Diff: ltc26x6.c

Revision:

1:cab5535713ee

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ltc26x6.c	Mon Dec 06 05:17:03 2021 +0000
@@ -0,0 +1,155 @@
+/***************************************************************************//**
+ *   @file   ltc26x6.c
+ *   @brief  Implementation of LTC2606,LTC2616,LTC2626 Driver.
+********************************************************************************
+ * Copyright 2021(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 <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include "ltc26x6.h"
+
+/**
+ * Initialize the device.
+ * @param device - The device structure.
+ * @param init_param - The structure that contains the device initial
+ *                     parameters.
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int32_t ltc26x6_init(struct ltc26x6_dev **device,
+             struct ltc26x6_init_param init_param)
+{
+    struct ltc26x6_dev *dev;
+    int32_t ret;
+
+    dev = (struct ltc26x6_dev *)malloc(sizeof(*dev));
+    if (!dev)
+        return -1;
+
+    ret = i2c_init(&dev->i2c_desc, &init_param.i2c_init);
+    dev->resolution = init_param.resolution;
+    dev->vref = init_param.vref;
+    dev->typical_offset = init_param.typical_offset;
+    *device = dev;
+    return ret;
+}
+
+/**
+ * Calculates an LTC26X6 DAC code for the desired output voltage.
+ * Based on the desired output voltage, the offset, and lsb parameters, return the corresponding DAC code that should be written to the LTC26X6.
+ * @param dac_voltage       Desired output voltage
+ * @param *code             Returned DAC code
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int16_t ltc26x6_voltage_to_code(struct ltc26x6_dev *device, float dac_voltage,
+                uint16_t *code)
+{
+    uint32_t ltc26x6_full_scale = (2 << device->resolution) - 1;
+    // The LTC26X6 least significant bit value with given voltage reference
+    float   ltc26x6_lsb = (float)(device->vref/ltc26x6_full_scale); 
+    int32_t dac_code, ret;
+    float float_code;
+    
+    // 1) Calculate the DAC code: (DAC voltage/LSB)- typical offset volatge
+    float_code = (dac_voltage / ltc26x6_lsb) - device->typical_offset;
+    // 2) Round
+    float_code = (float_code > (floor(float_code) + 0.5)) ? ceil(float_code) : floor(float_code); 
+    // 3) Convert to unsigned integer      
+    dac_code = (int32_t)(float_code);                                                                   
+
+    if(dac_code >  ltc26x6_full_scale) { 
+        // Requesetd voltage is bigger than reference voltage  
+        // Return fullscale code                                                         
+        dac_code =  ltc26x6_full_scale; 
+        // Return Overflow error                                                                              
+        ret = LTC26X6_CODE_OVERFLOW;
+    } else if(dac_code < 0) {  
+        // Requested voltage is lower than offset voltage                                                                                                      
+        dac_code = 0;     
+        // Return Underflow error                                                                              
+        ret = LTC26X6_CODE_UNDERFLOW;
+    } else // Requestedd volage is in supported range                                                                                               
+        ret = SUCCESS;
+
+    *code = ((uint16_t)(dac_code));
+    return ret;
+}
+
+/**
+ * Write code to LTC26X6
+ * @param dev               The device structure.
+ * @param dac_command       Command for the DAC
+ *                          Accepted values:    write_command
+ *                                              write_update_command
+ *
+ * @param dac_code          16-bit DAC output voltage code
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int32_t ltc26x6_write_code(struct ltc26x6_dev *dev,
+               enum ltc26x6_write_command write_command, uint16_t dac_code)
+{
+    uint8_t data[3];
+
+    data[0] = write_command;      // Write command
+    data[1] = dac_code >>8;       // MSB code
+    data[2] = dac_code & 0x00FF;  // LSB code
+
+    return(i2c_write(dev->i2c_desc, data, 3, 1));
+}
+
+/**
+ * Power down the device
+ * @param device - The device structure.
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int32_t ltc26x6_power_down(struct ltc26x6_dev *dev)
+{
+    uint8_t command = LTC26X6_POWER_DOWN_COMMAND;
+    return (i2c_write(dev->i2c_desc, &command, 1, 1));
+}
+
+/**
+ * Power up the device
+ * @param device - The device structure.
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int32_t ltc26x6_power_up(struct ltc26x6_dev *dev)
+{
+    uint8_t command = LTC26X6_UPDATE_COMMAND;
+    return (i2c_write(dev->i2c_desc, &command, 1, 1));
+}
+