Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  Digital Audio (PCM) abstract layer

 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>

 *

 *

 *   This program is free software; you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation; either version 2 of the License, or

 *   (at your option) any later version.

 *

 *   This program is distributed in the hope that it will be useful,

 *   but WITHOUT ANY WARRANTY; without even the implied warranty of

 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *   GNU General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program; if not, write to the Free Software

 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 *

 */

#include <sound/driver.h>

#include <asm/io.h>

#include <linux/time.h>

#include <linux/init.h>

#include <linux/moduleparam.h>

#include <sound/core.h>

#include <sound/pcm.h>

#include <sound/info.h>

#include <sound/initval.h>

static int preallocate_dma = 1;

module_param(preallocate_dma, int, 0444);

MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");

static int maximum_substreams = 4;

module_param(maximum_substreams, int, 0444);

MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");

static const size_t snd_minimum_buffer = 16384;

/*

 * try to allocate as the large pages as possible.

 * stores the resultant memory size in *res_size.

 *

 * the minimum size is snd_minimum_buffer.  it should be power of 2.

 */

static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)

{

        struct snd_dma_buffer *dmab = &substream->dma_buffer;

        int err;

        snd_assert(size > 0, return -EINVAL);

        /* already reserved? */

        if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {

                if (dmab->bytes >= size)

                        return 0; /* yes */

                /* no, free the reserved block */

                snd_dma_free_pages(dmab);

                dmab->bytes = 0;

        }

        do {

                if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,

                                               size, dmab)) < 0) {

                        if (err != -ENOMEM)

                                return err; /* fatal error */

                } else

                        return 0;

                size >>= 1;

        } while (size >= snd_minimum_buffer);

        dmab->bytes = 0; /* tell error */

        return 0;

}

/*

 * release the preallocated buffer if not yet done.

 */

static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)

{

        if (substream->dma_buffer.area == NULL)

                return;

        if (substream->dma_buf_id)

                snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id);

        else

                snd_dma_free_pages(&substream->dma_buffer);

        substream->dma_buffer.area = NULL;

}

/**

 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.

 * @substream: the pcm substream instance

 *

 * Releases the pre-allocated buffer of the given substream.

 *

 * Returns zero if successful, or a negative error code on failure.

 */

int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)

{

        snd_pcm_lib_preallocate_dma_free(substream);

#ifdef CONFIG_SND_VERBOSE_PROCFS

        snd_info_free_entry(substream->proc_prealloc_max_entry);

        substream->proc_prealloc_max_entry = NULL;

        snd_info_free_entry(substream->proc_prealloc_entry);

        substream->proc_prealloc_entry = NULL;

#endif

        return 0;

}

/**

 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm

 * @pcm: the pcm instance

 *

 * Releases all the pre-allocated buffers on the given pcm.

 *

 * Returns zero if successful, or a negative error code on failure.

 */

int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)

{

        struct snd_pcm_substream *substream;

        int stream;

        for (stream = 0; stream < 2; stream++)

                for (substream = pcm->streams[stream].substream; substream; substream = substream->next)

                        snd_pcm_lib_preallocate_free(substream);

        return 0;

}

EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);

#ifdef CONFIG_SND_VERBOSE_PROCFS

/*

 * read callback for prealloc proc file

 *

 * prints the current allocated size in kB.

 */

static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,

                                              struct snd_info_buffer *buffer)

{

        struct snd_pcm_substream *substream = entry->private_data;

        snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);

}

/*

 * read callback for prealloc_max proc file

 *

 * prints the maximum allowed size in kB.

 */

static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,

                                                  struct snd_info_buffer *buffer)

{

        struct snd_pcm_substream *substream = entry->private_data;

        snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);

}

/*

 * write callback for prealloc proc file

 *

 * accepts the preallocation size in kB.

 */

static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,

                                               struct snd_info_buffer *buffer)

{

        struct snd_pcm_substream *substream = entry->private_data;

        char line[64], str[64];

        size_t size;

        struct snd_dma_buffer new_dmab;

        if (substream->runtime) {

                buffer->error = -EBUSY;

                return;

        }

        if (!snd_info_get_line(buffer, line, sizeof(line))) {

                snd_info_get_str(str, line, sizeof(str));

                size = simple_strtoul(str, NULL, 10) * 1024;

                if ((size != 0 && size < 8192) || size > substream->dma_max) {

                        buffer->error = -EINVAL;

                        return;

                }

                if (substream->dma_buffer.bytes == size)

                        return;

                memset(&new_dmab, 0, sizeof(new_dmab));

                new_dmab.dev = substream->dma_buffer.dev;

                if (size > 0) {

                        if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,

                                                substream->dma_buffer.dev.dev,

                                                size, &new_dmab) < 0) {

                                buffer->error = -ENOMEM;

                                return;

                        }

                        substream->buffer_bytes_max = size;

                } else {

                        substream->buffer_bytes_max = UINT_MAX;

                }

                if (substream->dma_buffer.area)

                        snd_dma_free_pages(&substream->dma_buffer);

                substream->dma_buffer = new_dmab;

        } else {

                buffer->error = -EINVAL;

        }

}

static inline void preallocate_info_init(struct snd_pcm_substream *substream)

{

        struct snd_info_entry *entry;

        if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {

                entry->c.text.read = snd_pcm_lib_preallocate_proc_read;

                entry->c.text.write = snd_pcm_lib_preallocate_proc_write;

                entry->mode |= S_IWUSR;

                entry->private_data = substream;

                if (snd_info_register(entry) < 0) {

                        snd_info_free_entry(entry);

                        entry = NULL;

                }

        }

        substream->proc_prealloc_entry = entry;

        if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {

                entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;

                entry->private_data = substream;

                if (snd_info_register(entry) < 0) {

                        snd_info_free_entry(entry);

                        entry = NULL;

                }

        }

        substream->proc_prealloc_max_entry = entry;

}

#else /* !CONFIG_SND_VERBOSE_PROCFS */

#define preallocate_info_init(s)

#endif /* CONFIG_SND_VERBOSE_PROCFS */

/*

 * pre-allocate the buffer and create a proc file for the substream

 */

static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,

                                          size_t size, size_t max)

{

        if (size > 0 && preallocate_dma && substream->number < maximum_substreams)

                preallocate_pcm_pages(substream, size);

        if (substream->dma_buffer.bytes > 0)

                substream->buffer_bytes_max = substream->dma_buffer.bytes;

        substream->dma_max = max;

        preallocate_info_init(substream);

        return 0;

}

/**

 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type

 * @substream: the pcm substream instance

 * @type: DMA type (SNDRV_DMA_TYPE_*)

 * @data: DMA type dependant data

 * @size: the requested pre-allocation size in bytes

 * @max: the max. allowed pre-allocation size

 *

 * Do pre-allocation for the given DMA buffer type.

 *

 * When substream->dma_buf_id is set, the function tries to look for

 * the reserved buffer, and the buffer is not freed but reserved at

 * destruction time.  The dma_buf_id must be unique for all systems

 * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().

 *

 * Returns zero if successful, or a negative error code on failure.

 */

int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,

                                  int type, struct device *data,

                                  size_t size, size_t max)

{

        substream->dma_buffer.dev.type = type;

        substream->dma_buffer.dev.dev = data;

        return snd_pcm_lib_preallocate_pages1(substream, size, max);

}

EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);

/**

 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)

 * @pcm: the pcm instance

 * @type: DMA type (SNDRV_DMA_TYPE_*)

 * @data: DMA type dependant data

 * @size: the requested pre-allocation size in bytes

 * @max: the max. allowed pre-allocation size

 *

 * Do pre-allocation to all substreams of the given pcm for the

 * specified DMA type.

 *

 * Returns zero if successful, or a negative error code on failure.

 */

int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,

                                          int type, void *data,

                                          size_t size, size_t max)

{

        struct snd_pcm_substream *substream;

        int stream, err;

        for (stream = 0; stream < 2; stream++)

                for (substream = pcm->streams[stream].substream; substream; substream = substream->next)

                        if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)

                                return err;

        return 0;

}

EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);

/**

 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset

 * @substream: the pcm substream instance

 * @offset: the buffer offset

 *

 * Returns the page struct at the given buffer offset.

 * Used as the page callback of PCM ops.

 */

struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)

{

        struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);

        unsigned int idx = offset >> PAGE_SHIFT;

        if (idx >= (unsigned int)sgbuf->pages)

                return NULL;

        return sgbuf->page_table[idx];

}

EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);

/**

 * snd_pcm_lib_malloc_pages - allocate the DMA buffer

 * @substream: the substream to allocate the DMA buffer to

 * @size: the requested buffer size in bytes

 *

 * Allocates the DMA buffer on the BUS type given earlier to

 * snd_pcm_lib_preallocate_xxx_pages().

 *

 * Returns 1 if the buffer is changed, 0 if not changed, or a negative

 * code on failure.

 */

int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)

{

        struct snd_pcm_runtime *runtime;

        struct snd_dma_buffer *dmab = NULL;

        snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL);

        snd_assert(substream != NULL, return -EINVAL);

        runtime = substream->runtime;

        snd_assert(runtime != NULL, return -EINVAL);

        if (runtime->dma_buffer_p) {

                /* perphaps, we might free the large DMA memory region

                   to save some space here, but the actual solution

                   costs us less time */

                if (runtime->dma_buffer_p->bytes >= size) {

                        runtime->dma_bytes = size;

                        return 0;        /* ok, do not change */

                }

                snd_pcm_lib_free_pages(substream);

        }

        if (substream->dma_buffer.area != NULL &&

            substream->dma_buffer.bytes >= size) {

                dmab = &substream->dma_buffer; /* use the pre-allocated buffer */

        } else {

                dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);

                if (! dmab)

                        return -ENOMEM;

                dmab->dev = substream->dma_buffer.dev;

                if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,

                                        substream->dma_buffer.dev.dev,

                                        size, dmab) < 0) {

                        kfree(dmab);

                        return -ENOMEM;

                }

        }

        snd_pcm_set_runtime_buffer(substream, dmab);

        runtime->dma_bytes = size;

        return 1;                       /* area was changed */

}

EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);

/**

 * snd_pcm_lib_free_pages - release the allocated DMA buffer.

 * @substream: the substream to release the DMA buffer

 *

 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().

 *

 * Returns zero if successful, or a negative error code on failure.

 */

int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)

{

        struct snd_pcm_runtime *runtime;

        snd_assert(substream != NULL, return -EINVAL);

        runtime = substream->runtime;

        snd_assert(runtime != NULL, return -EINVAL);

        if (runtime->dma_area == NULL)

                return 0;

        if (runtime->dma_buffer_p != &substream->dma_buffer) {

                /* it's a newly allocated buffer.  release it now. */

                snd_dma_free_pages(runtime->dma_buffer_p);

                kfree(runtime->dma_buffer_p);

        }

        snd_pcm_set_runtime_buffer(substream, NULL);

        return 0;

}

EXPORT_SYMBOL(snd_pcm_lib_free_pages);