drivers/media/usb/dvb-usb/pctv452e.c

Source file repositories/reference/linux-study-clean/drivers/media/usb/dvb-usb/pctv452e.c

File Facts

System
Linux kernel
Corpus path
drivers/media/usb/dvb-usb/pctv452e.c
Extension
.c
Size
25644 bytes
Lines
1114
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

struct pctv452e_state {
	struct dvb_ca_en50221 ca;
	struct mutex ca_mutex;

	u8 c;	   /* transaction counter, wraps around...  */
	u8 initialized; /* set to 1 if 0x15 has been sent */
	u16 last_rc_key;
};

static int tt3650_ci_msg(struct dvb_usb_device *d, u8 cmd, u8 *data,
			 unsigned int write_len, unsigned int read_len)
{
	struct pctv452e_state *state = d->priv;
	u8 *buf;
	u8 id;
	unsigned int rlen;
	int ret;

	if (!data || (write_len > 64 - 4) || (read_len > 64 - 4)) {
		err("%s: transfer data invalid", __func__);
		return -EIO;
	}

	buf = kmalloc(64, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	id = state->c++;

	buf[0] = SYNC_BYTE_OUT;
	buf[1] = id;
	buf[2] = cmd;
	buf[3] = write_len;

	memcpy(buf + 4, data, write_len);

	rlen = (read_len > 0) ? 64 : 0;
	ret = dvb_usb_generic_rw(d, buf, 4 + write_len,
				  buf, rlen, /* delay_ms */ 0);
	if (0 != ret)
		goto failed;

	ret = -EIO;
	if (SYNC_BYTE_IN != buf[0] || id != buf[1])
		goto failed;

	memcpy(data, buf + 4, read_len);

	kfree(buf);
	return 0;

failed:
	err("CI error %d; %02X %02X %02X -> %*ph.",
	     ret, SYNC_BYTE_OUT, id, cmd, 3, buf);

	kfree(buf);
	return ret;
}

static int tt3650_ci_msg_locked(struct dvb_ca_en50221 *ca,
				u8 cmd, u8 *data, unsigned int write_len,
				unsigned int read_len)
{
	struct dvb_usb_device *d = ca->data;
	struct pctv452e_state *state = d->priv;
	int ret;

	mutex_lock(&state->ca_mutex);
	ret = tt3650_ci_msg(d, cmd, data, write_len, read_len);
	mutex_unlock(&state->ca_mutex);

	return ret;
}

static int tt3650_ci_read_attribute_mem(struct dvb_ca_en50221 *ca,
				 int slot, int address)
{
	u8 buf[3];
	int ret;

	if (0 != slot)
		return -EINVAL;

	buf[0] = (address >> 8) & 0x0F;
	buf[1] = address;

	ret = tt3650_ci_msg_locked(ca, TT3650_CMD_CI_RD_ATTR, buf, 2, 3);

	ci_dbg("%s %04x -> %d 0x%02x",
		__func__, address, ret, buf[2]);

Annotation

Implementation Notes