&i2cspm_init);
-            common_hal_mcu_pin_claim(scl);
-            common_hal_mcu_pin_claim(sda);
-            in_used = true;
-        } else {
-            mp_raise_ValueError(MP_ERROR_TEXT("Hardware in use, try alternative pins"));
-        }
-    } else {
-        raise_ValueError_invalid_pins();
-    }
+
 }
 
 // Never reset I2C obj when reload
@@ -85,53 +54,26 @@ bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
 
 // Deinit i2c obj, reset I2C pin
 void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
-    if (common_hal_busio_i2c_deinited(self)) {
-        return;
-    }
-    I2C_Reset(self->i2cspm);
-    common_hal_reset_pin(self->sda);
-    common_hal_reset_pin(self->scl);
-    self->i2cspm = NULL;
-    in_used = false;
-    common_hal_busio_i2c_mark_deinit(self);
+    // FIXME: Implement
 }
 
 void common_hal_busio_i2c_mark_deinit(busio_i2c_obj_t *self) {
-    self->sda = NULL;
+    // FIXME: Implement
 }
 
 // Probe device in I2C bus
 bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
-    I2C_TransferSeq_TypeDef seq;
-    I2C_TransferReturn_TypeDef ret;
-    uint8_t data = 0;
-
-    seq.addr = addr << 1;
-    seq.flags = I2C_FLAG_READ;
-
-    seq.buf[0].data = &data;
-    seq.buf[0].len = 1;
+    // FIXME: Implement
 
-    ret = I2CSPM_Transfer(self->i2cspm, &seq);
-    if (ret != i2cTransferDone) {
-        return false;
-    }
     return true;
 }
 
 // Lock I2C bus
 bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
-    if (common_hal_busio_i2c_deinited(self)) {
-        return false;
-    }
-    bool grabbed_lock = false;
 
-    if (!self->has_lock) {
-        grabbed_lock = true;
-        self->has_lock = true;
-    }
+    // FIXME: Implement
 
-    return grabbed_lock;
+    return false;
 }
 
 // Check I2C lock status
@@ -148,19 +90,7 @@ void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
 uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
     const uint8_t *data, size_t len) {
 
-    I2C_TransferSeq_TypeDef seq;
-    I2C_TransferReturn_TypeDef ret;
-
-    seq.addr = addr << 1;
-    seq.flags = I2C_FLAG_WRITE;
-
-    seq.buf[0].data = (uint8_t *)data;
-    seq.buf[0].len = len;
-
-    ret = I2CSPM_Transfer(self->i2cspm, &seq);
-    if (ret != i2cTransferDone) {
-        return MP_EIO;
-    }
+    // FIXME: Implement
     return 0;
 }
 
@@ -169,19 +99,7 @@ uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self,
     uint16_t addr,
     uint8_t *data, size_t len) {
 
-    I2C_TransferSeq_TypeDef seq;
-    I2C_TransferReturn_TypeDef ret;
-
-    seq.addr = addr << 1;
-    seq.flags = I2C_FLAG_READ;
-
-    seq.buf[0].data = data;
-    seq.buf[0].len = len;
-
-    ret = I2CSPM_Transfer(self->i2cspm, &seq);
-    if (ret != i2cTransferDone) {
-        return MP_EIO;
-    }
+    // FIXME: Implement
     return 0;
 }
 
@@ -190,21 +108,7 @@ uint8_t common_hal_busio_i2c_write_read(busio_i2c_obj_t *self, uint16_t addr,
     uint8_t *out_data, size_t out_len,
     uint8_t *in_data, size_t in_len) {
 
-    I2C_TransferSeq_TypeDef seq;
-    I2C_TransferReturn_TypeDef ret;
-
-    seq.addr = addr << 1;
-    seq.flags = I2C_FLAG_WRITE_READ;
-    // Select command to issue
-    seq.buf[0].data = out_data;
-    seq.buf[0].len = out_len;
-    // Select location/length of data to be read
-    seq.buf[1].data = in_data;
-    seq.buf[1].len = in_len;
-
-    ret = I2CSPM_Transfer(self->i2cspm, &seq);
-    if (ret != i2cTransferDone) {
-        return MP_EIO;
-    }
+    // FIXME: Implement
+
     return 0;
 }

ports/analog/common-hal/busio/SPI.c

@@ -34,17 +34,9 @@
 // Note that any bugs introduced in this file can cause crashes
 // at startupfor chips using external SPI flash.
 
-static SPIDRV_HandleData_t spidrv_eusart_handle;
-static SPIDRV_Init_t spidrv_eusart_init = SPIDRV_MASTER_EUSART1;
-static bool in_used = false;
-static bool never_reset = false;
-
 // Reset SPI when reload
 void spi_reset(void) {
-    if (!never_reset && in_used) {
-        SPIDRV_DeInit(&spidrv_eusart_handle);
-        in_used = false;
-    }
+    // FIXME: Implement
     return;
 }
 
@@ -54,64 +46,14 @@ void common_hal_busio_spi_construct(busio_spi_obj_t *self,
     const mcu_pin_obj_t *mosi,
     const mcu_pin_obj_t *miso,
     bool half_duplex) {
-    Ecode_t sc = ECODE_OK;
-
-    if (half_duplex) {
-        mp_raise_NotImplementedError(
-            MP_ERROR_TEXT("Half duplex SPI is not implemented"));
-    }
-
-    if ((sck != NULL) && (mosi != NULL) && (miso != NULL)) {
-        if (sck->function_list[FN_EUSART1_SCLK] == 1
-            && miso->function_list[FN_EUSART1_RX] == 1
-            && mosi->function_list[FN_EUSART1_TX] == 1) {
-
-            self->sck = sck;
-            self->mosi = mosi;
-            self->miso = miso;
-            self->handle = &spidrv_eusart_handle;
-            self->polarity = 0;
-            self->phase = 0;
-            self->bits = 8;
-
-            spidrv_eusart_init.portTx = mosi->port;
-            spidrv_eusart_init.portRx = miso->port;
-            spidrv_eusart_init.portClk = sck->port;
-            spidrv_eusart_init.pinTx = mosi->number;
-            spidrv_eusart_init.pinRx = miso->number;
-            spidrv_eusart_init.pinClk = sck->number;
-            spidrv_eusart_init.bitRate = 1000000;
-            spidrv_eusart_init.frameLength = 8;
-            spidrv_eusart_init.dummyTxValue = 0;
-            spidrv_eusart_init.type = spidrvMaster;
-            spidrv_eusart_init.bitOrder = spidrvBitOrderMsbFirst;
-            spidrv_eusart_init.clockMode = spidrvClockMode0;
-            spidrv_eusart_init.csControl = spidrvCsControlApplication;
-            spidrv_eusart_init.slaveStartMode = spidrvSlaveStartImmediate;
-
-            sc = SPIDRV_Init(self->handle, &spidrv_eusart_init);
-            if (sc != ECODE_EMDRV_SPIDRV_OK) {
-                mp_raise_ValueError(MP_ERROR_TEXT("SPI init error"));
-            }
-        } else {
-            mp_raise_ValueError(MP_ERROR_TEXT("Hardware in use, try alternative pins"));
-        }
-    } else {
-        raise_ValueError_invalid_pins();
-    }
-
-    in_used = true;
-    common_hal_mcu_pin_claim(sck);
-    common_hal_mcu_pin_claim(mosi);
-    common_hal_mcu_pin_claim(miso);
+
+
+    // FIXME: Implement
 }
 
 // Never reset SPI when reload
 void common_hal_busio_spi_never_reset(busio_spi_obj_t *self) {
-    never_reset = true;
-    common_hal_never_reset_pin(self->mosi);
-    common_hal_never_reset_pin(self->miso);
-    common_hal_never_reset_pin(self->sck);
+    // FIXME: Implement
 }
 
 // Check SPI status, deinited or not
@@ -122,23 +64,7 @@ bool common_hal_busio_spi_deinited(busio_spi_obj_t *self) {
 // Deinit SPI obj
 void common_hal_busio_spi_deinit(busio_spi_obj_t *self) {
 
-    if (common_hal_busio_spi_deinited(self)) {
-        return;
-    }
-
-    Ecode_t sc = SPIDRV_DeInit(self->handle);
-    if (sc != ECODE_EMDRV_SPIDRV_OK) {
-        mp_raise_RuntimeError(MP_ERROR_TEXT("SPI re-init"));
-    }
-
-    in_used = false;
-    self->sck = NULL;
-    self->mosi = NULL;
-    self->miso = NULL;
-    self->handle = NULL;
-    common_hal_reset_pin(self->mosi);
-    common_hal_reset_pin(self->miso);
-    common_hal_reset_pin(self->sck);
+    // FIXME: Implement
 }
 
 // Configures the SPI bus. The SPI object must be locked.
@@ -147,55 +73,15 @@ bool common_hal_busio_spi_configure(busio_spi_obj_t *self,
     uint8_t polarity,
     uint8_t phase,
     uint8_t bits) {
-    Ecode_t sc;
-    // This resets the SPI, so check before updating it redundantly
-    if (baudrate == self->baudrate && polarity == self->polarity
-        && phase == self->phase && bits == self->bits) {
-        return true;
-    }
-
-    sc = SPIDRV_DeInit(self->handle);
-    if (sc != ECODE_EMDRV_SPIDRV_OK) {
-        mp_raise_RuntimeError(MP_ERROR_TEXT("SPI re-init"));
-    }
-    in_used = false;
-    self->baudrate = baudrate;
-    self->phase = phase;
-    self->bits = bits;
-    self->polarity = polarity;
-
-    spidrv_eusart_init.bitRate = baudrate;
-    spidrv_eusart_init.frameLength = 8;
-    if (polarity == 0 && phase == 0) {
-        spidrv_eusart_init.clockMode = spidrvClockMode0;
-    } else if (polarity == 0 && phase == 1) {
-        spidrv_eusart_init.clockMode = spidrvClockMode1;
-    } else if (polarity == 1 && phase == 0) {
-        spidrv_eusart_init.clockMode = spidrvClockMode2;
-    } else if (polarity == 1 && phase == 1) {
-        spidrv_eusart_init.clockMode = spidrvClockMode3;
-    }
-
-    sc = SPIDRV_Init(self->handle, &spidrv_eusart_init);
-    if (sc != ECODE_EMDRV_SPIDRV_OK) {
-        mp_raise_RuntimeError(MP_ERROR_TEXT("SPI re-init"));
-    }
-    in_used = true;
+
+    // FIXME: Implement
     return true;
 }
 
 // Lock SPI bus
 bool common_hal_busio_spi_try_lock(busio_spi_obj_t *self) {
-    if (common_hal_busio_spi_deinited(self)) {
-        return false;
-    }
-    bool grabbed_lock = false;
-    if (!self->has_lock) {
-        grabbed_lock = true;
-        self->has_lock = true;
-    }
-
-    return grabbed_lock;
+    // FIXME: Implement
+    return false;
 }
 
 // Check SPI lock status
@@ -213,18 +99,17 @@ bool common_hal_busio_spi_write(busio_spi_obj_t *self,
     const uint8_t *data,
     size_t len) {
 
-    Ecode_t result = SPIDRV_MTransmitB(self->handle, data, len);
-    return result == ECODE_EMDRV_SPIDRV_OK;
+    // FIXME: Implement
+    return false;
 }
 
 // Read data into buffer
 bool common_hal_busio_spi_read(busio_spi_obj_t *self,
     uint8_t *data, size_t len,
     uint8_t write_value) {
 
-    self->handle->initData.dummyTxValue = write_value;
-    Ecode_t result = SPIDRV_MReceiveB(self->handle, data, len);
-    return result == ECODE_EMDRV_SPIDRV_OK;
+    // FIXME: Implement
+    return false;
 }
 
 // Write out the data in data_out
@@ -234,8 +119,8 @@ bool common_hal_busio_spi_transfer(busio_spi_obj_t *self,
     uint8_t *data_in,
     size_t len) {
 
-    Ecode_t result = SPIDRV_MTransferB(self->handle, data_out, data_in, len);
-    return result == ECODE_EMDRV_SPIDRV_OK;
+    // FIXME: Implement
+    return false;
 }
 
 // Get SPI baudrate