Analog Devices / platform_drivers

Platform drivers for Mbed.

Dependents:   EVAL-CN0535-FMCZ EVAL-CN0535-FMCZ EVAL-AD568x-AD569x EVAL-AD7606 ... more

adc_data_capture.c@20:4951ea6abee5, 2021-11-29 (annotated)

Committer:
Kjansen
Date:
Mon Nov 29 12:39:54 2021 +0000
Revision:
20:4951ea6abee5
Parent:
18:5ae03a197e59 
The following changes were made:

1.) Modified udelay() function for generating more accurate smaller usec delays

2.) Implemented the irq_enable and irq_disable functions

3.) Removed the confusion b/w application created peripheral object and interrupt specific object

4.) Created PWM extra init structure and added PWM pin

5.) Added a module for timer and its related header file

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mahphalke 17:af1f2416dd26 1 /***************************************************************************//**
mahphalke 17:af1f2416dd26 2 * @file adc_data_capture.c
mahphalke 17:af1f2416dd26 3 * @brief ADC common data capture interface for IIO based applications
mahphalke 17:af1f2416dd26 4 * @details This module handles the ADC data capturing for IIO client
mahphalke 17:af1f2416dd26 5 ********************************************************************************
mahphalke 17:af1f2416dd26 6 * Copyright (c) 2021 Analog Devices, Inc.
mahphalke 17:af1f2416dd26 7 * All rights reserved.
mahphalke 17:af1f2416dd26 8 *
mahphalke 17:af1f2416dd26 9 * This software is proprietary to Analog Devices, Inc. and its licensors.
mahphalke 17:af1f2416dd26 10 * By using this software you agree to the terms of the associated
mahphalke 17:af1f2416dd26 11 * Analog Devices Software License Agreement.
mahphalke 17:af1f2416dd26 12 *******************************************************************************/
mahphalke 17:af1f2416dd26 13
mahphalke 17:af1f2416dd26 14 /******************************************************************************/
mahphalke 17:af1f2416dd26 15 /***************************** Include Files **********************************/
mahphalke 17:af1f2416dd26 16 /******************************************************************************/
mahphalke 17:af1f2416dd26 17
mahphalke 17:af1f2416dd26 18 #include <stdint.h>
mahphalke 17:af1f2416dd26 19 #include <stdbool.h>
mahphalke 17:af1f2416dd26 20 #include <string.h>
mahphalke 17:af1f2416dd26 21
mahphalke 17:af1f2416dd26 22 #include "adc_data_capture.h"
mahphalke 17:af1f2416dd26 23 #include "error.h"
mahphalke 17:af1f2416dd26 24
mahphalke 17:af1f2416dd26 25 /******************************************************************************/
mahphalke 17:af1f2416dd26 26 /********************** Macros and Constants Definition ***********************/
mahphalke 17:af1f2416dd26 27 /******************************************************************************/
mahphalke 17:af1f2416dd26 28
mahphalke 18:5ae03a197e59 29 /* Max available channels for continuous data capture. Actual number of channels
mahphalke 18:5ae03a197e59 30 * to be captured are supplied from an application */
mahphalke 18:5ae03a197e59 31 #define MAX_AVAILABLE_CHANNELS (16)
mahphalke 17:af1f2416dd26 32
mahphalke 18:5ae03a197e59 33 /* Max size of the acquisition buffer (in terms of bytes) */
mahphalke 18:5ae03a197e59 34 #define DATA_BUFFER_SIZE (32768) // 32Kbytes
mahphalke 17:af1f2416dd26 35
mahphalke 17:af1f2416dd26 36 /* Timeout count to avoid stuck into potential infinite loop while checking
mahphalke 17:af1f2416dd26 37 * for new data into an acquisition buffer. The actual timeout factor is determined
mahphalke 18:5ae03a197e59 38 * through 'sampling_frequency' attribute of IIO app, but this period here makes sure
mahphalke 18:5ae03a197e59 39 * we are not stuck into a forever loop in case data capture is interrupted
mahphalke 18:5ae03a197e59 40 * or failed in between.
mahphalke 18:5ae03a197e59 41 * Note: This timeout factor is dependent upon the MCU clock frequency. Below timeout
mahphalke 18:5ae03a197e59 42 * is tested for SDP-K1 platform @180Mhz default core clock */
mahphalke 17:af1f2416dd26 43 #define BUF_READ_TIMEOUT (100000000)
mahphalke 17:af1f2416dd26 44
mahphalke 17:af1f2416dd26 45 /******************************************************************************/
mahphalke 17:af1f2416dd26 46 /********************** Variables and User Defined Data Types *****************/
mahphalke 17:af1f2416dd26 47 /******************************************************************************/
mahphalke 17:af1f2416dd26 48
mahphalke 18:5ae03a197e59 49 /* Extern declaration for device specific data capture operations structure
mahphalke 18:5ae03a197e59 50 * (actual definition should be present in an application) */
mahphalke 17:af1f2416dd26 51 extern struct data_capture_ops data_capture_ops;
mahphalke 17:af1f2416dd26 52
mahphalke 17:af1f2416dd26 53 /*
mahphalke 17:af1f2416dd26 54 *@enum acq_buffer_state_e
mahphalke 17:af1f2416dd26 55 *@details Enum holding the data acquisition buffer states
mahphalke 17:af1f2416dd26 56 **/
mahphalke 17:af1f2416dd26 57 typedef enum {
mahphalke 17:af1f2416dd26 58 BUF_AVAILABLE,
mahphalke 17:af1f2416dd26 59 BUF_EMPTY,
mahphalke 17:af1f2416dd26 60 BUF_FULL
mahphalke 17:af1f2416dd26 61 } acq_buffer_state_e;
mahphalke 17:af1f2416dd26 62
mahphalke 17:af1f2416dd26 63 /*
mahphalke 17:af1f2416dd26 64 *@struct acq_buf_t
mahphalke 17:af1f2416dd26 65 *@details Structure holding the data acquisition buffer parameters
mahphalke 17:af1f2416dd26 66 **/
mahphalke 17:af1f2416dd26 67 typedef struct {
mahphalke 18:5ae03a197e59 68 acq_buffer_state_e state; // Buffer state
mahphalke 18:5ae03a197e59 69 bool refill_buffer; // Flag to start refilling acquisition buffer
mahphalke 18:5ae03a197e59 70 uint32_t rd_indx; // Buffer read index (incremented per sample transmit)
mahphalke 18:5ae03a197e59 71 uint32_t wr_indx; // Buffer write index (incremented per sample read)
mahphalke 18:5ae03a197e59 72 uint8_t sample_size; // ADC sample/raw data size received from application
mahphalke 18:5ae03a197e59 73 uint8_t chn_indx; // ADC channel index into acquisition buffer
mahphalke 18:5ae03a197e59 74 uint8_t active_chn[MAX_AVAILABLE_CHANNELS]; // Active channel number sequence
mahphalke 18:5ae03a197e59 75 uint8_t data[DATA_BUFFER_SIZE]; // buffer data (adc raw values)
mahphalke 18:5ae03a197e59 76 uint8_t *pdata; // Pointer to data buffer
mahphalke 17:af1f2416dd26 77 } acq_buf_t;
mahphalke 17:af1f2416dd26 78
mahphalke 17:af1f2416dd26 79 /* ADC data acquisition buffers */
mahphalke 17:af1f2416dd26 80 static volatile acq_buf_t acq_buffer;
mahphalke 17:af1f2416dd26 81
mahphalke 17:af1f2416dd26 82 /* Flag to indicate data capture status */
mahphalke 17:af1f2416dd26 83 static volatile bool start_adc_data_capture = false;
mahphalke 17:af1f2416dd26 84
mahphalke 17:af1f2416dd26 85 /* Number of active channels in any data buffer read request */
mahphalke 17:af1f2416dd26 86 static volatile uint8_t num_of_active_channels = 0;
mahphalke 17:af1f2416dd26 87
mahphalke 17:af1f2416dd26 88 /* Count to track number of actual samples requested by IIO client */
mahphalke 17:af1f2416dd26 89 static volatile uint16_t num_of_requested_samples = 0;
mahphalke 17:af1f2416dd26 90
mahphalke 18:5ae03a197e59 91 /* Channel alignment offset */
mahphalke 18:5ae03a197e59 92 static volatile uint8_t chn_alignment_offset = 0;
mahphalke 18:5ae03a197e59 93
mahphalke 17:af1f2416dd26 94 /* Actual or max available size of acquisition buffer */
mahphalke 17:af1f2416dd26 95 static volatile uint16_t max_available_buffer_size = 0;
mahphalke 17:af1f2416dd26 96
mahphalke 17:af1f2416dd26 97 /******************************************************************************/
mahphalke 17:af1f2416dd26 98 /************************ Functions Declarations ******************************/
mahphalke 17:af1f2416dd26 99 /******************************************************************************/
mahphalke 17:af1f2416dd26 100
mahphalke 17:af1f2416dd26 101 /******************************************************************************/
mahphalke 17:af1f2416dd26 102 /************************ Functions Definitions *******************************/
mahphalke 17:af1f2416dd26 103 /******************************************************************************/
mahphalke 17:af1f2416dd26 104
mahphalke 17:af1f2416dd26 105 /*!
mahphalke 18:5ae03a197e59 106 * @brief Function to read the single ADC sample (raw data) for input channel
mahphalke 17:af1f2416dd26 107 * @param input_chn[in] - Input channel to sample and read data for
mahphalke 17:af1f2416dd26 108 * @param raw_data[in, out]- ADC raw data
mahphalke 17:af1f2416dd26 109 * @return SUCCESS in case of success, FAILURE otherwise
mahphalke 17:af1f2416dd26 110 */
mahphalke 18:5ae03a197e59 111 int32_t read_single_sample(uint8_t input_chn, uint32_t *raw_data)
mahphalke 17:af1f2416dd26 112 {
mahphalke 17:af1f2416dd26 113 uint32_t read_adc_data = 0;
mahphalke 17:af1f2416dd26 114 int32_t status = SUCCESS;
mahphalke 17:af1f2416dd26 115
mahphalke 17:af1f2416dd26 116 do {
mahphalke 18:5ae03a197e59 117 /* Perform operations required before single sample conversion read */
mahphalke 18:5ae03a197e59 118 if (data_capture_ops.single_sample_read_start_ops) {
mahphalke 18:5ae03a197e59 119 if (data_capture_ops.single_sample_read_start_ops(input_chn) != SUCCESS) {
mahphalke 17:af1f2416dd26 120 status = FAILURE;
mahphalke 17:af1f2416dd26 121 break;
mahphalke 17:af1f2416dd26 122 }
mahphalke 17:af1f2416dd26 123 }
mahphalke 17:af1f2416dd26 124
mahphalke 18:5ae03a197e59 125 /* Perform ADC conversion and read the converted sample after EOC */
mahphalke 18:5ae03a197e59 126 if (data_capture_ops.perform_conv_and_read_sample(&read_adc_data, input_chn) !=
mahphalke 17:af1f2416dd26 127 SUCCESS) {
mahphalke 17:af1f2416dd26 128 status = FAILURE;
mahphalke 17:af1f2416dd26 129 break;
mahphalke 17:af1f2416dd26 130 }
mahphalke 17:af1f2416dd26 131 } while (0);
mahphalke 17:af1f2416dd26 132
mahphalke 18:5ae03a197e59 133 /* Perform operations required post single sample conversion read */
mahphalke 18:5ae03a197e59 134 if (data_capture_ops.single_sample_read_stop_ops) {
mahphalke 18:5ae03a197e59 135 if (data_capture_ops.single_sample_read_stop_ops(input_chn) != SUCCESS) {
mahphalke 18:5ae03a197e59 136 status = FAILURE;
mahphalke 18:5ae03a197e59 137 }
mahphalke 17:af1f2416dd26 138 }
mahphalke 17:af1f2416dd26 139
mahphalke 17:af1f2416dd26 140 *raw_data = read_adc_data;
mahphalke 17:af1f2416dd26 141 return status;
mahphalke 17:af1f2416dd26 142 }
mahphalke 17:af1f2416dd26 143
mahphalke 17:af1f2416dd26 144
mahphalke 17:af1f2416dd26 145 /*!
mahphalke 18:5ae03a197e59 146 * @brief Function to store the number of actul requested ADC samples from IIO client
mahphalke 17:af1f2416dd26 147 * @param bytes[in] - Number of bytes corresponding to requested samples
mahphalke 17:af1f2416dd26 148 * @param sample_size_in_bytes[in] - Size of each sample in bytes (eqv to ADC resolution)
mahphalke 17:af1f2416dd26 149 * @return none
mahphalke 18:5ae03a197e59 150 * @note The information about sample and buffer size is required for continuous
mahphalke 18:5ae03a197e59 151 * data acquisition
mahphalke 17:af1f2416dd26 152 */
mahphalke 17:af1f2416dd26 153 void store_requested_samples_count(size_t bytes, uint8_t sample_size_in_bytes)
mahphalke 17:af1f2416dd26 154 {
mahphalke 17:af1f2416dd26 155 /* This gets the number of samples requested by IIO client for all active channels */
mahphalke 17:af1f2416dd26 156 num_of_requested_samples = bytes / sample_size_in_bytes;
mahphalke 17:af1f2416dd26 157
mahphalke 18:5ae03a197e59 158 /* Store the ADC sample size */
mahphalke 18:5ae03a197e59 159 acq_buffer.sample_size = sample_size_in_bytes;
mahphalke 18:5ae03a197e59 160
mahphalke 17:af1f2416dd26 161 /* Get the actual available size of buffer by aligning with number of requested samples.
mahphalke 18:5ae03a197e59 162 * e.g. if requested samples are 400 and sample size is 2 bytes, the max available
mahphalke 18:5ae03a197e59 163 * size of buffer is: available size = ((32768 / 2) / 400) * 400 = 40 * 400 = 16000.
mahphalke 17:af1f2416dd26 164 * The max samples to be requested should always be less than half the max size of buffer
mahphalke 18:5ae03a197e59 165 * (in this case: (32768/2) / 2 = 8192).
mahphalke 17:af1f2416dd26 166 * */
mahphalke 18:5ae03a197e59 167 max_available_buffer_size = ((DATA_BUFFER_SIZE / sample_size_in_bytes) /
mahphalke 18:5ae03a197e59 168 num_of_requested_samples) * num_of_requested_samples;
mahphalke 17:af1f2416dd26 169 }
mahphalke 17:af1f2416dd26 170
mahphalke 17:af1f2416dd26 171
mahphalke 17:af1f2416dd26 172 /*!
mahphalke 18:5ae03a197e59 173 * @brief Function to read acquired samples into buffer without IIO request timeout
mahphalke 17:af1f2416dd26 174 * @param input_buffer[in] - Input data acquisition buffer
mahphalke 17:af1f2416dd26 175 * @param output_buffer[in, out] - Output data buffer
mahphalke 17:af1f2416dd26 176 * @param samples_to_read[in] - Number of samples to read
mahphalke 17:af1f2416dd26 177 * @param sample_size_in_bytes[in] - Size of each sample in bytes (eqv to ADC resolution)
mahphalke 17:af1f2416dd26 178 * @return none
mahphalke 17:af1f2416dd26 179 */
mahphalke 18:5ae03a197e59 180 static void read_acquired_samples(char *output_buffer,
mahphalke 18:5ae03a197e59 181 size_t samples_to_read,
mahphalke 18:5ae03a197e59 182 uint8_t sample_size_in_bytes)
mahphalke 17:af1f2416dd26 183 {
mahphalke 18:5ae03a197e59 184 int32_t buff_rd_wr_indx_offset; // Offset b/w buffer read and write indexes
mahphalke 18:5ae03a197e59 185 uint32_t timeout = BUF_READ_TIMEOUT; // Buffer new data read timeout count
mahphalke 17:af1f2416dd26 186 size_t bytes = samples_to_read * sample_size_in_bytes;
mahphalke 17:af1f2416dd26 187
mahphalke 17:af1f2416dd26 188 /* Copy the bytes into buffer provided there is enough offset b/w read and write counts.
mahphalke 17:af1f2416dd26 189 * If there is overlap b/w read and write indexes (read is faster than write), empty buffer
mahphalke 17:af1f2416dd26 190 * should be returned to IIO client to avoid IIO request timeout */
mahphalke 17:af1f2416dd26 191 do {
mahphalke 17:af1f2416dd26 192 buff_rd_wr_indx_offset = (acq_buffer.wr_indx - acq_buffer.rd_indx);
mahphalke 17:af1f2416dd26 193 timeout--;
mahphalke 17:af1f2416dd26 194 } while (((buff_rd_wr_indx_offset < (int32_t)(samples_to_read))
mahphalke 17:af1f2416dd26 195 || (acq_buffer.wr_indx < acq_buffer.rd_indx)) && (timeout > 0)
mahphalke 17:af1f2416dd26 196 && start_adc_data_capture);
mahphalke 17:af1f2416dd26 197
mahphalke 17:af1f2416dd26 198 if ((timeout == 0) || (acq_buffer.wr_indx <= 0)) {
mahphalke 17:af1f2416dd26 199 /* This returns the empty buffer */
mahphalke 17:af1f2416dd26 200 return;
mahphalke 17:af1f2416dd26 201 }
mahphalke 17:af1f2416dd26 202
mahphalke 17:af1f2416dd26 203 memcpy(output_buffer,
mahphalke 18:5ae03a197e59 204 (void const *)&acq_buffer.data[acq_buffer.rd_indx * sample_size_in_bytes],
mahphalke 17:af1f2416dd26 205 bytes);
mahphalke 17:af1f2416dd26 206 acq_buffer.rd_indx += samples_to_read;
mahphalke 17:af1f2416dd26 207 }
mahphalke 17:af1f2416dd26 208
mahphalke 17:af1f2416dd26 209
mahphalke 17:af1f2416dd26 210 /*!
mahphalke 17:af1f2416dd26 211 * @brief Function to read and align the ADC buffered raw data
mahphalke 17:af1f2416dd26 212 * @param device[in]- Device instance
mahphalke 17:af1f2416dd26 213 * @param pbuf[out] - Buffer to load ADC raw data
mahphalke 17:af1f2416dd26 214 * @param bytes[in] - Number of bytes to be read
mahphalke 17:af1f2416dd26 215 * @param active_chns_mask[in] - Active channels mask
mahphalke 17:af1f2416dd26 216 * @return Number of bytes read
mahphalke 17:af1f2416dd26 217 */
mahphalke 18:5ae03a197e59 218 size_t read_buffered_data(char *pbuf,
mahphalke 18:5ae03a197e59 219 size_t bytes,
mahphalke 18:5ae03a197e59 220 size_t offset,
mahphalke 18:5ae03a197e59 221 uint32_t active_chns_mask,
mahphalke 18:5ae03a197e59 222 uint8_t sample_size_in_bytes)
mahphalke 17:af1f2416dd26 223 {
mahphalke 17:af1f2416dd26 224 size_t samples_to_read = bytes /
mahphalke 18:5ae03a197e59 225 sample_size_in_bytes; // Bytes to sample conversion
mahphalke 17:af1f2416dd26 226
mahphalke 17:af1f2416dd26 227 /* Make sure requested samples size is less than ADC buffer size. Return constant
mahphalke 17:af1f2416dd26 228 * value to avoid IIO client getting timed-out */
mahphalke 18:5ae03a197e59 229 if(num_of_requested_samples >= max_available_buffer_size) {
mahphalke 17:af1f2416dd26 230 memset(pbuf, 1, bytes);
mahphalke 17:af1f2416dd26 231 return bytes;
mahphalke 17:af1f2416dd26 232 }
mahphalke 17:af1f2416dd26 233
mahphalke 18:5ae03a197e59 234 /* Increment read counter to point to next acquired data of 1st active channel */
mahphalke 18:5ae03a197e59 235 if ((offset == 0) && (acq_buffer.rd_indx > 0)) {
mahphalke 18:5ae03a197e59 236 acq_buffer.rd_indx += chn_alignment_offset;
mahphalke 18:5ae03a197e59 237 }
mahphalke 17:af1f2416dd26 238
mahphalke 18:5ae03a197e59 239 read_acquired_samples(pbuf, samples_to_read, sample_size_in_bytes);
mahphalke 18:5ae03a197e59 240
mahphalke 18:5ae03a197e59 241 /* Make buffer available again once it is read/transmited completely */
mahphalke 17:af1f2416dd26 242 if (acq_buffer.rd_indx >= max_available_buffer_size) {
mahphalke 17:af1f2416dd26 243 acq_buffer.rd_indx = 0;
mahphalke 17:af1f2416dd26 244 acq_buffer.wr_indx = 0;
mahphalke 18:5ae03a197e59 245 acq_buffer.pdata = acq_buffer.data;
mahphalke 17:af1f2416dd26 246 acq_buffer.state = BUF_AVAILABLE;
mahphalke 18:5ae03a197e59 247 acq_buffer.refill_buffer = true;
mahphalke 17:af1f2416dd26 248 }
mahphalke 17:af1f2416dd26 249
mahphalke 17:af1f2416dd26 250 return bytes;
mahphalke 17:af1f2416dd26 251 }
mahphalke 17:af1f2416dd26 252
mahphalke 17:af1f2416dd26 253
mahphalke 17:af1f2416dd26 254 /*!
mahphalke 17:af1f2416dd26 255 * @brief This is an ISR (Interrupt Service Routine) to monitor end of conversion event.
mahphalke 17:af1f2416dd26 256 * @param *ctx[in] - Callback context (unused)
mahphalke 17:af1f2416dd26 257 * @param event[in] - Callback event (unused)
mahphalke 17:af1f2416dd26 258 * @param extra[in] - Callback extra (unused)
mahphalke 17:af1f2416dd26 259 * @return none
mahphalke 17:af1f2416dd26 260 * @details This is an Interrupt callback function/ISR invoked in synchronous/asynchronous
mahphalke 17:af1f2416dd26 261 * manner depending upon the application implementation. The conversion results
mahphalke 17:af1f2416dd26 262 * are read into acquisition buffer and control continue to sample next channel.
mahphalke 17:af1f2416dd26 263 * This continues until conversion is stopped (through IIO client command)
mahphalke 18:5ae03a197e59 264 * @note This function also handles the logic to align the first channel data after
mahphalke 17:af1f2416dd26 265 * every 'n' sample transmission. This is required to visualize data properly
mahphalke 18:5ae03a197e59 266 * on IIO client application.
mahphalke 17:af1f2416dd26 267 */
mahphalke 17:af1f2416dd26 268 void data_capture_callback(void *ctx, uint32_t event, void *extra)
mahphalke 17:af1f2416dd26 269 {
mahphalke 17:af1f2416dd26 270 uint32_t adc_sample;
mahphalke 17:af1f2416dd26 271
mahphalke 17:af1f2416dd26 272 if (start_adc_data_capture == true) {
mahphalke 18:5ae03a197e59 273 /* Read the sample(s) for channel(s) which has/have been sampled recently and
mahphalke 18:5ae03a197e59 274 * get the number of samples read count */
mahphalke 18:5ae03a197e59 275 if (data_capture_ops.read_converted_sample(&adc_sample,
mahphalke 18:5ae03a197e59 276 acq_buffer.active_chn[acq_buffer.chn_indx]) != FAILURE) {
mahphalke 18:5ae03a197e59 277 do {
mahphalke 18:5ae03a197e59 278 if (acq_buffer.state == BUF_AVAILABLE) {
mahphalke 18:5ae03a197e59 279 if (acq_buffer.refill_buffer) {
mahphalke 18:5ae03a197e59 280 /* Buffer refilling must start with first active channel data
mahphalke 18:5ae03a197e59 281 * for IIO client to synchronize the buffered data */
mahphalke 18:5ae03a197e59 282 if (acq_buffer.chn_indx != 0) {
mahphalke 18:5ae03a197e59 283 break;
mahphalke 18:5ae03a197e59 284 }
mahphalke 18:5ae03a197e59 285 acq_buffer.refill_buffer = false;
mahphalke 18:5ae03a197e59 286 }
mahphalke 17:af1f2416dd26 287
mahphalke 18:5ae03a197e59 288 /* Copy adc samples into acquisition buffer to transport over
mahphalke 18:5ae03a197e59 289 * communication link */
mahphalke 18:5ae03a197e59 290 memcpy(acq_buffer.pdata, &adc_sample, acq_buffer.sample_size);
mahphalke 18:5ae03a197e59 291 acq_buffer.pdata += acq_buffer.sample_size;
mahphalke 17:af1f2416dd26 292
mahphalke 18:5ae03a197e59 293 /* Check for acquisition buffer full condition */
mahphalke 18:5ae03a197e59 294 acq_buffer.wr_indx++;
mahphalke 18:5ae03a197e59 295 if (acq_buffer.wr_indx >= max_available_buffer_size) {
mahphalke 18:5ae03a197e59 296 acq_buffer.state = BUF_FULL;
mahphalke 18:5ae03a197e59 297 }
mahphalke 17:af1f2416dd26 298 }
mahphalke 18:5ae03a197e59 299 } while (0);
mahphalke 17:af1f2416dd26 300
mahphalke 18:5ae03a197e59 301 /* Keep tracking channel index as it is needed to refill the buffer
mahphalke 18:5ae03a197e59 302 * starting with first channel data */
mahphalke 18:5ae03a197e59 303 acq_buffer.chn_indx++;
mahphalke 18:5ae03a197e59 304 if (acq_buffer.chn_indx >= num_of_active_channels) {
mahphalke 18:5ae03a197e59 305 acq_buffer.chn_indx = 0;
mahphalke 17:af1f2416dd26 306 }
mahphalke 18:5ae03a197e59 307 }
mahphalke 17:af1f2416dd26 308
mahphalke 17:af1f2416dd26 309 /* Trigger next continuous conversion (optional or device dependent) */
mahphalke 18:5ae03a197e59 310 if (data_capture_ops.trigger_next_conversion) {
mahphalke 18:5ae03a197e59 311 data_capture_ops.trigger_next_conversion();
mahphalke 17:af1f2416dd26 312 }
mahphalke 17:af1f2416dd26 313 }
mahphalke 17:af1f2416dd26 314 }
mahphalke 17:af1f2416dd26 315
mahphalke 17:af1f2416dd26 316
mahphalke 17:af1f2416dd26 317 /*!
mahphalke 17:af1f2416dd26 318 * @brief Reset the data capture specific variables
mahphalke 17:af1f2416dd26 319 * @return none
mahphalke 17:af1f2416dd26 320 */
mahphalke 17:af1f2416dd26 321 static void reset_data_capture(void)
mahphalke 17:af1f2416dd26 322 {
mahphalke 17:af1f2416dd26 323 /* Reset data capture flags */
mahphalke 17:af1f2416dd26 324 start_adc_data_capture = false;
mahphalke 17:af1f2416dd26 325 num_of_active_channels = 0;
mahphalke 17:af1f2416dd26 326
mahphalke 17:af1f2416dd26 327 /* Reset acquisition buffer states and clear old data */
mahphalke 17:af1f2416dd26 328 acq_buffer.state = BUF_EMPTY;
mahphalke 17:af1f2416dd26 329
mahphalke 17:af1f2416dd26 330 acq_buffer.wr_indx = 0;
mahphalke 17:af1f2416dd26 331 acq_buffer.rd_indx = 0;
mahphalke 18:5ae03a197e59 332 acq_buffer.chn_indx = 0;
mahphalke 18:5ae03a197e59 333 acq_buffer.refill_buffer = false;
mahphalke 18:5ae03a197e59 334 acq_buffer.pdata = acq_buffer.data;
mahphalke 17:af1f2416dd26 335 }
mahphalke 17:af1f2416dd26 336
mahphalke 17:af1f2416dd26 337
mahphalke 17:af1f2416dd26 338 /*!
mahphalke 17:af1f2416dd26 339 * @brief Function to trigger ADC conversion for new READBUFF
mahphalke 17:af1f2416dd26 340 * request from IIO client (for active channels)
mahphalke 17:af1f2416dd26 341 * @param ch_mask[in] - Channels to enable for data capturing
mahphalke 17:af1f2416dd26 342 * @param num_of_chns[in] - ADC channel count
mahphalke 17:af1f2416dd26 343 * @return none
mahphalke 17:af1f2416dd26 344 */
mahphalke 17:af1f2416dd26 345 void start_data_capture(uint32_t ch_mask, uint8_t num_of_chns)
mahphalke 17:af1f2416dd26 346 {
mahphalke 17:af1f2416dd26 347 uint32_t mask = 0x1;
mahphalke 18:5ae03a197e59 348 uint8_t index = 0;
mahphalke 17:af1f2416dd26 349
mahphalke 18:5ae03a197e59 350 /* Make sure requested samples size is less than max available buffer size */
mahphalke 17:af1f2416dd26 351 if (num_of_requested_samples >= max_available_buffer_size) {
mahphalke 17:af1f2416dd26 352 return;
mahphalke 17:af1f2416dd26 353 }
mahphalke 17:af1f2416dd26 354
mahphalke 18:5ae03a197e59 355 /* Reset data capture module specific flags and variables */
mahphalke 17:af1f2416dd26 356 reset_data_capture();
mahphalke 17:af1f2416dd26 357
mahphalke 18:5ae03a197e59 358 /* Count active channels based on channel mask set in the IIO client */
mahphalke 17:af1f2416dd26 359 for (uint8_t chn = 0; chn < num_of_chns; chn++) {
mahphalke 17:af1f2416dd26 360 if (ch_mask & mask) {
mahphalke 18:5ae03a197e59 361 acq_buffer.active_chn[index++] = chn;
mahphalke 17:af1f2416dd26 362 num_of_active_channels++;
mahphalke 17:af1f2416dd26 363 }
mahphalke 17:af1f2416dd26 364
mahphalke 17:af1f2416dd26 365 mask <<= 1;
mahphalke 17:af1f2416dd26 366 }
mahphalke 17:af1f2416dd26 367
mahphalke 18:5ae03a197e59 368 /* Note: As shown below, after nth sample read, next sample must be for the first
mahphalke 18:5ae03a197e59 369 * channel present in the list of enabled channels */
mahphalke 18:5ae03a197e59 370 /*+-----------------------+-------------------------+---------------------------+
mahphalke 18:5ae03a197e59 371 *| 0 | 1 | 2 | ------| n | 0 | 1 | 2 | --------| n | 0 | 1 | 2 |-----------| l |
mahphalke 18:5ae03a197e59 372 *+-^-------------------^-+-^---------------------^-+-^-----------------------^-+
mahphalke 18:5ae03a197e59 373 * | | | | | |
mahphalke 18:5ae03a197e59 374 * 1st chn data nth data 1st chn data nth data 1st chn data last data
mahphalke 18:5ae03a197e59 375 * n = number of requested samples. l = last data (channel unknown)
mahphalke 18:5ae03a197e59 376 * To achieve this, offset value is determined based on the requested samples count
mahphalke 18:5ae03a197e59 377 * and number of active channels. The read index is then incremented by offset value
mahphalke 18:5ae03a197e59 378 * to read the data for first enabled channel by mapping into acquisition buffer.
mahphalke 18:5ae03a197e59 379 **/
mahphalke 18:5ae03a197e59 380 if (num_of_requested_samples % num_of_active_channels) {
mahphalke 18:5ae03a197e59 381 chn_alignment_offset = (num_of_requested_samples - ((num_of_requested_samples /
mahphalke 18:5ae03a197e59 382 num_of_active_channels) * num_of_active_channels)) + 1;
mahphalke 18:5ae03a197e59 383 } else {
mahphalke 18:5ae03a197e59 384 chn_alignment_offset = 0;
mahphalke 18:5ae03a197e59 385 }
mahphalke 18:5ae03a197e59 386
mahphalke 18:5ae03a197e59 387 /* Make acquisition buffer available and start continuous conversion */
mahphalke 17:af1f2416dd26 388 acq_buffer.state = BUF_AVAILABLE;
mahphalke 18:5ae03a197e59 389 if (data_capture_ops.continuous_sample_read_start_ops) {
mahphalke 18:5ae03a197e59 390 if (data_capture_ops.continuous_sample_read_start_ops(ch_mask) != FAILURE) {
mahphalke 18:5ae03a197e59 391 start_adc_data_capture = true;
mahphalke 18:5ae03a197e59 392 }
mahphalke 18:5ae03a197e59 393 } else {
mahphalke 17:af1f2416dd26 394 start_adc_data_capture = true;
mahphalke 17:af1f2416dd26 395 }
mahphalke 17:af1f2416dd26 396 }
mahphalke 17:af1f2416dd26 397
mahphalke 17:af1f2416dd26 398
mahphalke 17:af1f2416dd26 399 /*!
mahphalke 17:af1f2416dd26 400 * @brief Function to stop ADC data capture
mahphalke 17:af1f2416dd26 401 * @return none
mahphalke 17:af1f2416dd26 402 */
mahphalke 17:af1f2416dd26 403 void stop_data_capture(void)
mahphalke 17:af1f2416dd26 404 {
mahphalke 17:af1f2416dd26 405 start_adc_data_capture = false;
mahphalke 17:af1f2416dd26 406
mahphalke 18:5ae03a197e59 407 /* Enable operations required post continuous sample read */
mahphalke 18:5ae03a197e59 408 if (data_capture_ops.continuous_sample_read_stop_ops) {
mahphalke 18:5ae03a197e59 409 data_capture_ops.continuous_sample_read_stop_ops();
mahphalke 17:af1f2416dd26 410 }
mahphalke 17:af1f2416dd26 411
mahphalke 18:5ae03a197e59 412 /* Reset data capture module specific flags and variables */
mahphalke 17:af1f2416dd26 413 reset_data_capture();
mahphalke 17:af1f2416dd26 414 }