/**************************************************************************** * audio/audio.c * * Copyright (C) 2013 Ken Pettit. All rights reserved. * Author: Ken Pettit * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 */