Diff: ad7124.cpp

Revision:

1:22ed45e195a9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ad7124.cpp	Thu Sep 05 20:45:41 2019 +0000
@@ -0,0 +1,524 @@
+/***************************************************************************//**
+*   @file    AD7124.c
+*   @brief   AD7124 implementation file.
+*   @devices AD7124-4, AD7124-8
+*
+********************************************************************************
+* Copyright 2015(c) Analog Devices, Inc.
+*
+* 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 Analog Devices, Inc. nor the names of its
+*    contributors may be used to endorse or promote products derived
+*    from this software without specific prior written permission.
+*  - The use of this software may or may not infringe the patent rights
+*    of one or more patent holders.  This license does not release you
+*    from the requirement that you obtain separate licenses from these
+*    patent holders to use this software.
+*  - Use of the software either in source or binary form, must be run
+*    on or directly connected to an Analog Devices Inc. component.
+*
+* THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED
+* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY
+* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+* IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+* INTELLECTUAL PROPERTY RIGHTS, 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 Files **********************************/
+/******************************************************************************/
+#include <stdlib.h>
+#include "ad7124.h"
+
+/* Error codes */
+#define INVALID_VAL -1 /* Invalid argument */
+#define COMM_ERR    -2 /* Communication error on receive */
+#define TIMEOUT     -3 /* A timeout has occured */
+
+/***************************************************************************//**
+ * @brief Reads the value of the specified register without checking if the
+ *        device is ready to accept user requests.
+ *
+ * @param dev   - The handler of the instance of the driver.
+ * @param p_reg - Pointer to the register structure holding info about the
+ *               register to be read. The read value is stored inside the
+ *               register structure.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_no_check_read_register(struct ad7124_dev *dev,
+                      struct ad7124_st_reg* p_reg)
+{
+    int32_t ret = 0;
+    uint8_t buffer[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    uint8_t i = 0;
+    uint8_t check8 = 0;
+    uint8_t msg_buf[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+    if(!dev || !p_reg)
+        return INVALID_VAL;
+
+    /* Build the Command word */
+    buffer[0] = AD7124_COMM_REG_WEN | AD7124_COMM_REG_RD |
+            AD7124_COMM_REG_RA(p_reg->addr);
+
+    /* Read data from the device */
+    ret = spi_write_and_read(dev->spi_desc,
+                 buffer,
+                 ((dev->use_crc != AD7124_DISABLE_CRC) ? p_reg->size + 1
+                  : p_reg->size) + 1);
+    if(ret < 0)
+        return ret;
+
+    /* Check the CRC */
+    if(dev->use_crc == AD7124_USE_CRC) {
+        msg_buf[0] = AD7124_COMM_REG_WEN | AD7124_COMM_REG_RD |
+                 AD7124_COMM_REG_RA(p_reg->addr);
+        for(i = 1; i < p_reg->size + 2; ++i) {
+            msg_buf[i] = buffer[i];
+        }
+        check8 = ad7124_compute_crc8(msg_buf, p_reg->size + 2);
+    }
+
+    if(check8 != 0) {
+        /* ReadRegister checksum failed. */
+        return COMM_ERR;
+    }
+
+    /* Build the result */
+    p_reg->value = 0;
+    for(i = 1; i < p_reg->size + 1; i++) {
+        p_reg->value <<= 8;
+        p_reg->value += buffer[i];
+    }
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Writes the value of the specified register without checking if the
+ *        device is ready to accept user requests.
+ *
+ * @param dev - The handler of the instance of the driver.
+ * @param reg - Register structure holding info about the register to be written
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_no_check_write_register(struct ad7124_dev *dev,
+                       struct ad7124_st_reg reg)
+{
+    int32_t ret = 0;
+    int32_t reg_value = 0;
+    uint8_t wr_buf[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    uint8_t i = 0;
+    uint8_t crc8 = 0;
+
+    if(!dev)
+        return INVALID_VAL;
+
+    /* Build the Command word */
+    wr_buf[0] = AD7124_COMM_REG_WEN | AD7124_COMM_REG_WR |
+            AD7124_COMM_REG_RA(reg.addr);
+
+    /* Fill the write buffer */
+    reg_value = reg.value;
+    for(i = 0; i < reg.size; i++) {
+        wr_buf[reg.size - i] = reg_value & 0xFF;
+        reg_value >>= 8;
+    }
+
+    /* Compute the CRC */
+    if(dev->use_crc != AD7124_DISABLE_CRC) {
+        crc8 = ad7124_compute_crc8(wr_buf, reg.size + 1);
+        wr_buf[reg.size + 1] = crc8;
+    }
+
+    /* Write data to the device */
+    ret = spi_write_and_read(dev->spi_desc,
+                 wr_buf,
+                 (dev->use_crc != AD7124_DISABLE_CRC) ? reg.size + 2
+                 : reg.size + 1);
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Reads the value of the specified register only when the device is ready
+ *        to accept user requests. If the device ready flag is deactivated the
+ *        read operation will be executed without checking the device state.
+ *
+ * @param dev   - The handler of the instance of the driver.
+ * @param p_reg - Pointer to the register structure holding info about the
+ *               register to be read. The read value is stored inside the
+ *               register structure.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_read_register(struct ad7124_dev *dev,
+                 struct ad7124_st_reg* p_reg)
+{
+    int32_t ret;
+
+    if (p_reg->addr != AD7124_ERR_REG && dev->check_ready) {
+        ret = ad7124_wait_for_spi_ready(dev,
+                        dev->spi_rdy_poll_cnt);
+        if (ret < 0)
+            return ret;
+    }
+    ret = ad7124_no_check_read_register(dev,
+                        p_reg);
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Writes the value of the specified register only when the device is
+ *        ready to accept user requests. If the device ready flag is deactivated
+ *        the write operation will be executed without checking the device state.
+ *
+ * @param dev - The handler of the instance of the driver.
+ * @param reg - Register structure holding info about the register to be written
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_write_register(struct ad7124_dev *dev,
+                  struct ad7124_st_reg p_reg)
+{
+    int32_t ret;
+
+    if (dev->check_ready) {
+        ret = ad7124_wait_for_spi_ready(dev,
+                        dev->spi_rdy_poll_cnt);
+        if (ret < 0)
+            return ret;
+    }
+    ret = ad7124_no_check_write_register(dev,
+                         p_reg);
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Resets the device.
+ *
+ * @param dev - The handler of the instance of the driver.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_reset(struct ad7124_dev *dev)
+{
+    int32_t ret = 0;
+    uint8_t wr_buf[8] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+
+    if(!dev)
+        return INVALID_VAL;
+
+    ret = spi_write_and_read(dev->spi_desc,
+                 wr_buf,
+                 8);
+
+    /* Wait for the reset to complete */
+    ret = ad7124_wait_to_power_on(dev,
+                      dev->spi_rdy_poll_cnt);
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Waits until the device can accept read and write user actions.
+ *
+ * @param dev     - The handler of the instance of the driver.
+ * @param timeout - Count representing the number of polls to be done until the
+ *                  function returns.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_wait_for_spi_ready(struct ad7124_dev *dev,
+                  uint32_t timeout)
+{
+    struct ad7124_st_reg *regs;
+    int32_t ret;
+    int8_t ready = 0;
+
+    if(!dev)
+        return INVALID_VAL;
+
+    regs = dev->regs;
+
+    while(!ready && --timeout) {
+        /* Read the value of the Error Register */
+        ret = ad7124_read_register(dev, &regs[AD7124_Error]);
+        if(ret < 0)
+            return ret;
+
+        /* Check the SPI IGNORE Error bit in the Error Register */
+        ready = (regs[AD7124_Error].value &
+             AD7124_ERR_REG_SPI_IGNORE_ERR) == 0;
+    }
+
+    return timeout ? 0 : TIMEOUT;
+}
+
+/***************************************************************************//**
+ * @brief Waits until the device finishes the power-on reset operation.
+ *
+ * @param dev     - The handler of the instance of the driver.
+ * @param timeout - Count representing the number of polls to be done until the
+ *                  function returns.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_wait_to_power_on(struct ad7124_dev *dev,
+                uint32_t timeout)
+{
+    struct ad7124_st_reg *regs;
+    int32_t ret;
+    int8_t powered_on = 0;
+
+    if(!dev)
+        return INVALID_VAL;
+
+    regs = dev->regs;
+
+    while(!powered_on && timeout--) {
+        ret = ad7124_read_register(dev,
+                       &regs[AD7124_Status]);
+        if(ret < 0)
+            return ret;
+
+        /* Check the POR_FLAG bit in the Status Register */
+        powered_on = (regs[AD7124_Status].value &
+                  AD7124_STATUS_REG_POR_FLAG) == 0;
+    }
+
+    return (timeout || powered_on) ? 0 : TIMEOUT;
+}
+
+/***************************************************************************//**
+ * @brief Waits until a new conversion result is available.
+ *
+ * @param dev     - The handler of the instance of the driver.
+ * @param timeout - Count representing the number of polls to be done until the
+ *                  function returns if no new data is available.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_wait_for_conv_ready(struct ad7124_dev *dev,
+                   uint32_t timeout)
+{
+    struct ad7124_st_reg *regs;
+    int32_t ret;
+    int8_t ready = 0;
+
+    if(!dev)
+        return INVALID_VAL;
+
+    regs = dev->regs;
+
+    while(!ready && --timeout) {
+        /* Read the value of the Status Register */
+        ret = ad7124_read_register(dev, &regs[AD7124_Status]);
+        if(ret < 0)
+            return ret;
+
+        /* Check the RDY bit in the Status Register */
+        ready = (regs[AD7124_Status].value &
+             AD7124_STATUS_REG_RDY) == 0;
+    }
+
+    return timeout ? 0 : TIMEOUT;
+}
+
+/***************************************************************************//**
+ * @brief Reads the conversion result from the device.
+ *
+ * @param dev     - The handler of the instance of the driver.
+ * @param p_data  - Pointer to store the read data.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_read_data(struct ad7124_dev *dev,
+             int32_t* p_data)
+{
+    struct ad7124_st_reg *regs;
+    int32_t ret;
+
+    if(!dev)
+        return INVALID_VAL;
+
+    regs = dev->regs;
+
+    /* Read the value of the Status Register */
+    ret = ad7124_read_register(dev, &regs[AD7124_Data]);
+
+    /* Get the read result */
+    *p_data = regs[AD7124_Data].value;
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Computes the CRC checksum for a data buffer.
+ *
+ * @param p_buf    - Data buffer
+ * @param buf_size - Data buffer size in bytes
+ *
+ * @return Returns the computed CRC checksum.
+*******************************************************************************/
+uint8_t ad7124_compute_crc8(uint8_t * p_buf, uint8_t buf_size)
+{
+    uint8_t i = 0;
+    uint8_t crc = 0;
+
+    while(buf_size) {
+        for(i = 0x80; i != 0; i >>= 1) {
+            bool cmp1 = (crc & 0x80) != 0;
+            bool cmp2 = (*p_buf & i) != 0;
+            if(cmp1 != cmp2) { /* MSB of CRC register XOR input Bit from Data */
+                crc <<= 1;
+                crc ^= AD7124_CRC8_POLYNOMIAL_REPRESENTATION;
+            } else {
+                crc <<= 1;
+            }
+        }
+        p_buf++;
+        buf_size--;
+    }
+    return crc;
+}
+
+/***************************************************************************//**
+ * @brief Updates the CRC settings.
+ *
+ * @param dev - The handler of the instance of the driver.
+ *
+ * @return None.
+*******************************************************************************/
+void ad7124_update_crcsetting(struct ad7124_dev *dev)
+{
+    struct ad7124_st_reg *regs;
+
+    if(!dev)
+        return;
+
+    regs = dev->regs;
+
+    /* Get CRC State. */
+    if (regs[AD7124_Error_En].value & AD7124_ERREN_REG_SPI_CRC_ERR_EN) {
+        dev->use_crc = AD7124_USE_CRC;
+    } else {
+        dev->use_crc = AD7124_DISABLE_CRC;
+    }
+}
+
+/***************************************************************************//**
+ * @brief Updates the device SPI interface settings.
+ *
+ * @param dev - The handler of the instance of the driver.
+ *
+ * @return None.
+*******************************************************************************/
+void ad7124_update_dev_spi_settings(struct ad7124_dev *dev)
+{
+    struct ad7124_st_reg *regs;
+
+    if(!dev)
+        return;
+
+    regs = dev->regs;
+
+    if (regs[AD7124_Error_En].value & AD7124_ERREN_REG_SPI_IGNORE_ERR_EN) {
+        dev->check_ready = 1;
+    } else {
+        dev->check_ready = 0;
+    }
+}
+
+/***************************************************************************//**
+ * @brief Initializes the AD7124.
+ *
+ * @param device     - The device structure.
+ * @param init_param - The structure that contains the device initial
+ *             parameters.
+ *
+ * @return Returns 0 for success or negative error code.
+*******************************************************************************/
+int32_t ad7124_setup(struct ad7124_dev **device,
+             struct ad7124_init_param init_param)
+{
+    int32_t ret;
+    int reg_nr;
+    struct ad7124_dev *dev;
+
+    dev = (struct ad7124_dev *)malloc(sizeof(*dev));
+    if (!dev)
+        return INVALID_VAL;
+
+    dev->regs = init_param.regs;
+    dev->spi_rdy_poll_cnt = init_param.spi_rdy_poll_cnt;
+
+    /* Initialize the SPI communication. */
+    ret = spi_init(&dev->spi_desc, &init_param.spi_init);
+    if (ret < 0)
+        return ret;
+
+    /*  Reset the device interface.*/
+    ret = ad7124_reset(dev);
+    if (ret < 0)
+        return ret;
+
+    /* Update the device structure with power-on/reset settings */
+    dev->check_ready = 1;
+
+    /* Initialize registers AD7124_ADC_Control through AD7124_Filter_7. */
+    for(reg_nr = AD7124_Status; (reg_nr < AD7124_Offset_0) && !(ret < 0);
+        reg_nr++) {
+        if (dev->regs[reg_nr].rw == AD7124_RW) {
+            ret = ad7124_write_register(dev, dev->regs[reg_nr]);
+            if (ret < 0)
+                break;
+        }
+
+        /* Get CRC State and device SPI interface settings */
+        if (reg_nr == AD7124_Error_En) {
+            ad7124_update_crcsetting(dev);
+            ad7124_update_dev_spi_settings(dev);
+        }
+    }
+
+    *device = dev;
+
+    return ret;
+}
+
+/***************************************************************************//**
+ * @brief Free the resources allocated by AD7124_Setup().
+ *
+ * @param dev - The device structure.
+ *
+ * @return SUCCESS in case of success, negative error code otherwise.
+*******************************************************************************/
+int32_t ad7124_remove(struct ad7124_dev *dev)
+{
+    int32_t ret;
+
+    ret = spi_remove(dev->spi_desc);
+
+    free(dev);
+
+    return ret;
+}
\ No newline at end of file