drivers/media/dvb-frontends/lnbp21.c

File Facts

System

Linux kernel

Corpus path

drivers/media/dvb-frontends/lnbp21.c

Extension

.c

Size

4363 bytes

Lines

172

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/delay.h
• linux/errno.h
• linux/init.h
• linux/kernel.h
• linux/module.h
• linux/string.h
• linux/slab.h
• media/dvb_frontend.h
• lnbp21.h
• lnbh24.h

Detected Declarations

• struct lnbp21
• function lnbp21_set_voltage
• function lnbp21_enable_high_lnb_voltage
• function lnbp21_set_tone
• function lnbp21_release
• export lnbh24_attach
• export lnbp21_attach

Annotated Snippet

struct lnbp21 {
	u8			config;
	u8			override_or;
	u8			override_and;
	struct i2c_adapter	*i2c;
	u8			i2c_addr;
};

static int lnbp21_set_voltage(struct dvb_frontend *fe,
			      enum fe_sec_voltage voltage)
{
	struct lnbp21 *lnbp21 = (struct lnbp21 *) fe->sec_priv;
	struct i2c_msg msg = {	.addr = lnbp21->i2c_addr, .flags = 0,
				.buf = &lnbp21->config,
				.len = sizeof(lnbp21->config) };

	lnbp21->config &= ~(LNBP21_VSEL | LNBP21_EN);

	switch(voltage) {
	case SEC_VOLTAGE_OFF:
		break;
	case SEC_VOLTAGE_13:
		lnbp21->config |= LNBP21_EN;
		break;
	case SEC_VOLTAGE_18:
		lnbp21->config |= (LNBP21_EN | LNBP21_VSEL);
		break;
	default:
		return -EINVAL;
	}

	lnbp21->config |= lnbp21->override_or;
	lnbp21->config &= lnbp21->override_and;

	return (i2c_transfer(lnbp21->i2c, &msg, 1) == 1) ? 0 : -EIO;
}

static int lnbp21_enable_high_lnb_voltage(struct dvb_frontend *fe, long arg)
{
	struct lnbp21 *lnbp21 = (struct lnbp21 *) fe->sec_priv;
	struct i2c_msg msg = {	.addr = lnbp21->i2c_addr, .flags = 0,
				.buf = &lnbp21->config,
				.len = sizeof(lnbp21->config) };

	if (arg)
		lnbp21->config |= LNBP21_LLC;
	else
		lnbp21->config &= ~LNBP21_LLC;

	lnbp21->config |= lnbp21->override_or;
	lnbp21->config &= lnbp21->override_and;

	return (i2c_transfer(lnbp21->i2c, &msg, 1) == 1) ? 0 : -EIO;
}

static int lnbp21_set_tone(struct dvb_frontend *fe,
			   enum fe_sec_tone_mode tone)
{
	struct lnbp21 *lnbp21 = (struct lnbp21 *) fe->sec_priv;
	struct i2c_msg msg = {	.addr = lnbp21->i2c_addr, .flags = 0,
				.buf = &lnbp21->config,
				.len = sizeof(lnbp21->config) };

	switch (tone) {
	case SEC_TONE_OFF:
		lnbp21->config &= ~LNBP21_TEN;
		break;
	case SEC_TONE_ON:
		lnbp21->config |= LNBP21_TEN;
		break;
	default:
		return -EINVAL;
	}

	lnbp21->config |= lnbp21->override_or;
	lnbp21->config &= lnbp21->override_and;

	return (i2c_transfer(lnbp21->i2c, &msg, 1) == 1) ? 0 : -EIO;
}

static void lnbp21_release(struct dvb_frontend *fe)
{
	/* LNBP power off */
	lnbp21_set_voltage(fe, SEC_VOLTAGE_OFF);

	/* free data */
	kfree(fe->sec_priv);
	fe->sec_priv = NULL;
}

Annotation

• Immediate include surface: `linux/delay.h`, `linux/errno.h`, `linux/init.h`, `linux/kernel.h`, `linux/module.h`, `linux/string.h`, `linux/slab.h`, `media/dvb_frontend.h`.
• Detected declarations: `struct lnbp21`, `function lnbp21_set_voltage`, `function lnbp21_enable_high_lnb_voltage`, `function lnbp21_set_tone`, `function lnbp21_release`, `export lnbh24_attach`, `export lnbp21_attach`.
• 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.