This is an automated email from the ASF dual-hosted git repository. xiaoxiang pushed a commit to branch master in repository https://gitbox.apache.org/repos/asf/nuttx.git
commit 585c25bac0099367553a0c53ee5bbd011baf2b56 Author: Tiago Medicci Serrano <[email protected]> AuthorDate: Mon Aug 25 14:34:22 2025 -0300 drivers/i2s/i2schar: Implement blocking read/write operations This commit implements simple (blocking) read and write operations for the i2schar driver. Although it already contained such methods, the read/write operation was not being properly handled by the `i2schar_[rx|tx]callback` (called when the operation has finished). A semaphore is used to ensure that read data was received by the receiver and another semaphore ensures that data was written by the transmitter. Please note that the already-existing mutex for the I2S peripheral was replaced by two mutexes, one for the receiver and other for the transmitter to allow full-duplex communication. Signed-off-by: Tiago Medicci Serrano <[email protected]> --- drivers/i2s/i2schar.c | 72 +++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 59 insertions(+), 13 deletions(-) diff --git a/drivers/i2s/i2schar.c b/drivers/i2s/i2schar.c index b2fd7c3b60..b312f3640a 100644 --- a/drivers/i2s/i2schar.c +++ b/drivers/i2s/i2schar.c @@ -44,6 +44,7 @@ #include <assert.h> #include <debug.h> #include <errno.h> +#include <semaphore.h> #include <nuttx/mutex.h> #include <nuttx/kmalloc.h> @@ -76,7 +77,12 @@ struct i2schar_dev_s { FAR struct i2s_dev_s *i2s; /* The lower half i2s driver */ - mutex_t lock; /* Assures mutually exclusive access */ + mutex_t rx_lock; /* Assures mutually exclusive access to RX operations */ + mutex_t tx_lock; /* Assures mutually exclusive access to TX operations */ + sem_t rx_sem; /* Semaphore for blocking read operations */ + sem_t tx_sem; /* Semaphore for blocking write operations */ + int rx_result; /* Result of the last read operation */ + int tx_result; /* Result of the last write operation */ }; /**************************************************************************** @@ -156,10 +162,17 @@ static void i2schar_rxcallback(FAR struct i2s_dev_s *dev, FAR struct i2schar_dev_s *priv = (FAR struct i2schar_dev_s *)arg; DEBUGASSERT(priv != NULL && apb != NULL); - UNUSED(priv); i2sinfo("apb=%p nbytes=%d result=%d\n", apb, apb->nbytes, result); + /* Store the result and signal completion */ + + priv->rx_result = result; + + /* Signal that the read operation has completed */ + + nxsem_post(&priv->rx_sem); + /* REVISIT: If you want this to actually do something other than * test I2S data transfer, then this is the point where you would * want to pass the received I2S to some application. @@ -206,10 +219,17 @@ static void i2schar_txcallback(FAR struct i2s_dev_s *dev, FAR struct i2schar_dev_s *priv = (FAR struct i2schar_dev_s *)arg; DEBUGASSERT(priv != NULL && apb != NULL); - UNUSED(priv); i2sinfo("apb=%p nbytes=%d result=%d\n", apb, apb->nbytes, result); + /* Store the result and signal completion */ + + priv->tx_result = result; + + /* Signal that the write operation has completed */ + + nxsem_post(&priv->tx_sem); + /* REVISIT: If you want this to actually do something other than * test I2S data transfer, then this is the point where you would * want to let some application know that the transfer has completed. @@ -284,7 +304,7 @@ static ssize_t i2schar_read(FAR struct file *filep, FAR char *buffer, /* Get exclusive access to i2c character driver */ - ret = nxmutex_lock(&priv->lock); + ret = nxmutex_lock(&priv->rx_lock); if (ret < 0) { i2serr("ERROR: nxsem_wait returned: %d\n", ret); @@ -301,16 +321,34 @@ static ssize_t i2schar_read(FAR struct file *filep, FAR char *buffer, goto errout_with_reference; } - /* Lie to the caller and tell them that all of the bytes have been - * received - */ + /* Wait for the RX callback to signal completion */ - nxmutex_unlock(&priv->lock); - return sizeof(struct ap_buffer_s) + nbytes; + ret = nxsem_wait(&priv->rx_sem); + if (ret < 0) + { + i2serr("ERROR: nxsem_wait returned: %d\n", ret); + goto errout_with_reference; + } + + /* Get the result from the private data */ + + ret = priv->rx_result; + + /* If the operation was successful, return the number of bytes received */ + + if (ret >= 0) + { + ret = sizeof(struct ap_buffer_s) + apb->nbytes; + } + + /* Release our reference to the audio buffer */ + + nxmutex_unlock(&priv->rx_lock); + return ret; errout_with_reference: apb_free(apb); - nxmutex_unlock(&priv->lock); + nxmutex_unlock(&priv->rx_lock); return ret; } @@ -375,7 +413,7 @@ static ssize_t i2schar_write(FAR struct file *filep, FAR const char *buffer, /* Get exclusive access to i2c character driver */ - ret = nxmutex_lock(&priv->lock); + ret = nxmutex_lock(&priv->tx_lock); if (ret < 0) { i2serr("ERROR: nxsem_wait returned: %d\n", ret); @@ -595,7 +633,12 @@ int i2schar_register(FAR struct i2s_dev_s *i2s, int minor) /* Initialize the I2S character device structure */ priv->i2s = i2s; - nxmutex_init(&priv->lock); + nxmutex_init(&priv->rx_lock); + nxmutex_init(&priv->tx_lock); + nxsem_init(&priv->rx_sem, 0, 0); + nxsem_init(&priv->tx_sem, 0, 0); + priv->rx_result = 0; + priv->tx_result = 0; /* Create the character device name */ @@ -607,7 +650,10 @@ int i2schar_register(FAR struct i2s_dev_s *i2s, int minor) * device. */ - nxmutex_destroy(&priv->lock); + nxsem_destroy(&priv->tx_sem); + nxsem_destroy(&priv->rx_sem); + nxmutex_destroy(&priv->rx_lock); + nxmutex_destroy(&priv->tx_lock); kmm_free(priv); return ret; }
