/****************************************************************************
* audio/audio.c
*
* Copyright (C) 2013 Ken Pettit. All rights reserved.
* Author: Ken Pettit <pettitkd@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, 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.
*
****************************************************************************/
/****************************************************************************
* Compilation Switches
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <semaphore.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/arch.h>
#include <nuttx/audio/audio.h>
#include <arch/irq.h>
#ifdef CONFIG_AUDIO
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Debug ********************************************************************/
/* Non-standard debug that may be enabled just for testing Audio */
#ifndef AUDIO_MAX_DEVICE_PATH
# define AUDIO_MAX_DEVICE_PATH 32
#endif
/****************************************************************************
* Private Type Definitions
****************************************************************************/
/* This structure describes the state of the upper half driver */
struct audio_upperhalf_s
{
uint8_t crefs; /* The number of times the device has been opened */
volatile bool started; /* True: pulsed output is being generated */
sem_t exclsem; /* Supports mutual exclusion */
struct audio_info_s info; /* Pulsed output characteristics */
FAR struct audio_lowerhalf_s *dev; /* lower-half state */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int audio_open(FAR struct file *filep);
static int audio_close(FAR struct file *filep);
static ssize_t audio_read(FAR struct file *filep, FAR char *buffer, size_t buflen);
static ssize_t audio_write(FAR struct file *filep, FAR const char *buffer, size_t buflen);
static int audio_start(FAR struct audio_upperhalf_s *upper, unsigned int oflags);
static int audio_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
static void audio_callback(FAR void *priv, uint16_t reason,
FAR struct ap_buffer_s *apb, uint16_t status);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_audioops =
{
audio_open, /* open */
audio_close, /* close */
audio_read, /* read */
audio_write, /* write */
0, /* seek */
audio_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, 0 /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/************************************************************************************
* Name: audio_open
*
* Description:
* This function is called whenever the Audio device is opened.
*
************************************************************************************/
static int audio_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct audio_upperhalf_s *upper = inode->i_private;
uint8_t tmp;
int ret;
audvdbg("crefs: %d\n", upper->crefs);
/* Get exclusive access to the device structures */
ret = sem_wait(&upper->exclsem);
if (ret < 0)
{
ret = -errno;
goto errout;
}
/* Increment the count of references to the device. If this the first
* time that the driver has been opened for this device, then initialize
* the device.
*/
tmp = upper->crefs + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
ret = -EMFILE;
goto errout_with_sem;
}
/* Save the new open count on success */
upper->crefs = tmp;
ret = OK;
errout_with_sem:
sem_post(&upper->exclsem);
errout:
return ret;
}
/************************************************************************************
* Name: audio_close
*
* Description:
* This function is called when the Audio device is closed.
*
************************************************************************************/
static int audio_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct audio_upperhalf_s *upper = inode->i_private;
int ret;
audvdbg("crefs: %d\n", upper->crefs);
/* Get exclusive access to the device structures */
ret = sem_wait(&upper->exclsem);
if (ret < 0)
{
ret = -errno;
goto errout;
}
/* Decrement the references to the driver. If the reference count will
* decrement to 0, then uninitialize the driver.
*/
if (upper->crefs > 1)
{
upper->crefs--;
}
else
{
FAR struct audio_lowerhalf_s *lower = upper->dev;
/* There are no more references to the port */
upper->crefs = 0;
/* Disable the Audio device */
DEBUGASSERT(lower->ops->shutdown != NULL);
audvdbg("calling shutdown: %d\n");
lower->ops->shutdown(lower);
}
ret = OK;
//errout_with_sem:
sem_post(&upper->exclsem);
errout:
return ret;
}
/************************************************************************************
* Name: audio_read
*
* Description:
* A dummy read method. This is provided only to satsify the VFS layer.
*
************************************************************************************/
static ssize_t audio_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
{
/* Return zero -- usually meaning end-of-file */
return 0;
}
/************************************************************************************
* Name: audio_write
*
* Description:
* A dummy write method. This is provided only to satsify the VFS layer.
*
************************************************************************************/
static ssize_t audio_write(FAR struct file *filep, FAR const char *buffer, size_t buflen)
{
return 0;
}
/************************************************************************************
* Name: audio_start
*
* Description:
* Handle the AUDIOIOC_START ioctl command
*
************************************************************************************/
static int audio_start(FAR struct audio_upperhalf_s *upper, unsigned int oflags)
{
FAR struct audio_lowerhalf_s *lower = upper->dev;
int ret = OK;
DEBUGASSERT(upper != NULL && lower->ops->start != NULL);
/* Verify that the Audio is not already running */
if (!upper->started)
{
/* Invoke the bottom half method to start the pulse train */
ret = lower->ops->start(lower);
/* A return value of zero means that the pulse train was started
* successfully.
*/
if (ret == OK)
{
/* Indicate that the pulse train has started */
upper->started = true;
}
}
return ret;
}
/************************************************************************************
* Name: audio_ioctl
*
* Description:
* The standard ioctl method. This is where ALL of the Audio work is done.
*
************************************************************************************/
static int audio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct audio_upperhalf_s *upper = inode->i_private;
FAR struct audio_lowerhalf_s *lower = upper->dev;
int ret;
audvdbg("cmd: %d arg: %ld\n", cmd, arg);
/* Get exclusive access to the device structures */
ret = sem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
/* Handle built-in ioctl commands */
switch (cmd)
{
/* AUDIOIOC_GETCAPS - Get the audio device capabilities.
*
* ioctl argument: A pointer to the audio_caps_s structure.
*/
case AUDIOIOC_GETCAPS:
{
FAR struct audio_caps_s *caps = (FAR struct audio_caps_s*)((uintptr_t)arg);
DEBUGASSERT(lower->ops->getcaps != NULL);
audvdbg("AUDIOIOC_GETCAPS: Device=%d", caps->ac_type);
/* Call the lower-half driver capabilities handler */
ret = lower->ops->getcaps(lower, caps->ac_type, caps);
}
break;
case AUDIOIOC_CONFIGURE:
{
FAR const struct audio_caps_s *caps = (FAR const struct audio_caps_s*)((uintptr_t)arg);
DEBUGASSERT(lower->ops->configure != NULL);
audvdbg("AUDIOIOC_INITIALIZE: Device=%d", caps->ac_type);
/* Call the lower-half driver configure handler */
ret = lower->ops->configure(lower, caps, &audio_callback, upper);
}
break;
case AUDIOIOC_SHUTDOWN:
{
DEBUGASSERT(lower->ops->shutdown != NULL);
audvdbg("AUDIOIOC_SHUTDOWN\n");
/* Call the lower-half driver initialize handler */
ret = lower->ops->shutdown(lower);
}
break;
/* AUDIOIOC_START - Start the pulsed output. The AUDIOIOC_SETCHARACTERISTICS
* command must have previously been sent.
*
* ioctl argument: None
*/
case AUDIOIOC_START:
{
audvdbg("AUDIOIOC_START\n");
DEBUGASSERT(lower->ops->start != NULL);
/* Start the pulse train */
ret = audio_start(upper, filep->f_oflags);
}
break;
/* AUDIOIOC_STOP - Stop the pulsed output.
*
* ioctl argument: None
*/
case AUDIOIOC_STOP:
{
audvdbg("AUDIOIOC_STOP\n");
DEBUGASSERT(lower->ops->stop != NULL);
if (upper->started)
{
ret = lower->ops->stop(lower);
upper->started = false;
}
}
break;
/* Any unrecognized IOCTL commands might be platform-specific ioctl commands */
default:
{
audvdbg("Forwarding unrecognized cmd: %d arg: %ld\n", cmd, arg);
DEBUGASSERT(lower->ops->ioctl != NULL);
ret = lower->ops->ioctl(lower, cmd, arg);
}
break;
}
sem_post(&upper->exclsem);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: audio_register
*
* Description:
* This function binds an instance of a "lower half" audio driver with the
* "upper half" Audio device and registers that device so that can be used
* by application code.
*
* When this function is called, the "lower half" driver should be in the
* reset state (as if the shutdown() method had already been called).
*
* Input parameters:
* path - The full path to the driver to be registers in the NuttX pseudo-
* filesystem. The recommended convention is to name Audio drivers
* based on the function they provide, such as "/dev/pcm0", "/dev/mp31",
* etc.
* dev - A pointer to an instance of lower half audio driver. This instance
* is bound to the Audio driver and must persists as long as the driver
* persists.
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int audio_register(FAR const char *name, FAR struct audio_lowerhalf_s *dev)
{
FAR struct audio_upperhalf_s *upper;
char path[AUDIO_MAX_DEVICE_PATH];
static bool dev_audio_created = false;
#ifndef CONFIG_AUDIO_CUSTOM_DEV_PATH
const char* devname = "/dev/audio";
#elif !defined(CONFIG_AUDIO_DEV_ROOT)
const char* devname = CONFIG_AUDIO_DEV_PATH;
const char* ptr;
char* pathptr;
#endif
/* Allocate the upper-half data structure */
upper = (FAR struct audio_upperhalf_s *)kzalloc(sizeof(struct audio_upperhalf_s));
if (!upper)
{
auddbg("Allocation failed\n");
return -ENOMEM;
}
/* Initialize the Audio device structure (it was already zeroed by kzalloc()) */
sem_init(&upper->exclsem, 0, 1);
upper->dev = dev;
#ifdef CONFIG_AUDIO_CUSTOM_DEV_PATH
#ifdef CONFIG_AUDIO_DEV_ROOT
/* This is the simple case ... No need to make a directory */
strcpy(path, "/dev/");
strcat(path, name);
#else
/* Ensure the path begins with "/dev" as we don't support placing device
* anywhere but in the /dev directory
*/
DEBUGASSERT(strncmp(devname, "/dev", 4) == 0);
/* Create a /dev/audio directory. */
if (!dev_audio_created)
{
/* Get path name after "/dev" */
ptr = &devname[4];
if (*ptr == '/')
{
ptr++;
}
strcpy(path, "/dev/");
pathptr = &path[5];
/* Do mkdir for each segment of the path */
while (*ptr != '\0')
{
/* Build next path segment into path variable */
while (*ptr != '/' && *ptr != '\0')
{
*pathptr++ = *ptr++;
}
*pathptr = '\0';
/* Make this level of directory */
mkdir(path, 0644);
/* Check for another level */
*pathptr++ = '/';
if (*ptr == '/')
{
ptr++;
}
}
/* Indicate we have created the audio dev path */
dev_audio_created = true;
}
/* Now build the path for registration */
strcpy(path, devname);
if (devname[sizeof(devname)-1] != '/')
{
strcat(path, "/");
}
strcat(path, name);
#endif /* CONFIG_AUDIO_DEV_PATH=="/dev" */
#else /* CONFIG_AUDIO_CUSTOM_DEV_PATH */
/* Create a /dev/audio directory. */
if (!dev_audio_created)
{
/* We don't check for error here because even if it fails, then
* the register_driver call below will return an error condition
* for us.
*/
mkdir(devname, 0644);
dev_audio_created = true;
}
/* Register the Audio device */
memset(path, 0, AUDIO_MAX_DEVICE_PATH);
strcpy(path, devname);
strcat(path, "/");
strncat(path, name, AUDIO_MAX_DEVICE_PATH - 11);
#endif
audvdbg("Registering %s\n", path);
return register_driver(path, &g_audioops, 0666, upper);
}
/****************************************************************************
* Name: audio_dequeuebuffer
*
* Description:
* Dequeues a previously enqueued Audio Pipeline Buffer.
*
* 1. The upper half driver calls the enqueuebuffer method, providing the
* lower half driver with the ab_buffer to process.
* 2. The lower half driver's enqueuebuffer will either processes the
* buffer directly, or more likely add it to a queue for processing
* by a background thread or worker task.
* 3. When the lower half driver has completed processing of the enqueued
* ab_buffer, it will call this routine to indicated processing of the
* buffer is complete.
* 4. When this routine is called, it will check if any threads are waiting
* to enqueue additional buffers and "wake them up" for further
* processing.
*
* Input parameters:
* handle - This is the handle that was provided to the lower-half
* start() method.
* apb - A pointer to the previsously enqueued ap_buffer_s
* status - Status of the dequeue operation
*
* Returned Value:
* None
*
* Assumptions:
* This function may be called from an interrupt handler.
*
****************************************************************************/
static inline void audio_dequeuebuffer(FAR struct audio_upperhalf_s *upper,
FAR struct ap_buffer_s *apb, uint16_t status)
{
audllvdbg("Entry\n");
/* TODO: Implement the logic */
}
/****************************************************************************
* Name: audio_callback
*
* Description:
* Provides a callback interface for lower-half drivers to call to the
* upper-half for buffer dequeueing, error reporting, etc.
*
* Input parameters:
* priv - Private context data owned by the upper-half
* reason - The reason code for the callback
* apb - A pointer to the previsously enqueued ap_buffer_s
* status - Status information associated with the callback
*
* Returned Value:
* None
*
* Assumptions:
* This function may be called from an interrupt handler.
*
****************************************************************************/
static void audio_callback(FAR void *handle, uint16_t reason,
FAR struct ap_buffer_s *apb, uint16_t status)
{
FAR struct audio_upperhalf_s *upper = (FAR struct audio_upperhalf_s *)handle;
audllvdbg("Entry\n");
/* Perform operation based on reason code */
switch (reason)
{
case AUDIO_CALLBACK_DEQUEUE:
{
/* Call the dequeue routine */
audio_dequeuebuffer(upper, apb, status);
break;
}
case AUDIO_CALLBACK_IOERR:
{
}
break;
default:
{
auddbg("Unknown callback reason code %d\n", reason);
break;
}
}
}
#endif /* CONFIG_AUDIO */
