sound/drivers/vx/vx_core.c

Source file repositories/reference/linux-study-clean/sound/drivers/vx/vx_core.c

File Facts

System
Linux kernel
Corpus path
sound/drivers/vx/vx_core.c
Extension
.c
Size
19550 bytes
Lines
809
Domain
Driver Families
Bucket
sound/drivers
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (err < 0) {
			dev_dbg(chip->card->dev,
				"transfer_end: error in rx_full\n");
			return err;
		}
		err = vx_inb(chip, RXH) << 16;
		err |= vx_inb(chip, RXM) << 8;
		err |= vx_inb(chip, RXL);
		dev_dbg(chip->card->dev, "transfer_end: error = 0x%x\n", err);
		return -(VX_ERR_MASK | err);
	}
	return 0;
}

/*
 * vx_read_status - return the status rmh
 * @rmh: rmh record to store the status
 *
 * returns 0 if successful, or a negative error code.
 * the error code can be VX-specific, retrieved via vx_get_error().
 * NB: call with mutex held!
 */
static int vx_read_status(struct vx_core *chip, struct vx_rmh *rmh)
{
	int i, err, val, size;

	/* no read necessary? */
	if (rmh->DspStat == RMH_SSIZE_FIXED && rmh->LgStat == 0)
		return 0;

	/* Wait for RX full (with timeout protection)
	 * The first word of status is in RX
	 */
	err = vx_wait_for_rx_full(chip);
	if (err < 0)
		return err;

	/* Read RX */
	val = vx_inb(chip, RXH) << 16;
	val |= vx_inb(chip, RXM) << 8;
	val |= vx_inb(chip, RXL);

	/* If status given by DSP, let's decode its size */
	switch (rmh->DspStat) {
	case RMH_SSIZE_ARG:
		size = val & 0xff;
		rmh->Stat[0] = val & 0xffff00;
		rmh->LgStat = size + 1;
		break;
	case RMH_SSIZE_MASK:
		/* Let's count the arg numbers from a mask */
		rmh->Stat[0] = val;
		size = 0;
		while (val) {
			if (val & 0x01)
				size++;
			val >>= 1;
		}
		rmh->LgStat = size + 1;
		break;
	default:
		/* else retrieve the status length given by the driver */
		size = rmh->LgStat;
		rmh->Stat[0] = val;  /* Val is the status 1st word */
		size--;              /* hence adjust remaining length */
		break;
        }

	if (size < 1)
		return 0;
	if (snd_BUG_ON(size >= SIZE_MAX_STATUS))
		return -EINVAL;

	for (i = 1; i <= size; i++) {
		/* trigger an irq MESS_WRITE_NEXT */
		err = vx_send_irq_dsp(chip, IRQ_MESS_WRITE_NEXT);
		if (err < 0)
			return err;
		/* Wait for RX full (with timeout protection) */
		err = vx_wait_for_rx_full(chip);
		if (err < 0)
			return err;
		rmh->Stat[i] = vx_inb(chip, RXH) << 16;
		rmh->Stat[i] |= vx_inb(chip, RXM) <<  8;
		rmh->Stat[i] |= vx_inb(chip, RXL);
	}

	return vx_transfer_end(chip, IRQ_MESS_WRITE_END);
}

Annotation

Implementation Notes