static ssize_t stm32l4_rngread(struct file *filep, char *buffer, size_t buflen)
{
if (sem_wait(&g_rngdev.rd_devsem) != OK)
{
return -errno;
}
else
{
/* We've got the device semaphore, proceed with reading */
/* Initialize the operation semaphore with 0 for blocking until the
* buffer is filled from interrupts. The waitsem semaphore is used
* for signaling and, hence, should not have priority inheritance
* enabled.
*/
sem_init(&g_rngdev.rd_readsem, 0, 0);
sem_setprotocol(&g_rngdev.rd_readsem, SEM_PRIO_NONE);
g_rngdev.rd_buflen = buflen;
g_rngdev.rd_buf = buffer;
/* Enable RNG with interrupts */
stm32l4_rngenable();
/* Wait until the buffer is filled */
sem_wait(&g_rngdev.rd_readsem);
/* Done with the operation semaphore */
sem_destroy(&g_rngdev.rd_readsem);
/* Free RNG via the device semaphore for next use */
sem_post(&g_rngdev.rd_devsem);
return buflen;
}
}
static ssize_t stm32l4_rngread(struct file *filep, char *buffer, size_t buflen)
{
if (sem_wait(&g_rngdev.rd_devsem) != OK)
{
return -errno;
}
else
{
/* We've got the device semaphore, proceed with reading */
/* Initialize the operation semaphore with 0 for blocking until
* the buffer is filled from interrupts.
*/
sem_init(&g_rngdev.rd_readsem, 0, 0);
g_rngdev.rd_buflen = buflen;
g_rngdev.rd_buf = buffer;
/* Enable RNG with interrupts */
stm32l4_rngenable();
/* Wait until the buffer is filled */
sem_wait(&g_rngdev.rd_readsem);
/* Done with the operation semaphore */
sem_destroy(&g_rngdev.rd_readsem);
/* Free RNG via the device semaphore for next use */
sem_post(&g_rngdev.rd_devsem);
return buflen;
}
}
