vx_pcm.c

鼎力推荐！本程序是基于嵌入式LUNUX系统开发的源程序代码

/*
 * Driver for Digigram VX soundcards
 *
 * PCM part
 *
 * Copyright (c) 2002,2003 by Takashi Iwai <[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 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
 *
 *
 * STRATEGY
 *  for playback, we send series of "chunks", which size is equal with the
 *  IBL size, typically 126 samples.  at each end of chunk, the end-of-buffer
 *  interrupt is notified, and the interrupt handler will feed the next chunk.
 *
 *  the current position is calculated from the sample count RMH.
 *  pipe->transferred is the counter of data which has been already transferred.
 *  if this counter reaches to the period size, snd_pcm_period_elapsed() will
 *  be issued.
 *
 *  for capture, the situation is much easier.
 *  to get a low latency response, we'll check the capture streams at each
 *  interrupt (capture stream has no EOB notification).  if the pending
 *  data is accumulated to the period size, snd_pcm_period_elapsed() is
 *  called and the pointer is updated.
 *
 *  the current point of read buffer is kept in pipe->hw_ptr.  note that
 *  this is in bytes.
 *
 *
 * TODO
 *  - linked trigger for full-duplex mode.
 *  - scheduled action on the stream.
 */

#include <sound/driver.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <sound/core.h>
#include <sound/asoundef.h>
#include <sound/pcm.h>
#include <sound/vx_core.h>
#include "vx_cmd.h"


/*
 * we use a vmalloc'ed (sg-)buffer
 */

/* get the physical page pointer on the given offset */
static struct page *snd_pcm_get_vmalloc_page(snd_pcm_substream_t *subs, unsigned long offset)
{
	void *pageptr = subs->runtime->dma_area + offset;
	return vmalloc_to_page(pageptr);
}

/*
 * allocate a buffer via vmalloc_32().
 * called from hw_params
 * NOTE: this may be called not only once per pcm open!
 */
static int snd_pcm_alloc_vmalloc_buffer(snd_pcm_substream_t *subs, size_t size)
{
	snd_pcm_runtime_t *runtime = subs->runtime;
	if (runtime->dma_area) {
		/* already allocated */
		if (runtime->dma_bytes >= size)
			return 0; /* already enough large */
		vfree_nocheck(runtime->dma_area); /* bypass the memory wrapper */
	}
	runtime->dma_area = vmalloc_32(size);
	if (! runtime->dma_area)
		return -ENOMEM;
	memset(runtime->dma_area, 0, size);
	runtime->dma_bytes = size;
	return 1; /* changed */
}

/*
 * free the buffer.
 * called from hw_free callback
 * NOTE: this may be called not only once per pcm open!
 */
static int snd_pcm_free_vmalloc_buffer(snd_pcm_substream_t *subs)
{
	snd_pcm_runtime_t *runtime = subs->runtime;
	if (runtime->dma_area) {
		vfree_nocheck(runtime->dma_area); /* bypass the memory wrapper */
		runtime->dma_area = NULL;
	}
	return 0;
}


/*
 * read three pending pcm bytes via inb()
 */
static void vx_pcm_read_per_bytes(vx_core_t *chip, snd_pcm_runtime_t *runtime, vx_pipe_t *pipe)
{
	int offset = pipe->hw_ptr;
	unsigned char *buf = (unsigned char *)(runtime->dma_area + offset);
	*buf++ = vx_inb(chip, RXH);
	if (++offset >= pipe->buffer_bytes) {
		offset = 0;
		buf = (unsigned char *)runtime->dma_area;
	}
	*buf++ = vx_inb(chip, RXM);
	if (++offset >= pipe->buffer_bytes) {
		offset = 0;
		buf = (unsigned char *)runtime->dma_area;
	}
	*buf++ = vx_inb(chip, RXL);
	if (++offset >= pipe->buffer_bytes) {
		offset = 0;
		buf = (unsigned char *)runtime->dma_area;
	}
	pipe->hw_ptr = offset;
}

/*
 * vx_set_pcx_time - convert from the PC time to the RMH status time.
 * @pc_time: the pointer for the PC-time to set
 * @dsp_time: the pointer for RMH status time array
 */
static void vx_set_pcx_time(vx_core_t *chip, pcx_time_t *pc_time, unsigned int *dsp_time)
{
	dsp_time[0] = (unsigned int)((*pc_time) >> 24) & PCX_TIME_HI_MASK;
	dsp_time[1] = (unsigned int)(*pc_time) &  MASK_DSP_WORD;
}

/*
 * vx_set_differed_time - set the differed time if specified
 * @rmh: the rmh record to modify
 * @pipe: the pipe to be checked
 *
 * if the pipe is programmed with the differed time, set the DSP time
 * on the rmh and changes its command length.
 *
 * returns the increase of the command length.
 */
static int vx_set_differed_time(vx_core_t *chip, struct vx_rmh *rmh, vx_pipe_t *pipe)
{
	/* Update The length added to the RMH command by the timestamp */
	if (! (pipe->differed_type & DC_DIFFERED_DELAY))
		return 0;
		
	/* Set the T bit */
	rmh->Cmd[0] |= DSP_DIFFERED_COMMAND_MASK;

	/* Time stamp is the 1st following parameter */
	vx_set_pcx_time(chip, &pipe->pcx_time, &rmh->Cmd[1]);

	/* Add the flags to a notified differed command */
	if (pipe->differed_type & DC_NOTIFY_DELAY)
		rmh->Cmd[1] |= NOTIFY_MASK_TIME_HIGH ;

	/* Add the flags to a multiple differed command */
	if (pipe->differed_type & DC_MULTIPLE_DELAY)
		rmh->Cmd[1] |= MULTIPLE_MASK_TIME_HIGH;

	/* Add the flags to a stream-time differed command */
	if (pipe->differed_type & DC_STREAM_TIME_DELAY)
		rmh->Cmd[1] |= STREAM_MASK_TIME_HIGH;
		
	rmh->LgCmd += 2;
	return 2;
}

/*
 * vx_set_stream_format - send the stream format command
 * @pipe: the affected pipe
 * @data: format bitmask
 */
static int vx_set_stream_format(vx_core_t *chip, vx_pipe_t *pipe, unsigned int data)
{
	struct vx_rmh rmh;

	vx_init_rmh(&rmh, pipe->is_capture ?
		    CMD_FORMAT_STREAM_IN : CMD_FORMAT_STREAM_OUT);
	rmh.Cmd[0] |= pipe->number << FIELD_SIZE;

        /* Command might be longer since we may have to add a timestamp */
	vx_set_differed_time(chip, &rmh, pipe);

	rmh.Cmd[rmh.LgCmd] = (data & 0xFFFFFF00) >> 8;
	rmh.Cmd[rmh.LgCmd + 1] = (data & 0xFF) << 16 /*| (datal & 0xFFFF00) >> 8*/;
	rmh.LgCmd += 2;
    
	return vx_send_msg(chip, &rmh);
}


/*
 * vx_set_format - set the format of a pipe
 * @pipe: the affected pipe
 * @runtime: pcm runtime instance to be referred
 *
 * returns 0 if successful, or a negative error code.
 */
static int vx_set_format(vx_core_t *chip, vx_pipe_t *pipe,
			 snd_pcm_runtime_t *runtime)
{
	unsigned int header = HEADER_FMT_BASE;

	if (runtime->channels == 1)
		header |= HEADER_FMT_MONO;
	if (snd_pcm_format_little_endian(runtime->format))
		header |= HEADER_FMT_INTEL;
	if (runtime->rate < 32000 && runtime->rate > 11025)
		header |= HEADER_FMT_UPTO32;
	else if (runtime->rate <= 11025)
		header |= HEADER_FMT_UPTO11;

	switch (snd_pcm_format_physical_width(runtime->format)) {
	// case 8: break;
	case 16: header |= HEADER_FMT_16BITS; break;
	case 24: header |= HEADER_FMT_24BITS; break;
	default : 
		snd_BUG();
		return -EINVAL;
        };

	return vx_set_stream_format(chip, pipe, header);
}

/*
 * set / query the IBL size
 */
static int vx_set_ibl(vx_core_t *chip, struct vx_ibl_info *info)
{
	int err;
	struct vx_rmh rmh;

	vx_init_rmh(&rmh, CMD_IBL);
	rmh.Cmd[0] |= info->size & 0x03ffff;
	err = vx_send_msg(chip, &rmh);
	if (err < 0)
		return err;
	info->size = rmh.Stat[0];
	info->max_size = rmh.Stat[1];
	info->min_size = rmh.Stat[2];
	info->granularity = rmh.Stat[3];
	snd_printdd(KERN_DEBUG "vx_set_ibl: size = %d, max = %d, min = %d, gran = %d\n",
		   info->size, info->max_size, info->min_size, info->granularity);
	return 0;
}


/*
 * vx_get_pipe_state - get the state of a pipe
 * @pipe: the pipe to be checked
 * @state: the pointer for the returned state
 *
 * checks the state of a given pipe, and stores the state (1 = running,
 * 0 = paused) on the given pointer.
 *
 * called from trigger callback only
 */
static int vx_get_pipe_state(vx_core_t *chip, vx_pipe_t *pipe, int *state)
{
	int err;
	struct vx_rmh rmh;

	vx_init_rmh(&rmh, CMD_PIPE_STATE);
	vx_set_pipe_cmd_params(&rmh, pipe->is_capture, pipe->number, 0);
	err = vx_send_msg_nolock(chip, &rmh); /* no lock needed for trigger */ 
	if (! err)
		*state = (rmh.Stat[0] & (1 << pipe->number)) ? 1 : 0;
	return err;
}


/*
 * vx_query_hbuffer_size - query available h-buffer size in bytes
 * @pipe: the pipe to be checked
 *
 * return the available size on h-buffer in bytes,
 * or a negative error code.
 *
 * NOTE: calling this function always switches to the stream mode.
 *       you'll need to disconnect the host to get back to the
 *       normal mode.
 */
static int vx_query_hbuffer_size(vx_core_t *chip, vx_pipe_t *pipe)
{
	int result;
	struct vx_rmh rmh;

	vx_init_rmh(&rmh, CMD_SIZE_HBUFFER);
	vx_set_pipe_cmd_params(&rmh, pipe->is_capture, pipe->number, 0);
	if (pipe->is_capture)
		rmh.Cmd[0] |= 0x00000001;
	result = vx_send_msg(chip, &rmh);
	if (! result)
		result = rmh.Stat[0] & 0xffff;
	return result;
}


/*
 * vx_pipe_can_start - query whether a pipe is ready for start
 * @pipe: the pipe to be checked
 *
 * return 1 if ready, 0 if not ready, and negative value on error.
 *
 * called from trigger callback only
 */
static int vx_pipe_can_start(vx_core_t *chip, vx_pipe_t *pipe)
{
	int err;
	struct vx_rmh rmh;
        
	vx_init_rmh(&rmh, CMD_CAN_START_PIPE);
	vx_set_pipe_cmd_params(&rmh, pipe->is_capture, pipe->number, 0);
	rmh.Cmd[0] |= 1;

	err = vx_send_msg_nolock(chip, &rmh); /* no lock needed for trigger */ 
	if (! err) {
		if (rmh.Stat[0])
			err = 1;
	}
	return err;
}

/*
 * vx_conf_pipe - tell the pipe to stand by and wait for IRQA.
 * @pipe: the pipe to be configured
 */
static int vx_conf_pipe(vx_core_t *chip, vx_pipe_t *pipe)
{
	struct vx_rmh rmh;

	vx_init_rmh(&rmh, CMD_CONF_PIPE);
	if (pipe->is_capture)
		rmh.Cmd[0] |= COMMAND_RECORD_MASK;
	rmh.Cmd[1] = 1 << pipe->number;
	return vx_send_msg_nolock(chip, &rmh); /* no lock needed for trigger */
}

/*
 * vx_send_irqa - trigger IRQA
 */
static int vx_send_irqa(vx_core_t *chip)
{
	struct vx_rmh rmh;

	vx_init_rmh(&rmh, CMD_SEND_IRQA);
	return vx_send_msg_nolock(chip, &rmh); /* no lock needed for trigger */ 
}


#define MAX_WAIT_FOR_DSP        250
/*
 * vx boards do not support inter-card sync, besides
 * only 126 samples require to be prepared before a pipe can start
 */
#define CAN_START_DELAY         2	/* wait 2ms only before asking if the pipe is ready*/
#define WAIT_STATE_DELAY        2	/* wait 2ms after irqA was requested and check if the pipe state toggled*/

/*
 * vx_toggle_pipe - start / pause a pipe
 * @pipe: the pipe to be triggered
 * @state: start = 1, pause = 0
 *
 * called from trigger callback only
 *
 */
static int vx_toggle_pipe(vx_core_t *chip, vx_pipe_t *pipe, int state)
{
	int err, i, cur_state;

	/* Check the pipe is not already in the requested state */
	if (vx_get_pipe_state(chip, pipe, &cur_state) < 0)
		return -EBADFD;
	if (state == cur_state)
		return 0;

	/* If a start is requested, ask the DSP to get prepared
	 * and wait for a positive acknowledge (when there are
	 * enough sound buffer for this pipe)
	 */
	if (state) {
		for (i = 0 ; i < MAX_WAIT_FOR_DSP; i++) {
			err = vx_pipe_can_start(chip, pipe);
			if (err > 0)
				break;
			/* Wait for a few, before asking again
			 * to avoid flooding the DSP with our requests
			 */
			mdelay(1);
		}
	}
    
	if ((err = vx_conf_pipe(chip, pipe)) < 0)
		return err;

	if ((err = vx_send_irqa(chip)) < 0)
		return err;
    
	/* If it completes successfully, wait for the pipes
	 * reaching the expected state before returning
	 * Check one pipe only (since they are synchronous)
	 */
	for (i = 0; i < MAX_WAIT_FOR_DSP; i++) {
		err = vx_get_pipe_state(chip, pipe, &cur_state);
		if (err < 0 || cur_state == state)
			break;
		err = -EIO;
		mdelay(1);
	}
	return err < 0 ? -EIO : 0;
}

    
/*
 * vx_stop_pipe - stop a pipe
 * @pipe: the pipe to be stopped
 *
 * called from trigger callback only
 */
static int vx_stop_pipe(vx_core_t *chip, vx_pipe_t *pipe)
{
	struct vx_rmh rmh;
	vx_init_rmh(&rmh, CMD_STOP_PIPE);
	vx_set_pipe_cmd_params(&rmh, pipe->is_capture, pipe->number, 0);