Merge pull request #1 from plb500/raspberry_pico

Sample implementation for Raspberry Pico

sample-implementations/Raspberry_Pico/sensirion_i2c_hal.c

@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2018, Sensirion AG
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * * Neither the name of Sensirion AG nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "sensirion_i2c_hal.h"
+#include "sensirion_common.h"
+#include "sensirion_config.h"
+
+// Raspberry Pico includes
+#include "hardware/gpio.h"
+#include "hardware/i2c.h"
+
+/*
+ * INSTRUCTIONS
+ * ============
+ *
+ * Implement all functions where they are marked as IMPLEMENT.
+ * Follow the function specification in the comments.
+ */
+
+/*
+ * I2C parameters which will be used in the sensirion functions
+ *
+ * Values MUST be populated prior to using below functions
+ * e.g. by declaring them extern and setting them:
+ *
+ * extern i2c_inst_t *sensirion_i2c_inst;
+ * extern int sensirion_i2c_baud;
+ * extern int sensirion_sda_pin;
+ * extern int sensirion_scl_pin;
+ *
+ * void main() {
+ *     sensirion_i2c_inst = i2c1;
+ *     sensirion_i2c_baud = 100 * 1000;
+ *     sensirion_sda_pin = 2;
+ *     sensirion_scl_pin = 3;
+ * }
+ *
+ */
+i2c_inst_t* sensirion_i2c_inst = NULL;
+int sensirion_i2c_baud = 100 * 1000;
+int sensirion_sda_pin = -1;
+int sensirion_scl_pin = -1;
+
+#define SENSIRION_I2C_PARAMS_VALID                                \
+    ((sensirion_i2c_inst != NULL) && (sensirion_sda_pin != -1) && \
+     (sensirion_scl_pin != -1))
+
+/**
+ * Select the current i2c bus by index.
+ * All following i2c operations will be directed at that bus.
+ *
+ * THE IMPLEMENTATION IS OPTIONAL ON SINGLE-BUS SETUPS (all sensors on the same
+ * bus)
+ *
+ * @param bus_idx   Bus index to select
+ * @returns         0 on success, an error code otherwise
+ */
+int16_t sensirion_i2c_hal_select_bus(uint8_t bus_idx) {
+    /* TODO:IMPLEMENT or leave empty if all sensors are located on one single
+     * bus
+     */
+    return NOT_IMPLEMENTED_ERROR;
+}
+
+/**
+ * Initialize all hard- and software components that are needed for the I2C
+ * communication.
+ */
+void sensirion_i2c_hal_init(void) {
+    if (!SENSIRION_I2C_PARAMS_VALID) {
+        return;
+    }
+
+    i2c_init(sensirion_i2c_inst, sensirion_i2c_baud);
+    gpio_set_function(sensirion_sda_pin, GPIO_FUNC_I2C);
+    gpio_set_function(sensirion_scl_pin, GPIO_FUNC_I2C);
+
+    gpio_pull_up(sensirion_sda_pin);
+    gpio_pull_up(sensirion_scl_pin);
+}
+
+/**
+ * Release all resources initialized by sensirion_i2c_hal_init().
+ */
+void sensirion_i2c_hal_free(void) {
+    i2c_deinit(sensirion_i2c_inst);
+}
+
+/**
+ * Execute one read transaction on the I2C bus, reading a given number of bytes.
+ * If the device does not acknowledge the read command, an error shall be
+ * returned.
+ *
+ * @param address 7-bit I2C address to read from
+ * @param data    pointer to the buffer where the data is to be stored
+ * @param count   number of bytes to read from I2C and store in the buffer
+ * @returns 0 on success, error code otherwise
+ */
+int8_t sensirion_i2c_hal_read(uint8_t address, uint8_t* data, uint16_t count) {
+    if (!SENSIRION_I2C_PARAMS_VALID) {
+        return NOT_IMPLEMENTED_ERROR;
+    }
+
+    if (count) {
+        int r =
+            i2c_read_blocking(sensirion_i2c_inst, address, data, count, false);
+        return (r > 0) ? !(r == count) : r;
+    }
+    return 0;
+}
+
+/**
+ * Execute one write transaction on the I2C bus, sending a given number of
+ * bytes. The bytes in the supplied buffer must be sent to the given address. If
+ * the slave device does not acknowledge any of the bytes, an error shall be
+ * returned.
+ *
+ * @param address 7-bit I2C address to write to
+ * @param data    pointer to the buffer containing the data to write
+ * @param count   number of bytes to read from the buffer and send over I2C
+ * @returns 0 on success, error code otherwise
+ */
+int8_t sensirion_i2c_hal_write(uint8_t address, const uint8_t* data,
+                               uint16_t count) {
+    if (!SENSIRION_I2C_PARAMS_VALID) {
+        return NOT_IMPLEMENTED_ERROR;
+    }
+
+    int r = i2c_write_blocking(sensirion_i2c_inst, address, data, count, false);
+    return (r >= 0) ? 0 : r;
+}
+
+/**
+ * Sleep for a given number of microseconds. The function should delay the
+ * execution for at least the given time, but may also sleep longer.
+ *
+ * Despite the unit, a <10 millisecond precision is sufficient.
+ *
+ * @param useconds the sleep time in microseconds
+ */
+void sensirion_i2c_hal_sleep_usec(uint32_t useconds) {
+    sleep_us(useconds);
+}