drivers/media/dvb-frontends/stv0900_core.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/stv0900_core.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/stv0900_core.c
Extension
.c
Size
50441 bytes
Lines
1965
Domain
Driver Families
Bucket
drivers/media
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

struct stv0900_inode {
	/* pointer for internal params, one for each pair of demods */
	struct stv0900_internal		*internal;
	struct stv0900_inode		*next_inode;
};

/* first internal params */
static struct stv0900_inode *stv0900_first_inode;

/* find chip by i2c adapter and i2c address */
static struct stv0900_inode *find_inode(struct i2c_adapter *i2c_adap,
							u8 i2c_addr)
{
	struct stv0900_inode *temp_chip = stv0900_first_inode;

	if (temp_chip != NULL) {
		/*
		 Search of the last stv0900 chip or
		 find it by i2c adapter and i2c address */
		while ((temp_chip != NULL) &&
			((temp_chip->internal->i2c_adap != i2c_adap) ||
			(temp_chip->internal->i2c_addr != i2c_addr)))

			temp_chip = temp_chip->next_inode;

	}

	return temp_chip;
}

/* deallocating chip */
static void remove_inode(struct stv0900_internal *internal)
{
	struct stv0900_inode *prev_node = stv0900_first_inode;
	struct stv0900_inode *del_node = find_inode(internal->i2c_adap,
						internal->i2c_addr);

	if (del_node != NULL) {
		if (del_node == stv0900_first_inode) {
			stv0900_first_inode = del_node->next_inode;
		} else {
			while (prev_node->next_inode != del_node)
				prev_node = prev_node->next_inode;

			if (del_node->next_inode == NULL)
				prev_node->next_inode = NULL;
			else
				prev_node->next_inode =
					prev_node->next_inode->next_inode;
		}

		kfree(del_node);
	}
}

/* allocating new chip */
static struct stv0900_inode *append_internal(struct stv0900_internal *internal)
{
	struct stv0900_inode *new_node = stv0900_first_inode;

	if (new_node == NULL) {
		new_node = kmalloc_obj(struct stv0900_inode);
		stv0900_first_inode = new_node;
	} else {
		while (new_node->next_inode != NULL)
			new_node = new_node->next_inode;

		new_node->next_inode = kmalloc_obj(struct stv0900_inode);
		if (new_node->next_inode != NULL)
			new_node = new_node->next_inode;
		else
			new_node = NULL;
	}

	if (new_node != NULL) {
		new_node->internal = internal;
		new_node->next_inode = NULL;
	}

	return new_node;
}

s32 ge2comp(s32 a, s32 width)
{
	if (width == 32)
		return a;
	else
		return (a >= (1 << (width - 1))) ? (a - (1 << width)) : a;
}

Annotation

Implementation Notes