au1x00.c

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/*
 * BRIEF MODULE DESCRIPTION
 *  Driver for AMD Au1000 MIPS Processor, AC'97 Sound Port
 *
 * Copyright 2004 Cooper Street Innovations Inc.
 * Author: Charles Eidsness	<[e-mail]>
 *
 *  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  SOFTWARE  IS PROVIDED   ``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 AUTHOR  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.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * History:
 *
 * 2004-09-09 Charles Eidsness	-- Original verion -- based on
 * 				  sa11xx-uda1341.c ALSA driver and the
 *				  au1000.c OSS driver.
 * 2004-09-09 Matt Porter	-- Added support for ALSA 1.0.6
 *
 */

#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <sound/driver.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/version.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/ac97_codec.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/au1000_dma.h>

MODULE_AUTHOR("Charles Eidsness <[e-mail]>");
MODULE_DESCRIPTION("Au1000 AC'97 ALSA Driver");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{AMD,Au1000 AC'97}}");

#define PLAYBACK 0
#define CAPTURE 1
#define AC97_SLOT_3 0x01
#define AC97_SLOT_4 0x02
#define AC97_SLOT_6 0x08
#define AC97_CMD_IRQ 31
#define READ 0
#define WRITE 1
#define READ_WAIT 2
#define RW_DONE 3

struct au1000_period
{
	u32 start;
	u32 relative_end;	/*realtive to start of buffer*/
	struct au1000_period * next;
};

/*Au1000 AC97 Port Control Reisters*/
struct au1000_ac97_reg {
	u32 volatile config;
	u32 volatile status;
	u32 volatile data;
	u32 volatile cmd;
	u32 volatile cntrl;
};

struct audio_stream {
	struct snd_pcm_substream *substream;
	int dma;
	spinlock_t dma_lock;
	struct au1000_period * buffer;
	unsigned int period_size;
	unsigned int periods;
};

struct snd_au1000 {
	struct snd_card *card;
	struct au1000_ac97_reg volatile *ac97_ioport;

	struct resource *ac97_res_port;
	spinlock_t ac97_lock;
	struct snd_ac97 *ac97;

	struct snd_pcm *pcm;
	struct audio_stream *stream[2];	/* playback & capture */
};

/*--------------------------- Local Functions --------------------------------*/
static void
au1000_set_ac97_xmit_slots(struct snd_au1000 *au1000, long xmit_slots)
{
	u32 volatile ac97_config;

	spin_lock(&au1000->ac97_lock);
	ac97_config = au1000->ac97_ioport->config;
	ac97_config = ac97_config & ~AC97C_XMIT_SLOTS_MASK;
	ac97_config |= (xmit_slots << AC97C_XMIT_SLOTS_BIT);
	au1000->ac97_ioport->config = ac97_config;
	spin_unlock(&au1000->ac97_lock);
}

static void
au1000_set_ac97_recv_slots(struct snd_au1000 *au1000, long recv_slots)
{
	u32 volatile ac97_config;

	spin_lock(&au1000->ac97_lock);
	ac97_config = au1000->ac97_ioport->config;
	ac97_config = ac97_config & ~AC97C_RECV_SLOTS_MASK;
	ac97_config |= (recv_slots << AC97C_RECV_SLOTS_BIT);
	au1000->ac97_ioport->config = ac97_config;
	spin_unlock(&au1000->ac97_lock);
}


static void
au1000_release_dma_link(struct audio_stream *stream)
{
	struct au1000_period * pointer;
	struct au1000_period * pointer_next;

	stream->period_size = 0;
	stream->periods = 0;
	pointer = stream->buffer;
	if (! pointer)
		return;
	do {
		pointer_next = pointer->next;
		kfree(pointer);
		pointer = pointer_next;
	} while (pointer != stream->buffer);
	stream->buffer = NULL;
}

static int
au1000_setup_dma_link(struct audio_stream *stream, unsigned int period_bytes,
		      unsigned int periods)
{
	struct snd_pcm_substream *substream = stream->substream;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct au1000_period *pointer;
	unsigned long dma_start;
	int i;

	dma_start = virt_to_phys(runtime->dma_area);

	if (stream->period_size == period_bytes &&
	    stream->periods == periods)
		return 0; /* not changed */

	au1000_release_dma_link(stream);

	stream->period_size = period_bytes;
	stream->periods = periods;

	stream->buffer = kmalloc(sizeof(struct au1000_period), GFP_KERNEL);
	if (! stream->buffer)
		return -ENOMEM;
	pointer = stream->buffer;
	for (i = 0; i < periods; i++) {
		pointer->start = (u32)(dma_start + (i * period_bytes));
		pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
		if (i < periods - 1) {
			pointer->next = kmalloc(sizeof(struct au1000_period), GFP_KERNEL);
			if (! pointer->next) {
				au1000_release_dma_link(stream);
				return -ENOMEM;
			}
			pointer = pointer->next;
		}
	}
	pointer->next = stream->buffer;
	return 0;
}

static void
au1000_dma_stop(struct audio_stream *stream)
{
	snd_assert(stream->buffer, return);
	disable_dma(stream->dma);
}

static void
au1000_dma_start(struct audio_stream *stream)
{
	snd_assert(stream->buffer, return);

	init_dma(stream->dma);
	if (get_dma_active_buffer(stream->dma) == 0) {
		clear_dma_done0(stream->dma);
		set_dma_addr0(stream->dma, stream->buffer->start);
		set_dma_count0(stream->dma, stream->period_size >> 1);
		set_dma_addr1(stream->dma, stream->buffer->next->start);
		set_dma_count1(stream->dma, stream->period_size >> 1);
	} else {
		clear_dma_done1(stream->dma);
		set_dma_addr1(stream->dma, stream->buffer->start);
		set_dma_count1(stream->dma, stream->period_size >> 1);
		set_dma_addr0(stream->dma, stream->buffer->next->start);
		set_dma_count0(stream->dma, stream->period_size >> 1);
	}
	enable_dma_buffers(stream->dma);
	start_dma(stream->dma);
}

static irqreturn_t
au1000_dma_interrupt(int irq, void *dev_id)
{
	struct audio_stream *stream = (struct audio_stream *) dev_id;
	struct snd_pcm_substream *substream = stream->substream;

	spin_lock(&stream->dma_lock);
	switch (get_dma_buffer_done(stream->dma)) {
	case DMA_D0:
		stream->buffer = stream->buffer->next;
		clear_dma_done0(stream->dma);
		set_dma_addr0(stream->dma, stream->buffer->next->start);
		set_dma_count0(stream->dma, stream->period_size >> 1);
		enable_dma_buffer0(stream->dma);
		break;
	case DMA_D1:
		stream->buffer = stream->buffer->next;
		clear_dma_done1(stream->dma);
		set_dma_addr1(stream->dma, stream->buffer->next->start);
		set_dma_count1(stream->dma, stream->period_size >> 1);
		enable_dma_buffer1(stream->dma);
		break;
	case (DMA_D0 | DMA_D1):
		printk(KERN_ERR "DMA %d missed interrupt.\n",stream->dma);
		au1000_dma_stop(stream);
		au1000_dma_start(stream);
		break;
	case (~DMA_D0 & ~DMA_D1):
		printk(KERN_ERR "DMA %d empty irq.\n",stream->dma);
	}
	spin_unlock(&stream->dma_lock);
	snd_pcm_period_elapsed(substream);
	return IRQ_HANDLED;
}

/*-------------------------- PCM Audio Streams -------------------------------*/

static unsigned int rates[] = {8000, 11025, 16000, 22050};
static struct snd_pcm_hw_constraint_list hw_constraints_rates = {
	.count	= ARRAY_SIZE(rates),
	.list	= rates,
	.mask	= 0,
};

static struct snd_pcm_hardware snd_au1000_hw =
{
	.info			= (SNDRV_PCM_INFO_INTERLEAVED | \
				SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
	.rates			= (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |
				SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050),
	.rate_min		= 8000,
	.rate_max		= 22050,
	.channels_min		= 1,
	.channels_max		= 2,
	.buffer_bytes_max	= 128*1024,
	.period_bytes_min	= 32,
	.period_bytes_max	= 16*1024,
	.periods_min		= 8,
	.periods_max		= 255,
	.fifo_size		= 16,
};

static int
snd_au1000_playback_open(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[PLAYBACK]->substream = substream;
	au1000->stream[PLAYBACK]->buffer = NULL;
	substream->private_data = au1000->stream[PLAYBACK];
	substream->runtime->hw = snd_au1000_hw;
	return (snd_pcm_hw_constraint_list(substream->runtime, 0,
		SNDRV_PCM_HW_PARAM_RATE, &hw_constraints_rates) < 0);
}

static int
snd_au1000_capture_open(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[CAPTURE]->substream = substream;
	au1000->stream[CAPTURE]->buffer = NULL;
	substream->private_data = au1000->stream[CAPTURE];
	substream->runtime->hw = snd_au1000_hw;
	return (snd_pcm_hw_constraint_list(substream->runtime, 0,
		SNDRV_PCM_HW_PARAM_RATE, &hw_constraints_rates) < 0);
}

static int
snd_au1000_playback_close(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[PLAYBACK]->substream = NULL;
	return 0;
}

static int
snd_au1000_capture_close(struct snd_pcm_substream *substream)
{
	struct snd_au1000 *au1000 = substream->pcm->private_data;

	au1000->stream[CAPTURE]->substream = NULL;
	return 0;
}

static int
snd_au1000_hw_params(struct snd_pcm_substream *substream,
					struct snd_pcm_hw_params *hw_params)
{
	struct audio_stream *stream = substream->private_data;
	int err;

	err = snd_pcm_lib_malloc_pages(substream,
				       params_buffer_bytes(hw_params));
	if (err < 0)
		return err;
	return au1000_setup_dma_link(stream,
				     params_period_bytes(hw_params),
				     params_periods(hw_params));
}

static int
snd_au1000_hw_free(struct snd_pcm_substream *substream)
{