vwsnd.c

iis s3c2410-uda1341语音系统的 开发

	/* 4. Put the conversion resources into standby. */

	ad1843_write_bits(lith, &ad1843_PDNI, 0);
	later = jiffies + HZ / 2;	/* roughly half a second */
	DBGDO(shut_up++);
	while (ad1843_read_bits(lith, &ad1843_PDNO)) {
		if (jiffies > later) {
			printk(KERN_ERR
			       "vwsnd audio: AD1843 won't power up\n");
			return -EIO;
		}
		schedule();
	}
	DBGDO(shut_up--);

	/* 5. Power up the clock generators and enable clock output pins. */

	ad1843_write_multi(lith, 2, &ad1843_C1EN, 1, &ad1843_C2EN, 1);

	/* 6. Configure conversion resources while they are in standby. */

 	/* DAC1 uses clock 1 as source, ADC uses clock 2.  Always. */

	ad1843_write_multi(lith, 3,
			   &ad1843_DA1C, 1,
			   &ad1843_ADLC, 2,
			   &ad1843_ADRC, 2);

	/* 7. Enable conversion resources. */

	ad1843_write_bits(lith, &ad1843_ADTLK, 1);
	ad1843_write_multi(lith, 5,
			   &ad1843_ANAEN, 1,
			   &ad1843_AAMEN, 1,
			   &ad1843_DA1EN, 1,
			   &ad1843_ADLEN, 1,
			   &ad1843_ADREN, 1);

	/* 8. Configure conversion resources while they are enabled. */

	ad1843_write_bits(lith, &ad1843_DA1C, 1);

	/* Unmute all channels. */

	ad1843_set_outsrc(lith,
			  (SOUND_MASK_PCM | SOUND_MASK_LINE |
			   SOUND_MASK_MIC | SOUND_MASK_CD));
	ad1843_write_multi(lith, 2, &ad1843_LDA1AM, 0, &ad1843_RDA1AM, 0);

	/* Set default recording source to Line In and set
	 * mic gain to +20 dB.
	 */

	ad1843_set_recsrc(lith, SOUND_MASK_LINE);
	ad1843_write_multi(lith, 2, &ad1843_LMGE, 1, &ad1843_RMGE, 1);

	/* Set Speaker Out level to +/- 4V and unmute it. */

	ad1843_write_multi(lith, 2, &ad1843_HPOS, 1, &ad1843_HPOM, 0);

	return 0;
}

/*****************************************************************************/
/* PCM I/O */

#define READ_INTR_MASK  (LI_INTR_COMM1_TRIG | LI_INTR_COMM1_OVERFLOW)
#define WRITE_INTR_MASK (LI_INTR_COMM2_TRIG | LI_INTR_COMM2_UNDERFLOW)

typedef enum vwsnd_port_swstate {	/* software state */
	SW_OFF,
	SW_INITIAL,
	SW_RUN,
	SW_DRAIN,
} vwsnd_port_swstate_t;

typedef enum vwsnd_port_hwstate {	/* hardware state */
	HW_STOPPED,
	HW_RUNNING,
} vwsnd_port_hwstate_t;

/*
 * These flags are read by ISR, but only written at baseline.
 */

typedef enum vwsnd_port_flags {
	DISABLED = 1 << 0,
	ERFLOWN  = 1 << 1,		/* overflown or underflown */
	HW_BUSY  = 1 << 2,
} vwsnd_port_flags_t;

/*
 * vwsnd_port is the per-port data structure.  Each device has two
 * ports, one for input and one for output.
 *
 * Locking:
 *
 *	port->lock protects: hwstate, flags, swb_[iu]_avail.
 *
 *	devc->io_sema protects: swstate, sw_*, swb_[iu]_idx.
 *
 *	everything else is only written by open/release or
 *	pcm_{setup,shutdown}(), which are serialized by a
 *	combination of devc->open_sema and devc->io_sema.
 */

typedef struct vwsnd_port {

	spinlock_t	lock;
	wait_queue_head_t queue;
	vwsnd_port_swstate_t swstate;
	vwsnd_port_hwstate_t hwstate;
	vwsnd_port_flags_t flags;

	int		sw_channels;
	int		sw_samplefmt;
	int		sw_framerate;
	int		sample_size;
	int		frame_size;
	unsigned int	zero_word;	/* zero for the sample format */

	int		sw_fragshift;
	int		sw_fragcount;
	int		sw_subdivshift;

	unsigned int	hw_fragshift;
	unsigned int	hw_fragsize;
	unsigned int	hw_fragcount;

	int		hwbuf_size;
	unsigned long	hwbuf_paddr;
	unsigned long	hwbuf_vaddr;
	caddr_t		hwbuf;		/* hwbuf == hwbuf_vaddr */
	int		hwbuf_max;	/* max bytes to preload */

	caddr_t		swbuf;
	unsigned int	swbuf_size;	/* size in bytes */
	unsigned int	swb_u_idx;	/* index of next user byte */
	unsigned int	swb_i_idx;	/* index of next intr byte */
	unsigned int	swb_u_avail;	/* # bytes avail to user */
	unsigned int	swb_i_avail;	/* # bytes avail to intr */

	dma_chan_t	chan;

	/* Accounting */

	int		byte_count;
	int		frag_count;
	int		MSC_offset;

} vwsnd_port_t;

/* vwsnd_dev is the per-device data structure. */

typedef struct vwsnd_dev {
	struct vwsnd_dev *next_dev;
	int		audio_minor;	/* minor number of audio device */
	int		mixer_minor;	/* minor number of mixer device */

	struct semaphore open_sema;
	struct semaphore io_sema;
	struct semaphore mix_sema;
	mode_t		open_mode;
	wait_queue_head_t open_wait;

	lithium_t	lith;

	vwsnd_port_t	rport;
	vwsnd_port_t	wport;
} vwsnd_dev_t;

static vwsnd_dev_t *vwsnd_dev_list;	/* linked list of all devices */

static atomic_t vwsnd_use_count = ATOMIC_INIT(0);

# define INC_USE_COUNT (atomic_inc(&vwsnd_use_count))
# define DEC_USE_COUNT (atomic_dec(&vwsnd_use_count))
# define IN_USE        (atomic_read(&vwsnd_use_count) != 0)

/*
 * Lithium can only DMA multiples of 32 bytes.  Its DMA buffer may
 * be up to 8 Kb.  This driver always uses 8 Kb.
 *
 * Memory bug workaround -- I'm not sure what's going on here, but
 * somehow pcm_copy_out() was triggering segv's going on to the next
 * page of the hw buffer.  So, I make the hw buffer one size bigger
 * than we actually use.  That way, the following page is allocated
 * and mapped, and no error.  I suspect that something is broken
 * in Cobalt, but haven't really investigated.  HBO is the actual
 * size of the buffer, and HWBUF_ORDER is what we allocate.
 */

#define HWBUF_SHIFT 13
#define HWBUF_SIZE (1 << HWBUF_SHIFT)
# define HBO         (HWBUF_SHIFT > PAGE_SHIFT ? HWBUF_SHIFT - PAGE_SHIFT : 0)
# define HWBUF_ORDER (HBO + 1)		/* next size bigger */
#define MIN_SPEED 4000
#define MAX_SPEED 49000

#define MIN_FRAGSHIFT			(DMACHUNK_SHIFT + 1)
#define MAX_FRAGSHIFT			(PAGE_SHIFT)
#define MIN_FRAGSIZE			(1 << MIN_FRAGSHIFT)
#define MAX_FRAGSIZE			(1 << MAX_FRAGSHIFT)
#define MIN_FRAGCOUNT(fragsize)		3
#define MAX_FRAGCOUNT(fragsize)		(32 * PAGE_SIZE / (fragsize))
#define DEFAULT_FRAGSHIFT		12
#define DEFAULT_FRAGCOUNT		16
#define DEFAULT_SUBDIVSHIFT		0

/*
 * The software buffer (swbuf) is a ring buffer shared between user
 * level and interrupt level.  Each level owns some of the bytes in
 * the buffer, and may give bytes away by calling swb_inc_{u,i}().
 * User level calls _u for user, and interrupt level calls _i for
 * interrupt.
 *
 * port->swb_{u,i}_avail is the number of bytes available to that level.
 *
 * port->swb_{u,i}_idx is the index of the first available byte in the
 * buffer.
 *
 * Each level calls swb_inc_{u,i}() to atomically increment its index,
 * recalculate the number of bytes available for both sides, and
 * return the number of bytes available.  Since each side can only
 * give away bytes, the other side can only increase the number of
 * bytes available to this side.  Each side updates its own index
 * variable, swb_{u,i}_idx, so no lock is needed to read it.
 *
 * To query the number of bytes available, call swb_inc_{u,i} with an
 * increment of zero.
 */

static __inline__ unsigned int __swb_inc_u(vwsnd_port_t *port, int inc)
{
	if (inc) {
		port->swb_u_idx += inc;
		port->swb_u_idx %= port->swbuf_size;
		port->swb_u_avail -= inc;
		port->swb_i_avail += inc;
	}
	return port->swb_u_avail;
}

static __inline__ unsigned int swb_inc_u(vwsnd_port_t *port, int inc)
{
	unsigned long flags;
	unsigned int ret;

	spin_lock_irqsave(&port->lock, flags);
	{
		ret = __swb_inc_u(port, inc);
	}
	spin_unlock_irqrestore(&port->lock, flags);
	return ret;
}

static __inline__ unsigned int __swb_inc_i(vwsnd_port_t *port, int inc)
{
	if (inc) {
		port->swb_i_idx += inc;
		port->swb_i_idx %= port->swbuf_size;
		port->swb_i_avail -= inc;
		port->swb_u_avail += inc;
	}
	return port->swb_i_avail;
}

static __inline__ unsigned int swb_inc_i(vwsnd_port_t *port, int inc)
{
	unsigned long flags;
	unsigned int ret;

	spin_lock_irqsave(&port->lock, flags);
	{
		ret = __swb_inc_i(port, inc);
	}
	spin_unlock_irqrestore(&port->lock, flags);
	return ret;
}

/*
 * pcm_setup - this routine initializes all port state after
 * mode-setting ioctls have been done, but before the first I/O is
 * done.
 *
 * Locking: called with devc->io_sema held.
 *
 * Returns 0 on success, -errno on failure.
 */

static int pcm_setup(vwsnd_dev_t *devc,
		     vwsnd_port_t *rport,
		     vwsnd_port_t *wport)
{
	vwsnd_port_t *aport = rport ? rport : wport;
	int sample_size;
	unsigned int zero_word;

	DBGEV("(devc=0x%p, rport=0x%p, wport=0x%p)\n", devc, rport, wport);

	ASSERT(aport != NULL);
	if (aport->swbuf != NULL)
		return 0;
	switch (aport->sw_samplefmt) {
	case AFMT_MU_LAW:
		sample_size = 1;
		zero_word = 0xFFFFFFFF ^ 0x80808080;
		break;

	case AFMT_A_LAW:
		sample_size = 1;
		zero_word = 0xD5D5D5D5 ^ 0x80808080;
		break;

	case AFMT_U8:
		sample_size = 1;
		zero_word = 0x80808080;
		break;

	case AFMT_S8:
		sample_size = 1;
		zero_word = 0x00000000;
		break;

	case AFMT_S16_LE:
		sample_size = 2;
		zero_word = 0x00000000;
		break;

	default:
		sample_size = 0;	/* prevent compiler warning */
		zero_word = 0;
		ASSERT(0);
	}
	aport->sample_size  = sample_size;
	aport->zero_word    = zero_word;
	aport->frame_size   = aport->sw_channels * aport->sample_size;
	aport->hw_fragshift = aport->sw_fragshift - aport->sw_subdivshift;
	aport->hw_fragsize  = 1 << aport->hw_fragshift;
	aport->hw_fragcount = aport->sw_fragcount << aport->sw_subdivshift;
	ASSERT(aport->hw_fragsize >= MIN_FRAGSIZE);
	ASSERT(aport->hw_fragsize <= MAX_FRAGSIZE);
	ASSERT(aport->hw_fragcount >= MIN_FRAGCOUNT(aport->hw_fragsize));
	ASSERT(aport->hw_fragcount <= MAX_FRAGCOUNT(aport->hw_fragsize));
	if (rport) {
		int hwfrags, swfrags;
		rport->hwbuf_max = aport->hwbuf_size - DMACHUNK_SIZE;
		hwfrags = rport->hwbuf_max >> aport->hw_fragshift;
		swfrags = aport->hw_fragcount - hwfrags;
		if (swfrags < 2)
			swfrags = 2;
		rport->swbuf_size = swfrags * aport->hw_fragsize;
		DBGPV("hwfrags = %d, swfrags = %d\n", hwfrags, swfrags);
		DBGPV("read hwbuf_max = %d, swbuf_size = %d\n",
		     rport->hwbuf_max, rport->swbuf_size);
	}
	if (wport) {
		int hwfrags, swfrags;
		int total_bytes = aport->hw_fragcount * aport->hw_fragsize;
		wport->hwbuf_max = aport->hwbuf_size - DMACHUNK_SIZE;
		if (wport->hwbuf_max > total_bytes)
			wport->hwbuf_max = total_bytes;
		hwfrags = wport->hwbuf_max >> aport->hw_fragshift;
		DBGPV("hwfrags = %d\n", hwfrags);
		swfrags = aport->hw_fragcount - hwfrags;
		if (swfrags < 2)
			swfrags = 2;
		wport->swbuf_size = swfrags * aport->hw_fragsize;
		DBGPV("hwfrags = %d, swfrags = %d\n", hwfrags, swfrags);
		DBGPV("write hwbuf_max = %d, swbuf_size = %d\n",
		     wport->hwbuf_max, wport->swbuf_size);
	}

	aport->swb_u_idx    = 0;
	aport->swb_i_idx    = 0;
	aport->byte_count   = 0;

	/*
	 * Is this a Cobalt bug?  We need to make this buffer extend
	 * one page further than we actually use -- somehow memcpy
	 * causes an exceptoin otherwise.  I suspect there's a bug in
	 * Cobalt (or somewhere) where it's generating a fault on a
	 * speculative load or something.  Obviously, I haven't taken
	 * the time to track it down.
	 */

	aport->swbuf        = vmalloc(aport->swbuf_size + PAGE_SIZE);
	if (!aport->swbuf)
		return -ENOMEM;
	if (rport && wport) {
		ASSERT(aport == rport);
		ASSERT(wport->swbuf == NULL);
		/* One extra page - see comment above. */
		wport->swbuf = vmalloc(aport->swbuf_size + PAGE_SIZE);
		if (!wport->swbuf) {
			vfree(aport->swbuf);
			aport->swbuf = NULL;
			return -ENOMEM;
		}
		wport->sample_size  = rport->sample_size;
		wport->zero_word    = rport->zero_word;
		wport->frame_size   = rport->frame_size;
		wport->hw_fragshift = rport->hw_fragshift;
		wport->hw_fragsize  = rport->hw_fragsize;
		wport->hw_fragcount = rport->hw_fragcount;
		wport->swbuf_size   = rport->swbuf_size;
		wport->hwbuf_max    = rport->hwbuf_max;
		wport->swb_u_idx    = rport->swb_u_idx;
		wport->swb_i_idx    = rport->swb_i_idx;
		wport->byte_count   = rport->byte_count;
	}
	if (rport) {
		rport->swb_u_avail = 0;
		rport->swb_i_avail = rport->swbuf_size;
		rport->swstate = SW_RUN;
		li_setup_dma(&rport->chan,
			     &li_comm1,
			     &devc->lith,
			     rport->hwbuf_paddr,
			     HWBUF_SHIFT,
			     rport->hw_fragshift,
			     rport->sw_channels,
			     rport->sample_size);
		ad1843_setup_adc(&devc->lith,
				 rport->sw_framerate,
				 rport->sw_samplefmt,
				 rport->sw_channels);
		li_enable_interrupts(&devc->lith, READ_INTR_MASK);
		if (!(rport->flags & DISABLED)) {
			ustmsc_t ustmsc;
			rport->hwstate = HW_RUNNING;
			li_activate_dma(&rport->chan);
			li_read_USTMSC(&rport->chan, &ustmsc);
			rport->MSC_offset = ustmsc.msc;
		}
	}
	if (wport) {
		if (wport->hwbuf_max > wport->swbuf_size)
			wport->hwbuf_max = wport->swbuf_size;
		wport->flags &= ~ERFLOWN;
		wport->swb_u_avail = wport->swbuf_size;
		wport->swb_i_avail = 0;
		wport->swstate = SW_RUN;
		li_setup_dma(&wport->chan,
			     &li_comm2,
			     &devc->lith,
			     wport->hwbuf_paddr,
			     HWBUF_SHIFT,
			     wport->hw_fragshift,
			     wport->sw_channels,