drivers/media/usb/ttusb-dec/ttusbdecfe.c

Source file repositories/reference/linux-study-clean/drivers/media/usb/ttusb-dec/ttusbdecfe.c

File Facts

System
Linux kernel
Corpus path
drivers/media/usb/ttusb-dec/ttusbdecfe.c
Extension
.c
Size
7241 bytes
Lines
290
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 ttusbdecfe_state {

	/* configuration settings */
	const struct ttusbdecfe_config* config;

	struct dvb_frontend frontend;

	u8 hi_band;
	u8 voltage;
};


static int ttusbdecfe_dvbs_read_status(struct dvb_frontend *fe,
				       enum fe_status *status)
{
	*status = FE_HAS_SIGNAL | FE_HAS_VITERBI |
		FE_HAS_SYNC | FE_HAS_CARRIER | FE_HAS_LOCK;
	return 0;
}


static int ttusbdecfe_dvbt_read_status(struct dvb_frontend *fe,
				       enum fe_status *status)
{
	struct ttusbdecfe_state* state = fe->demodulator_priv;
	u8 b[] = { 0x00, 0x00, 0x00, 0x00,
		   0x00, 0x00, 0x00, 0x00 };
	u8 result[4];
	int len, ret;

	*status=0;

	ret=state->config->send_command(fe, 0x73, sizeof(b), b, &len, result);
	if(ret)
		return ret;

	if(len != 4) {
		printk(KERN_ERR "%s: unexpected reply\n", __func__);
		return -EIO;
	}

	switch(result[3]) {
		case 1:  /* not tuned yet */
		case 2:  /* no signal/no lock*/
			break;
		case 3:	 /* signal found and locked*/
			*status = FE_HAS_SIGNAL | FE_HAS_VITERBI |
			FE_HAS_SYNC | FE_HAS_CARRIER | FE_HAS_LOCK;
			break;
		case 4:
			*status = FE_TIMEDOUT;
			break;
		default:
			pr_info("%s: returned unknown value: %d\n",
				__func__, result[3]);
			return -EIO;
	}

	return 0;
}

static int ttusbdecfe_dvbt_set_frontend(struct dvb_frontend *fe)
{
	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
	struct ttusbdecfe_state *state = fe->demodulator_priv;
	u8 b[] = { 0x00, 0x00, 0x00, 0x03,
		   0x00, 0x00, 0x00, 0x00,
		   0x00, 0x00, 0x00, 0x01,
		   0x00, 0x00, 0x00, 0xff,
		   0x00, 0x00, 0x00, 0xff };

	__be32 freq = htonl(p->frequency / 1000);
	memcpy(&b[4], &freq, sizeof (u32));
	state->config->send_command(fe, 0x71, sizeof(b), b, NULL, NULL);

	return 0;
}

static int ttusbdecfe_dvbt_get_tune_settings(struct dvb_frontend* fe,
					struct dvb_frontend_tune_settings* fesettings)
{
		fesettings->min_delay_ms = 1500;
		/* Drift compensation makes no sense for DVB-T */
		fesettings->step_size = 0;
		fesettings->max_drift = 0;
		return 0;
}

static int ttusbdecfe_dvbs_set_frontend(struct dvb_frontend *fe)
{

Annotation

Implementation Notes