drivers/media/pci/saa7164/saa7164-cmd.c

Source file repositories/reference/linux-study-clean/drivers/media/pci/saa7164/saa7164-cmd.c

File Facts

System
Linux kernel
Corpus path
drivers/media/pci/saa7164/saa7164-cmd.c
Extension
.c
Size
13470 bytes
Lines
541
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: implementation source
Status
source 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 (dev->cmds[i].inuse == 0) {
			dev->cmds[i].inuse = 1;
			dev->cmds[i].signalled = 0;
			dev->cmds[i].timeout = 0;
			ret = dev->cmds[i].seqno;
			break;
		}
	}
	mutex_unlock(&dev->lock);

	return ret;
}

static void saa7164_cmd_free_seqno(struct saa7164_dev *dev, u8 seqno)
{
	mutex_lock(&dev->lock);
	if ((dev->cmds[seqno].inuse == 1) &&
		(dev->cmds[seqno].seqno == seqno)) {
		dev->cmds[seqno].inuse = 0;
		dev->cmds[seqno].signalled = 0;
		dev->cmds[seqno].timeout = 0;
	}
	mutex_unlock(&dev->lock);
}

static void saa7164_cmd_timeout_seqno(struct saa7164_dev *dev, u8 seqno)
{
	mutex_lock(&dev->lock);
	if ((dev->cmds[seqno].inuse == 1) &&
		(dev->cmds[seqno].seqno == seqno)) {
		dev->cmds[seqno].timeout = 1;
	}
	mutex_unlock(&dev->lock);
}

static u32 saa7164_cmd_timeout_get(struct saa7164_dev *dev, u8 seqno)
{
	int ret = 0;

	mutex_lock(&dev->lock);
	if ((dev->cmds[seqno].inuse == 1) &&
		(dev->cmds[seqno].seqno == seqno)) {
		ret = dev->cmds[seqno].timeout;
	}
	mutex_unlock(&dev->lock);

	return ret;
}

/* Commands to the f/w get marshelled to/from this code then onto the PCI
 * -bus/c running buffer. */
int saa7164_irq_dequeue(struct saa7164_dev *dev)
{
	int ret = SAA_OK, i = 0;
	u32 timeout;
	wait_queue_head_t *q = NULL;
	u8 tmp[512];
	dprintk(DBGLVL_CMD, "%s()\n", __func__);

	/* While any outstand message on the bus exists... */
	do {

		/* Peek the msg bus */
		struct tmComResInfo tRsp = { 0, 0, 0, 0, 0, 0 };
		ret = saa7164_bus_get(dev, &tRsp, NULL, 1);
		if (ret != SAA_OK)
			break;

		q = &dev->cmds[tRsp.seqno].wait;
		timeout = saa7164_cmd_timeout_get(dev, tRsp.seqno);
		dprintk(DBGLVL_CMD, "%s() timeout = %d\n", __func__, timeout);
		if (!timeout) {
			dprintk(DBGLVL_CMD,
				"%s() signalled seqno(%d) (for dequeue)\n",
				__func__, tRsp.seqno);
			dev->cmds[tRsp.seqno].signalled = 1;
			wake_up(q);
		} else {
			printk(KERN_ERR
				"%s() found timed out command on the bus\n",
					__func__);

			/* Clean the bus */
			ret = saa7164_bus_get(dev, &tRsp, &tmp, 0);
			printk(KERN_ERR "%s() ret = %x\n", __func__, ret);
			if (ret == SAA_ERR_EMPTY)
				/* Someone else already fetched the response */
				return SAA_OK;

			if (ret != SAA_OK)

Annotation

Implementation Notes