swarm_cs4297a.c

来自「linux 内核源代码」· C语言 代码 · 共 1,971 行 · 第 1/5 页

//   Mixer file operations struct.
// ******************************************************************************************
static /*const */ struct file_operations cs4297a_mixer_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.ioctl		= cs4297a_ioctl_mixdev,
	.open		= cs4297a_open_mixdev,
	.release	= cs4297a_release_mixdev,
};

// --------------------------------------------------------------------- 


static int drain_adc(struct cs4297a_state *s, int nonblock)
{
        /* This routine serves no purpose currently - any samples
           sitting in the receive queue will just be processed by the
           background consumer.  This would be different if DMA
           actually stopped when there were no clients. */
	return 0;
}

static int drain_dac(struct cs4297a_state *s, int nonblock)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
        unsigned hwptr;
	unsigned tmo;
	int count;

	if (s->dma_dac.mapped)
		return 0;
        if (nonblock)
                return -EBUSY;
	add_wait_queue(&s->dma_dac.wait, &wait);
        while ((count = __raw_readq(SS_CSR(R_SER_DMA_DSCR_COUNT_TX))) ||
               (s->dma_dac.count > 0)) {
                if (!signal_pending(current)) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        /* XXXKW is this calculation working? */
                        tmo = ((count * FRAME_TX_US) * HZ) / 1000000;
                        schedule_timeout(tmo + 1);
                } else {
                        /* XXXKW do I care if there is a signal pending? */
                }
        }
        spin_lock_irqsave(&s->lock, flags);
        /* Reset the bookkeeping */
        hwptr = (int)(((__raw_readq(SS_CSR(R_SER_DMA_CUR_DSCR_ADDR_TX)) & M_DMA_CURDSCR_ADDR) -
                       s->dma_dac.descrtab_phys) / sizeof(serdma_descr_t));
        s->dma_dac.hwptr = s->dma_dac.swptr = hwptr;
        spin_unlock_irqrestore(&s->lock, flags);
	remove_wait_queue(&s->dma_dac.wait, &wait);
	current->state = TASK_RUNNING;
	return 0;
}


// --------------------------------------------------------------------- 

static ssize_t cs4297a_read(struct file *file, char *buffer, size_t count,
			   loff_t * ppos)
{
	struct cs4297a_state *s =
	    (struct cs4297a_state *) file->private_data;
	ssize_t ret;
	unsigned long flags;
	int cnt, count_fr, cnt_by;
	unsigned copied = 0;

	CS_DBGOUT(CS_FUNCTION | CS_WAVE_READ, 2,
		  printk(KERN_INFO "cs4297a: cs4297a_read()+ %d \n", count));

	VALIDATE_STATE(s);
	if (s->dma_adc.mapped)
		return -ENXIO;
	if (!s->dma_adc.ready && (ret = prog_dmabuf_adc(s)))
		return ret;
	if (!access_ok(VERIFY_WRITE, buffer, count))
		return -EFAULT;
	ret = 0;
//
// "count" is the amount of bytes to read (from app), is decremented each loop
//      by the amount of bytes that have been returned to the user buffer.
// "cnt" is the running total of each read from the buffer (changes each loop)
// "buffer" points to the app's buffer
// "ret" keeps a running total of the amount of bytes that have been copied
//      to the user buffer.
// "copied" is the total bytes copied into the user buffer for each loop.
//
	while (count > 0) {
		CS_DBGOUT(CS_WAVE_READ, 8, printk(KERN_INFO
			"_read() count>0 count=%d .count=%d .swptr=%d .hwptr=%d \n",
				count, s->dma_adc.count,
				s->dma_adc.swptr, s->dma_adc.hwptr));
		spin_lock_irqsave(&s->lock, flags);

                /* cnt will be the number of available samples (16-bit
                   stereo); it starts out as the maxmimum consequetive
                   samples */
		cnt = (s->dma_adc.sb_end - s->dma_adc.sb_swptr) / 2;
                count_fr = s->dma_adc.count / FRAME_SAMPLE_BYTES;

		// dma_adc.count is the current total bytes that have not been read.
		// if the amount of unread bytes from the current sw pointer to the
		// end of the buffer is greater than the current total bytes that
		// have not been read, then set the "cnt" (unread bytes) to the
		// amount of unread bytes.  

		if (count_fr < cnt)
			cnt = count_fr;
                cnt_by = cnt * FRAME_SAMPLE_BYTES;
		spin_unlock_irqrestore(&s->lock, flags);
		//
		// if we are converting from 8/16 then we need to copy
		// twice the number of 16 bit bytes then 8 bit bytes.
		// 
		if (s->conversion) {
			if (cnt_by > (count * 2)) {
				cnt = (count * 2) / FRAME_SAMPLE_BYTES;
                                cnt_by = count * 2;
                        }
		} else {
			if (cnt_by > count) {
				cnt = count / FRAME_SAMPLE_BYTES;
                                cnt_by = count;
                        }
		}
		//
		// "cnt" NOW is the smaller of the amount that will be read,
		// and the amount that is requested in this read (or partial).
		// if there are no bytes in the buffer to read, then start the
		// ADC and wait for the interrupt handler to wake us up.
		//
		if (cnt <= 0) {

			// start up the dma engine and then continue back to the top of
			// the loop when wake up occurs.
			start_adc(s);
			if (file->f_flags & O_NONBLOCK)
				return ret ? ret : -EAGAIN;
			interruptible_sleep_on(&s->dma_adc.wait);
			if (signal_pending(current))
				return ret ? ret : -ERESTARTSYS;
			continue;
		}
		// there are bytes in the buffer to read.
		// copy from the hw buffer over to the user buffer.
		// user buffer is designated by "buffer"
		// virtual address to copy from is dma_buf+swptr
		// the "cnt" is the number of bytes to read.

		CS_DBGOUT(CS_WAVE_READ, 2, printk(KERN_INFO
			"_read() copy_to cnt=%d count=%d ", cnt_by, count));
		CS_DBGOUT(CS_WAVE_READ, 8, printk(KERN_INFO
			 " .sbufsz=%d .count=%d buffer=0x%.8x ret=%d\n",
				 s->dma_adc.sbufsz, s->dma_adc.count,
				 (unsigned) buffer, ret));

		if (copy_to_user (buffer, ((void *)s->dma_adc.sb_swptr), cnt_by))
			return ret ? ret : -EFAULT;
                copied = cnt_by;

                /* Return the descriptors */
		spin_lock_irqsave(&s->lock, flags);
                CS_DBGOUT(CS_FUNCTION, 2, 
                          printk(KERN_INFO "cs4297a: upd_rcv sw->hw %x/%x\n", s->dma_adc.swptr, s->dma_adc.hwptr));
		s->dma_adc.count -= cnt_by;
                s->dma_adc.sb_swptr += cnt * 2;
                if (s->dma_adc.sb_swptr == s->dma_adc.sb_end)
                        s->dma_adc.sb_swptr = s->dma_adc.sample_buf;
		spin_unlock_irqrestore(&s->lock, flags);
		count -= copied;
		buffer += copied;
		ret += copied;
		start_adc(s);
	}
	CS_DBGOUT(CS_FUNCTION | CS_WAVE_READ, 2,
		  printk(KERN_INFO "cs4297a: cs4297a_read()- %d\n", ret));
	return ret;
}


static ssize_t cs4297a_write(struct file *file, const char *buffer,
			    size_t count, loff_t * ppos)
{
	struct cs4297a_state *s =
	    (struct cs4297a_state *) file->private_data;
	ssize_t ret;
	unsigned long flags;
	unsigned swptr, hwptr;
	int cnt;

	CS_DBGOUT(CS_FUNCTION | CS_WAVE_WRITE, 2,
		  printk(KERN_INFO "cs4297a: cs4297a_write()+ count=%d\n",
			 count));
	VALIDATE_STATE(s);

	if (s->dma_dac.mapped)
		return -ENXIO;
	if (!s->dma_dac.ready && (ret = prog_dmabuf_dac(s)))
		return ret;
	if (!access_ok(VERIFY_READ, buffer, count))
		return -EFAULT;
	ret = 0;
	while (count > 0) {
                serdma_t *d = &s->dma_dac;
                int copy_cnt;
                u32 *s_tmpl;
                u32 *t_tmpl;
                u32 left, right;
                int swap = (s->prop_dac.fmt == AFMT_S16_LE) || (s->prop_dac.fmt == AFMT_U16_LE);
                
                /* XXXXXX this is broken for BLOAT_FACTOR */
		spin_lock_irqsave(&s->lock, flags);
		if (d->count < 0) {
			d->count = 0;
			d->swptr = d->hwptr;
		}
		if (d->underrun) {
			d->underrun = 0;
                        hwptr = (unsigned) (((__raw_readq(SS_CSR(R_SER_DMA_CUR_DSCR_ADDR_TX)) & M_DMA_CURDSCR_ADDR) -
                                             d->descrtab_phys) / sizeof(serdma_descr_t));
			d->swptr = d->hwptr = hwptr;
		}
		swptr = d->swptr;
		cnt = d->sbufsz - (swptr * FRAME_SAMPLE_BYTES);
                /* Will this write fill up the buffer? */
		if (d->count + cnt > d->sbufsz)
			cnt = d->sbufsz - d->count;
		spin_unlock_irqrestore(&s->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			start_dac(s);
			if (file->f_flags & O_NONBLOCK)
				return ret ? ret : -EAGAIN;
			interruptible_sleep_on(&d->wait);
			if (signal_pending(current))
				return ret ? ret : -ERESTARTSYS;
			continue;
		}
		if (copy_from_user(d->sample_buf, buffer, cnt))
			return ret ? ret : -EFAULT;

                copy_cnt = cnt;
                s_tmpl = (u32 *)d->sample_buf;
                t_tmpl = (u32 *)(d->dma_buf + (swptr * 4));

                /* XXXKW assuming 16-bit stereo! */
                do {
			u32 tmp;

			t_tmpl[0] = cpu_to_be32(0x98000000);

			tmp = be32_to_cpu(s_tmpl[0]);
			left = tmp & 0xffff;
			right = tmp >> 16;
			if (swap) {
				left = swab16(left);
				right = swab16(right);
			}
			t_tmpl[1] = cpu_to_be32(left >> 8);
			t_tmpl[2] = cpu_to_be32(((left & 0xff) << 24) |
						(right << 4));

                        s_tmpl++;
                        t_tmpl += 8;
                        copy_cnt -= 4;
                } while (copy_cnt);

                /* Mux in any pending read/write accesses */
                if (s->reg_request) {
			*(u64 *)(d->dma_buf + (swptr * 4)) |=
				cpu_to_be64(s->reg_request);
                        s->reg_request = 0;
                        wake_up(&s->dma_dac.reg_wait);
                }

                CS_DBGOUT(CS_WAVE_WRITE, 4,
                          printk(KERN_INFO
                                 "cs4297a: copy in %d to swptr %x\n", cnt, swptr));

		swptr = (swptr + (cnt/FRAME_SAMPLE_BYTES)) % d->ringsz;
                __raw_writeq(cnt/FRAME_SAMPLE_BYTES, SS_CSR(R_SER_DMA_DSCR_COUNT_TX));
		spin_lock_irqsave(&s->lock, flags);
		d->swptr = swptr;
		d->count += cnt;
		d->endcleared = 0;
		spin_unlock_irqrestore(&s->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
		start_dac(s);
	}
	CS_DBGOUT(CS_FUNCTION | CS_WAVE_WRITE, 2,
		  printk(KERN_INFO "cs4297a: cs4297a_write()- %d\n", ret));
	return ret;
}


static unsigned int cs4297a_poll(struct file *file,
				struct poll_table_struct *wait)
{
	struct cs4297a_state *s =
	    (struct cs4297a_state *) file->private_data;
	unsigned long flags;
	unsigned int mask = 0;

	CS_DBGOUT(CS_FUNCTION | CS_WAVE_WRITE | CS_WAVE_READ, 4,
		  printk(KERN_INFO "cs4297a: cs4297a_poll()+\n"));
	VALIDATE_STATE(s);
	if (file->f_mode & FMODE_WRITE) {
		CS_DBGOUT(CS_FUNCTION | CS_WAVE_WRITE | CS_WAVE_READ, 4,
			  printk(KERN_INFO
				 "cs4297a: cs4297a_poll() wait on FMODE_WRITE\n"));
		if(!s->dma_dac.ready && prog_dmabuf_dac(s))
			return 0;
		poll_wait(file, &s->dma_dac.wait, wait);
	}
	if (file->f_mode & FMODE_READ) {
		CS_DBGOUT(CS_FUNCTION | CS_WAVE_WRITE | CS_WAVE_READ, 4,
			  printk(KERN_INFO
				 "cs4297a: cs4297a_poll() wait on FMODE_READ\n"));
		if(!s->dma_dac.ready && prog_dmabuf_adc(s))
			return 0;
		poll_wait(file, &s->dma_adc.wait, wait);
	}
	spin_lock_irqsave(&s->lock, flags);
	cs4297a_update_ptr(s,CS_FALSE);
	if (file->f_mode & FMODE_WRITE) {
		if (s->dma_dac.mapped) {
			if (s->dma_dac.count >=
			    (signed) s->dma_dac.fragsize) {
				if (s->dma_dac.wakeup)
					mask |= POLLOUT | POLLWRNORM;
				else
					mask = 0;
				s->dma_dac.wakeup = 0;
			}
		} else {
			if ((signed) (s->dma_dac.sbufsz/2) >= s->dma_dac.count)
				mask |= POLLOUT | POLLWRNORM;
		}
	} else if (file->f_mode & FMODE_READ) {
		if (s->dma_adc.mapped) {
			if (s->dma_adc.count >= (signed) s->dma_adc.fragsize) 
				mask |= POLLIN | POLLRDNORM;
		} else {
			if (s->dma_adc.count > 0)
				mask |= POLLIN | POLLRDNORM;
		}
	}
	spin_unlock_irqrestore(&s->lock, flags);
	CS_DBGOUT(CS_FUNCTION | CS_WAVE_WRITE | CS_WAVE_READ, 4,
		  printk(KERN_INFO "cs4297a: cs4297a_poll()- 0x%.8x\n",
			 mask));
	return mask;
}


static int cs4297a_mmap(struct file *file, struct vm_area_struct *vma)
{
        /* XXXKW currently no mmap support */
        return -EINVAL;
	return 0;
}


static int cs4297a_ioctl(struct inode *inode, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	struct cs4297a_state *s =
	    (struct cs4297a_state *) file->private_data;
	unsigned long flags;
	audio_buf_info abinfo;
	count_info cinfo;
	int val, mapped, ret;

	CS_DBGOUT(CS_FUNCTION|CS_IOCTL, 4, printk(KERN_INFO
		 "cs4297a: cs4297a_ioctl(): file=0x%.8x cmd=0x%.8x\n",
			 (unsigned) file, cmd));
#if CSDEBUG
	cs_printioctl(cmd);
#endif
	VALIDATE_STATE(s);
	mapped = ((file->f_mode & FMODE_WRITE) && s->dma_dac.mapped) ||
	    ((file->f_mode & FMODE_READ) && s->dma_adc.mapped);
	switch (cmd) {
	case OSS_GETVERSION:
		CS_DBGOUT(CS_IOCTL | CS_PARMS, 4, printk(