Setup files for busio

Author: Brandon-Hurst

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

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+/*
+ * This file is part of Adafruit for EFR32 project
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright 2023 Silicon Laboratories Inc. www.silabs.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/busio/I2C.h"
+#include "py/mperrno.h"
+#include "py/runtime.h"
+#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
+void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
+    const mcu_pin_obj_t *scl,
+    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
+void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
+    common_hal_never_reset_pin(self->sda);
+    common_hal_never_reset_pin(self->scl);
+}
+
+// Check I2C status, deinited or not
+bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
+    return self->sda == NULL;
+}
+
+// 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);
+}
+
+void common_hal_busio_i2c_mark_deinit(busio_i2c_obj_t *self) {
+    self->sda = NULL;
+}
+
+// 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;
+
+    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;
+    }
+
+    return grabbed_lock;
+}
+
+// Check I2C lock status
+bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
+    return self->has_lock;
+}
+
+// Unlock I2C bus
+void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
+    self->has_lock = false;
+}
+
+// Write data to the device selected by address
+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;
+    }
+    return 0;
+}
+
+// Read into buffer from the device selected by address
+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;
+    }
+    return 0;
+}
+
+// Write the bytes from out_data to the device selected by address,
+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;
+    }
+    return 0;
+}

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

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+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2024 Brandon Hurst, Analog Devices, Inc.
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "common-hal/microcontroller/Pin.h"
+// FIXME: Silabs includes "peripherals/periph.h. Figure out what's in this file. "
+#include "py/obj.h"
+
+// HAL-specific
+#include "i2c.h"
+#include "gpio.h"
+
+// Define a struct for what BUSIO.I2C should carry
+typedef struct {
+    mp_obj_base_t base;
+    mxc_i2c_regs_t* i2c_regs;
+    bool has_lock;
+    const mcu_pin_obj_t *scl;
+    const mcu_pin_obj_t *sda;
+} busio_i2c_obj_t;