examples/i2schar: Implement loopback mode check
This commit implements the loopback mode for the i2schar example
application. This mode - available only when both RX and TX are
enabled - allows the user to test the I2S buses when the TX pin is
connected to the RX pin. This is done by pre-filling a buffer with
known data (additionally, it checks the peripheral's data width to
format the data in the buffer accordingly) and passing it for both
the transmitter and the receiver threads. This buffer is written to
the TX and the received buffer is compared to the known buffer.
Signed-off-by: Tiago Medicci <tiago.medicci@espressif.com>
diff --git a/examples/i2schar/i2schar.h b/examples/i2schar/i2schar.h
index fb73a6c..73e9f6e 100644
--- a/examples/i2schar/i2schar.h
+++ b/examples/i2schar/i2schar.h
@@ -73,7 +73,7 @@
#endif
#ifndef CONFIG_EXAMPLES_I2SCHAR_BUFSIZE
-# define CONFIG_EXAMPLES_I2SCHAR_BUFSIZE 256
+# define CONFIG_EXAMPLES_I2SCHAR_BUFSIZE 256
#endif
/****************************************************************************
@@ -83,6 +83,7 @@
struct i2schar_state_s
{
bool initialized;
+ bool loopback;
FAR char *devpath;
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
int txcount;
diff --git a/examples/i2schar/i2schar_main.c b/examples/i2schar/i2schar_main.c
index ea5d685..dec7b70 100644
--- a/examples/i2schar/i2schar_main.c
+++ b/examples/i2schar/i2schar_main.c
@@ -34,6 +34,10 @@
#include <pthread.h>
#include <errno.h>
#include <debug.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <nuttx/audio/audio.h>
+#include <nuttx/audio/i2s.h>
#include "i2schar.h"
@@ -91,12 +95,18 @@
printf("Usage: i2schar [OPTIONS]\n");
printf("\nArguments are \"sticky\".\n");
printf("For example, once the I2C character device is\n");
- printf("specified, that device will be re-used until it is changed.\n");
+ printf("specified, that device will be reused until it is changed.\n");
printf("\n\"sticky\" OPTIONS include:\n");
printf(" [-p devpath] selects the I2C character device path. "
"Default: %s Current: %s\n",
CONFIG_EXAMPLES_I2SCHAR_DEVPATH,
g_i2schar.devpath ? g_i2schar.devpath : "NONE");
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ printf(" [-l [0|1]] enables/disables loopback mode "
+ "(0=disable, 1=enable, no value=enable). "
+ "Default: disabled Current: %s\n",
+ g_i2schar.loopback ? "enabled" : "disabled");
+#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
printf(" [-t count] selects the number of audio buffers to send. "
"Default: %d Current: %d\n",
@@ -175,8 +185,81 @@
index += nargs;
break;
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ case 'l':
+
+ /* Check if a value is provided */
+
+ if (ptr[2] == '\0' && index + 1 < argc &&
+ argv[index + 1][0] != '-')
+ {
+ /* Value provided as next argument */
+
+ long loopback = strtol(argv[index + 1], NULL, 10);
+
+ if (loopback == 0)
+ {
+ i2schar->loopback = false;
+ }
+ else if (loopback == 1)
+ {
+ i2schar->loopback = true;
+ }
+ else
+ {
+ printf("Invalid loopback value: %ld (must be 0 or 1)\n",
+ loopback);
+ exit(1);
+ }
+
+ index += 2;
+ }
+ else if (ptr[2] == '\0')
+ {
+ /* No value provided, default to enable */
+
+ i2schar->loopback = true;
+ index += 1;
+ }
+
+ else
+ {
+ /* Value provided as part of the same argument */
+
+ long loopback = strtol(&ptr[2], NULL, 10);
+
+ if (loopback == 0)
+ {
+ i2schar->loopback = false;
+ }
+ else if (loopback == 1)
+ {
+ i2schar->loopback = true;
+ }
+ else
+ {
+ printf("Invalid loopback value: %ld (must be 0 or 1)\n",
+ loopback);
+ exit(1);
+ }
+
+ index += 1;
+ }
+ break;
+#endif
+
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
case 'r':
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ if (i2schar->loopback)
+ {
+ printf("i2schar_main: Warning: -r argument "
+ "ignored in loopback mode\n");
+ index += 1;
+ break;
+ }
+#endif
+
nargs = arg_decimal(&argv[index], &value);
if (value < 0)
{
@@ -191,6 +274,16 @@
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
case 't':
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ if (i2schar->loopback)
+ {
+ printf("i2schar_main: Warning: -t argument "
+ "ignored in loopback mode\n");
+ index += 1;
+ break;
+ }
+#endif
+
nargs = arg_decimal(&argv[index], &value);
if (value < 0)
{
@@ -215,6 +308,107 @@
}
}
+#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
+
+/****************************************************************************
+ * Name: i2schar_prepare_tx_buffer
+ ****************************************************************************/
+
+static struct ap_buffer_s *i2schar_prepare_tx_buffer(uint32_t data_width)
+{
+ FAR struct ap_buffer_s *apb;
+ struct audio_buf_desc_s desc;
+ int ret;
+ int j;
+ uint32_t crap = 0;
+
+ /* Allocate an audio buffer of the configured size */
+
+ desc.numbytes = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
+ desc.u.pbuffer = &apb;
+
+ ret = apb_alloc(&desc);
+ if (ret < 0)
+ {
+ printf("i2schar_prepare_tx_buffer: ERROR: failed to "
+ "allocate buffer: %d\n", ret);
+ return NULL;
+ }
+
+ /* Fill the audio buffer with sequential data based on data width */
+
+ if (data_width == 8)
+ {
+ uint8_t *ptr8 = (uint8_t *)apb->samp;
+
+ /* 8-bit data: fill with sequential bytes */
+
+ for (j = 0; j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
+ {
+ *ptr8++ = crap++;
+ }
+ }
+ else if (data_width == 16)
+ {
+ /* 16-bit data: fill with sequential 16-bit values */
+
+ uint16_t *ptr16 = (uint16_t *)apb->samp;
+ int samples_16bit = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE / 2;
+ for (j = 0; j < samples_16bit; j++)
+ {
+ *ptr16++ = crap++;
+ }
+ }
+ else if (data_width == 24)
+ {
+ /* 24-bit data: fill with sequential 24-bit values (3 bytes each) */
+
+ uint8_t *ptr8 = apb->samp;
+ int samples_24bit = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE / 3;
+ for (j = 0; j < samples_24bit; j++)
+ {
+ /* Store 24-bit value in little-endian format */
+
+ *ptr8++ = crap & 0xff;
+ *ptr8++ = (crap >> 8) & 0xff;
+ *ptr8++ = (crap >> 16) & 0xff;
+ crap++;
+ }
+ }
+ else if (data_width == 32)
+ {
+ /* 32-bit data: fill with sequential 32-bit values */
+
+ uint32_t *ptr32 = (uint32_t *)apb->samp;
+ int samples_32bit = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE / 4;
+ for (j = 0; j < samples_32bit; j++)
+ {
+ *ptr32++ = crap++;
+ }
+ }
+ else
+ {
+ uint8_t *ptr = (uint8_t *)apb->samp;
+
+ /* Unknown data width, fall back to byte-by-byte */
+
+ printf("i2schar_prepare_tx_buffer: Unknown data width %"PRIu32", "
+ "using byte mode\n", data_width);
+ for (j = 0, ptr = apb->samp; j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
+ {
+ *ptr++ = crap++;
+ }
+ }
+
+ apb->nbytes = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
+
+ printf("i2schar_prepare_tx_buffer: Prepared transmitter buffer "
+ "with %"PRIu32"-bit data\n", data_width);
+
+ return apb;
+}
+#endif
+
/****************************************************************************
* Public Functions
****************************************************************************/
@@ -229,6 +423,7 @@
pthread_addr_t result;
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
pthread_t transmitter;
+ int fd;
#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
pthread_t receiver;
@@ -236,6 +431,8 @@
#if defined(CONFIG_EXAMPLES_I2SCHAR_RX) & defined(CONFIG_EXAMPLES_I2SCHAR_TX)
struct sched_param param;
#endif
+ FAR struct ap_buffer_s *transmitter_apb = NULL;
+ uint32_t data_width = 16; /* Default data width */
int ret;
UNUSED(ret);
@@ -269,6 +466,10 @@
g_i2schar.rxcount = CONFIG_EXAMPLES_I2SCHAR_RXBUFFERS;
#endif
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ g_i2schar.loopback = false; /* Default to disabled */
+#endif
+
g_i2schar.initialized = true;
}
@@ -276,6 +477,66 @@
parse_args(&g_i2schar, argc, argv);
+#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
+
+ /* Get I2S configuration parameters to set data width */
+
+ fd = open(g_i2schar.devpath, O_RDONLY);
+ if (fd >= 0)
+ {
+ ret = ioctl(fd, I2SIOC_GTXDATAWIDTH, (unsigned long)&data_width);
+ if (ret >= 0)
+ {
+ printf("i2schar_main: TX data width: %" PRIu32 " bits\n",
+ data_width);
+ }
+ else
+ {
+ printf("i2schar_main: Failed to get TX data width: %d\n", ret);
+ printf("i2schar_main: Using default data width: %" PRIu32 " "
+ "bits\n", data_width);
+ }
+
+ close(fd);
+ }
+ else
+ {
+ printf("i2schar_main: Failed to open device for data width query: "
+ "%d\n", errno);
+ printf("i2schar_main: Using default data width: %" PRIu32 " bits\n",
+ data_width);
+ }
+
+ /* Always prepare the transmitter buffer when transmitter is enabled */
+
+ transmitter_apb = i2schar_prepare_tx_buffer(data_width);
+
+ if (transmitter_apb == NULL)
+ {
+ printf("i2schar_main: ERROR: failed to prepare transmitter buffer\n");
+ return EXIT_FAILURE;
+ }
+#endif
+
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+
+ /* Handle loopback mode */
+
+ if (g_i2schar.loopback)
+ {
+ printf("i2schar_main: Loopback mode enabled\n");
+
+ /* In loopback mode, we only send/receive one buffer each */
+
+ g_i2schar.txcount = 1;
+ g_i2schar.rxcount = 1;
+ }
+ else
+ {
+ printf("i2schar_main: Loopback mode disabled\n");
+ }
+#endif
+
sched_lock();
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
/* Start the receiver thread */
@@ -301,7 +562,9 @@
/* Start the receiver */
- ret = pthread_create(&receiver, &attr, i2schar_receiver, NULL);
+ ret = pthread_create(&receiver, &attr, i2schar_receiver,
+ g_i2schar.loopback ? \
+ (pthread_addr_t)transmitter_apb : NULL);
if (ret != OK)
{
sched_unlock();
@@ -325,7 +588,8 @@
/* Start the transmitter */
- ret = pthread_create(&transmitter, &attr, i2schar_transmitter, NULL);
+ ret = pthread_create(&transmitter, &attr, i2schar_transmitter,
+ (pthread_addr_t)transmitter_apb);
if (ret != OK)
{
sched_unlock();
@@ -349,6 +613,13 @@
{
printf("i2schar_main: ERROR: pthread_join failed: %d\n", ret);
}
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ else if (g_i2schar.loopback && result != NULL)
+ {
+ printf("i2schar_main: ERROR: Loopback verification failed\n");
+ ret = EXIT_FAILURE;
+ }
+#endif
#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
@@ -358,7 +629,23 @@
{
printf("i2schar_main: ERROR: pthread_join failed: %d\n", ret);
}
+#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
+ else if (g_i2schar.loopback && result != NULL)
+ {
+ printf("i2schar_main: ERROR: Loopback verification failed\n");
+ ret = EXIT_FAILURE;
+ }
+#endif
#endif
- return EXIT_SUCCESS;
+#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
+ /* Clean up transmitter buffer if it was allocated */
+
+ if (transmitter_apb != NULL)
+ {
+ apb_free(transmitter_apb);
+ }
+#endif
+
+ return ret;
}
diff --git a/examples/i2schar/i2schar_receiver.c b/examples/i2schar/i2schar_receiver.c
index 843381c..fdcc0c8 100644
--- a/examples/i2schar/i2schar_receiver.c
+++ b/examples/i2schar/i2schar_receiver.c
@@ -33,6 +33,7 @@
#include <errno.h>
#include <debug.h>
#include <unistd.h>
+#include <string.h>
#include <nuttx/audio/audio.h>
@@ -79,12 +80,15 @@
pthread_addr_t i2schar_receiver(pthread_addr_t arg)
{
FAR struct ap_buffer_s *apb;
+ FAR struct ap_buffer_s *transmitter_apb = (FAR struct ap_buffer_s *)arg;
struct audio_buf_desc_s desc;
int bufsize;
int nread;
int ret;
int fd;
int i;
+ int j;
+ bool loopback = (transmitter_apb != NULL);
/* Open the I2C character device */
@@ -101,7 +105,7 @@
for (i = 0; i < g_i2schar.rxcount; i++)
{
- /* Allocate an audio buffer of the configured size */
+ /* Allocate an audio buffer of the configured size for receiving data */
desc.numbytes = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
desc.u.pbuffer = &apb;
@@ -118,7 +122,13 @@
bufsize = sizeof(struct ap_buffer_s) + CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
- /* Then receifve into the buffer */
+ if (loopback)
+ {
+ printf("i2schar_receiver: Using allocated buffer for "
+ "loopback verification\n");
+ }
+
+ /* Then receive into the buffer */
do
{
@@ -137,6 +147,7 @@
printf("i2schar_receiver: ERROR: read failed: %d\n",
errcode);
close(fd);
+ apb_free(apb);
pthread_exit(NULL);
}
}
@@ -145,6 +156,7 @@
printf("i2schar_receiver: ERROR: partial read: %d\n",
nread);
close(fd);
+ apb_free(apb);
pthread_exit(NULL);
}
else
@@ -154,6 +166,51 @@
}
while (nread != bufsize);
+ /* Print received buffer data (first 16 bytes) regardless of mode */
+
+ printf("i2schar_receiver: Received data (first 16 bytes): ");
+ for (j = 0; j < 16 && j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
+ {
+ printf("0x%02x ", ((uint8_t *)apb->samp)[j]);
+ }
+
+ printf("\n");
+
+ /* Verify the received data in loopback mode */
+
+ if (loopback)
+ {
+ /* Compare the received data with the expected transmitter buffer */
+
+ if (memcmp(apb->samp, transmitter_apb->samp,
+ CONFIG_EXAMPLES_I2SCHAR_BUFSIZE) == 0)
+ {
+ printf("i2schar_receiver: Loopback verification PASSED - "
+ "data matches expected\n");
+ }
+ else
+ {
+ printf("i2schar_receiver: Loopback verification FAILED - "
+ "data mismatch!\n");
+ printf("i2schar_receiver: Expected data (first 16 bytes): ");
+ for (j = 0;
+ j < 16 && j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
+ {
+ printf("0x%02x ",
+ ((uint8_t *)transmitter_apb->samp)[j]);
+ }
+
+ printf("\n");
+ close(fd);
+ apb_free(apb);
+ pthread_exit((pthread_addr_t)1); /* Return error */
+ }
+ }
+
+ /* Free the buffer after use */
+
+ apb_free(apb);
+
/* Make sure that the transmitter thread has a chance to run */
pthread_yield();
diff --git a/examples/i2schar/i2schar_transmitter.c b/examples/i2schar/i2schar_transmitter.c
index 2fb9ded..df1560a 100644
--- a/examples/i2schar/i2schar_transmitter.c
+++ b/examples/i2schar/i2schar_transmitter.c
@@ -33,6 +33,7 @@
#include <errno.h>
#include <debug.h>
#include <unistd.h>
+#include <sys/ioctl.h>
#include <nuttx/audio/audio.h>
@@ -79,17 +80,13 @@
pthread_addr_t i2schar_transmitter(pthread_addr_t arg)
{
FAR struct ap_buffer_s *apb;
- struct audio_buf_desc_s desc;
- uint8_t crap;
- uint8_t *ptr;
+ FAR struct ap_buffer_s *transmitter_apb = (FAR struct ap_buffer_s *)arg;
int bufsize;
int nwritten;
- int ret;
int fd;
int i;
- int j;
- /* Open the I2C character device */
+ /* Open the I2S character device */
fd = open(g_i2schar.devpath, O_WRONLY);
if (fd < 0)
@@ -102,33 +99,13 @@
/* Loop for the requested number of times */
- for (i = 0, crap = 0; i < g_i2schar.txcount; i++)
+ for (i = 0; i < g_i2schar.txcount; i++)
{
- /* Allocate an audio buffer of the configured size */
+ /* Use the provided transmitter buffer */
- desc.numbytes = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
- desc.u.pbuffer = &apb;
-
- ret = apb_alloc(&desc);
- if (ret < 0)
- {
- printf("i2schar_transmitter:"
- "ERROR: failed to allocate buffer %d: %d\n", i + 1, ret);
- close(fd);
- pthread_exit(NULL);
- }
-
+ apb = transmitter_apb;
bufsize = sizeof(struct ap_buffer_s) + CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
- /* Fill the audio buffer with crap */
-
- for (j = 0, ptr = apb->samp; j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
- {
- *ptr++ = crap++;
- }
-
- apb->nbytes = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
-
/* Then send the buffer */
do
