drivers/media/dvb-frontends/dvb_dummy_fe.c

File Facts

System

Linux kernel

Corpus path

drivers/media/dvb-frontends/dvb_dummy_fe.c

Extension

.c

Size

6580 bytes

Lines

287

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.

• 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.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/init.h
• linux/string.h
• linux/slab.h
• media/dvb_frontend.h
• dvb_dummy_fe.h

Detected Declarations

• struct dvb_dummy_fe_state
• function dvb_dummy_fe_read_status
• function dvb_dummy_fe_read_ber
• function dvb_dummy_fe_read_signal_strength
• function dvb_dummy_fe_read_snr
• function dvb_dummy_fe_read_ucblocks
• function dvb_dummy_fe_get_frontend
• function dvb_dummy_fe_set_frontend
• function dvb_dummy_fe_sleep
• function dvb_dummy_fe_init
• function dvb_dummy_fe_set_tone
• function dvb_dummy_fe_set_voltage
• function dvb_dummy_fe_release
• export dvb_dummy_fe_ofdm_attach
• export dvb_dummy_fe_qpsk_attach
• export dvb_dummy_fe_qam_attach

Annotated Snippet

struct dvb_dummy_fe_state {
	struct dvb_frontend frontend;
};


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

	return 0;
}

static int dvb_dummy_fe_read_ber(struct dvb_frontend *fe, u32 *ber)
{
	*ber = 0;
	return 0;
}

static int dvb_dummy_fe_read_signal_strength(struct dvb_frontend *fe,
					     u16 *strength)
{
	*strength = 0;
	return 0;
}

static int dvb_dummy_fe_read_snr(struct dvb_frontend *fe, u16 *snr)
{
	*snr = 0;
	return 0;
}

static int dvb_dummy_fe_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
	*ucblocks = 0;
	return 0;
}

/*
 * Should only be implemented if it actually reads something from the hardware.
 * Also, it should check for the locks, in order to avoid report wrong data
 * to userspace.
 */
static int dvb_dummy_fe_get_frontend(struct dvb_frontend *fe,
				     struct dtv_frontend_properties *p)
{
	return 0;
}

static int dvb_dummy_fe_set_frontend(struct dvb_frontend *fe)
{
	if (fe->ops.tuner_ops.set_params) {
		fe->ops.tuner_ops.set_params(fe);
		if (fe->ops.i2c_gate_ctrl)
			fe->ops.i2c_gate_ctrl(fe, 0);
	}

	return 0;
}

static int dvb_dummy_fe_sleep(struct dvb_frontend *fe)
{
	return 0;
}

static int dvb_dummy_fe_init(struct dvb_frontend *fe)
{
	return 0;
}

static int dvb_dummy_fe_set_tone(struct dvb_frontend *fe,
				 enum fe_sec_tone_mode tone)
{
	return 0;
}

static int dvb_dummy_fe_set_voltage(struct dvb_frontend *fe,
				    enum fe_sec_voltage voltage)
{
	return 0;
}

static void dvb_dummy_fe_release(struct dvb_frontend *fe)
{
	struct dvb_dummy_fe_state *state = fe->demodulator_priv;

Annotation

• Immediate include surface: `linux/module.h`, `linux/init.h`, `linux/string.h`, `linux/slab.h`, `media/dvb_frontend.h`, `dvb_dummy_fe.h`.
• Detected declarations: `struct dvb_dummy_fe_state`, `function dvb_dummy_fe_read_status`, `function dvb_dummy_fe_read_ber`, `function dvb_dummy_fe_read_signal_strength`, `function dvb_dummy_fe_read_snr`, `function dvb_dummy_fe_read_ucblocks`, `function dvb_dummy_fe_get_frontend`, `function dvb_dummy_fe_set_frontend`, `function dvb_dummy_fe_sleep`, `function dvb_dummy_fe_init`.
• Atlas domain: Driver Families / drivers/media.
• Implementation status: integration implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.