drivers/media/dvb-frontends/tda665x.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/tda665x.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/tda665x.c
Extension
.c
Size
5380 bytes
Lines
235
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 tda665x_state {
	struct dvb_frontend		*fe;
	struct i2c_adapter		*i2c;
	const struct tda665x_config	*config;

	u32 frequency;
	u32 bandwidth;
};

static int tda665x_read(struct tda665x_state *state, u8 *buf)
{
	const struct tda665x_config *config = state->config;
	int err = 0;
	struct i2c_msg msg = { .addr = config->addr, .flags = I2C_M_RD, .buf = buf, .len = 2 };

	err = i2c_transfer(state->i2c, &msg, 1);
	if (err != 1)
		goto exit;

	return err;
exit:
	printk(KERN_ERR "%s: I/O Error err=<%d>\n", __func__, err);
	return err;
}

static int tda665x_write(struct tda665x_state *state, u8 *buf, u8 length)
{
	const struct tda665x_config *config = state->config;
	int err = 0;
	struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = length };

	err = i2c_transfer(state->i2c, &msg, 1);
	if (err != 1)
		goto exit;

	return err;
exit:
	printk(KERN_ERR "%s: I/O Error err=<%d>\n", __func__, err);
	return err;
}

static int tda665x_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
	struct tda665x_state *state = fe->tuner_priv;

	*frequency = state->frequency;

	return 0;
}

static int tda665x_get_status(struct dvb_frontend *fe, u32 *status)
{
	struct tda665x_state *state = fe->tuner_priv;
	u8 result = 0;
	int err = 0;

	*status = 0;

	err = tda665x_read(state, &result);
	if (err < 0)
		goto exit;

	if ((result >> 6) & 0x01) {
		printk(KERN_DEBUG "%s: Tuner Phase Locked\n", __func__);
		*status = 1;
	}

	return err;
exit:
	printk(KERN_ERR "%s: I/O Error\n", __func__);
	return err;
}

static int tda665x_set_frequency(struct dvb_frontend *fe,
				 u32 new_frequency)
{
	struct tda665x_state *state = fe->tuner_priv;
	const struct tda665x_config *config = state->config;
	u32 frequency, status = 0;
	u8 buf[4];
	int err = 0;

	if ((new_frequency < config->frequency_max)
	    || (new_frequency > config->frequency_min)) {
		printk(KERN_ERR "%s: Frequency beyond limits, frequency=%d\n",
		       __func__, new_frequency);
		return -EINVAL;
	}

	frequency = new_frequency;

Annotation

Implementation Notes