add circuitpython code

1 files changed, 309 insertions, 0 deletions

diff --git a/circuitpython/shared-module/bitbangio/SPI.c b/circuitpython/shared-module/bitbangio/SPI.c
new file mode 100644
index 0000000..6551196
--- /dev/null
+++ b/circuitpython/shared-module/bitbangio/SPI.c
@@ -0,0 +1,309 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George
+ *
+ * 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 "py/mpconfig.h"
+#include "py/obj.h"
+#include "py/runtime.h"
+
+#include "common-hal/microcontroller/Pin.h"
+#include "shared-bindings/bitbangio/SPI.h"
+#include "shared-bindings/digitalio/DigitalInOut.h"
+#include "shared-bindings/microcontroller/__init__.h"
+#include "supervisor/shared/translate.h"
+
+#define MAX_BAUDRATE (common_hal_mcu_get_clock_frequency() / 48)
+
+void shared_module_bitbangio_spi_construct(bitbangio_spi_obj_t *self,
+    const mcu_pin_obj_t *clock, const mcu_pin_obj_t *mosi,
+    const mcu_pin_obj_t *miso) {
+    digitalinout_result_t result = common_hal_digitalio_digitalinout_construct(&self->clock, clock);
+    if (result != DIGITALINOUT_OK) {
+        mp_raise_ValueError(translate("Clock pin init failed."));
+    }
+    common_hal_digitalio_digitalinout_switch_to_output(&self->clock, self->polarity == 1, DRIVE_MODE_PUSH_PULL);
+
+    if (mosi != NULL) {
+        result = common_hal_digitalio_digitalinout_construct(&self->mosi, mosi);
+        if (result != DIGITALINOUT_OK) {
+            common_hal_digitalio_digitalinout_deinit(&self->clock);
+            mp_raise_ValueError(translate("MOSI pin init failed."));
+        }
+        self->has_mosi = true;
+        common_hal_digitalio_digitalinout_switch_to_output(&self->mosi, false, DRIVE_MODE_PUSH_PULL);
+    }
+
+    if (miso != NULL) {
+        // Starts out as input by default, no need to change.
+        result = common_hal_digitalio_digitalinout_construct(&self->miso, miso);
+        if (result != DIGITALINOUT_OK) {
+            common_hal_digitalio_digitalinout_deinit(&self->clock);
+            if (mosi != NULL) {
+                common_hal_digitalio_digitalinout_deinit(&self->mosi);
+            }
+            mp_raise_ValueError(translate("MISO pin init failed."));
+        }
+        self->has_miso = true;
+    }
+    self->delay_half = 5;
+    self->polarity = 0;
+    self->phase = 0;
+}
+
+bool shared_module_bitbangio_spi_deinited(bitbangio_spi_obj_t *self) {
+    return common_hal_digitalio_digitalinout_deinited(&self->clock);
+}
+
+void shared_module_bitbangio_spi_deinit(bitbangio_spi_obj_t *self) {
+    if (shared_module_bitbangio_spi_deinited(self)) {
+        return;
+    }
+    common_hal_digitalio_digitalinout_deinit(&self->clock);
+    if (self->has_mosi) {
+        common_hal_digitalio_digitalinout_deinit(&self->mosi);
+    }
+    if (self->has_miso) {
+        common_hal_digitalio_digitalinout_deinit(&self->miso);
+    }
+}
+
+void shared_module_bitbangio_spi_configure(bitbangio_spi_obj_t *self,
+    uint32_t baudrate, uint8_t polarity, uint8_t phase, uint8_t bits) {
+    self->delay_half = 500000 / baudrate;
+    // round delay_half up so that: actual_baudrate <= requested_baudrate
+    if (500000 % baudrate != 0) {
+        self->delay_half += 1;
+    }
+
+    self->polarity = polarity;
+    self->phase = phase;
+}
+
+bool shared_module_bitbangio_spi_try_lock(bitbangio_spi_obj_t *self) {
+    bool success = false;
+    common_hal_mcu_disable_interrupts();
+    if (!self->locked) {
+        self->locked = true;
+        success = true;
+    }
+    common_hal_mcu_enable_interrupts();
+    return success;
+}
+
+bool shared_module_bitbangio_spi_has_lock(bitbangio_spi_obj_t *self) {
+    return self->locked;
+}
+
+void shared_module_bitbangio_spi_unlock(bitbangio_spi_obj_t *self) {
+    self->locked = false;
+}
+
+// Writes out the given data.
+bool shared_module_bitbangio_spi_write(bitbangio_spi_obj_t *self, const uint8_t *data, size_t len) {
+    if (len > 0 && !self->has_mosi) {
+        mp_raise_ValueError(translate("Cannot write without MOSI pin."));
+    }
+    uint32_t delay_half = self->delay_half;
+
+    // only MSB transfer is implemented
+
+    // If a port defines MICROPY_PY_MACHINE_SPI_MIN_DELAY, and the configured
+    // delay_half is equal to this value, then the software SPI implementation
+    // will run as fast as possible, limited only by CPU speed and GPIO time.
+    #ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
+    if (delay_half <= MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
+        for (size_t i = 0; i < len; ++i) {
+            uint8_t data_out = data[i];
+            for (int j = 0; j < 8; ++j, data_out <<= 1) {
+                common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+            }
+            if (dest != NULL) {
+                dest[i] = data_in;
+            }
+        }
+        return true;
+    }
+    #endif
+
+    for (size_t i = 0; i < len; ++i) {
+        uint8_t data_out = data[i];
+        for (int j = 0; j < 8; ++j, data_out <<= 1) {
+            common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
+            if (self->phase == 0) {
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+            } else {
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+            }
+        }
+
+        // Some ports need a regular callback, but probably we don't need
+        // to do this every byte, or even at all.
+        #ifdef MICROPY_EVENT_POLL_HOOK
+        MICROPY_EVENT_POLL_HOOK;
+        #endif
+    }
+    return true;
+}
+
+// Reads in len bytes while outputting zeroes.
+bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data, size_t len, uint8_t write_data) {
+    if (len > 0 && !self->has_miso) {
+        mp_raise_ValueError(translate("Cannot read without MISO pin."));
+    }
+
+    uint32_t delay_half = self->delay_half;
+
+    // only MSB transfer is implemented
+
+    // If a port defines MICROPY_PY_MACHINE_SPI_MIN_DELAY, and the configured
+    // delay_half is equal to this value, then the software SPI implementation
+    // will run as fast as possible, limited only by CPU speed and GPIO time.
+    #ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
+    if (delay_half <= MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
+        // Clock out zeroes while we read.
+        if (self->has_mosi) {
+            common_hal_digitalio_digitalinout_set_value(&self->mosi, false);
+        }
+        for (size_t i = 0; i < len; ++i) {
+            uint8_t data_in = 0;
+            for (int j = 0; j < 8; ++j, data_out <<= 1) {
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+            }
+            data[i] = data_in;
+        }
+        return true;
+    }
+    #endif
+    if (self->has_mosi) {
+        common_hal_digitalio_digitalinout_set_value(&self->mosi, false);
+    }
+    for (size_t i = 0; i < len; ++i) {
+        uint8_t data_out = write_data;
+        uint8_t data_in = 0;
+        for (int j = 0; j < 8; ++j, data_out <<= 1) {
+            if (self->has_mosi) {
+                common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
+            }
+            if (self->phase == 0) {
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+            } else {
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+            }
+            data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
+            if (self->phase == 0) {
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+            } else {
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+            }
+        }
+        data[i] = data_in;
+
+        // Some ports need a regular callback, but probably we don't need
+        // to do this every byte, or even at all.
+        #ifdef MICROPY_EVENT_POLL_HOOK
+        MICROPY_EVENT_POLL_HOOK;
+        #endif
+    }
+    return true;
+}
+
+// transfer
+bool shared_module_bitbangio_spi_transfer(bitbangio_spi_obj_t *self, const uint8_t *dout, uint8_t *din, size_t len) {
+    if (len > 0 && (!self->has_mosi || !self->has_miso)) {
+        mp_raise_ValueError(translate("Cannot transfer without MOSI and MISO pins."));
+    }
+    uint32_t delay_half = self->delay_half;
+
+    // only MSB transfer is implemented
+
+    // If a port defines MICROPY_PY_MACHINE_SPI_MIN_DELAY, and the configured
+    // delay_half is equal to this value, then the software SPI implementation
+    // will run as fast as possible, limited only by CPU speed and GPIO time.
+    #ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
+    if (delay_half <= MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
+        for (size_t i = 0; i < len; ++i) {
+            uint8_t data_out = dout[i];
+            uint8_t data_in = 0;
+            for (int j = 0; j < 8; ++j, data_out <<= 1) {
+                common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+            }
+            din[i] = data_in;
+
+            if (dest != NULL) {
+                dest[i] = data_in;
+            }
+        }
+        return true;
+    }
+    #endif
+
+    for (size_t i = 0; i < len; ++i) {
+        uint8_t data_out = dout[i];
+        uint8_t data_in = 0;
+        for (int j = 0; j < 8; ++j, data_out <<= 1) {
+            common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
+            if (self->phase == 0) {
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+            } else {
+                common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+            }
+            data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
+            if (self->phase == 0) {
+                common_hal_mcu_delay_us(delay_half);
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+            } else {
+                common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
+                common_hal_mcu_delay_us(delay_half);
+            }
+        }
+        din[i] = data_in;
+
+        // Some ports need a regular callback, but probably we don't need
+        // to do this every byte, or even at all.
+        #ifdef MICROPY_EVENT_POLL_HOOK
+        MICROPY_EVENT_POLL_HOOK;
+        #endif
+    }
+    return true;
+}